Blame - doc/xml.html - platform/external/libxml2

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Daniel Veillard	09ab7e1	2001-07-10 15:49:44 +0000	[diff] [blame]	1	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
				2	"http://www.w3.org/TR/html4/loose.dtd">
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	3	<html>
				4	<head>
Daniel Veillard	ec78c0f	2000-08-25 10:25:23 +0000	[diff] [blame]	5	<title>The XML C library for Gnome</title>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	6	<meta name="GENERATOR" content="amaya 5.1">
Daniel Veillard	b24054a	1999-12-18 15:32:46 +0000	[diff] [blame]	7	<meta http-equiv="Content-Type" content="text/html">
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	8	</head>
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	9
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	10	<body bgcolor="#ffffff">
Daniel Veillard	ec78c0f	2000-08-25 10:25:23 +0000	[diff] [blame]	11	<h1 align="center">The XML C library for Gnome</h1>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	12
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	13	<h1>Note: this is the flat content of the <a href="index.html">web
				14	site</a></h1>
				15
Daniel Veillard	c948420	2001-10-24 12:35:52 +0000	[diff] [blame]	16	<h1 style="text-align: center">libxml, a.k.a. gnome-xml</h1>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	17
				18	<p></p>
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	19
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	20	<p>Libxml is the XML C library developed for the Gnome project. XML itself
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	21	is a metalanguage to design markup languages, i.e. text language where
				22	semantic and structure are added to the content using extra "markup"
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	23	information enclosed between angle brackets. HTML is the most well-known
Daniel Veillard	1eb2424	2002-03-18 11:33:03 +0000	[diff] [blame]	24	markup language. Though the library is written in C <a href="python.html">a
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	25	variety of language bindings</a> make it available in other environments.</p>
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	26
Daniel Veillard	710823b	2003-03-04 10:05:52 +0000	[diff] [blame]	27	<p>Libxml2 is known to be very portable, the library should build and work
				28	without serious troubles on a variety of systems (Linux, Unix, Windows,
				29	CygWin, MacOS, MacOS X, RISC Os, OS/2, VMS, QNX, MVS, ...)</p>
				30
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	31	<p>Libxml2 implements a number of existing standards related to markup
				32	languages:</p>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	33	<ul>
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	34	<li>the XML standard: <a
				35	href="http://www.w3.org/TR/REC-xml">http://www.w3.org/TR/REC-xml</a></li>
				36	<li>Namespaces in XML: <a
				37	href="http://www.w3.org/TR/REC-xml-names/">http://www.w3.org/TR/REC-xml-names/</a></li>
				38	<li>XML Base: <a
				39	href="http://www.w3.org/TR/xmlbase/">http://www.w3.org/TR/xmlbase/</a></li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	40	<li><a href="http://www.cis.ohio-state.edu/rfc/rfc2396.txt">RFC 2396</a> :
				41	Uniform Resource Identifiers <a
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	42	href="http://www.ietf.org/rfc/rfc2396.txt">http://www.ietf.org/rfc/rfc2396.txt</a></li>
				43	<li>XML Path Language (XPath) 1.0: <a
				44	href="http://www.w3.org/TR/xpath">http://www.w3.org/TR/xpath</a></li>
				45	<li>HTML4 parser: <a
				46	href="http://www.w3.org/TR/html401/">http://www.w3.org/TR/html401/</a></li>
				47	<li>most of XML Pointer Language (XPointer) Version 1.0: <a
				48	href="http://www.w3.org/TR/xptr">http://www.w3.org/TR/xptr</a></li>
				49	<li>XML Inclusions (XInclude) Version 1.0: <a
				50	href="http://www.w3.org/TR/xinclude/">http://www.w3.org/TR/xinclude/</a></li>
				51	<li>[ISO-8859-1], <a
				52	href="http://www.cis.ohio-state.edu/rfc/rfc2044.txt">rfc2044</a> [UTF-8]
				53	and <a href="http://www.cis.ohio-state.edu/rfc/rfc2781.txt">rfc2781</a>
				54	[UTF-16] core encodings</li>
				55	<li>part of SGML Open Technical Resolution TR9401:1997</li>
				56	<li>XML Catalogs Working Draft 06 August 2001: <a
				57	href="http://www.oasis-open.org/committees/entity/spec-2001-08-06.html">http://www.oasis-open.org/committees/entity/spec-2001-08-06.html</a></li>
Daniel Veillard	5c39654	2002-03-15 07:57:50 +0000	[diff] [blame]	58	<li>Canonical XML Version 1.0: <a
				59	href="http://www.w3.org/TR/xml-c14n">http://www.w3.org/TR/xml-c14n</a>
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	60	and the Exclusive XML Canonicalization CR draft <a
				61	href="http://www.w3.org/TR/xml-exc-c14n">http://www.w3.org/TR/xml-exc-c14n</a></li>
Daniel Veillard	17bed98	2003-02-24 20:11:43 +0000	[diff] [blame]	62	<li>Relax NG Committee Specification 3 December 2001 <a
				63	href="http://www.oasis-open.org/committees/relax-ng/spec-20011203.html">http://www.oasis-open.org/committees/relax-ng/spec-20011203.html</a></li>
Daniel Veillard	9698445	2000-08-31 13:50:12 +0000	[diff] [blame]	64	</ul>
				65
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	66	<p>In most cases libxml tries to implement the specifications in a relatively
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	67	strictly compliant way. As of release 2.4.16, libxml2 passes all 1800+ tests
				68	from the <a
Daniel Veillard	a539356	2002-02-20 11:40:49 +0000	[diff] [blame]	69	href="http://www.oasis-open.org/committees/xml-conformance/">OASIS XML Tests
				70	Suite</a>.</p>
Daniel Veillard	5b16f58	2002-02-20 11:38:46 +0000	[diff] [blame]	71
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	72	<p>To some extent libxml2 provides support for the following additional
				73	specifications but doesn't claim to implement them completely:</p>
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	74	<ul>
				75	<li>Document Object Model (DOM) <a
				76	href="http://www.w3.org/TR/DOM-Level-2-Core/">http://www.w3.org/TR/DOM-Level-2-Core/</a>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	77	it doesn't implement the API itself, gdome2 does this on top of
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	78	libxml2</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	79	<li><a href="http://www.cis.ohio-state.edu/rfc/rfc959.txt">RFC 959</a> :
				80	libxml implements a basic FTP client code</li>
				81	<li><a href="http://www.cis.ohio-state.edu/rfc/rfc1945.txt">RFC 1945</a> :
				82	HTTP/1.0, again a basic HTTP client code</li>
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	83	<li>SAX: a minimal SAX implementation compatible with early expat
				84	versions</li>
				85	<li>DocBook SGML v4: libxml2 includes a hackish parser to transition to
				86	XML</li>
				87	</ul>
				88
Daniel Veillard	72fef16	2003-02-05 14:31:19 +0000	[diff] [blame]	89	<p>A partial implementation of XML Schemas is being worked on but it would be
				90	far too early to make any conformance statement about it at the moment.</p>
Daniel Veillard	e6d8e20	2002-05-02 06:11:10 +0000	[diff] [blame]	91
Daniel Veillard	9698445	2000-08-31 13:50:12 +0000	[diff] [blame]	92	<p>Separate documents:</p>
				93	<ul>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	94	<li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a> providing an
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	95	implementation of XSLT 1.0 and common extensions like EXSLT for
				96	libxml2</li>
Daniel Veillard	c6271d2	2001-10-27 07:50:58 +0000	[diff] [blame]	97	<li><a href="http://www.cs.unibo.it/~casarini/gdome2/">the gdome2 page</a>
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	98	: a standard DOM2 implementation for libxml2</li>
				99	<li><a href="http://www.aleksey.com/xmlsec/">the XMLSec page</a>: an
				100	implementation of <a href="http://www.w3.org/TR/xmldsig-core/">W3C XML
				101	Digital Signature</a> for libxml2</li>
Daniel Veillard	e6d8e20	2002-05-02 06:11:10 +0000	[diff] [blame]	102	<li>also check the related links section below for more related and active
				103	projects.</li>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	104	</ul>
				105
Daniel Veillard	806cada	2003-03-19 21:58:59 +0000	[diff] [blame]	106	<p>Results of the <a
				107	href="http://xmlbench.sourceforge.net/results/benchmark/index.html">xmlbench
				108	benchmark</a> on sourceforge 19 March 2003 (smaller is better):</p>
Daniel Veillard	d8da01c	2003-03-24 15:58:23 +0000	[diff] [blame]	109
				110	<p align="center"><img src="benchmark.gif"
				111	alt="benchmark results for Expat Xerces libxml2 Oracle and Sun toolkits"></p>
Daniel Veillard	806cada	2003-03-19 21:58:59 +0000	[diff] [blame]	112
Daniel Veillard	e166254	2002-08-28 11:50:59 +0000	[diff] [blame]	113	<p>Logo designed by <a href="mailto:liyanage@access.ch">Marc Liyanage</a>.</p>
				114
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	115	<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	116
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	117	<p>This document describes libxml, the <a
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	118	href="http://www.w3.org/XML/">XML</a> C library developed for the <a
Daniel Veillard	ec78c0f	2000-08-25 10:25:23 +0000	[diff] [blame]	119	href="http://www.gnome.org/">Gnome</a> project. <a
				120	href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
				121	structured documents/data.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	122
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	123	<p>Here are some key points about libxml:</p>
				124	<ul>
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	125	<li>Libxml exports Push (progressive) and Pull (blocking) type parser
				126	interfaces for both XML and HTML.</li>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	127	<li>Libxml can do DTD validation at parse time, using a parsed document
				128	instance, or with an arbitrary DTD.</li>
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	129	<li>Libxml includes complete <a
Daniel Veillard	8c2ecaf	2001-07-10 17:53:07 +0000	[diff] [blame]	130	href="http://www.w3.org/TR/xpath">XPath</a>, <a
				131	href="http://www.w3.org/TR/xptr">XPointer</a> and <a
				132	href="http://www.w3.org/TR/xinclude">XInclude</a> implementations.</li>
Daniel Veillard	ec78c0f	2000-08-25 10:25:23 +0000	[diff] [blame]	133	<li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard	189446d	2000-10-13 10:23:06 +0000	[diff] [blame]	134	sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	135	Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	136	<li>Basic support for HTTP and FTP client allowing applications to fetch
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	137	remote resources.</li>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	138	<li>The design is modular, most of the extensions can be compiled out.</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	139	<li>The internal document representation is as close as possible to the <a
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	140	href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
				141	<li>Libxml also has a <a href="http://www.megginson.com/SAX/index.html">SAX
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	142	like interface</a>; the interface is designed to be compatible with <a
				143	href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillard	c575b99	2002-02-08 13:28:40 +0000	[diff] [blame]	144	<li>This library is released under the <a
				145	href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	146	License</a>. See the Copyright file in the distribution for the precise
Daniel Veillard	c575b99	2002-02-08 13:28:40 +0000	[diff] [blame]	147	wording.</li>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	148	</ul>
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	149
Daniel Veillard	e0c1d72	2001-03-21 10:28:36 +0000	[diff] [blame]	150	<p>Warning: unless you are forced to because your application links with a
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	151	Gnome-1.X library requiring it, <strong><span
Daniel Veillard	e0c1d72	2001-03-21 10:28:36 +0000	[diff] [blame]	152	style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
				153	libxml2</p>
				154
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	155	<h2><a name="FAQ">FAQ</a></h2>
				156
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	157	<p>Table of Contents:</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	158	<ul>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	159	<li><a href="FAQ.html#License">License(s)</a></li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	160	<li><a href="FAQ.html#Installati">Installation</a></li>
				161	<li><a href="FAQ.html#Compilatio">Compilation</a></li>
				162	<li><a href="FAQ.html#Developer">Developer corner</a></li>
				163	</ul>
				164
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	165	<h3><a name="License">License</a>(s)</h3>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	166	<ol>
				167	<li><em>Licensing Terms for libxml</em>
Daniel Veillard	c575b99	2002-02-08 13:28:40 +0000	[diff] [blame]	168	<p>libxml is released under the <a
				169	href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	170	License</a>; see the file Copyright in the distribution for the precise
Daniel Veillard	c575b99	2002-02-08 13:28:40 +0000	[diff] [blame]	171	wording</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	172	</li>
				173	<li><em>Can I embed libxml in a proprietary application ?</em>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	174	<p>Yes. The MIT License allows you to keep proprietary the changes you
				175	made to libxml, but it would be graceful to send-back bug fixes and
				176	improvements as patches for possible incorporation in the main
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	177	development tree.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	178	</li>
				179	</ol>
				180
				181	<h3><a name="Installati">Installation</a></h3>
				182	<ol>
				183	<li>Unless you are forced to because your application links with a Gnome
				184	library requiring it, <strong><span style="background-color: #FF0000">Do
				185	Not Use libxml1</span></strong>, use libxml2</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	186	<li><em>Where can I get libxml</em> ?
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	187	<p>The original distribution comes from <a
				188	href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a
Daniel Veillard	6581e1b	2003-02-09 22:21:43 +0000	[diff] [blame]	189	href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.5/">gnome.org</a></p>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	190	<p>Most Linux and BSD distributions include libxml, this is probably the
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	191	safer way for end-users to use libxml.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	192	<p>David Doolin provides precompiled Windows versions at <a
				193	href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
				194	</li>
				195	<li><em>I see libxml and libxml2 releases, which one should I install ?</em>
				196	<ul>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	197	<li>If you are not constrained by backward compatibility issues with
				198	existing applications, install libxml2 only</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	199	<li>If you are not doing development, you can safely install both.
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	200	Usually the packages <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	201	href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a
				202	href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	203	compatible (this is not the case for development packages).</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	204	<li>If you are a developer and your system provides separate packaging
				205	for shared libraries and the development components, it is possible
				206	to install libxml and libxml2, and also <a
				207	href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
				208	and <a
				209	href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
				210	too for libxml2 >= 2.3.0</li>
				211	<li>If you are developing a new application, please develop against
				212	libxml2(-devel)</li>
				213	</ul>
				214	</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	215	<li><em>I can't install the libxml package, it conflicts with libxml0</em>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	216	<p>You probably have an old libxml0 package used to provide the shared
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	217	library for libxml.so.0, you can probably safely remove it. The libxml
				218	packages provided on <a
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	219	href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provide
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	220	libxml.so.0</p>
				221	</li>
				222	<li><em>I can't install the libxml(2) RPM package due to failed
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	223	dependencies</em>
				224	<p>The most generic solution is to re-fetch the latest src.rpm , and
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	225	rebuild it locally with</p>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	226	<p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code>.</p>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	227	<p>If everything goes well it will generate two binary rpm packages (one
				228	providing the shared libs and xmllint, and the other one, the -devel
				229	package, providing includes, static libraries and scripts needed to build
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	230	applications with libxml(2)) that you can install locally.</p>
				231	</li>
				232	</ol>
				233
				234	<h3><a name="Compilatio">Compilation</a></h3>
				235	<ol>
				236	<li><em>What is the process to compile libxml ?</em>
				237	<p>As most UNIX libraries libxml follows the "standard":</p>
				238	<p><code>gunzip -c xxx.tar.gz \| tar xvf -</code></p>
				239	<p><code>cd libxml-xxxx</code></p>
				240	<p><code>./configure --help</code></p>
				241	<p>to see the options, then the compilation/installation proper</p>
				242	<p><code>./configure [possible options]</code></p>
				243	<p><code>make</code></p>
				244	<p><code>make install</code></p>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	245	<p>At that point you may have to rerun ldconfig or a similar utility to
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	246	update your list of installed shared libs.</p>
				247	</li>
				248	<li><em>What other libraries are needed to compile/install libxml ?</em>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	249	<p>Libxml does not require any other library, the normal C ANSI API
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	250	should be sufficient (please report any violation to this rule you may
				251	find).</p>
				252	<p>However if found at configuration time libxml will detect and use the
				253	following libs:</p>
				254	<ul>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	255	<li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a> : a
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	256	highly portable and available widely compression library.</li>
				257	<li>iconv: a powerful character encoding conversion library. It is
				258	included by default in recent glibc libraries, so it doesn't need to
				259	be installed specifically on Linux. It now seems a <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	260	href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
				261	of the official UNIX</a> specification. Here is one <a
Daniel Veillard	dad3f68	2002-11-17 16:47:27 +0000	[diff] [blame]	262	href="http://www.gnu.org/software/libiconv/">implementation of the
				263	library</a> which source can be found <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	264	href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
				265	</ul>
				266	</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	267	<li><em>Make check fails on some platforms</em>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	268	<p>Sometimes the regression tests' results don't completely match the
				269	value produced by the parser, and the makefile uses diff to print the
				270	delta. On some platforms the diff return breaks the compilation process;
				271	if the diff is small this is probably not a serious problem.</p>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	272	<p>Sometimes (especially on Solaris) make checks fail due to limitations
Daniel Veillard	e46182c	2002-02-12 14:29:11 +0000	[diff] [blame]	273	in make. Try using GNU-make instead.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	274	</li>
				275	<li><em>I use the CVS version and there is no configure script</em>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	276	<p>The configure script (and other Makefiles) are generated. Use the
				277	autogen.sh script to regenerate the configure script and Makefiles,
				278	like:</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	279	<p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
				280	</li>
				281	<li><em>I have troubles when running make tests with gcc-3.0</em>
				282	<p>It seems the initial release of gcc-3.0 has a problem with the
				283	optimizer which miscompiles the URI module. Please use another
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	284	compiler.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	285	</li>
				286	</ol>
				287
				288	<h3><a name="Developer">Developer</a> corner</h3>
				289	<ol>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	290	<li><em>xmlDocDump() generates output on one line.</em>
				291	<p>Libxml will not <strong>invent</strong> spaces in the content of a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	292	document since <strong>all spaces in the content of a document are
				293	significant</strong>. If you build a tree from the API and want
				294	indentation:</p>
				295	<ol>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	296	<li>the correct way is to generate those yourself too.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	297	<li>the dangerous way is to ask libxml to add those blanks to your
				298	content <strong>modifying the content of your document in the
				299	process</strong>. The result may not be what you expect. There is
				300	<strong>NO</strong> way to guarantee that such a modification won't
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	301	affect other parts of the content of your document. See <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	302	href="http://xmlsoft.org/html/libxml-parser.html#XMLKEEPBLANKSDEFAULT">xmlKeepBlanksDefault
				303	()</a> and <a
				304	href="http://xmlsoft.org/html/libxml-tree.html#XMLSAVEFORMATFILE">xmlSaveFormatFile
				305	()</a></li>
				306	</ol>
				307	</li>
				308	<li>Extra nodes in the document:
				309	<p><em>For a XML file as below:</em></p>
				310	<pre><?xml version="1.0"?>
				311	<PLAN xmlns="http://www.argus.ca/autotest/1.0/">
				312	<NODE CommFlag="0"/>
				313	<NODE CommFlag="1"/>
				314	</PLAN></pre>
				315	<p><em>after parsing it with the function
				316	pxmlDoc=xmlParseFile(...);</em></p>
				317	<p><em>I want to the get the content of the first node (node with the
				318	CommFlag="0")</em></p>
				319	<p><em>so I did it as following;</em></p>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	320	<pre>xmlNodePtr pnode;
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	321	pnode=pxmlDoc->children->children;</pre>
				322	<p><em>but it does not work. If I change it to</em></p>
				323	<pre>pnode=pxmlDoc->children->children->next;</pre>
				324	<p><em>then it works. Can someone explain it to me.</em></p>
				325	<p></p>
				326	<p>In XML all characters in the content of the document are significant
				327	<strong>including blanks and formatting line breaks</strong>.</p>
				328	<p>The extra nodes you are wondering about are just that, text nodes with
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	329	the formatting spaces which are part of the document but that people tend
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	330	to forget. There is a function <a
				331	href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
				332	()</a> to remove those at parse time, but that's an heuristic, and its
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	333	use should be limited to cases where you are certain there is no
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	334	mixed-content in the document.</p>
				335	</li>
				336	<li><em>I get compilation errors of existing code like when accessing
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	337	<strong>root</strong> or <strong>child fields</strong> of nodes.</em>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	338	<p>You are compiling code developed for libxml version 1 and using a
				339	libxml2 development environment. Either switch back to libxml v1 devel or
				340	even better fix the code to compile with libxml2 (or both) by <a
				341	href="upgrade.html">following the instructions</a>.</p>
				342	</li>
				343	<li><em>I get compilation errors about non existing
				344	<strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	345	fields.</em>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	346	<p>The source code you are using has been <a
				347	href="upgrade.html">upgraded</a> to be able to compile with both libxml
				348	and libxml2, but you need to install a more recent version:
				349	libxml(-devel) >= 1.8.8 or libxml2(-devel) >= 2.1.0</p>
				350	</li>
				351	<li><em>XPath implementation looks seriously broken</em>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	352	<p>XPath implementation prior to 2.3.0 was really incomplete. Upgrade to
				353	a recent version, there are no known bugs in the current version.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	354	</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	355	<li><em>The example provided in the web page does not compile.</em>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	356	<p>It's hard to maintain the documentation in sync with the code
				357	<grin/> ...</p>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	358	<p>Check the previous points 1/ and 2/ raised before, and please send
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	359	patches.</p>
				360	</li>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	361	<li><em>Where can I get more examples and information than privoded on the
				362	web page?</em>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	363	<p>Ideally a libxml book would be nice. I have no such plan ... But you
				364	can:</p>
				365	<ul>
				366	<li>check more deeply the <a href="html/libxml-lib.html">existing
				367	generated doc</a></li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	368	<li>look for examples of use for libxml function using the Gnome code.
				369	For example the following will query the full Gnome CVS base for the
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	370	use of the <strong>xmlAddChild()</strong> function:
				371	<p><a
				372	href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p>
				373	<p>This may be slow, a large hardware donation to the gnome project
				374	could cure this :-)</p>
				375	</li>
				376	<li><a
				377	href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&dir=gnome-xml">Browse
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	378	the libxml source</a> , I try to write code as clean and documented
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	379	as possible, so looking at it may be helpful. In particular the code
				380	of xmllint.c and of the various testXXX.c test programs should
				381	provide good examples of how to do things with the library.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	382	</ul>
				383	</li>
				384	<li>What about C++ ?
				385	<p>libxml is written in pure C in order to allow easy reuse on a number
				386	of platforms, including embedded systems. I don't intend to convert to
				387	C++.</p>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	388	<p>There are however a few C++ wrappers which may fulfill your needs:</p>
Daniel Veillard	9b6fd30	2002-05-13 12:06:47 +0000	[diff] [blame]	389	<ul>
				390	<li>by Ari Johnson <ari@btigate.com>:
				391	<p>Website: <a
				392	href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
				393	<p>Download: <a
				394	href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
				395	</li>
				396	<li>by Peter Jones <pjones@pmade.org>
				397	<p>Website: <a
				398	href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
				399	</li>
				400	</ul>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	401	</li>
				402	<li>How to validate a document a posteriori ?
				403	<p>It is possible to validate documents which had not been validated at
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	404	initial parsing time or documents which have been built from scratch
				405	using the API. Use the <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	406	href="http://xmlsoft.org/html/libxml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	407	function. It is also possible to simply add a DTD to an existing
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	408	document:</p>
				409	<pre>xmlDocPtr doc; /* your existing document */
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	410	xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
				411
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	412	dtd->name = xmlStrDup((xmlChar)"root_name"); / use the given root */
				413
				414	doc->intSubset = dtd;
				415	if (doc->children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
				416	else xmlAddPrevSibling(doc->children, (xmlNodePtr)dtd);
				417	</pre>
				418	</li>
Daniel Veillard	dad3f68	2002-11-17 16:47:27 +0000	[diff] [blame]	419	<li>So what is this funky "xmlChar" used all the time?
				420	<p>It is a null terminated sequence of utf-8 characters. And only utf-8!
				421	You need to convert strings encoded in different ways to utf-8 before
				422	passing them to the API. This can be accomplished with the iconv library
				423	for instance.</p>
John Fleck	61f6fb6	2002-10-31 15:23:29 +0000	[diff] [blame]	424	</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	425	<li>etc ...</li>
				426	</ol>
				427
				428	<p></p>
				429
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	430	<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	431
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	432	<p>There are several on-line resources related to using libxml:</p>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	433	<ol>
Daniel Veillard	321be0c	2002-10-08 21:26:42 +0000	[diff] [blame]	434	<li>Use the <a href="search.php">search engine</a> to lookup
				435	informations.</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	436	<li>Check the <a href="FAQ.html">FAQ.</a></li>
Daniel Veillard	c19fccc	2000-07-03 11:52:01 +0000	[diff] [blame]	437	<li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard	8c6d6af	2000-08-25 17:14:13 +0000	[diff] [blame]	438	documentation</a> automatically extracted from code comments (using <a
				439	href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&dir=gtk-doc">gtk
				440	doc</a>).</li>
Daniel Veillard	8d86964	2000-07-14 12:12:59 +0000	[diff] [blame]	441	<li>Look at the documentation about <a href="encoding.html">libxml
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	442	internationalization support</a>.</li>
Daniel Veillard	bc66f85	2002-01-14 09:49:20 +0000	[diff] [blame]	443	<li>This page provides a global overview and <a href="example.html">some
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	444	examples</a> on how to use libxml.</li>
Daniel Veillard	dad3f68	2002-11-17 16:47:27 +0000	[diff] [blame]	445	<li>John Fleck's libxml tutorial: <a href="tutorial/index.html">html</a> or
				446	<a href="tutorial/xmltutorial.pdf">pdf</a>.</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	447	<li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	448	href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
				449	documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	450	<li>George Lebl wrote <a
				451	href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	452	for IBM developerWorks</a> about using libxml.</li>
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	453	<li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	454	file</a>.</li>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	455	<li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>
				456	description. If you are starting a new project using libxml you should
				457	really use the 2.x version.</li>
Daniel Veillard	845cce4	2002-01-09 11:51:37 +0000	[diff] [blame]	458	<li>And don't forget to look at the <a
				459	href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	460	</ol>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	461
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	462	<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard	4c3a203	1999-11-19 17:46:26 +0000	[diff] [blame]	463
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	464	<p>Well, bugs or missing features are always possible, and I will make a
				465	point of fixing them in a timely fashion. The best way to report a bug is to
				466	use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	467	bug tracking database</a> (make sure to use the "libxml2" module name). I
				468	look at reports there regularly and it's good to have a reminder when a bug
				469	is still open. Be sure to specify that the bug is for the package libxml2.</p>
Daniel Veillard	4c3a203	1999-11-19 17:46:26 +0000	[diff] [blame]	470
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	471	<p>There is also a mailing-list <a
Daniel Veillard	3197f16	2001-04-04 00:40:08 +0000	[diff] [blame]	472	href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
				473	href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	474	href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
				475	please visit the <a
				476	href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
				477	follow the instructions. <strong>Do not send code, I won't debug it</strong>
				478	(but patches are really appreciated!).</p>
Daniel Veillard	234547b	2001-07-05 09:46:10 +0000	[diff] [blame]	479
Daniel Veillard	008186f	2001-09-13 14:24:44 +0000	[diff] [blame]	480	<p>Check the following <strong><span style="color: #FF0000">before
				481	posting</span></strong>:</p>
Daniel Veillard	234547b	2001-07-05 09:46:10 +0000	[diff] [blame]	482	<ul>
Daniel Veillard	321be0c	2002-10-08 21:26:42 +0000	[diff] [blame]	483	<li>Read the <a href="FAQ.html">FAQ</a> and <a href="search.php">use the
				484	search engine</a> to get informations related to your problem.</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	485	<li>Make sure you are <a href="ftp://xmlsoft.org/">using a recent
				486	version</a>, and that the problem still shows up in a recent version.</li>
				487	<li>Check the <a href="http://mail.gnome.org/archives/xml/">list
				488	archives</a> to see if the problem was reported already. In this case
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	489	there is probably a fix available, similarly check the <a
Daniel Veillard	e7ead2d	2001-08-22 23:44:09 +0000	[diff] [blame]	490	href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">registered
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	491	open bugs</a>.</li>
				492	<li>Make sure you can reproduce the bug with xmllint or one of the test
				493	programs found in source in the distribution.</li>
Daniel Veillard	234547b	2001-07-05 09:46:10 +0000	[diff] [blame]	494	<li>Please send the command showing the error as well as the input (as an
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	495	attachment)</li>
Daniel Veillard	234547b	2001-07-05 09:46:10 +0000	[diff] [blame]	496	</ul>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	497
Daniel Veillard	dadd087	2001-09-15 09:21:44 +0000	[diff] [blame]	498	<p>Then send the bug with associated informations to reproduce it to the <a
Daniel Veillard	33a6780	2001-03-07 09:44:02 +0000	[diff] [blame]	499	href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillard	98d071d	2003-01-10 09:22:44 +0000	[diff] [blame]	500	related I will approve it. Please do not send mail to me directly, it makes
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	501	things really hard to track and in some cases I am not the best person to
Daniel Veillard	98d071d	2003-01-10 09:22:44 +0000	[diff] [blame]	502	answer a given question, ask on the list.</p>
				503
				504	<p>To <span style="color: #E50000">be really clear about support</span>:</p>
				505	<ul>
				506	<li>Support or help <span style="color: #E50000">request MUST be sent to
				507	the list or on bugzilla</span> in case of problems, so that the Question
				508	and Answers can be shared publicly. Failing to do so carries the implicit
				509	message "I want free support but I don't want to share the benefits with
Daniel Veillard	831e8fd	2003-01-25 11:45:34 +0000	[diff] [blame]	510	others" and is not welcome. I will automatically Carbon-Copy the
				511	xml@gnome.org mailing list for any technical reply made about libxml2 or
				512	libxslt.</li>
Daniel Veillard	98d071d	2003-01-10 09:22:44 +0000	[diff] [blame]	513	<li>There is <span style="color: #E50000">no garantee for support</span>,
				514	if your question remains unanswered after a week, repost it, making sure
				515	you gave all the detail needed and the informations requested.</li>
				516	<li>Failing to provide informations as requested or double checking first
				517	for prior feedback also carries the implicit message "the time of the
				518	library maintainers is less valuable than my time" and might not be
				519	welcome.</li>
				520	</ul>
Daniel Veillard	4c3a203	1999-11-19 17:46:26 +0000	[diff] [blame]	521
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	522	<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	523	probably be processed faster than those without.</p>
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	524
				525	<p>If you're looking for help, a quick look at <a
Daniel Veillard	f7ed336	2001-08-17 12:01:21 +0000	[diff] [blame]	526	href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	527	provide the answer. I usually send source samples when answering libxml usage
Daniel Veillard	6f0adb5	2000-07-03 11:41:26 +0000	[diff] [blame]	528	questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	529	documentation</a> is not as polished as I would like (i need to learn more
				530	about DocBook), but it's a good starting point.</p>
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	531
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	532	<h2><a name="help">How to help</a></h2>
				533
				534	<p>You can help the project in various ways, the best thing to do first is to
				535	subscribe to the mailing-list as explained before, check the <a
Daniel Veillard	f7ed336	2001-08-17 12:01:21 +0000	[diff] [blame]	536	href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
				537	href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	538	database</a>:</p>
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	539	<ol>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	540	<li>Provide patches when you find problems.</li>
				541	<li>Provide the diffs when you port libxml to a new platform. They may not
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	542	be integrated in all cases but help pinpointing portability problems
				543	and</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	544	<li>Provide documentation fixes (either as patches to the code comments or
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	545	as HTML diffs).</li>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	546	<li>Provide new documentations pieces (translations, examples, etc
				547	...).</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	548	<li>Check the TODO file and try to close one of the items.</li>
				549	<li>Take one of the points raised in the archive or the bug database and
Daniel Veillard	e7ead2d	2001-08-22 23:44:09 +0000	[diff] [blame]	550	provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me
				551	</a>before to avoid synchronization problems and check that the suggested
				552	fix will fit in nicely :-)</li>
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	553	</ol>
				554
Daniel Veillard	10a2c65	1999-12-12 13:03:50 +0000	[diff] [blame]	555	<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	556
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	557	<p>The latest versions of libxml can be found on <a
Daniel Veillard	20c8cf2	2001-06-26 22:47:36 +0000	[diff] [blame]	558	href="ftp://xmlsoft.org/">xmlsoft.org</a> (<a
				559	href="ftp://speakeasy.rpmfind.net/pub/libxml/">Seattle</a>, <a
				560	href="ftp://fr.rpmfind.net/pub/libxml/">France</a>) or on the <a
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	561	href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard	6581e1b	2003-02-09 22:21:43 +0000	[diff] [blame]	562	as a <a href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.5/">source
MDT 2002 John Fleck	30c7054	2002-09-24 14:24:54 +0000	[diff] [blame]	563	archive</a><!-- commenting this out because they seem to have disappeared or <a
Daniel Veillard	a41123c	2001-04-22 19:31:20 +0000	[diff] [blame]	564	href="ftp://ftp.gnome.org/pub/GNOME/stable/redhat/i386/libxml/">RPM
Daniel Veillard	e16b574	2002-09-26 17:50:03 +0000	[diff] [blame]	565	packages</a> -->
Daniel Veillard	321be0c	2002-10-08 21:26:42 +0000	[diff] [blame]	566	, Antonin Sprinzl also provide <a href="ftp://gd.tuwien.ac.at/pub/libxml/">a
Daniel Veillard	e16b574	2002-09-26 17:50:03 +0000	[diff] [blame]	567	mirror in Austria</a>. (NOTE that you need both the <a
Daniel Veillard	c19fccc	2000-07-03 11:52:01 +0000	[diff] [blame]	568	href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
				569	href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard	9518953	2001-07-26 18:30:26 +0000	[diff] [blame]	570	packages installed to compile applications using libxml.) <a
Daniel Veillard	7b4b2f9	2003-01-06 13:11:20 +0000	[diff] [blame]	571	href="mailto:igor@zlatkovic.com">Igor Zlatkovic</a> is now the maintainer of
				572	the Windows port, <a
				573	href="http://www.zlatkovic.com/projects/libxml/index.html">he provides
				574	binaries</a>. <a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a>
				575	provides <a href="http://garypennington.net/libxml2/">Solaris binaries</a>.
				576	<a href="mailto:Steve.Ball@zveno.com">Steve Ball</a> provides <a
				577	href="http://www.zveno.com/open_source/libxml2xslt.html">Mac Os X
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	578	binaries</a>.</p>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	579
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	580	<p><a name="Snapshot">Snapshot:</a></p>
				581	<ul>
				582	<li>Code from the W3C cvs base libxml <a
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	583	href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a>.</li>
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	584	<li>Docs, content of the web site, the list archive included <a
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	585	href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a>.</li>
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	586	</ul>
				587
Daniel Veillard	c6271d2	2001-10-27 07:50:58 +0000	[diff] [blame]	588	<p><a name="Contribs">Contributions:</a></p>
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	589
				590	<p>I do accept external contributions, especially if compiling on another
Daniel Veillard	c6271d2	2001-10-27 07:50:58 +0000	[diff] [blame]	591	platform, get in touch with me to upload the package, wrappers for various
Daniel Veillard	5109531	2001-10-28 18:51:57 +0000	[diff] [blame]	592	languages have been provided, and can be found in the <a
				593	href="contribs.html">contrib section</a></p>
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	594
Daniel Veillard	8268716	2001-01-22 15:32:01 +0000	[diff] [blame]	595	<p>Libxml is also available from CVS:</p>
Daniel Veillard	10a2c65	1999-12-12 13:03:50 +0000	[diff] [blame]	596	<ul>
Daniel Veillard	10a2c65	1999-12-12 13:03:50 +0000	[diff] [blame]	597	<li><p>The <a
				598	href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&dir=gnome-xml">Gnome
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	599	CVS base</a>. Check the <a
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	600	href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a>
				601	page; the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard	10a2c65	1999-12-12 13:03:50 +0000	[diff] [blame]	602	</li>
Daniel Veillard	8268716	2001-01-22 15:32:01 +0000	[diff] [blame]	603	<li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard	10a2c65	1999-12-12 13:03:50 +0000	[diff] [blame]	604	</ul>
				605
				606	<h2><a name="News">News</a></h2>
				607
Daniel Veillard	944b5ff	1999-12-15 19:08:24 +0000	[diff] [blame]	608	<h3>CVS only : check the <a
				609	href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard	189446d	2000-10-13 10:23:06 +0000	[diff] [blame]	610	for a really accurate description</h3>
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	611
Daniel Veillard	e6d8e20	2002-05-02 06:11:10 +0000	[diff] [blame]	612	<p>Items not finished and worked on, get in touch with the list if you want
				613	to test those</p>
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	614	<ul>
Daniel Veillard	72fef16	2003-02-05 14:31:19 +0000	[diff] [blame]	615	<li>More testing on RelaxNG</li>
Daniel Veillard	cf27f7c	2002-04-30 07:12:39 +0000	[diff] [blame]	616	<li>Finishing up <a href="http://www.w3.org/TR/xmlschema-1/">XML
Daniel Veillard	72fef16	2003-02-05 14:31:19 +0000	[diff] [blame]	617	Schemas</a></li>
				618	</ul>
				619
Daniel Veillard	c2d4a93	2003-04-01 11:13:05 +0000	[diff] [blame^]	620	<h3>2.5.6: Apr 1 2003</h3>
				621	<ul>
				622	<li>Fixed W3C XML Schemas datatype, should be compliant now except for
				623	binHex and base64 which are not supported yet.</li>
				624	<li>bug fixes: non-ASCII IDs, HTML output, XInclude on large docs and
				625	XInclude entities handling, encoding detection on external subsets, XML
				626	Schemas bugs and memory leaks, HTML parser (James Bursa)</li>
				627	<li>portability: python/trio (Albert Chin), Sun compiler warnings</li>
				628	<li>documentation: added --relaxng option to xmllint man page (John)</li>
				629	<li>improved error reporting: xml:space, start/end tag mismatches, Relax NG
				630	errors</li>
				631	</ul>
				632
				633	<h3>2.5.5: Mar 24 2003</h3>
Daniel Veillard	d8da01c	2003-03-24 15:58:23 +0000	[diff] [blame]	634	<ul>
				635	<li>Lot of fixes on the Relax NG implementation. More testing including
				636	DocBook and TEI examples.</li>
				637	<li>Increased the support for W3C XML Schemas datatype</li>
				638	<li>Several bug fixes in the URI handling layer</li>
				639	<li>Bug fixes: HTML parser, xmlReader, DTD validation, XPath, encoding
				640	conversion, line counting in the parser.</li>
				641	<li>Added support for $XMLLINT_INDENT environment variable, FTP delete</li>
				642	<li>Fixed the RPM spec file name</li>
				643	</ul>
				644
Daniel Veillard	17bed98	2003-02-24 20:11:43 +0000	[diff] [blame]	645	<h3>2.5.4: Feb 20 2003</h3>
				646	<ul>
				647	<li>Conformance testing and lot of fixes on Relax NG and XInclude
				648	implementation</li>
				649	<li>Implementation of XPointer element() scheme</li>
				650	<li>Bug fixes: XML parser, XInclude entities merge, validity checking on
				651	namespaces,
				652	<p>2 serialization bugs, node info generation problems, a DTD regexp
				653	generation problem.</p>
				654	</li>
				655	<li>Portability: windows updates and path canonicalization (Igor)</li>
				656	<li>A few typo fixes (Kjartan Maraas)</li>
				657	<li>Python bindings generator fixes (Stephane Bidoul)</li>
				658	</ul>
				659
Daniel Veillard	1d788d2	2003-02-10 16:21:58 +0000	[diff] [blame]	660	<h3>2.5.3: Feb 10 2003</h3>
				661	<ul>
				662	<li>RelaxNG and XML Schemas datatypes improvements, and added a first
				663	version of RelaxNG Python bindings</li>
				664	<li>Fixes: XLink (Sean Chittenden), XInclude (Sean Chittenden), API fix for
				665	serializing namespace nodes, encoding conversion bug, XHTML1
				666	serialization</li>
				667	<li>Portability fixes: Windows (Igor), AMD 64bits RPM spec file</li>
				668	</ul>
				669
Daniel Veillard	72fef16	2003-02-05 14:31:19 +0000	[diff] [blame]	670	<h3>2.5.2: Feb 5 2003</h3>
				671	<ul>
				672	<li>First implementation of RelaxNG, added --relaxng flag to xmllint</li>
				673	<li>Schemas support now compiled in by default.</li>
				674	<li>Bug fixes: DTD validation, namespace checking, XInclude and entities,
				675	delegateURI in XML Catalogs, HTML parser, XML reader (Stéphane Bidoul),
				676	XPath parser and evaluation, UTF8ToUTF8 serialization, XML reader memory
				677	consumption, HTML parser, HTML serialization in the presence of
				678	namespaces</li>
				679	<li>added an HTML API to check elements and attributes.</li>
				680	<li>Documentation improvement, PDF for the tutorial (John Fleck), doc
				681	patches (Stefan Kost)</li>
				682	<li>Portability fixes: NetBSD (Julio Merino), Windows (Igor Zlatkovic)</li>
				683	<li>Added python bindings for XPointer, contextual error reporting
				684	(Stéphane Bidoul)</li>
				685	<li>URI/file escaping problems (Stefano Zacchiroli)</li>
Daniel Veillard	cf27f7c	2002-04-30 07:12:39 +0000	[diff] [blame]	686	</ul>
				687
Daniel Veillard	e2830f1	2003-01-08 17:47:49 +0000	[diff] [blame]	688	<h3>2.5.1: Jan 8 2003</h3>
				689	<ul>
				690	<li>Fixes a memory leak and configuration/compilation problems in 2.5.0</li>
				691	<li>documentation updates (John)</li>
				692	<li>a couple of XmlTextReader fixes</li>
				693	</ul>
				694
Daniel Veillard	7b4b2f9	2003-01-06 13:11:20 +0000	[diff] [blame]	695	<h3>2.5.0: Jan 6 2003</h3>
				696	<ul>
				697	<li>New <a href="xmlreader.html">XmltextReader interface</a> based on C#
				698	API (with help of Stéphane Bidoul)</li>
				699	<li>Windows: more exports, including the new API (Igor)</li>
				700	<li>XInclude fallback fix</li>
				701	<li>Python: bindings for the new API, packaging (Stéphane Bidoul),
				702	drv_libxml2.py Python xml.sax driver (Stéphane Bidoul), fixes, speedup
				703	and iterators for Python-2.2 (Hannu Krosing)</li>
				704	<li>Tutorial fixes (john Fleck and Niraj Tolia) xmllint man update
				705	(John)</li>
				706	<li>Fix an XML parser bug raised by Vyacheslav Pindyura</li>
				707	<li>Fix for VMS serialization (Nigel Hall) and config (Craig A. Berry)</li>
				708	<li>Entities handling fixes</li>
				709	<li>new API to optionally track node creation and deletion (Lukas
				710	Schroeder)</li>
				711	<li>Added documentation for the XmltextReader interface and some <a
				712	href="guidelines.html">XML guidelines</a></li>
				713	</ul>
				714
Daniel Veillard	c1eed32	2002-12-12 11:01:32 +0000	[diff] [blame]	715	<h3>2.4.30: Dec 12 2002</h3>
				716	<ul>
				717	<li>2.4.29 broke the python bindings, rereleasing</li>
				718	<li>Improvement/fixes of the XML API generator, and couple of minor code
				719	fixes.</li>
				720	</ul>
				721
Daniel Veillard	9b4bb4d	2002-12-11 19:28:47 +0000	[diff] [blame]	722	<h3>2.4.29: Dec 11 2002</h3>
				723	<ul>
				724	<li>Windows fixes (Igor): Windows CE port, pthread linking, python bindings
				725	(Stéphane Bidoul), Mingw (Magnus Henoch), and export list updates</li>
				726	<li>Fix for prev in python bindings (ERDI Gergo)</li>
				727	<li>Fix for entities handling (Marcus Clarke)</li>
				728	<li>Refactored the XML and HTML dumps to a single code path, fixed XHTML1
				729	dump</li>
				730	<li>Fix for URI parsing when handling URNs with fragment identifiers</li>
				731	<li>Fix for HTTP URL escaping problem</li>
				732	<li>added an TextXmlReader (C#) like API (work in progress)</li>
				733	<li>Rewrote the API in XML generation script, includes a C parser and saves
				734	more informations needed for C# bindings</li>
				735	</ul>
				736
Daniel Veillard	f9c4cad	2002-11-22 15:57:07 +0000	[diff] [blame]	737	<h3>2.4.28: Nov 22 2002</h3>
				738	<ul>
				739	<li>a couple of python binding fixes</li>
				740	<li>2 bug fixes in the XML push parser</li>
				741	<li>potential memory leak removed (Martin Stoilov)</li>
				742	<li>fix to the configure script for Unix (Dimitri Papadopoulos)</li>
				743	<li>added encoding support for XInclude parse="text"</li>
				744	<li>autodetection of XHTML1 and specific serialization rules added</li>
Daniel Veillard	9b4bb4d	2002-12-11 19:28:47 +0000	[diff] [blame]	745	<li>nasty threading bug fixed (William Brack)</li>
Daniel Veillard	f9c4cad	2002-11-22 15:57:07 +0000	[diff] [blame]	746	</ul>
				747
Daniel Veillard	dad3f68	2002-11-17 16:47:27 +0000	[diff] [blame]	748	<h3>2.4.27: Nov 17 2002</h3>
				749	<ul>
				750	<li>fixes for the Python bindings</li>
				751	<li>a number of bug fixes: SGML catalogs, xmlParseBalancedChunkMemory(),
				752	HTML parser, Schemas (Charles Bozeman), document fragment support
				753	(Christian Glahn), xmlReconciliateNs (Brian Stafford), XPointer,
				754	xmlFreeNode(), xmlSAXParseMemory (Peter Jones), xmlGetNodePath (Petr
				755	Pajas), entities processing</li>
				756	<li>added grep to xmllint --shell</li>
				757	<li>VMS update patch from Craig A. Berry</li>
				758	<li>cleanup of the Windows build with support for more compilers (Igor),
				759	better thread support on Windows</li>
				760	<li>cleanup of Unix Makefiles and spec file</li>
				761	<li>Improvements to the documentation (John Fleck)</li>
				762	</ul>
				763
Daniel Veillard	4826743	2002-10-18 11:21:38 +0000	[diff] [blame]	764	<h3>2.4.26: Oct 18 2002</h3>
				765	<ul>
				766	<li>Patches for Windows CE port, improvements on Windows paths handling</li>
				767	<li>Fixes to the validation code (DTD and Schemas), xmlNodeGetPath() ,
				768	HTML serialization, Namespace compliance, and a number of small
				769	problems</li>
				770	</ul>
				771
Daniel Veillard	e16b574	2002-09-26 17:50:03 +0000	[diff] [blame]	772	<h3>2.4.25: Sep 26 2002</h3>
				773	<ul>
				774	<li>A number of bug fixes: XPath, validation, Python bindings, DOM and
				775	tree, xmlI/O, Html</li>
				776	<li>Serious rewrite of XInclude</li>
				777	<li>Made XML Schemas regexp part of the default build and APIs, small fix
				778	and improvement of the regexp core</li>
				779	<li>Changed the validation code to reuse XML Schemas regexp APIs</li>
				780	<li>Better handling of Windows file paths, improvement of Makefiles (Igor,
				781	Daniel Gehriger, Mark Vakoc)</li>
				782	<li>Improved the python I/O bindings, the tests, added resolver and regexp
Daniel Veillard	321be0c	2002-10-08 21:26:42 +0000	[diff] [blame]	783	APIs</li>
Daniel Veillard	e16b574	2002-09-26 17:50:03 +0000	[diff] [blame]	784	<li>New logos from Marc Liyanage</li>
				785	<li>Tutorial improvements: John Fleck, Christopher Harris</li>
				786	<li>Makefile: Fixes for AMD x86_64 (Mandrake), DESTDIR (Christophe
				787	Merlet)</li>
				788	<li>removal of all stderr/perror use for error reporting</li>
				789	<li>Better error reporting: XPath and DTD validation</li>
				790	<li>update of the trio portability layer (Bjorn Reese)</li>
				791	</ul>
				792
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	793	<p><strong>2.4.24: Aug 22 2002</strong></p>
				794	<ul>
				795	<li>XPath fixes (William), xf:escape-uri() (Wesley Terpstra)</li>
				796	<li>Python binding fixes: makefiles (William), generator, rpm build, x86-64
				797	(fcrozat)</li>
				798	<li>HTML <style> and boolean attributes serializer fixes</li>
				799	<li>C14N improvements by Aleksey</li>
Daniel Veillard	e166254	2002-08-28 11:50:59 +0000	[diff] [blame]	800	<li>doc cleanups: Rick Jones</li>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	801	<li>Windows compiler makefile updates: Igor and Elizabeth Barham</li>
				802	<li>XInclude: implementation of fallback and xml:base fixup added</li>
				803	</ul>
				804
Daniel Veillard	782afda	2002-07-08 15:12:49 +0000	[diff] [blame]	805	<h3>2.4.23: July 6 2002</h3>
				806	<ul>
				807	<li>performances patches: Peter Jacobi</li>
				808	<li>c14n fixes, testsuite and performances: Aleksey Sanin</li>
				809	<li>added xmlDocFormatDump: Chema Celorio</li>
				810	<li>new tutorial: John Fleck</li>
				811	<li>new hash functions and performances: Sander Vesik, portability fix from
				812	Peter Jacobi</li>
				813	<li>a number of bug fixes: XPath (William Brack, Richard Jinks), XML and
				814	HTML parsers, ID lookup function</li>
				815	<li>removal of all remaining sprintf: Aleksey Sanin</li>
				816	</ul>
				817
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	818	<h3>2.4.22: May 27 2002</h3>
				819	<ul>
				820	<li>a number of bug fixes: configure scripts, base handling, parser, memory
				821	usage, HTML parser, XPath, documentation (Christian Cornelssen),
Daniel Veillard	2147367	2002-06-17 07:29:22 +0000	[diff] [blame]	822	indentation, URI parsing</li>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	823	<li>Optimizations for XMLSec, fixing and making public some of the network
				824	protocol handlers (Aleksey)</li>
				825	<li>performance patch from Gary Pennington</li>
				826	<li>Charles Bozeman provided date and time support for XML Schemas
				827	datatypes</li>
				828	</ul>
				829
Daniel Veillard	cf27f7c	2002-04-30 07:12:39 +0000	[diff] [blame]	830	<h3>2.4.21: Apr 29 2002</h3>
				831
				832	<p>This release is both a bug fix release and also contains the early XML
				833	Schemas <a href="http://www.w3.org/TR/xmlschema-1/">structures</a> and <a
				834	href="http://www.w3.org/TR/xmlschema-2/">datatypes</a> code, beware, all
				835	interfaces are likely to change, there is huge holes, it is clearly a work in
				836	progress and don't even think of putting this code in a production system,
Daniel Veillard	e6d8e20	2002-05-02 06:11:10 +0000	[diff] [blame]	837	it's actually not compiled in by default. The real fixes are:</p>
Daniel Veillard	cf27f7c	2002-04-30 07:12:39 +0000	[diff] [blame]	838	<ul>
				839	<li>a couple of bugs or limitations introduced in 2.4.20</li>
				840	<li>patches for Borland C++ and MSC by Igor</li>
				841	<li>some fixes on XPath strings and conformance patches by Richard
				842	Jinks</li>
				843	<li>patch from Aleksey for the ExcC14N specification</li>
				844	<li>OSF/1 bug fix by Bjorn</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	845	</ul>
				846
Daniel Veillard	a7084cd	2002-04-15 17:12:47 +0000	[diff] [blame]	847	<h3>2.4.20: Apr 15 2002</h3>
				848	<ul>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	849	<li>bug fixes: file descriptor leak, XPath, HTML output, DTD validation</li>
Daniel Veillard	a7084cd	2002-04-15 17:12:47 +0000	[diff] [blame]	850	<li>XPath conformance testing by Richard Jinks</li>
				851	<li>Portability fixes: Solaris, MPE/iX, Windows, OSF/1, python bindings,
				852	libxml.m4</li>
				853	</ul>
				854
Daniel Veillard	1927409	2002-03-25 16:48:03 +0000	[diff] [blame]	855	<h3>2.4.19: Mar 25 2002</h3>
				856	<ul>
				857	<li>bug fixes: half a dozen XPath bugs, Validation, ISO-Latin to UTF8
				858	encoder</li>
				859	<li>portability fixes in the HTTP code</li>
Daniel Veillard	b2fb8ed	2002-04-01 09:33:12 +0000	[diff] [blame]	860	<li>memory allocation checks using valgrind, and profiling tests</li>
Daniel Veillard	1927409	2002-03-25 16:48:03 +0000	[diff] [blame]	861	<li>revamp of the Windows build and Makefiles</li>
				862	</ul>
				863
Daniel Veillard	34ce8be	2002-03-18 19:37:11 +0000	[diff] [blame]	864	<h3>2.4.18: Mar 18 2002</h3>
				865	<ul>
				866	<li>bug fixes: tree, SAX, canonicalization, validation, portability,
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	867	XPath</li>
Daniel Veillard	34ce8be	2002-03-18 19:37:11 +0000	[diff] [blame]	868	<li>removed the --with-buffer option it was becoming unmaintainable</li>
				869	<li>serious cleanup of the Python makefiles</li>
				870	<li>speedup patch to XPath very effective for DocBook stylesheets</li>
				871	<li>Fixes for Windows build, cleanup of the documentation</li>
				872	</ul>
				873
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	874	<h3>2.4.17: Mar 8 2002</h3>
				875	<ul>
				876	<li>a lot of bug fixes, including "namespace nodes have no parents in
				877	XPath"</li>
				878	<li>fixed/improved the Python wrappers, added more examples and more
				879	regression tests, XPath extension functions can now return node-sets</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	880	<li>added the XML Canonicalization support from Aleksey Sanin</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	881	</ul>
				882
Daniel Veillard	5f4b599	2002-02-20 10:22:49 +0000	[diff] [blame]	883	<h3>2.4.16: Feb 20 2002</h3>
				884	<ul>
				885	<li>a lot of bug fixes, most of them were triggered by the XML Testsuite
				886	from OASIS and W3C. Compliance has been significantly improved.</li>
				887	<li>a couple of portability fixes too.</li>
				888	</ul>
				889
Daniel Veillard	397ff11	2002-02-11 18:27:20 +0000	[diff] [blame]	890	<h3>2.4.15: Feb 11 2002</h3>
				891	<ul>
				892	<li>Fixed the Makefiles, especially the python module ones</li>
				893	<li>A few bug fixes and cleanup</li>
				894	<li>Includes cleanup</li>
				895	</ul>
				896
Daniel Veillard	b6c1e2f	2002-02-08 14:52:52 +0000	[diff] [blame]	897	<h3>2.4.14: Feb 8 2002</h3>
				898	<ul>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	899	<li>Change of License to the <a
Daniel Veillard	b6c1e2f	2002-02-08 14:52:52 +0000	[diff] [blame]	900	href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	901	License</a> basically for integration in XFree86 codebase, and removing
				902	confusion around the previous dual-licensing</li>
Daniel Veillard	b6c1e2f	2002-02-08 14:52:52 +0000	[diff] [blame]	903	<li>added Python bindings, beta software but should already be quite
				904	complete</li>
				905	<li>a large number of fixes and cleanups, especially for all tree
				906	manipulations</li>
				907	<li>cleanup of the headers, generation of a reference API definition in
				908	XML</li>
				909	</ul>
				910
				911	<h3>2.4.13: Jan 14 2002</h3>
Daniel Veillard	744683d	2002-01-14 17:30:20 +0000	[diff] [blame]	912	<ul>
				913	<li>update of the documentation: John Fleck and Charlie Bozeman</li>
				914	<li>cleanup of timing code from Justin Fletcher</li>
				915	<li>fixes for Windows and initial thread support on Win32: Igor and Serguei
				916	Narojnyi</li>
				917	<li>Cygwin patch from Robert Collins</li>
				918	<li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
				919	</ul>
				920
Daniel Veillard	ef90ba7	2001-12-07 14:24:22 +0000	[diff] [blame]	921	<h3>2.4.12: Dec 7 2001</h3>
				922	<ul>
				923	<li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
				924	XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
				925	(robert)</li>
				926	<li>Eric Lavigne contributed project files for MacOS</li>
				927	<li>some makefiles cleanups</li>
				928	</ul>
				929
Daniel Veillard	a487105	2001-11-26 13:19:48 +0000	[diff] [blame]	930	<h3>2.4.11: Nov 26 2001</h3>
				931	<ul>
				932	<li>fixed a couple of errors in the includes, fixed a few bugs, some code
				933	cleanups</li>
				934	<li>xmllint man pages improvement by Heiko Rupp</li>
				935	<li>updated VMS build instructions from John A Fotheringham</li>
				936	<li>Windows Makefiles updates from Igor</li>
				937	</ul>
				938
Daniel Veillard	43d3f61	2001-11-10 11:57:23 +0000	[diff] [blame]	939	<h3>2.4.10: Nov 10 2001</h3>
				940	<ul>
				941	<li>URI escaping fix (Joel Young)</li>
				942	<li>added xmlGetNodePath() (for paths or XPointers generation)</li>
				943	<li>Fixes namespace handling problems when using DTD and validation</li>
				944	<li>improvements on xmllint: Morus Walter patches for --format and
				945	--encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
				946	<li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
				947	<li>fixes to the HTML parser</li>
				948	</ul>
				949
				950	<h3>2.4.9: Nov 6 2001</h3>
				951	<ul>
				952	<li>fixes more catalog bugs</li>
				953	<li>avoid a compilation problem, improve xmlGetLineNo()</li>
				954	</ul>
				955
Daniel Veillard	ed421aa	2001-11-04 21:22:45 +0000	[diff] [blame]	956	<h3>2.4.8: Nov 4 2001</h3>
				957	<ul>
				958	<li>fixed SGML catalogs broken in previous release, updated xmlcatalog
				959	tool</li>
				960	<li>fixed a compile errors and some includes troubles.</li>
				961	</ul>
				962
Daniel Veillard	52dcab3	2001-10-30 12:51:17 +0000	[diff] [blame]	963	<h3>2.4.7: Oct 30 2001</h3>
				964	<ul>
				965	<li>exported some debugging interfaces</li>
				966	<li>serious rewrite of the catalog code</li>
				967	<li>integrated Gary Pennington thread safety patch, added configure option
				968	and regression tests</li>
				969	<li>removed an HTML parser bug</li>
				970	<li>fixed a couple of potentially serious validation bugs</li>
				971	<li>integrated the SGML DocBook support in xmllint</li>
				972	<li>changed the nanoftp anonymous login passwd</li>
				973	<li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
				974	<li>general bug fixes</li>
				975	<li>updated xmllint man page by John Fleck</li>
				976	<li>some VMS and Windows updates</li>
				977	</ul>
				978
Daniel Veillard	60087f3	2001-10-10 09:45:09 +0000	[diff] [blame]	979	<h3>2.4.6: Oct 10 2001</h3>
				980	<ul>
Daniel Veillard	52dcab3	2001-10-30 12:51:17 +0000	[diff] [blame]	981	<li>added an updated man pages by John Fleck</li>
Daniel Veillard	60087f3	2001-10-10 09:45:09 +0000	[diff] [blame]	982	<li>portability and configure fixes</li>
				983	<li>an infinite loop on the HTML parser was removed (William)</li>
				984	<li>Windows makefile patches from Igor</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	985	<li>fixed half a dozen bugs reported for libxml or libxslt</li>
Daniel Veillard	60087f3	2001-10-10 09:45:09 +0000	[diff] [blame]	986	<li>updated xmlcatalog to be able to modify SGML super catalogs</li>
				987	</ul>
				988
Daniel Veillard	dadd087	2001-09-15 09:21:44 +0000	[diff] [blame]	989	<h3>2.4.5: Sep 14 2001</h3>
				990	<ul>
				991	<li>Remove a few annoying bugs in 2.4.4</li>
				992	<li>forces the HTML serializer to output decimal charrefs since some
				993	version of Netscape can't handle hexadecimal ones</li>
				994	</ul>
				995
				996	<h3>1.8.16: Sep 14 2001</h3>
				997	<ul>
				998	<li>maintenance release of the old libxml1 branch, couple of bug and
				999	portability fixes</li>
				1000	</ul>
				1001
Daniel Veillard	04382ae	2001-09-12 18:51:30 +0000	[diff] [blame]	1002	<h3>2.4.4: Sep 12 2001</h3>
				1003	<ul>
				1004	<li>added --convert to xmlcatalog, bug fixes and cleanups of XML
				1005	Catalog</li>
				1006	<li>a few bug fixes and some portability changes</li>
				1007	<li>some documentation cleanups</li>
				1008	</ul>
				1009
Daniel Veillard	3993690	2001-08-24 00:49:01 +0000	[diff] [blame]	1010	<h3>2.4.3: Aug 23 2001</h3>
				1011	<ul>
				1012	<li>XML Catalog support see the doc</li>
				1013	<li>New NaN/Infinity floating point code</li>
				1014	<li>A few bug fixes</li>
				1015	</ul>
				1016
				1017	<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1018	<ul>
				1019	<li>adds xmlLineNumbersDefault() to control line number generation</li>
				1020	<li>lot of bug fixes</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1021	<li>the Microsoft MSC projects files should now be up to date</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1022	<li>inheritance of namespaces from DTD defaulted attributes</li>
				1023	<li>fixes a serious potential security bug</li>
				1024	<li>added a --format option to xmllint</li>
				1025	</ul>
				1026
				1027	<h3>2.4.1: July 24 2001</h3>
				1028	<ul>
				1029	<li>possibility to keep line numbers in the tree</li>
				1030	<li>some computation NaN fixes</li>
				1031	<li>extension of the XPath API</li>
				1032	<li>cleanup for alpha and ia64 targets</li>
				1033	<li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard	09ab7e1	2001-07-10 15:49:44 +0000	[diff] [blame]	1034	</ul>
				1035
				1036	<h3>2.4.0: July 10 2001</h3>
				1037	<ul>
				1038	<li>Fixed a few bugs in XPath, validation, and tree handling.</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1039	<li>Fixed XML Base implementation, added a couple of examples to the
Daniel Veillard	09ab7e1	2001-07-10 15:49:44 +0000	[diff] [blame]	1040	regression tests</li>
				1041	<li>A bit of cleanup</li>
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	1042	</ul>
				1043
Daniel Veillard	5b43fde	2001-07-05 23:31:40 +0000	[diff] [blame]	1044	<h3>2.3.14: July 5 2001</h3>
				1045	<ul>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1046	<li>fixed some entities problems and reduce memory requirement when
				1047	substituting them</li>
Daniel Veillard	5b43fde	2001-07-05 23:31:40 +0000	[diff] [blame]	1048	<li>lots of improvements in the XPath queries interpreter can be
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1049	substantially faster</li>
Daniel Veillard	5b43fde	2001-07-05 23:31:40 +0000	[diff] [blame]	1050	<li>Makefiles and configure cleanups</li>
				1051	<li>Fixes to XPath variable eval, and compare on empty node set</li>
				1052	<li>HTML tag closing bug fixed</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1053	<li>Fixed an URI reference computation problem when validating</li>
Daniel Veillard	5b43fde	2001-07-05 23:31:40 +0000	[diff] [blame]	1054	</ul>
				1055
Daniel Veillard	2adbb51	2001-06-28 16:20:36 +0000	[diff] [blame]	1056	<h3>2.3.13: June 28 2001</h3>
				1057	<ul>
				1058	<li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
				1059	<li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
				1060	</ul>
				1061
				1062	<h3>1.8.14: June 28 2001</h3>
				1063	<ul>
				1064	<li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
				1065	<li>Small Makefile fix</li>
				1066	</ul>
				1067
Daniel Veillard	1164810	2001-06-26 16:08:24 +0000	[diff] [blame]	1068	<h3>2.3.12: June 26 2001</h3>
				1069	<ul>
				1070	<li>lots of cleanup</li>
				1071	<li>a couple of validation fix</li>
				1072	<li>fixed line number counting</li>
				1073	<li>fixed serious problems in the XInclude processing</li>
				1074	<li>added support for UTF8 BOM at beginning of entities</li>
				1075	<li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
				1076	miscompile uri.c (William), Thomas Leitner provided a fix for the
				1077	optimizer on Tru64</li>
				1078	<li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
				1079	compilation on Windows MSC</li>
				1080	<li>update of libxml-doc.el (Felix Natter)</li>
				1081	<li>fixed 2 bugs in URI normalization code</li>
				1082	</ul>
				1083
Daniel Veillard	e3c81b5	2001-06-17 14:50:34 +0000	[diff] [blame]	1084	<h3>2.3.11: June 17 2001</h3>
				1085	<ul>
				1086	<li>updates to trio, Makefiles and configure should fix some portability
				1087	problems (alpha)</li>
				1088	<li>fixed some HTML serialization problems (pre, script, and block/inline
				1089	handling), added encoding aware APIs, cleanup of this code</li>
				1090	<li>added xmlHasNsProp()</li>
				1091	<li>implemented a specific PI for encoding support in the DocBook SGML
				1092	parser</li>
				1093	<li>some XPath fixes (-Infinity, / as a function parameter and namespaces
				1094	node selection)</li>
				1095	<li>fixed a performance problem and an error in the validation code</li>
				1096	<li>fixed XInclude routine to implement the recursive behaviour</li>
				1097	<li>fixed xmlFreeNode problem when libxml is included statically twice</li>
				1098	<li>added --version to xmllint for bug reports</li>
				1099	</ul>
				1100
Daniel Veillard	2e4f188	2001-06-01 10:11:57 +0000	[diff] [blame]	1101	<h3>2.3.10: June 1 2001</h3>
				1102	<ul>
				1103	<li>fixed the SGML catalog support</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1104	<li>a number of reported bugs got fixed, in XPath, iconv detection,
				1105	XInclude processing</li>
Daniel Veillard	2e4f188	2001-06-01 10:11:57 +0000	[diff] [blame]	1106	<li>XPath string function should now handle unicode correctly</li>
				1107	</ul>
				1108
Daniel Veillard	4623acd	2001-05-19 15:13:15 +0000	[diff] [blame]	1109	<h3>2.3.9: May 19 2001</h3>
				1110
				1111	<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
				1112	<ul>
				1113	<li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1114	<li>some serious speed optimization again</li>
Daniel Veillard	4623acd	2001-05-19 15:13:15 +0000	[diff] [blame]	1115	<li>some documentation cleanups</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1116	<li>trying to get better linking on Solaris (-R)</li>
Daniel Veillard	4623acd	2001-05-19 15:13:15 +0000	[diff] [blame]	1117	<li>XPath API cleanup from Thomas Broyer</li>
				1118	<li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
				1119	xmlValidGetValidElements()</li>
				1120	<li>Added an INSTALL file</li>
				1121	<li>Attribute removal added to API: #54433</li>
				1122	<li>added a basic support for SGML catalogs</li>
				1123	<li>fixed xmlKeepBlanksDefault(0) API</li>
				1124	<li>bugfix in xmlNodeGetLang()</li>
				1125	<li>fixed a small configure portability problem</li>
				1126	<li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
				1127	</ul>
				1128
Daniel Veillard	a265af7	2001-05-14 11:13:58 +0000	[diff] [blame]	1129	<h3>1.8.13: May 14 2001</h3>
				1130	<ul>
				1131	<li>bugfixes release of the old libxml1 branch used by Gnome</li>
				1132	</ul>
				1133
Daniel Veillard	3bbbe6f	2001-05-03 11:15:37 +0000	[diff] [blame]	1134	<h3>2.3.8: May 3 2001</h3>
				1135	<ul>
				1136	<li>Integrated an SGML DocBook parser for the Gnome project</li>
				1137	<li>Fixed a few things in the HTML parser</li>
				1138	<li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
				1139	point portability issue</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1140	<li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
				1141	DOM+validation using the XML REC as input and a 700MHz celeron).</li>
Daniel Veillard	3bbbe6f	2001-05-03 11:15:37 +0000	[diff] [blame]	1142	<li>incorporated more Windows cleanup</li>
				1143	<li>added xmlSaveFormatFile()</li>
				1144	<li>fixed problems in copying nodes with entities references (gdome)</li>
				1145	<li>removed some troubles surrounding the new validation module</li>
				1146	</ul>
				1147
Daniel Veillard	a41123c	2001-04-22 19:31:20 +0000	[diff] [blame]	1148	<h3>2.3.7: April 22 2001</h3>
				1149	<ul>
				1150	<li>lots of small bug fixes, corrected XPointer</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1151	<li>Non deterministic content model validation support</li>
Daniel Veillard	a41123c	2001-04-22 19:31:20 +0000	[diff] [blame]	1152	<li>added xmlDocCopyNode for gdome2</li>
				1153	<li>revamped the way the HTML parser handles end of tags</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1154	<li>XPath: corrections of namespaces support and number formatting</li>
Daniel Veillard	a41123c	2001-04-22 19:31:20 +0000	[diff] [blame]	1155	<li>Windows: Igor Zlatkovic patches for MSC compilation</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1156	<li>HTML output fixes from P C Chow and William M. Brack</li>
Daniel Veillard	a41123c	2001-04-22 19:31:20 +0000	[diff] [blame]	1157	<li>Improved validation speed sensible for DocBook</li>
				1158	<li>fixed a big bug with ID declared in external parsed entities</li>
				1159	<li>portability fixes, update of Trio from Bjorn Reese</li>
				1160	</ul>
				1161
Daniel Veillard	afc7311	2001-04-11 11:51:41 +0000	[diff] [blame]	1162	<h3>2.3.6: April 8 2001</h3>
				1163	<ul>
				1164	<li>Code cleanup using extreme gcc compiler warning options, found and
				1165	cleared half a dozen potential problem</li>
				1166	<li>the Eazel team found an XML parser bug</li>
				1167	<li>cleaned up the user of some of the string formatting function. used the
				1168	trio library code to provide the one needed when the platform is missing
				1169	them</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1170	<li>xpath: removed a memory leak and fixed the predicate evaluation
				1171	problem, extended the testsuite and cleaned up the result. XPointer seems
				1172	broken ...</li>
Daniel Veillard	afc7311	2001-04-11 11:51:41 +0000	[diff] [blame]	1173	</ul>
				1174
Daniel Veillard	56a4cb8	2001-03-24 17:00:36 +0000	[diff] [blame]	1175	<h3>2.3.5: Mar 23 2001</h3>
				1176	<ul>
				1177	<li>Biggest change is separate parsing and evaluation of XPath expressions,
				1178	there is some new APIs for this too</li>
				1179	<li>included a number of bug fixes(XML push parser, 51876, notations,
				1180	52299)</li>
				1181	<li>Fixed some portability issues</li>
				1182	</ul>
				1183
Daniel Veillard	e356c28	2001-03-10 12:32:04 +0000	[diff] [blame]	1184	<h3>2.3.4: Mar 10 2001</h3>
				1185	<ul>
				1186	<li>Fixed bugs #51860 and #51861</li>
				1187	<li>Added a global variable xmlDefaultBufferSize to allow default buffer
				1188	size to be application tunable.</li>
				1189	<li>Some cleanup in the validation code, still a bug left and this part
				1190	should probably be rewritten to support ambiguous content model :-\</li>
				1191	<li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
				1192	parser</li>
				1193	<li>Fixed another bug in xmlNodeGetContent()</li>
				1194	<li>Bjorn fixed XPath node collection and Number formatting</li>
				1195	<li>Fixed a loop reported in the HTML parsing</li>
				1196	<li>blank space are reported even if the Dtd content model proves that they
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1197	are formatting spaces, this is for XML conformance</li>
Daniel Veillard	e356c28	2001-03-10 12:32:04 +0000	[diff] [blame]	1198	</ul>
				1199
Daniel Veillard	b402c07	2001-03-01 17:28:58 +0000	[diff] [blame]	1200	<h3>2.3.3: Mar 1 2001</h3>
				1201	<ul>
				1202	<li>small change in XPath for XSLT</li>
				1203	<li>documentation cleanups</li>
				1204	<li>fix in validation by Gary Pennington</li>
				1205	<li>serious parsing performances improvements</li>
				1206	</ul>
				1207
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	1208	<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard	7168110	2001-02-24 17:48:53 +0000	[diff] [blame]	1209	<ul>
				1210	<li>chasing XPath bugs, found a bunch, completed some TODO</li>
				1211	<li>fixed a Dtd parsing bug</li>
				1212	<li>fixed a bug in xmlNodeGetContent</li>
				1213	<li>ID/IDREF support partly rewritten by Gary Pennington</li>
				1214	</ul>
				1215
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	1216	<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard	6e6a6cc	2001-02-15 15:55:44 +0000	[diff] [blame]	1217	<ul>
				1218	<li>some XPath and HTML bug fixes for XSLT</li>
				1219	<li>small extension of the hash table interfaces for DOM gdome2
				1220	implementation</li>
				1221	<li>A few bug fixes</li>
				1222	</ul>
				1223
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	1224	<h3>2.3.0: Feb 8 2001 (2.2.12 was on 25 Jan but I didn't kept track)</h3>
Daniel Veillard	6e6a6cc	2001-02-15 15:55:44 +0000	[diff] [blame]	1225	<ul>
				1226	<li>Lots of XPath bug fixes</li>
				1227	<li>Add a mode with Dtd lookup but without validation error reporting for
				1228	XSLT</li>
				1229	<li>Add support for text node without escaping (XSLT)</li>
				1230	<li>bug fixes for xmlCheckFilename</li>
				1231	<li>validation code bug fixes from Gary Pennington</li>
				1232	<li>Patch from Paul D. Smith correcting URI path normalization</li>
				1233	<li>Patch to allow simultaneous install of libxml-devel and
				1234	libxml2-devel</li>
				1235	<li>the example Makefile is now fixed</li>
				1236	<li>added HTML to the RPM packages</li>
				1237	<li>tree copying bugfixes</li>
				1238	<li>updates to Windows makefiles</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1239	<li>optimization patch from Bjorn Reese</li>
Daniel Veillard	6e6a6cc	2001-02-15 15:55:44 +0000	[diff] [blame]	1240	</ul>
				1241
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	1242	<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard	503b893	2001-01-05 06:36:31 +0000	[diff] [blame]	1243	<ul>
				1244	<li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
				1245	<li>added htmlHandleOmittedElem()</li>
				1246	<li>Applied Bjorn Reese's IPV6 first patch</li>
				1247	<li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard	8268716	2001-01-22 15:32:01 +0000	[diff] [blame]	1248	<li>added XPointer xmlns() new scheme support</li>
Daniel Veillard	503b893	2001-01-05 06:36:31 +0000	[diff] [blame]	1249	</ul>
				1250
Daniel Veillard	2ddd23d	2000-11-25 10:42:19 +0000	[diff] [blame]	1251	<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard	9d343c4	2000-11-25 10:12:43 +0000	[diff] [blame]	1252	<ul>
				1253	<li>Fix the Windows problems of 2.2.8</li>
				1254	<li>integrate OpenVMS patches</li>
				1255	<li>better handling of some nasty HTML input</li>
				1256	<li>Improved the XPointer implementation</li>
				1257	<li>integrate a number of provided patches</li>
				1258	</ul>
				1259
Daniel Veillard	2ddd23d	2000-11-25 10:42:19 +0000	[diff] [blame]	1260	<h3>2.2.9: Nov 25 2000</h3>
				1261	<ul>
				1262	<li>erroneous release :-(</li>
				1263	</ul>
				1264
Daniel Veillard	28929b2	2000-11-13 18:22:49 +0000	[diff] [blame]	1265	<h3>2.2.8: Nov 13 2000</h3>
				1266	<ul>
				1267	<li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
				1268	support</li>
				1269	<li>Patch in conditional section handling</li>
				1270	<li>updated MS compiler project</li>
				1271	<li>fixed some XPath problems</li>
				1272	<li>added an URI escaping function</li>
				1273	<li>some other bug fixes</li>
				1274	</ul>
				1275
				1276	<h3>2.2.7: Oct 31 2000</h3>
				1277	<ul>
				1278	<li>added message redirection</li>
				1279	<li>XPath improvements (thanks TOM !)</li>
				1280	<li>xmlIOParseDTD() added</li>
				1281	<li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
				1282	<li>some cleanup of the Makefile, autoconf and the distribution content</li>
				1283	</ul>
				1284
Daniel Veillard	29a11cc	2000-10-25 13:32:39 +0000	[diff] [blame]	1285	<h3>2.2.6: Oct 25 2000:</h3>
				1286	<ul>
				1287	<li>Added an hash table module, migrated a number of internal structure to
				1288	those</li>
				1289	<li>Fixed a posteriori validation problems</li>
				1290	<li>HTTP module cleanups</li>
				1291	<li>HTML parser improvements (tag errors, script/style handling, attribute
				1292	normalization)</li>
				1293	<li>coalescing of adjacent text nodes</li>
				1294	<li>couple of XPath bug fixes, exported the internal API</li>
				1295	</ul>
				1296
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	1297	<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard	4c3a203	1999-11-19 17:46:26 +0000	[diff] [blame]	1298	<ul>
Daniel Veillard	189446d	2000-10-13 10:23:06 +0000	[diff] [blame]	1299	<li>XPointer implementation and testsuite</li>
				1300	<li>Lot of XPath fixes, added variable and functions registration, more
				1301	tests</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1302	<li>Portability fixes, lots of enhancements toward an easy Windows build
				1303	and release</li>
Daniel Veillard	189446d	2000-10-13 10:23:06 +0000	[diff] [blame]	1304	<li>Late validation fixes</li>
				1305	<li>Integrated a lot of contributed patches</li>
				1306	<li>added memory management docs</li>
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	1307	<li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard	189446d	2000-10-13 10:23:06 +0000	[diff] [blame]	1308	</ul>
				1309
				1310	<h3>2.2.4: Oct 1 2000:</h3>
				1311	<ul>
				1312	<li>main XPath problem fixed</li>
				1313	<li>Integrated portability patches for Windows</li>
				1314	<li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	1315	</ul>
				1316
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	1317	<h3>2.2.3: Sep 17 2000</h3>
				1318	<ul>
				1319	<li>bug fixes</li>
				1320	<li>cleanup of entity handling code</li>
				1321	<li>overall review of all loops in the parsers, all sprintf usage has been
				1322	checked too</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1323	<li>Far better handling of larges Dtd. Validating against DocBook XML Dtd
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	1324	works smoothly now.</li>
				1325	</ul>
				1326
				1327	<h3>1.8.10: Sep 6 2000</h3>
				1328	<ul>
				1329	<li>bug fix release for some Gnome projects</li>
				1330	</ul>
				1331
				1332	<h3>2.2.2: August 12 2000</h3>
Daniel Veillard	786d7c8	2000-08-12 23:38:57 +0000	[diff] [blame]	1333	<ul>
				1334	<li>mostly bug fixes</li>
Daniel Veillard	ec78c0f	2000-08-25 10:25:23 +0000	[diff] [blame]	1335	<li>started adding routines to access xml parser context options</li>
Daniel Veillard	786d7c8	2000-08-12 23:38:57 +0000	[diff] [blame]	1336	</ul>
				1337
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	1338	<h3>2.2.1: July 21 2000</h3>
Daniel Veillard	a2679fa	2000-07-22 02:38:15 +0000	[diff] [blame]	1339	<ul>
				1340	<li>a purely bug fixes release</li>
				1341	<li>fixed an encoding support problem when parsing from a memory block</li>
				1342	<li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1343	<li>removed a bug in the function allowing to override the memory
				1344	allocation routines</li>
Daniel Veillard	a2679fa	2000-07-22 02:38:15 +0000	[diff] [blame]	1345	</ul>
				1346
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	1347	<h3>2.2.0: July 14 2000</h3>
Daniel Veillard	94e9060	2000-07-17 14:38:19 +0000	[diff] [blame]	1348	<ul>
				1349	<li>applied a lot of portability fixes</li>
				1350	<li>better encoding support/cleanup and saving (content is now always
				1351	encoded in UTF-8)</li>
				1352	<li>the HTML parser now correctly handles encodings</li>
				1353	<li>added xmlHasProp()</li>
				1354	<li>fixed a serious problem with &#38;</li>
				1355	<li>propagated the fix to FTP client</li>
				1356	<li>cleanup, bugfixes, etc ...</li>
				1357	<li>Added a page about <a href="encoding.html">libxml Internationalization
				1358	support</a></li>
				1359	</ul>
				1360
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	1361	<h3>1.8.9: July 9 2000</h3>
				1362	<ul>
				1363	<li>fixed the spec the RPMs should be better</li>
				1364	<li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
				1365	rpmfind users problem</li>
				1366	</ul>
				1367
Daniel Veillard	6388e17	2000-07-03 16:07:19 +0000	[diff] [blame]	1368	<h3>2.1.1: July 1 2000</h3>
				1369	<ul>
				1370	<li>fixes a couple of bugs in the 2.1.0 packaging</li>
				1371	<li>improvements on the HTML parser</li>
				1372	</ul>
				1373
Daniel Veillard	3f6f7f6	2000-06-30 17:58:25 +0000	[diff] [blame]	1374	<h3>2.1.0 and 1.8.8: June 29 2000</h3>
				1375	<ul>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	1376	<li>1.8.8 is mostly a commodity package for upgrading to libxml2 according
				1377	to <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
Daniel Veillard	3f6f7f6	2000-06-30 17:58:25 +0000	[diff] [blame]	1378	about &#38; charref parsing</li>
				1379	<li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
				1380	also contains numerous fixes and enhancements:
				1381	<ul>
				1382	<li>added xmlStopParser() to stop parsing</li>
				1383	<li>improved a lot parsing speed when there is large CDATA blocs</li>
				1384	<li>includes XPath patches provided by Picdar Technology</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1385	<li>tried to fix as much as possible DTD validation and namespace
Daniel Veillard	3f6f7f6	2000-06-30 17:58:25 +0000	[diff] [blame]	1386	related problems</li>
				1387	<li>output to a given encoding has been added/tested</li>
				1388	<li>lot of various fixes</li>
				1389	</ul>
				1390	</li>
				1391	</ul>
				1392
Daniel Veillard	e0aed30	2000-04-16 08:52:20 +0000	[diff] [blame]	1393	<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	1394	<ul>
				1395	<li>First public release of libxml2. If you are using libxml, it's a good
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1396	idea to check the 1.x to 2.x upgrade instructions. NOTE: while initially
				1397	scheduled for Apr 3 the release occurred only on Apr 12 due to massive
Daniel Veillard	e0aed30	2000-04-16 08:52:20 +0000	[diff] [blame]	1398	workload.</li>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	1399	<li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillard	e0aed30	2000-04-16 08:52:20 +0000	[diff] [blame]	1400	$prefix/include/gnome-xml), they also are referenced by
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	1401	<pre>#include <libxml/xxx.h></pre>
Daniel Veillard	e0aed30	2000-04-16 08:52:20 +0000	[diff] [blame]	1402	<p>instead of</p>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	1403	<pre>#include "xxx.h"</pre>
				1404	</li>
Daniel Veillard	8f62198	2000-03-20 13:07:15 +0000	[diff] [blame]	1405	<li>a new URI module for parsing URIs and following strictly RFC 2396</li>
				1406	<li>the memory allocation routines used by libxml can now be overloaded
				1407	dynamically by using xmlMemSetup()</li>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	1408	<li>The previously CVS only tool tester has been renamed
				1409	<strong>xmllint</strong> and is now installed as part of the libxml2
				1410	package</li>
Daniel Veillard	e0aed30	2000-04-16 08:52:20 +0000	[diff] [blame]	1411	<li>The I/O interface has been revamped. There is now ways to plug in
				1412	specific I/O modules, either at the URI scheme detection level using
				1413	xmlRegisterInputCallbacks() or by passing I/O functions when creating a
				1414	parser context using xmlCreateIOParserCtxt()</li>
				1415	<li>there is a C preprocessor macro LIBXML_VERSION providing the version
				1416	number of the libxml module in use</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1417	<li>a number of optional features of libxml can now be excluded at
				1418	configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillard	edfb29b	2000-03-14 19:59:05 +0000	[diff] [blame]	1419	</ul>
				1420
				1421	<h3>2.0.0beta: Mar 14 2000</h3>
				1422	<ul>
				1423	<li>This is a first Beta release of libxml version 2</li>
Daniel Veillard	e356c28	2001-03-10 12:32:04 +0000	[diff] [blame]	1424	<li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
				1425	FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
				1426	RPMs</li>
Daniel Veillard	edfb29b	2000-03-14 19:59:05 +0000	[diff] [blame]	1427	<li>This version is now the head in the Gnome CVS base, the old one is
				1428	available under the tag LIB_XML_1_X</li>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	1429	<li>This includes a very large set of changes. From a programmatic point
				1430	of view applications should not have to be modified too much, check the
				1431	<a href="upgrade.html">upgrade page</a></li>
Daniel Veillard	edfb29b	2000-03-14 19:59:05 +0000	[diff] [blame]	1432	<li>Some interfaces may changes (especially a bit about encoding).</li>
				1433	<li>the updates includes:
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	1434	<ul>
Daniel Veillard	edfb29b	2000-03-14 19:59:05 +0000	[diff] [blame]	1435	<li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
				1436	handled now</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1437	<li>Better handling of entities, especially well-formedness checking
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1438	and proper PEref extensions in external subsets</li>
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	1439	<li>DTD conditional sections</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1440	<li>Validation now correctly handle entities content</li>
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	1441	<li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1442	structures to accommodate DOM</a></li>
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	1443	</ul>
				1444	</li>
Daniel Veillard	edfb29b	2000-03-14 19:59:05 +0000	[diff] [blame]	1445	<li>Serious progress were made toward compliance, <a
				1446	href="conf/result.html">here are the result of the test</a> against the
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1447	OASIS testsuite (except the Japanese tests since I don't support that
Daniel Veillard	edfb29b	2000-03-14 19:59:05 +0000	[diff] [blame]	1448	encoding yet). This URL is rebuilt every couple of hours using the CVS
				1449	head version.</li>
Daniel Veillard	e41f2b7	2000-01-30 20:00:07 +0000	[diff] [blame]	1450	</ul>
				1451
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	1452	<h3>1.8.7: Mar 6 2000</h3>
				1453	<ul>
				1454	<li>This is a bug fix release:</li>
				1455	<li>It is possible to disable the ignorable blanks heuristic used by
				1456	libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1457	that for adherence to XML spec, this behaviour will be disabled by
				1458	default in 2.x . The same function will allow to keep compatibility for
				1459	old code.</li>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	1460	<li>Blanks in <a> </a> constructs are not ignored anymore,
				1461	avoiding heuristic is really the Right Way :-\</li>
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	1462	<li>The unchecked use of snprintf which was breaking libxml-1.8.6
				1463	compilation on some platforms has been fixed</li>
				1464	<li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
				1465	URIs</li>
				1466	</ul>
				1467
Daniel Veillard	e41f2b7	2000-01-30 20:00:07 +0000	[diff] [blame]	1468	<h3>1.8.6: Jan 31 2000</h3>
				1469	<ul>
				1470	<li>added a nanoFTP transport module, debugged until the new version of <a
				1471	href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
				1472	it without troubles</li>
Daniel Veillard	da07c34	2000-01-25 18:31:22 +0000	[diff] [blame]	1473	</ul>
				1474
				1475	<h3>1.8.5: Jan 21 2000</h3>
				1476	<ul>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	1477	<li>adding APIs to parse a well balanced chunk of XML (production <a
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1478	href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
				1479	XML spec)</li>
Daniel Veillard	461a66c	2000-01-18 18:01:01 +0000	[diff] [blame]	1480	<li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	1481	<li>Jody Goldberg <jgoldberg@home.com> provided another patch trying
				1482	to solve the zlib checks problems</li>
Daniel Veillard	461a66c	2000-01-18 18:01:01 +0000	[diff] [blame]	1483	<li>The current state in gnome CVS base is expected to ship as 1.8.5 with
				1484	gnumeric soon</li>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	1485	</ul>
				1486
				1487	<h3>1.8.4: Jan 13 2000</h3>
				1488	<ul>
				1489	<li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
				1490	<li>all exit() call should have been removed from libxml</li>
				1491	<li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
				1492	<li>added newDocFragment()</li>
Daniel Veillard	f84f71f	2000-01-05 19:54:23 +0000	[diff] [blame]	1493	</ul>
				1494
				1495	<h3>1.8.3: Jan 5 2000</h3>
				1496	<ul>
				1497	<li>a Push interface for the XML and HTML parsers</li>
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	1498	<li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1499	<li>lots of bug fixes and improvement added over XMas holidays</li>
Daniel Veillard	437b87b	2000-01-03 17:30:46 +0000	[diff] [blame]	1500	<li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillard	f84f71f	2000-01-05 19:54:23 +0000	[diff] [blame]	1501	<li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
				1502	<li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard	437b87b	2000-01-03 17:30:46 +0000	[diff] [blame]	1503	<li>External entity loading code has been revamped, now it uses
Daniel Veillard	f84f71f	2000-01-05 19:54:23 +0000	[diff] [blame]	1504	xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard	437b87b	2000-01-03 17:30:46 +0000	[diff] [blame]	1505	<li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard	5cb5ab8	1999-12-21 15:35:29 +0000	[diff] [blame]	1506	</ul>
				1507
				1508	<h3>1.8.2: Dec 21 1999</h3>
				1509	<ul>
Daniel Veillard	b24054a	1999-12-18 15:32:46 +0000	[diff] [blame]	1510	<li>I got another problem with includes and C++, I hope this issue is fixed
				1511	for good this time</li>
Daniel Veillard	5cb5ab8	1999-12-21 15:35:29 +0000	[diff] [blame]	1512	<li>Added a few tree modification functions: xmlReplaceNode,
				1513	xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
				1514	xmlDocSetRootElement</li>
				1515	<li>Tried to improve the HTML output with help from <a
				1516	href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillard	e4e5131	1999-12-18 15:32:46 +0000	[diff] [blame]	1517	</ul>
Daniel Veillard	b24054a	1999-12-18 15:32:46 +0000	[diff] [blame]	1518
Daniel Veillard	e4e5131	1999-12-18 15:32:46 +0000	[diff] [blame]	1519	<h3>1.8.1: Dec 18 1999</h3>
				1520	<ul>
				1521	<li>various patches to avoid troubles when using libxml with C++ compilers
				1522	the "namespace" keyword and C escaping in include files</li>
				1523	<li>a problem in one of the core macros IS_CHAR was corrected</li>
				1524	<li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
				1525	and more specifically the Dia application</li>
Daniel Veillard	944b5ff	1999-12-15 19:08:24 +0000	[diff] [blame]	1526	<li>fixed a posteriori validation (validation after parsing, or by using a
				1527	Dtd not specified in the original document)</li>
Daniel Veillard	b24054a	1999-12-18 15:32:46 +0000	[diff] [blame]	1528	<li>fixed a bug in</li>
Daniel Veillard	10a2c65	1999-12-12 13:03:50 +0000	[diff] [blame]	1529	</ul>
				1530
				1531	<h3>1.8.0: Dec 12 1999</h3>
				1532	<ul>
				1533	<li>cleanup, especially memory wise</li>
				1534	<li>the parser should be more reliable, especially the HTML one, it should
				1535	not crash, whatever the input !</li>
				1536	<li>Integrated various patches, especially a speedup improvement for large
				1537	dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
				1538	configure with --with-buffers to enable them.</li>
				1539	<li>attribute normalization, oops should have been added long ago !</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1540	<li>attributes defaulted from DTDs should be available, xmlSetProp() now
				1541	does entities escaping by default.</li>
Daniel Veillard	4c3a203	1999-11-19 17:46:26 +0000	[diff] [blame]	1542	</ul>
Daniel Veillard	3500838	1999-10-25 13:15:52 +0000	[diff] [blame]	1543
				1544	<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1545	<ul>
Daniel Veillard	3500838	1999-10-25 13:15:52 +0000	[diff] [blame]	1546	<li>Lots of HTML improvement</li>
				1547	<li>Fixed some errors when saving both XML and HTML</li>
				1548	<li>More examples, the regression tests should now look clean</li>
				1549	<li>Fixed a bug with contiguous charref</li>
				1550	</ul>
				1551
				1552	<h3>1.7.3: Sep 29 1999</h3>
				1553	<ul>
				1554	<li>portability problems fixed</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1555	<li>snprintf was used unconditionally, leading to link problems on system
Daniel Veillard	3500838	1999-10-25 13:15:52 +0000	[diff] [blame]	1556	were it's not available, fixed</li>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1557	</ul>
				1558
				1559	<h3>1.7.1: Sep 24 1999</h3>
				1560	<ul>
				1561	<li>The basic type for strings manipulated by libxml has been renamed in
				1562	1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1563	is that CHAR was conflicting with a predefined type on Windows. However
				1564	on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1565	<strong>#define </strong>.</li>
				1566	<li>Changed another error : the use of a structure field called errno, and
				1567	leading to troubles on platforms where it's a macro</li>
				1568	</ul>
				1569
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1570	<h3>1.7.0: Sep 23 1999</h3>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1571	<ul>
				1572	<li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard	9cb5ff4	2001-01-29 08:22:21 +0000	[diff] [blame]	1573	href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1574	<li>Added an errno to report errors by another mean than a simple printf
				1575	like callback</li>
				1576	<li>Finished ID/IDREF support and checking when validation</li>
				1577	<li>Serious memory leaks fixed (there is now a <a
Daniel Veillard	9cb5ff4	2001-01-29 08:22:21 +0000	[diff] [blame]	1578	href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1579	<li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
				1580	implementation</li>
				1581	<li>Added an HTML parser front-end</li>
				1582	</ul>
				1583
				1584	<h2><a name="XML">XML</a></h2>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	1585
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	1586	<p><a href="http://www.w3.org/TR/REC-xml">XML is a standard</a> for
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	1587	markup-based structured documents. Here is <a name="example">an example XML
				1588	document</a>:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	1589	<pre><?xml version="1.0"?>
				1590	<EXAMPLE prop1="gnome is great" prop2="&amp; linux too">
				1591	<head>
				1592	<title>Welcome to Gnome</title>
				1593	</head>
				1594	<chapter>
				1595	<title>The Linux adventure</title>
				1596	<p>bla bla bla ...</p>
				1597	<image href="linus.gif"/>
				1598	<p>...</p>
				1599	</chapter>
				1600	</EXAMPLE></pre>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	1601
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1602	<p>The first line specifies that it is an XML document and gives useful
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	1603	information about its encoding. Then the rest of the document is a text
				1604	format whose structure is specified by tags between brackets. <strong>Each
				1605	tag opened has to be closed</strong>. XML is pedantic about this. However, if
				1606	a tag is empty (no content), a single tag can serve as both the opening and
				1607	closing tag if it ends with <code>/></code> rather than with
				1608	<code>></code>. Note that, for example, the image tag has no content (just
				1609	an attribute) and is closed by ending the tag with <code>/></code>.</p>
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	1610
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	1611	<p>XML can be applied successfully to a wide range of tasks, ranging from
				1612	long term structured document maintenance (where it follows the steps of
				1613	SGML) to simple data encoding mechanisms like configuration file formatting
				1614	(glade), spreadsheets (gnumeric), or even shorter lived documents such as
				1615	WebDAV where it is used to encode remote calls between a client and a
				1616	server.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	1617
Daniel Veillard	8268716	2001-01-22 15:32:01 +0000	[diff] [blame]	1618	<h2><a name="XSLT">XSLT</a></h2>
				1619
Daniel Veillard	6e6a6cc	2001-02-15 15:55:44 +0000	[diff] [blame]	1620	<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
				1621
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1622	<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
				1623	language for transforming XML documents into other XML documents (or
				1624	HTML/textual output).</p>
Daniel Veillard	8268716	2001-01-22 15:32:01 +0000	[diff] [blame]	1625
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	1626	<p>A separate library called libxslt is being developed on top of libxml2.
				1627	This module "libxslt" too can be found in the Gnome CVS base.</p>
Daniel Veillard	8268716	2001-01-22 15:32:01 +0000	[diff] [blame]	1628
Daniel Veillard	383b147	2001-01-23 11:39:52 +0000	[diff] [blame]	1629	<p>You can check the <a
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1630	href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
				1631	supported and the progresses on the <a
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1632	href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog"
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1633	name="Changelog">Changelog</a>.</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1634
				1635	<h2><a name="Python">Python and bindings</a></h2>
				1636
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	1637	<p>There are a number of language bindings and wrappers available for
				1638	libxml2, the list below is not exhaustive. Please contact the <a
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1639	href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a>
				1640	(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in
				1641	order to get updates to this list or to discuss the specific topic of libxml2
				1642	or libxslt wrappers or bindings:</p>
				1643	<ul>
Daniel Veillard	c14401e	2002-11-20 14:28:17 +0000	[diff] [blame]	1644	<li><a href="http://libxmlplusplus.sourceforge.net/">Libxml++</a> seems the
				1645	most up-to-date C++ bindings for libxml2, check the <a
				1646	href="http://libxmlplusplus.sourceforge.net/reference/html/hierarchy.html">documentation</a>
				1647	and the <a
				1648	href="http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/libxmlplusplus/libxml%2b%2b/examples/">examples</a>.</li>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1649	<li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1650	based on the gdome2 bindings</a> maintained by Tobias Peters.</li>
Daniel Veillard	9b6fd30	2002-05-13 12:06:47 +0000	[diff] [blame]	1651	<li>and a third C++ wrapper by Peter Jones <pjones@pmade.org>
				1652	<p>Website: <a
				1653	href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
				1654	</li>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1655	<li><a
				1656	href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1657	Sergeant</a> developed <a
				1658	href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1659	libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1660	application server</a>.</li>
Daniel Veillard	2147367	2002-06-17 07:29:22 +0000	[diff] [blame]	1661	<li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides an
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1662	earlier version of the libxml/libxslt <a
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1663	href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li>
Daniel Veillard	2147367	2002-06-17 07:29:22 +0000	[diff] [blame]	1664	<li>Gopal.V and Peter Minten develop <a
				1665	href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1666	C# libxml2 bindings.</li>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1667	<li>Petr Kozelka provides <a
				1668	href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1669	libxml2</a> with Kylix, Delphi and other Pascal compilers.</li>
Daniel Veillard	b2fb8ed	2002-04-01 09:33:12 +0000	[diff] [blame]	1670	<li>Uwe Fechner also provides <a
				1671	href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1672	implementation for Kylix2/D5/D6 from Borland.</li>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1673	<li>Wai-Sun "Squidster" Chia provides <a
				1674	href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and
				1675	libxml2 bindings are also available in Ruby through the <a
				1676	href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module
				1677	maintained by Tobias Peters.</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1678	<li>Steve Ball and contributors maintains <a
				1679	href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1680	Tcl</a>.</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1681	<li>There is support for libxml2 in the DOM module of PHP.</li>
Daniel Veillard	41b01a8	2003-02-27 11:09:06 +0000	[diff] [blame]	1682	<li><a href="http://savannah.gnu.org/projects/classpathx/">LibxmlJ</a> is
Daniel Veillard	806cada	2003-03-19 21:58:59 +0000	[diff] [blame]	1683	an effort to create a 100% JAXP-compatible Java wrapper for libxml2 and
				1684	libxslt as part of GNU ClasspathX project.</li>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1685	</ul>
				1686
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	1687	<p>The distribution includes a set of Python bindings, which are guaranteed
				1688	to be maintained as part of the library in the future, though the Python
Daniel Veillard	41b01a8	2003-02-27 11:09:06 +0000	[diff] [blame]	1689	interface have not yet reached the completeness of the C API.</p>
Daniel Veillard	7b4b2f9	2003-01-06 13:11:20 +0000	[diff] [blame]	1690
Daniel Veillard	27907c7	2002-12-16 16:05:58 +0000	[diff] [blame]	1691	<p><a href="mailto:stephane.bidoul@softwareag.com">Stéphane Bidoul</a>
Daniel Veillard	7b4b2f9	2003-01-06 13:11:20 +0000	[diff] [blame]	1692	maintains <a href="http://users.skynet.be/sbi/libxml-python/">a Windows port
				1693	of the Python bindings</a>.</p>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1694
Daniel Veillard	7ef0fcb	2002-12-14 10:38:55 +0000	[diff] [blame]	1695	<p>Note to people interested in building bindings, the API is formalized as
				1696	<a href="libxml2-api.xml">an XML API description file</a> which allows to
				1697	automate a large part of the Python bindings, this includes function
Daniel Veillard	7b4b2f9	2003-01-06 13:11:20 +0000	[diff] [blame]	1698	descriptions, enums, structures, typedefs, etc... The Python script used to
				1699	build the bindings is python/generator.py in the source distribution.</p>
Daniel Veillard	7ef0fcb	2002-12-14 10:38:55 +0000	[diff] [blame]	1700
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1701	<p>To install the Python bindings there are 2 options:</p>
Daniel Veillard	0b79dfe	2002-02-23 13:02:31 +0000	[diff] [blame]	1702	<ul>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1703	<li>If you use an RPM based distribution, simply install the <a
				1704	href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python
				1705	RPM</a> (and if needed the <a
				1706	href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python
				1707	RPM</a>).</li>
				1708	<li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python
				1709	module distribution</a> corresponding to your installed version of
				1710	libxml2 and libxslt. Note that to install it you will need both libxml2
				1711	and libxslt installed and run "python setup.py build install" in the
				1712	module tree.</li>
Daniel Veillard	0b79dfe	2002-02-23 13:02:31 +0000	[diff] [blame]	1713	</ul>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1714
				1715	<p>The distribution includes a set of examples and regression tests for the
				1716	python bindings in the <code>python/tests</code> directory. Here are some
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1717	excerpts from those tests:</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1718
				1719	<h3>tst.py:</h3>
				1720
				1721	<p>This is a basic test of the file interface and DOM navigation:</p>
				1722	<pre>import libxml2
				1723
				1724	doc = libxml2.parseFile("tst.xml")
				1725	if doc.name != "tst.xml":
				1726	print "doc.name failed"
				1727	sys.exit(1)
				1728	root = doc.children
				1729	if root.name != "doc":
				1730	print "root.name failed"
				1731	sys.exit(1)
				1732	child = root.children
				1733	if child.name != "foo":
				1734	print "child.name failed"
				1735	sys.exit(1)
				1736	doc.freeDoc()</pre>
				1737
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1738	<p>The Python module is called libxml2; parseFile is the equivalent of
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1739	xmlParseFile (most of the bindings are automatically generated, and the xml
				1740	prefix is removed and the casing convention are kept). All node seen at the
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1741	binding level share the same subset of accessors:</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1742	<ul>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1743	<li><code>name</code> : returns the node name</li>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	1744	<li><code>type</code> : returns a string indicating the node type</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1745	<li><code>content</code> : returns the content of the node, it is based on
				1746	xmlNodeGetContent() and hence is recursive.</li>
				1747	<li><code>parent</code> , <code>children</code>, <code>last</code>,
				1748	<code>next</code>, <code>prev</code>, <code>doc</code>,
				1749	<code>properties</code>: pointing to the associated element in the tree,
				1750	those may return None in case no such link exists.</li>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1751	</ul>
				1752
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1753	<p>Also note the need to explicitly deallocate documents with freeDoc() .
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1754	Reference counting for libxml2 trees would need quite a lot of work to
				1755	function properly, and rather than risk memory leaks if not implemented
				1756	correctly it sounds safer to have an explicit function to free a tree. The
				1757	wrapper python objects like doc, root or child are them automatically garbage
				1758	collected.</p>
				1759
				1760	<h3>validate.py:</h3>
				1761
				1762	<p>This test check the validation interfaces and redirection of error
				1763	messages:</p>
				1764	<pre>import libxml2
				1765
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1766	#deactivate error messages from the validation
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1767	def noerr(ctx, str):
				1768	pass
				1769
				1770	libxml2.registerErrorHandler(noerr, None)
				1771
				1772	ctxt = libxml2.createFileParserCtxt("invalid.xml")
				1773	ctxt.validate(1)
				1774	ctxt.parseDocument()
				1775	doc = ctxt.doc()
				1776	valid = ctxt.isValid()
				1777	doc.freeDoc()
				1778	if valid != 0:
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1779	print "validity check failed"</pre>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1780
				1781	<p>The first thing to notice is the call to registerErrorHandler(), it
				1782	defines a new error handler global to the library. It is used to avoid seeing
				1783	the error messages when trying to validate the invalid document.</p>
				1784
				1785	<p>The main interest of that test is the creation of a parser context with
				1786	createFileParserCtxt() and how the behaviour can be changed before calling
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1787	parseDocument() . Similarly the informations resulting from the parsing phase
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1788	are also available using context methods.</p>
				1789
				1790	<p>Contexts like nodes are defined as class and the libxml2 wrappers maps the
				1791	C function interfaces in terms of objects method as much as possible. The
				1792	best to get a complete view of what methods are supported is to look at the
				1793	libxml2.py module containing all the wrappers.</p>
				1794
				1795	<h3>push.py:</h3>
				1796
				1797	<p>This test show how to activate the push parser interface:</p>
				1798	<pre>import libxml2
				1799
				1800	ctxt = libxml2.createPushParser(None, "<foo", 4, "test.xml")
				1801	ctxt.parseChunk("/>", 2, 1)
				1802	doc = ctxt.doc()
				1803
				1804	doc.freeDoc()</pre>
				1805
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1806	<p>The context is created with a special call based on the
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1807	xmlCreatePushParser() from the C library. The first argument is an optional
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1808	SAX callback object, then the initial set of data, the length and the name of
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1809	the resource in case URI-References need to be computed by the parser.</p>
				1810
				1811	<p>Then the data are pushed using the parseChunk() method, the last call
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1812	setting the third argument terminate to 1.</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1813
				1814	<h3>pushSAX.py:</h3>
				1815
				1816	<p>this test show the use of the event based parsing interfaces. In this case
				1817	the parser does not build a document, but provides callback information as
				1818	the parser makes progresses analyzing the data being provided:</p>
				1819	<pre>import libxml2
				1820	log = ""
				1821
				1822	class callback:
				1823	def startDocument(self):
				1824	global log
				1825	log = log + "startDocument:"
				1826
				1827	def endDocument(self):
				1828	global log
				1829	log = log + "endDocument:"
				1830
				1831	def startElement(self, tag, attrs):
				1832	global log
				1833	log = log + "startElement %s %s:" % (tag, attrs)
				1834
				1835	def endElement(self, tag):
				1836	global log
				1837	log = log + "endElement %s:" % (tag)
				1838
				1839	def characters(self, data):
				1840	global log
				1841	log = log + "characters: %s:" % (data)
				1842
				1843	def warning(self, msg):
				1844	global log
				1845	log = log + "warning: %s:" % (msg)
				1846
				1847	def error(self, msg):
				1848	global log
				1849	log = log + "error: %s:" % (msg)
				1850
				1851	def fatalError(self, msg):
				1852	global log
				1853	log = log + "fatalError: %s:" % (msg)
				1854
				1855	handler = callback()
				1856
				1857	ctxt = libxml2.createPushParser(handler, "<foo", 4, "test.xml")
				1858	chunk = " url='tst'>b"
				1859	ctxt.parseChunk(chunk, len(chunk), 0)
				1860	chunk = "ar</foo>"
				1861	ctxt.parseChunk(chunk, len(chunk), 1)
				1862
Daniel Veillard	fcbfa2d	2002-02-21 17:54:27 +0000	[diff] [blame]	1863	reference = "startDocument:startElement foo {'url': 'tst'}:" + \
				1864	"characters: bar:endElement foo:endDocument:"
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1865	if log != reference:
				1866	print "Error got: %s" % log
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1867	print "Expected: %s" % reference</pre>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1868
				1869	<p>The key object in that test is the handler, it provides a number of entry
				1870	points which can be called by the parser as it makes progresses to indicate
				1871	the information set obtained. The full set of callback is larger than what
				1872	the callback class in that specific example implements (see the SAX
				1873	definition for a complete list). The wrapper will only call those supplied by
				1874	the object when activated. The startElement receives the names of the element
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1875	and a dictionary containing the attributes carried by this element.</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1876
				1877	<p>Also note that the reference string generated from the callback shows a
				1878	single character call even though the string "bar" is passed to the parser
				1879	from 2 different call to parseChunk()</p>
				1880
				1881	<h3>xpath.py:</h3>
				1882
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1883	<p>This is a basic test of XPath wrappers support</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1884	<pre>import libxml2
				1885
				1886	doc = libxml2.parseFile("tst.xml")
				1887	ctxt = doc.xpathNewContext()
				1888	res = ctxt.xpathEval("//*")
				1889	if len(res) != 2:
				1890	print "xpath query: wrong node set size"
				1891	sys.exit(1)
				1892	if res[0].name != "doc" or res[1].name != "foo":
				1893	print "xpath query: wrong node set value"
				1894	sys.exit(1)
				1895	doc.freeDoc()
				1896	ctxt.xpathFreeContext()</pre>
				1897
				1898	<p>This test parses a file, then create an XPath context to evaluate XPath
				1899	expression on it. The xpathEval() method execute an XPath query and returns
				1900	the result mapped in a Python way. String and numbers are natively converted,
				1901	and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1902	the document, the XPath context need to be freed explicitly, also not that
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1903	the result of the XPath query may point back to the document tree and hence
				1904	the document must be freed after the result of the query is used.</p>
				1905
				1906	<h3>xpathext.py:</h3>
				1907
				1908	<p>This test shows how to extend the XPath engine with functions written in
				1909	python:</p>
				1910	<pre>import libxml2
				1911
				1912	def foo(ctx, x):
				1913	return x + 1
				1914
				1915	doc = libxml2.parseFile("tst.xml")
				1916	ctxt = doc.xpathNewContext()
				1917	libxml2.registerXPathFunction(ctxt._o, "foo", None, foo)
				1918	res = ctxt.xpathEval("foo(1)")
				1919	if res != 2:
				1920	print "xpath extension failure"
				1921	doc.freeDoc()
				1922	ctxt.xpathFreeContext()</pre>
				1923
				1924	<p>Note how the extension function is registered with the context (but that
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1925	part is not yet finalized, this may change slightly in the future).</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1926
				1927	<h3>tstxpath.py:</h3>
				1928
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1929	<p>This test is similar to the previous one but shows how the extension
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1930	function can access the XPath evaluation context:</p>
				1931	<pre>def foo(ctx, x):
				1932	global called
				1933
				1934	#
				1935	# test that access to the XPath evaluation contexts
				1936	#
				1937	pctxt = libxml2.xpathParserContext(_obj=ctx)
				1938	ctxt = pctxt.context()
				1939	called = ctxt.function()
				1940	return x + 1</pre>
				1941
				1942	<p>All the interfaces around the XPath parser(or rather evaluation) context
				1943	are not finalized, but it should be sufficient to do contextual work at the
				1944	evaluation point.</p>
				1945
				1946	<h3>Memory debugging:</h3>
				1947
				1948	<p>last but not least, all tests starts with the following prologue:</p>
				1949	<pre>#memory debug specific
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1950	libxml2.debugMemory(1)</pre>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1951
				1952	<p>and ends with the following epilogue:</p>
				1953	<pre>#memory debug specific
				1954	libxml2.cleanupParser()
				1955	if libxml2.debugMemory(1) == 0:
				1956	print "OK"
				1957	else:
				1958	print "Memory leak %d bytes" % (libxml2.debugMemory(1))
				1959	libxml2.dumpMemory()</pre>
				1960
				1961	<p>Those activate the memory debugging interface of libxml2 where all
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1962	allocated block in the library are tracked. The prologue then cleans up the
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1963	library state and checks that all allocated memory has been freed. If not it
				1964	calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p>
Daniel Veillard	8268716	2001-01-22 15:32:01 +0000	[diff] [blame]	1965
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	1966	<h2><a name="architecture">libxml architecture</a></h2>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1967
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	1968	<p>Libxml is made of multiple components; some of them are optional, and most
				1969	of the block interfaces are public. The main components are:</p>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1970	<ul>
				1971	<li>an Input/Output layer</li>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	1972	<li>FTP and HTTP client layers (optional)</li>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1973	<li>an Internationalization layer managing the encodings support</li>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	1974	<li>a URI module</li>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1975	<li>the XML parser and its basic SAX interface</li>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	1976	<li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1977	<li>a SAX tree module to build an in-memory DOM representation</li>
				1978	<li>a tree module to manipulate the DOM representation</li>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	1979	<li>a validation module using the DOM representation (optional)</li>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1980	<li>an XPath module for global lookup in a DOM representation
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	1981	(optional)</li>
				1982	<li>a debug module (optional)</li>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1983	</ul>
				1984
				1985	<p>Graphically this gives the following:</p>
				1986
				1987	<p><img src="libxml.gif" alt="a graphical view of the various"></p>
				1988
				1989	<p></p>
				1990
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1991	<h2><a name="tree">The tree output</a></h2>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	1992
				1993	<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	1994	returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	1995	<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard	306be99	2000-07-03 12:38:45 +0000	[diff] [blame]	1996	as the file name, the document type, and a <strong>children</strong> pointer
				1997	which is the root of the document (or more exactly the first child under the
				1998	root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	1999	chained in double-linked lists of siblings and with a children<->parent
Daniel Veillard	306be99	2000-07-03 12:38:45 +0000	[diff] [blame]	2000	relationship. An xmlNode can also carry properties (a chain of xmlAttr
				2001	structures). An attribute may have a value which is a list of TEXT or
				2002	ENTITY_REF nodes.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	2003
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	2004	<p>Here is an example (erroneous with respect to the XML spec since there
				2005	should be only one ELEMENT under the root):</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	2006
				2007	<p><img src="structure.gif" alt=" structure.gif "></p>
				2008
				2009	<p>In the source package there is a small program (not installed by default)
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	2010	called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	2011	prints them back as parsed. This is useful for detecting errors both in XML
				2012	code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	2013	which prints the actual in-memory structure of the document; here is the
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	2014	result with the <a href="#example">example</a> given before:</p>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	2015	<pre>DOCUMENT
				2016	version=1.0
				2017	standalone=true
				2018	ELEMENT EXAMPLE
				2019	ATTRIBUTE prop1
				2020	TEXT
				2021	content=gnome is great
				2022	ATTRIBUTE prop2
				2023	ENTITY_REF
				2024	TEXT
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	2025	content= linux too
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	2026	ELEMENT head
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	2027	ELEMENT title
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	2028	TEXT
				2029	content=Welcome to Gnome
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	2030	ELEMENT chapter
				2031	ELEMENT title
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	2032	TEXT
				2033	content=The Linux adventure
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	2034	ELEMENT p
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	2035	TEXT
				2036	content=bla bla bla ...
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	2037	ELEMENT image
				2038	ATTRIBUTE href
				2039	TEXT
				2040	content=linus.gif
				2041	ELEMENT p
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	2042	TEXT
				2043	content=...</pre>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	2044
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	2045	<p>This should be useful for learning the internal representation model.</p>
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	2046
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	2047	<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	2048
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	2049	<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	2050	memory. In that case (and if you don't expect to save back the XML document
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	2051	loaded using libxml), it's better to use the SAX interface of libxml. SAX is
				2052	a <strong>callback-based interface</strong> to the parser. Before parsing,
				2053	the application layer registers a customized set of callbacks which are
				2054	called by the library as it progresses through the XML input.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	2055
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	2056	<p>To get more detailed step-by-step guidance on using the SAX interface of
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	2057	libxml, see the <a
				2058	href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
				2059	documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	2060	Henstridge</a>.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	2061
				2062	<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
				2063	program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	2064	binary packages of libxml, but you can find it in the tar source
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	2065	distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	2066	testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	2067	<pre>SAX.setDocumentLocator()
				2068	SAX.startDocument()
				2069	SAX.getEntity(amp)
				2070	SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp; linux too')
				2071	SAX.characters( , 3)
				2072	SAX.startElement(head)
				2073	SAX.characters( , 4)
				2074	SAX.startElement(title)
				2075	SAX.characters(Welcome to Gnome, 16)
				2076	SAX.endElement(title)
				2077	SAX.characters( , 3)
				2078	SAX.endElement(head)
				2079	SAX.characters( , 3)
				2080	SAX.startElement(chapter)
				2081	SAX.characters( , 4)
				2082	SAX.startElement(title)
				2083	SAX.characters(The Linux adventure, 19)
				2084	SAX.endElement(title)
				2085	SAX.characters( , 4)
				2086	SAX.startElement(p)
				2087	SAX.characters(bla bla bla ..., 15)
				2088	SAX.endElement(p)
				2089	SAX.characters( , 4)
				2090	SAX.startElement(image, href='linus.gif')
				2091	SAX.endElement(image)
				2092	SAX.characters( , 4)
				2093	SAX.startElement(p)
				2094	SAX.characters(..., 3)
				2095	SAX.endElement(p)
				2096	SAX.characters( , 3)
				2097	SAX.endElement(chapter)
				2098	SAX.characters( , 1)
				2099	SAX.endElement(EXAMPLE)
				2100	SAX.endDocument()</pre>
				2101
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	2102	<p>Most of the other interfaces of libxml are based on the DOM tree-building
				2103	facility, so nearly everything up to the end of this document presupposes the
				2104	use of the standard DOM tree build. Note that the DOM tree itself is built by
				2105	a set of registered default callbacks, without internal specific
				2106	interface.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	2107
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2108	<h2><a name="Validation">Validation & DTDs</a></h2>
				2109
				2110	<p>Table of Content:</p>
				2111	<ol>
				2112	<li><a href="#General5">General overview</a></li>
				2113	<li><a href="#definition">The definition</a></li>
				2114	<li><a href="#Simple">Simple rules</a>
				2115	<ol>
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	2116	<li><a href="#reference">How to reference a DTD from a document</a></li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2117	<li><a href="#Declaring">Declaring elements</a></li>
				2118	<li><a href="#Declaring1">Declaring attributes</a></li>
				2119	</ol>
				2120	</li>
				2121	<li><a href="#Some">Some examples</a></li>
				2122	<li><a href="#validate">How to validate</a></li>
				2123	<li><a href="#Other">Other resources</a></li>
				2124	</ol>
				2125
				2126	<h3><a name="General5">General overview</a></h3>
				2127
				2128	<p>Well what is validation and what is a DTD ?</p>
				2129
				2130	<p>DTD is the acronym for Document Type Definition. This is a description of
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2131	the content for a family of XML files. This is part of the XML 1.0
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2132	specification, and allows one to describe and verify that a given document
				2133	instance conforms to the set of rules detailing its structure and content.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2134
				2135	<p>Validation is the process of checking a document against a DTD (more
				2136	generally against a set of construction rules).</p>
				2137
				2138	<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2139	of the XML life cycle. Briefly a DTD defines all the possible elements to be
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2140	found within your document, what is the formal shape of your document tree
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2141	(by defining the allowed content of an element; either text, a regular
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2142	expression for the allowed list of children, or mixed content i.e. both text
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	2143	and children). The DTD also defines the valid attributes for all elements and
				2144	the types of those attributes.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2145
				2146	<h3><a name="definition1">The definition</a></h3>
				2147
				2148	<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
				2149	href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
				2150	Rev1</a>):</p>
				2151	<ul>
				2152	<li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
				2153	elements</a></li>
				2154	<li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
				2155	attributes</a></li>
				2156	</ul>
				2157
				2158	<p>(unfortunately) all this is inherited from the SGML world, the syntax is
				2159	ancient...</p>
				2160
				2161	<h3><a name="Simple1">Simple rules</a></h3>
				2162
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	2163	<p>Writing DTDs can be done in many ways. The rules to build them if you need
				2164	something permanent or something which can evolve over time can be radically
				2165	different. Really complex DTDs like DocBook ones are flexible but quite
				2166	harder to design. I will just focus on DTDs for a formats with a fixed simple
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2167	structure. It is just a set of basic rules, and definitely not exhaustive nor
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2168	usable for complex DTD design.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2169
				2170	<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
				2171
				2172	<p>Assuming the top element of the document is <code>spec</code> and the dtd
				2173	is placed in the file <code>mydtd</code> in the subdirectory
				2174	<code>dtds</code> of the directory from where the document were loaded:</p>
				2175
				2176	<p><code><!DOCTYPE spec SYSTEM "dtds/mydtd"></code></p>
				2177
				2178	<p>Notes:</p>
				2179	<ul>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2180	<li>The system string is actually an URI-Reference (as defined in <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2181	href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396</a>) so you can use a
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2182	full URL string indicating the location of your DTD on the Web. This is a
				2183	really good thing to do if you want others to validate your document.</li>
				2184	<li>It is also possible to associate a <code>PUBLIC</code> identifier (a
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2185	magic string) so that the DTD is looked up in catalogs on the client side
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2186	without having to locate it on the web.</li>
				2187	<li>A DTD contains a set of element and attribute declarations, but they
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2188	don't define what the root of the document should be. This is explicitly
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2189	told to the parser/validator as the first element of the
				2190	<code>DOCTYPE</code> declaration.</li>
				2191	</ul>
				2192
				2193	<h4><a name="Declaring2">Declaring elements</a>:</h4>
				2194
				2195	<p>The following declares an element <code>spec</code>:</p>
				2196
				2197	<p><code><!ELEMENT spec (front, body, back?)></code></p>
				2198
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2199	<p>It also expresses that the spec element contains one <code>front</code>,
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	2200	one <code>body</code> and one optional <code>back</code> children elements in
				2201	this order. The declaration of one element of the structure and its content
				2202	are done in a single declaration. Similarly the following declares
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2203	<code>div1</code> elements:</p>
				2204
Daniel Veillard	5173727	2002-01-23 23:10:38 +0000	[diff] [blame]	2205	<p><code><!ELEMENT div1 (head, (p \| list \| note)*, div2?)></code></p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2206
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2207	<p>which means div1 contains one <code>head</code> then a series of optional
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2208	<code>p</code>, <code>list</code>s and <code>note</code>s and then an
				2209	optional <code>div2</code>. And last but not least an element can contain
				2210	text:</p>
				2211
				2212	<p><code><!ELEMENT b (#PCDATA)></code></p>
				2213
				2214	<p><code>b</code> contains text or being of mixed content (text and elements
				2215	in no particular order):</p>
				2216
				2217	<p><code><!ELEMENT p (#PCDATA\|a\|ul\|b\|i\|em)*></code></p>
				2218
				2219	<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
				2220	<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
				2221	order.</p>
				2222
				2223	<h4><a name="Declaring1">Declaring attributes</a>:</h4>
				2224
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2225	<p>Again the attributes declaration includes their content definition:</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2226
				2227	<p><code><!ATTLIST termdef name CDATA #IMPLIED></code></p>
				2228
				2229	<p>means that the element <code>termdef</code> can have a <code>name</code>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2230	attribute containing text (<code>CDATA</code>) and which is optional
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2231	(<code>#IMPLIED</code>). The attribute value can also be defined within a
				2232	set:</p>
				2233
				2234	<p><code><!ATTLIST list type (bullets\|ordered\|glossary)
				2235	"ordered"></code></p>
				2236
				2237	<p>means <code>list</code> element have a <code>type</code> attribute with 3
				2238	allowed values "bullets", "ordered" or "glossary" and which default to
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2239	"ordered" if the attribute is not explicitly specified.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2240
				2241	<p>The content type of an attribute can be text (<code>CDATA</code>),
				2242	anchor/reference/references
				2243	(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
				2244	(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
				2245	(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
				2246	<code>chapter</code> element can have an optional <code>id</code> attribute
				2247	of type <code>ID</code>, usable for reference from attribute of type
				2248	IDREF:</p>
				2249
				2250	<p><code><!ATTLIST chapter id ID #IMPLIED></code></p>
				2251
				2252	<p>The last value of an attribute definition can be <code>#REQUIRED
				2253	</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
				2254	meaning that it is optional, or the default value (possibly prefixed by
				2255	<code>#FIXED</code> if it is the only allowed).</p>
				2256
				2257	<p>Notes:</p>
				2258	<ul>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2259	<li>Usually the attributes pertaining to a given element are declared in a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2260	single expression, but it is just a convention adopted by a lot of DTD
				2261	writers:
				2262	<pre><!ATTLIST termdef
				2263	id ID #REQUIRED
				2264	name CDATA #IMPLIED></pre>
				2265	<p>The previous construct defines both <code>id</code> and
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2266	<code>name</code> attributes for the element <code>termdef</code>.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2267	</li>
				2268	</ul>
				2269
				2270	<h3><a name="Some1">Some examples</a></h3>
				2271
				2272	<p>The directory <code>test/valid/dtds/</code> in the libxml distribution
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	2273	contains some complex DTD examples. The example in the file
				2274	<code>test/valid/dia.xml</code> shows an XML file where the simple DTD is
				2275	directly included within the document.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2276
				2277	<h3><a name="validate1">How to validate</a></h3>
				2278
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2279	<p>The simplest way is to use the xmllint program included with libxml. The
				2280	<code>--valid</code> option turns-on validation of the files given as input.
				2281	For example the following validates a copy of the first revision of the XML
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2282	1.0 specification:</p>
				2283
				2284	<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
				2285
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2286	<p>the -- noout is used to disable output of the resulting tree.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2287
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	2288	<p>The <code>--dtdvalid dtd</code> allows validation of the document(s)
				2289	against a given DTD.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2290
				2291	<p>Libxml exports an API to handle DTDs and validation, check the <a
				2292	href="http://xmlsoft.org/html/libxml-valid.html">associated
				2293	description</a>.</p>
				2294
				2295	<h3><a name="Other1">Other resources</a></h3>
				2296
				2297	<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
				2298	will just list one for now, others pointers welcome:</p>
				2299	<ul>
				2300	<li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
				2301	</ul>
				2302
				2303	<p>I suggest looking at the examples found under test/valid/dtd and any of
				2304	the large number of books available on XML. The dia example in test/valid
				2305	should be both simple and complete enough to allow you to build your own.</p>
				2306
				2307	<p></p>
				2308
				2309	<h2><a name="Memory">Memory Management</a></h2>
				2310
				2311	<p>Table of Content:</p>
				2312	<ol>
				2313	<li><a href="#General3">General overview</a></li>
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	2314	<li><a href="#setting">Setting libxml set of memory routines</a></li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2315	<li><a href="#cleanup">Cleaning up after parsing</a></li>
				2316	<li><a href="#Debugging">Debugging routines</a></li>
				2317	<li><a href="#General4">General memory requirements</a></li>
				2318	</ol>
				2319
				2320	<h3><a name="General3">General overview</a></h3>
				2321
				2322	<p>The module <code><a
				2323	href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
				2324	provides the interfaces to the libxml memory system:</p>
				2325	<ul>
				2326	<li>libxml does not use the libc memory allocator directly but xmlFree(),
				2327	xmlMalloc() and xmlRealloc()</li>
				2328	<li>those routines can be reallocated to a specific set of routine, by
				2329	default the libc ones i.e. free(), malloc() and realloc()</li>
				2330	<li>the xmlmemory.c module includes a set of debugging routine</li>
				2331	</ul>
				2332
				2333	<h3><a name="setting">Setting libxml set of memory routines</a></h3>
				2334
				2335	<p>It is sometimes useful to not use the default memory allocator, either for
				2336	debugging, analysis or to implement a specific behaviour on memory management
				2337	(like on embedded systems). Two function calls are available to do so:</p>
				2338	<ul>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2339	<li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet
				2340	()</a> which return the current set of functions in use by the parser</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2341	<li><a
				2342	href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2343	which allow to set up a new set of memory allocation functions</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2344	</ul>
				2345
				2346	<p>Of course a call to xmlMemSetup() should probably be done before calling
				2347	any other libxml routines (unless you are sure your allocations routines are
				2348	compatibles).</p>
				2349
				2350	<h3><a name="cleanup">Cleaning up after parsing</a></h3>
				2351
				2352	<p>Libxml is not stateless, there is a few set of memory structures needing
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2353	allocation before the parser is fully functional (some encoding structures
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2354	for example). This also mean that once parsing is finished there is a tiny
				2355	amount of memory (a few hundred bytes) which can be recollected if you don't
				2356	reuse the parser immediately:</p>
				2357	<ul>
				2358	<li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2359	()</a> is a centralized routine to free the parsing states. Note that it
				2360	won't deallocate any produced tree if any (use the xmlFreeDoc() and
				2361	related routines for this).</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2362	<li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2363	()</a> is the dual routine allowing to preallocate the parsing state
				2364	which can be useful for example to avoid initialization reentrancy
				2365	problems when using libxml in multithreaded applications</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2366	</ul>
				2367
				2368	<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
				2369	at the next invocation of parser routines, but be careful of the consequences
				2370	in multithreaded applications.</p>
				2371
				2372	<h3><a name="Debugging">Debugging routines</a></h3>
				2373
				2374	<p>When configured using --with-mem-debug flag (off by default), libxml uses
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2375	a set of memory allocation debugging routines keeping track of all allocated
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2376	blocks and the location in the code where the routine was called. A couple of
				2377	other debugging routines allow to dump the memory allocated infos to a file
				2378	or call a specific routine when a given block number is allocated:</p>
				2379	<ul>
				2380	<li><a
				2381	href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2382	<a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2383	href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
				2384	and <a
				2385	href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
				2386	are the memory debugging replacement allocation routines</li>
				2387	<li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2388	()</a> dumps all the informations about the allocated memory block lefts
				2389	in the <code>.memdump</code> file</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2390	</ul>
				2391
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2392	<p>When developing libxml memory debug is enabled, the tests programs call
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2393	xmlMemoryDump () and the "make test" regression tests will check for any
				2394	memory leak during the full regression test sequence, this helps a lot
				2395	ensuring that libxml does not leak memory and bullet proof memory
				2396	allocations use (some libc implementations are known to be far too permissive
				2397	resulting in major portability problems!).</p>
				2398
				2399	<p>If the .memdump reports a leak, it displays the allocation function and
				2400	also tries to give some informations about the content and structure of the
				2401	allocated blocks left. This is sufficient in most cases to find the culprit,
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2402	but not always. Assuming the allocation problem is reproducible, it is
				2403	possible to find more easily:</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2404	<ol>
				2405	<li>write down the block number xxxx not allocated</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2406	<li>export the environment variable XML_MEM_BREAKPOINT=xxxx , the easiest
Daniel Veillard	7579482	2002-04-11 16:24:32 +0000	[diff] [blame]	2407	when using GDB is to simply give the command
				2408	<p><code>set environment XML_MEM_BREAKPOINT xxxx</code></p>
				2409	<p>before running the program.</p>
				2410	</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2411	<li>run the program under a debugger and set a breakpoint on
				2412	xmlMallocBreakpoint() a specific function called when this precise block
				2413	is allocated</li>
				2414	<li>when the breakpoint is reached you can then do a fine analysis of the
				2415	allocation an step to see the condition resulting in the missing
				2416	deallocation.</li>
				2417	</ol>
				2418
				2419	<p>I used to use a commercial tool to debug libxml memory problems but after
				2420	noticing that it was not detecting memory leaks that simple mechanism was
Daniel Veillard	7579482	2002-04-11 16:24:32 +0000	[diff] [blame]	2421	used and proved extremely efficient until now. Lately I have also used <a
				2422	href="http://developer.kde.org/~sewardj/">valgrind</a> with quite some
				2423	success, it is tied to the i386 architecture since it works by emulating the
				2424	processor and instruction set, it is slow but extremely efficient, i.e. it
				2425	spot memory usage errors in a very precise way.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2426
				2427	<h3><a name="General4">General memory requirements</a></h3>
				2428
				2429	<p>How much libxml memory require ? It's hard to tell in average it depends
				2430	of a number of things:</p>
				2431	<ul>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2432	<li>the parser itself should work in a fixed amount of memory, except for
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2433	information maintained about the stacks of names and entities locations.
				2434	The I/O and encoding handlers will probably account for a few KBytes.
				2435	This is true for both the XML and HTML parser (though the HTML parser
				2436	need more state).</li>
				2437	<li>If you are generating the DOM tree then memory requirements will grow
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2438	nearly linear with the size of the data. In general for a balanced
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2439	textual document the internal memory requirement is about 4 times the
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2440	size of the UTF8 serialization of this document (example the XML-1.0
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2441	recommendation is a bit more of 150KBytes and takes 650KBytes of main
				2442	memory when parsed). Validation will add a amount of memory required for
				2443	maintaining the external Dtd state which should be linear with the
				2444	complexity of the content model defined by the Dtd</li>
				2445	<li>If you don't care about the advanced features of libxml like
				2446	validation, DOM, XPath or XPointer, but really need to work fixed memory
				2447	requirements, then the SAX interface should be used.</li>
				2448	</ul>
				2449
				2450	<p></p>
				2451
				2452	<h2><a name="Encodings">Encodings support</a></h2>
				2453
				2454	<p>Table of Content:</p>
				2455	<ol>
				2456	<li><a href="encoding.html#What">What does internationalization support
				2457	mean ?</a></li>
				2458	<li><a href="encoding.html#internal">The internal encoding, how and
				2459	why</a></li>
				2460	<li><a href="encoding.html#implemente">How is it implemented ?</a></li>
				2461	<li><a href="encoding.html#Default">Default supported encodings</a></li>
				2462	<li><a href="encoding.html#extend">How to extend the existing
				2463	support</a></li>
				2464	</ol>
				2465
				2466	<h3><a name="What">What does internationalization support mean ?</a></h3>
				2467
				2468	<p>XML was designed from the start to allow the support of any character set
				2469	by using Unicode. Any conformant XML parser has to support the UTF-8 and
				2470	UTF-16 default encodings which can both express the full unicode ranges. UTF8
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2471	is a variable length encoding whose greatest points are to reuse the same
				2472	encoding for ASCII and to save space for Western encodings, but it is a bit
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2473	more complex to handle in practice. UTF-16 use 2 bytes per characters (and
				2474	sometimes combines two pairs), it makes implementation easier, but looks a
				2475	bit overkill for Western languages encoding. Moreover the XML specification
				2476	allows document to be encoded in other encodings at the condition that they
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2477	are clearly labeled as such. For example the following is a wellformed XML
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2478	document encoded in ISO-8859 1 and using accentuated letter that we French
				2479	likes for both markup and content:</p>
				2480	<pre><?xml version="1.0" encoding="ISO-8859-1"?>
				2481	<très>là</très></pre>
				2482
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2483	<p>Having internationalization support in libxml means the following:</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2484	<ul>
				2485	<li>the document is properly parsed</li>
				2486	<li>informations about it's encoding are saved</li>
				2487	<li>it can be modified</li>
				2488	<li>it can be saved in its original encoding</li>
				2489	<li>it can also be saved in another encoding supported by libxml (for
				2490	example straight UTF8 or even an ASCII form)</li>
				2491	</ul>
				2492
				2493	<p>Another very important point is that the whole libxml API, with the
				2494	exception of a few routines to read with a specific encoding or save to a
				2495	specific encoding, is completely agnostic about the original encoding of the
				2496	document.</p>
				2497
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2498	<p>It should be noted too that the HTML parser embedded in libxml now obey
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2499	the same rules too, the following document will be (as of 2.2.2) handled in
				2500	an internationalized fashion by libxml too:</p>
				2501	<pre><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
				2502	"http://www.w3.org/TR/REC-html40/loose.dtd">
				2503	<html lang="fr">
				2504	<head>
				2505	<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1">
				2506	</head>
				2507	<body>
				2508	<p>W3C crée des standards pour le Web.</body>
				2509	</html></pre>
				2510
				2511	<h3><a name="internal">The internal encoding, how and why</a></h3>
				2512
				2513	<p>One of the core decision was to force all documents to be converted to a
				2514	default internal encoding, and that encoding to be UTF-8, here are the
				2515	rationale for those choices:</p>
				2516	<ul>
				2517	<li>keeping the native encoding in the internal form would force the libxml
				2518	users (or the code associated) to be fully aware of the encoding of the
				2519	original document, for examples when adding a text node to a document,
				2520	the content would have to be provided in the document encoding, i.e. the
				2521	client code would have to check it before hand, make sure it's conformant
				2522	to the encoding, etc ... Very hard in practice, though in some specific
				2523	cases this may make sense.</li>
				2524	<li>the second decision was which encoding. From the XML spec only UTF8 and
				2525	UTF16 really makes sense as being the two only encodings for which there
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2526	is mandatory support. UCS-4 (32 bits fixed size encoding) could be
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2527	considered an intelligent choice too since it's a direct Unicode mapping
				2528	support. I selected UTF-8 on the basis of efficiency and compatibility
				2529	with surrounding software:
				2530	<ul>
				2531	<li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
				2532	more costly to import and export CPU wise) is also far more compact
				2533	than UTF-16 (and UCS-4) for a majority of the documents I see it used
				2534	for right now (RPM RDF catalogs, advogato data, various configuration
				2535	file formats, etc.) and the key point for today's computer
				2536	architecture is efficient uses of caches. If one nearly double the
				2537	memory requirement to store the same amount of data, this will trash
				2538	caches (main memory/external caches/internal caches) and my take is
				2539	that this harms the system far more than the CPU requirements needed
				2540	for the conversion to UTF-8</li>
				2541	<li>Most of libxml version 1 users were using it with straight ASCII
				2542	most of the time, doing the conversion with an internal encoding
				2543	requiring all their code to be rewritten was a serious show-stopper
				2544	for using UTF-16 or UCS-4.</li>
				2545	<li>UTF-8 is being used as the de-facto internal encoding standard for
				2546	related code like the <a href="http://www.pango.org/">pango</a>
				2547	upcoming Gnome text widget, and a lot of Unix code (yep another place
				2548	where Unix programmer base takes a different approach from Microsoft
				2549	- they are using UTF-16)</li>
				2550	</ul>
				2551	</li>
				2552	</ul>
				2553
				2554	<p>What does this mean in practice for the libxml user:</p>
				2555	<ul>
				2556	<li>xmlChar, the libxml data type is a byte, those bytes must be assembled
				2557	as UTF-8 valid strings. The proper way to terminate an xmlChar * string
				2558	is simply to append 0 byte, as usual.</li>
				2559	<li>One just need to make sure that when using chars outside the ASCII set,
				2560	the values has been properly converted to UTF-8</li>
				2561	</ul>
				2562
				2563	<h3><a name="implemente">How is it implemented ?</a></h3>
				2564
				2565	<p>Let's describe how all this works within libxml, basically the I18N
				2566	(internationalization) support get triggered only during I/O operation, i.e.
				2567	when reading a document or saving one. Let's look first at the reading
				2568	sequence:</p>
				2569	<ol>
				2570	<li>when a document is processed, we usually don't know the encoding, a
				2571	simple heuristic allows to detect UTF-18 and UCS-4 from whose where the
				2572	ASCII range (0-0x7F) maps with ASCII</li>
				2573	<li>the xml declaration if available is parsed, including the encoding
				2574	declaration. At that point, if the autodetected encoding is different
				2575	from the one declared a call to xmlSwitchEncoding() is issued.</li>
				2576	<li>If there is no encoding declaration, then the input has to be in either
				2577	UTF-8 or UTF-16, if it is not then at some point when processing the
				2578	input, the converter/checker of UTF-8 form will raise an encoding error.
				2579	You may end-up with a garbled document, or no document at all ! Example:
				2580	<pre>~/XML -> ./xmllint err.xml
				2581	err.xml:1: error: Input is not proper UTF-8, indicate encoding !
				2582	<très>là</très>
				2583	^
				2584	err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
				2585	<très>là</très>
				2586	^</pre>
				2587	</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2588	<li>xmlSwitchEncoding() does an encoding name lookup, canonicalize it, and
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2589	then search the default registered encoding converters for that encoding.
				2590	If it's not within the default set and iconv() support has been compiled
				2591	it, it will ask iconv for such an encoder. If this fails then the parser
				2592	will report an error and stops processing:
				2593	<pre>~/XML -> ./xmllint err2.xml
				2594	err2.xml:1: error: Unsupported encoding UnsupportedEnc
				2595	<?xml version="1.0" encoding="UnsupportedEnc"?>
				2596	^</pre>
				2597	</li>
Daniel Veillard	46c5c1d	2002-05-20 07:15:54 +0000	[diff] [blame]	2598	<li>From that point the encoder processes progressively the input (it is
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2599	plugged as a front-end to the I/O module) for that entity. It captures
				2600	and convert on-the-fly the document to be parsed to UTF-8. The parser
				2601	itself just does UTF-8 checking of this input and process it
				2602	transparently. The only difference is that the encoding information has
				2603	been added to the parsing context (more precisely to the input
				2604	corresponding to this entity).</li>
				2605	<li>The result (when using DOM) is an internal form completely in UTF-8
				2606	with just an encoding information on the document node.</li>
				2607	</ol>
				2608
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2609	<p>Ok then what happens when saving the document (assuming you
				2610	collected/built an xmlDoc DOM like structure) ? It depends on the function
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2611	called, xmlSaveFile() will just try to save in the original encoding, while
				2612	xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
				2613	encoding:</p>
				2614	<ol>
				2615	<li>if no encoding is given, libxml will look for an encoding value
				2616	associated to the document and if it exists will try to save to that
				2617	encoding,
				2618	<p>otherwise everything is written in the internal form, i.e. UTF-8</p>
				2619	</li>
				2620	<li>so if an encoding was specified, either at the API level or on the
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2621	document, libxml will again canonicalize the encoding name, lookup for a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2622	converter in the registered set or through iconv. If not found the
				2623	function will return an error code</li>
				2624	<li>the converter is placed before the I/O buffer layer, as another kind of
				2625	buffer, then libxml will simply push the UTF-8 serialization to through
				2626	that buffer, which will then progressively be converted and pushed onto
				2627	the I/O layer.</li>
				2628	<li>It is possible that the converter code fails on some input, for example
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2629	trying to push an UTF-8 encoded Chinese character through the UTF-8 to
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2630	ISO-8859-1 converter won't work. Since the encoders are progressive they
				2631	will just report the error and the number of bytes converted, at that
				2632	point libxml will decode the offending character, remove it from the
				2633	buffer and replace it with the associated charRef encoding &#123; and
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2634	resume the conversion. This guarantees that any document will be saved
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2635	without losses (except for markup names where this is not legal, this is
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2636	a problem in the current version, in practice avoid using non-ascii
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2637	characters for tags or attributes names @@). A special "ascii" encoding
				2638	name is used to save documents to a pure ascii form can be used when
				2639	portability is really crucial</li>
				2640	</ol>
				2641
				2642	<p>Here is a few examples based on the same test document:</p>
				2643	<pre>~/XML -> ./xmllint isolat1
				2644	<?xml version="1.0" encoding="ISO-8859-1"?>
				2645	<très>là</très>
				2646	~/XML -> ./xmllint --encode UTF-8 isolat1
				2647	<?xml version="1.0" encoding="UTF-8"?>
				2648	<trÃ¨s>lÃ </trÃ¨s>
				2649	~/XML -> </pre>
				2650
				2651	<p>The same processing is applied (and reuse most of the code) for HTML I18N
				2652	processing. Looking up and modifying the content encoding is a bit more
				2653	difficult since it is located in a <meta> tag under the <head>,
				2654	so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
				2655	been provided. The parser also attempts to switch encoding on the fly when
				2656	detecting such a tag on input. Except for that the processing is the same
				2657	(and again reuses the same code).</p>
				2658
				2659	<h3><a name="Default">Default supported encodings</a></h3>
				2660
				2661	<p>libxml has a set of default converters for the following encodings
				2662	(located in encoding.c):</p>
				2663	<ol>
				2664	<li>UTF-8 is supported by default (null handlers)</li>
				2665	<li>UTF-16, both little and big endian</li>
				2666	<li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
				2667	<li>ASCII, useful mostly for saving</li>
				2668	<li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
				2669	predefined entities like &copy; for the Copyright sign.</li>
				2670	</ol>
				2671
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	2672	<p>More over when compiled on an Unix platform with iconv support the full
				2673	set of encodings supported by iconv can be instantly be used by libxml. On a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2674	linux machine with glibc-2.1 the list of supported encodings and aliases fill
				2675	3 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
				2676	various Japanese ones.</p>
				2677
				2678	<h4>Encoding aliases</h4>
				2679
				2680	<p>From 2.2.3, libxml has support to register encoding names aliases. The
				2681	goal is to be able to parse document whose encoding is supported but where
				2682	the name differs (for example from the default set of names accepted by
				2683	iconv). The following functions allow to register and handle new aliases for
				2684	existing encodings. Once registered libxml will automatically lookup the
				2685	aliases when handling a document:</p>
				2686	<ul>
				2687	<li>int xmlAddEncodingAlias(const char name, const char alias);</li>
				2688	<li>int xmlDelEncodingAlias(const char *alias);</li>
				2689	<li>const char * xmlGetEncodingAlias(const char *alias);</li>
				2690	<li>void xmlCleanupEncodingAliases(void);</li>
				2691	</ul>
				2692
				2693	<h3><a name="extend">How to extend the existing support</a></h3>
				2694
				2695	<p>Well adding support for new encoding, or overriding one of the encoders
				2696	(assuming it is buggy) should not be hard, just write an input and output
				2697	conversion routines to/from UTF-8, and register them using
				2698	xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
				2699	called automatically if the parser(s) encounter such an encoding name
				2700	(register it uppercase, this will help). The description of the encoders,
				2701	their arguments and expected return values are described in the encoding.h
				2702	header.</p>
				2703
				2704	<p>A quick note on the topic of subverting the parser to use a different
				2705	internal encoding than UTF-8, in some case people will absolutely want to
				2706	keep the internal encoding different, I think it's still possible (but the
				2707	encoding must be compliant with ASCII on the same subrange) though I didn't
				2708	tried it. The key is to override the default conversion routines (by
				2709	registering null encoders/decoders for your charsets), and bypass the UTF-8
				2710	checking of the parser by setting the parser context charset
				2711	(ctxt->charset) to something different than XML_CHAR_ENCODING_UTF8, but
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2712	there is no guarantee that this will work. You may also have some troubles
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2713	saving back.</p>
				2714
				2715	<p>Basically proper I18N support is important, this requires at least
				2716	libxml-2.0.0, but a lot of features and corrections are really available only
				2717	starting 2.2.</p>
				2718
				2719	<h2><a name="IO">I/O Interfaces</a></h2>
				2720
				2721	<p>Table of Content:</p>
				2722	<ol>
				2723	<li><a href="#General1">General overview</a></li>
				2724	<li><a href="#basic">The basic buffer type</a></li>
				2725	<li><a href="#Input">Input I/O handlers</a></li>
				2726	<li><a href="#Output">Output I/O handlers</a></li>
				2727	<li><a href="#entities">The entities loader</a></li>
				2728	<li><a href="#Example2">Example of customized I/O</a></li>
				2729	</ol>
				2730
				2731	<h3><a name="General1">General overview</a></h3>
				2732
				2733	<p>The module <code><a
				2734	href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
				2735	the interfaces to the libxml I/O system. This consists of 4 main parts:</p>
				2736	<ul>
				2737	<li>Entities loader, this is a routine which tries to fetch the entities
				2738	(files) based on their PUBLIC and SYSTEM identifiers. The default loader
				2739	don't look at the public identifier since libxml do not maintain a
				2740	catalog. You can redefine you own entity loader by using
				2741	<code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	2742	<code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
				2743	example</a>.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2744	<li>Input I/O buffers which are a commodity structure used by the parser(s)
				2745	input layer to handle fetching the informations to feed the parser. This
				2746	provides buffering and is also a placeholder where the encoding
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2747	converters to UTF8 are piggy-backed.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2748	<li>Output I/O buffers are similar to the Input ones and fulfill similar
				2749	task but when generating a serialization from a tree.</li>
				2750	<li>A mechanism to register sets of I/O callbacks and associate them with
				2751	specific naming schemes like the protocol part of the URIs.
				2752	<p>This affect the default I/O operations and allows to use specific I/O
				2753	handlers for certain names.</p>
				2754	</li>
				2755	</ul>
				2756
				2757	<p>The general mechanism used when loading http://rpmfind.net/xml.html for
				2758	example in the HTML parser is the following:</p>
				2759	<ol>
				2760	<li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
				2761	the parsing context and the URI string.</li>
				2762	<li>the URI string is checked against the existing registered handlers
				2763	using their match() callback function, if the HTTP module was compiled
				2764	in, it is registered and its match() function will succeeds</li>
				2765	<li>the open() function of the handler is called and if successful will
				2766	return an I/O Input buffer</li>
				2767	<li>the parser will the start reading from this buffer and progressively
				2768	fetch information from the resource, calling the read() function of the
				2769	handler until the resource is exhausted</li>
				2770	<li>if an encoding change is detected it will be installed on the input
				2771	buffer, providing buffering and efficient use of the conversion
				2772	routines</li>
				2773	<li>once the parser has finished, the close() function of the handler is
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2774	called once and the Input buffer and associated resources are
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2775	deallocated.</li>
				2776	</ol>
				2777
				2778	<p>The user defined callbacks are checked first to allow overriding of the
				2779	default libxml I/O routines.</p>
				2780
				2781	<h3><a name="basic">The basic buffer type</a></h3>
				2782
				2783	<p>All the buffer manipulation handling is done using the
				2784	<code>xmlBuffer</code> type define in <code><a
				2785	href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
				2786	resizable memory buffer. The buffer allocation strategy can be selected to be
				2787	either best-fit or use an exponential doubling one (CPU vs. memory use
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2788	trade-off). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2789	<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
				2790	system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
				2791	of functions allows to manipulate buffers with names starting with the
				2792	<code>xmlBuffer...</code> prefix.</p>
				2793
				2794	<h3><a name="Input">Input I/O handlers</a></h3>
				2795
				2796	<p>An Input I/O handler is a simple structure
				2797	<code>xmlParserInputBuffer</code> containing a context associated to the
				2798	resource (file descriptor, or pointer to a protocol handler), the read() and
				2799	close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
				2800	encoding handler are also present to support charset conversion when
				2801	needed.</p>
				2802
				2803	<h3><a name="Output">Output I/O handlers</a></h3>
				2804
				2805	<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
				2806	Input one except the callbacks are write() and close().</p>
				2807
				2808	<h3><a name="entities">The entities loader</a></h3>
				2809
				2810	<p>The entity loader resolves requests for new entities and create inputs for
				2811	the parser. Creating an input from a filename or an URI string is done
				2812	through the xmlNewInputFromFile() routine. The default entity loader do not
				2813	handle the PUBLIC identifier associated with an entity (if any). So it just
				2814	calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
				2815	XML).</p>
				2816
				2817	<p>If you want to hook up a catalog mechanism then you simply need to
				2818	override the default entity loader, here is an example:</p>
				2819	<pre>#include <libxml/xmlIO.h>
				2820
				2821	xmlExternalEntityLoader defaultLoader = NULL;
				2822
				2823	xmlParserInputPtr
				2824	xmlMyExternalEntityLoader(const char URL, const char ID,
				2825	xmlParserCtxtPtr ctxt) {
				2826	xmlParserInputPtr ret;
				2827	const char *fileID = NULL;
				2828	/* lookup for the fileID depending on ID */
				2829
				2830	ret = xmlNewInputFromFile(ctxt, fileID);
				2831	if (ret != NULL)
				2832	return(ret);
				2833	if (defaultLoader != NULL)
				2834	ret = defaultLoader(URL, ID, ctxt);
				2835	return(ret);
				2836	}
				2837
				2838	int main(..) {
				2839	...
				2840
				2841	/*
				2842	* Install our own entity loader
				2843	*/
				2844	defaultLoader = xmlGetExternalEntityLoader();
				2845	xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
				2846
				2847	...
				2848	}</pre>
				2849
				2850	<h3><a name="Example2">Example of customized I/O</a></h3>
				2851
				2852	<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
				2853	real use case</a>, xmlDocDump() closes the FILE * passed by the application
				2854	and this was a problem. The <a
				2855	href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
				2856	new output handler with the closing call deactivated:</p>
				2857	<ol>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	2858	<li>First define a new I/O output allocator where the output don't close
				2859	the file:
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2860	<pre>xmlOutputBufferPtr
				2861	xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
				2862	xmlOutputBufferPtr ret;
				2863
				2864	if (xmlOutputCallbackInitialized == 0)
				2865	xmlRegisterDefaultOutputCallbacks();
				2866
				2867	if (file == NULL) return(NULL);
				2868	ret = xmlAllocOutputBuffer(encoder);
				2869	if (ret != NULL) {
				2870	ret->context = file;
				2871	ret->writecallback = xmlFileWrite;
				2872	ret->closecallback = NULL; /* No close callback */
				2873	}
				2874	return(ret); <br>
Daniel Veillard	1eb2424	2002-03-18 11:33:03 +0000	[diff] [blame]	2875
Daniel Veillard	34ce8be	2002-03-18 19:37:11 +0000	[diff] [blame]	2876
				2877
Daniel Veillard	1927409	2002-03-25 16:48:03 +0000	[diff] [blame]	2878
Daniel Veillard	b2fb8ed	2002-04-01 09:33:12 +0000	[diff] [blame]	2879
Daniel Veillard	7579482	2002-04-11 16:24:32 +0000	[diff] [blame]	2880
Daniel Veillard	a7084cd	2002-04-15 17:12:47 +0000	[diff] [blame]	2881
Daniel Veillard	0bfbb42	2002-04-26 09:21:45 +0000	[diff] [blame]	2882
Daniel Veillard	93d3a47	2002-04-26 14:04:55 +0000	[diff] [blame]	2883
Daniel Veillard	cf27f7c	2002-04-30 07:12:39 +0000	[diff] [blame]	2884
Daniel Veillard	e6d8e20	2002-05-02 06:11:10 +0000	[diff] [blame]	2885
Daniel Veillard	9b6fd30	2002-05-13 12:06:47 +0000	[diff] [blame]	2886
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	2887
Daniel Veillard	2147367	2002-06-17 07:29:22 +0000	[diff] [blame]	2888
Daniel Veillard	782afda	2002-07-08 15:12:49 +0000	[diff] [blame]	2889
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	2890
Daniel Veillard	e166254	2002-08-28 11:50:59 +0000	[diff] [blame]	2891
Daniel Veillard	e16b574	2002-09-26 17:50:03 +0000	[diff] [blame]	2892
Daniel Veillard	321be0c	2002-10-08 21:26:42 +0000	[diff] [blame]	2893
Daniel Veillard	4826743	2002-10-18 11:21:38 +0000	[diff] [blame]	2894
Daniel Veillard	dad3f68	2002-11-17 16:47:27 +0000	[diff] [blame]	2895
Daniel Veillard	c14401e	2002-11-20 14:28:17 +0000	[diff] [blame]	2896
Daniel Veillard	f9c4cad	2002-11-22 15:57:07 +0000	[diff] [blame]	2897
Daniel Veillard	9b4bb4d	2002-12-11 19:28:47 +0000	[diff] [blame]	2898
Daniel Veillard	c1eed32	2002-12-12 11:01:32 +0000	[diff] [blame]	2899
Daniel Veillard	7ef0fcb	2002-12-14 10:38:55 +0000	[diff] [blame]	2900
Daniel Veillard	7b4b2f9	2003-01-06 13:11:20 +0000	[diff] [blame]	2901
				2902
Daniel Veillard	e2830f1	2003-01-08 17:47:49 +0000	[diff] [blame]	2903
Daniel Veillard	98d071d	2003-01-10 09:22:44 +0000	[diff] [blame]	2904
				2905
Daniel Veillard	831e8fd	2003-01-25 11:45:34 +0000	[diff] [blame]	2906
Daniel Veillard	72fef16	2003-02-05 14:31:19 +0000	[diff] [blame]	2907
Daniel Veillard	1d788d2	2003-02-10 16:21:58 +0000	[diff] [blame]	2908
Daniel Veillard	17bed98	2003-02-24 20:11:43 +0000	[diff] [blame]	2909
Daniel Veillard	806cada	2003-03-19 21:58:59 +0000	[diff] [blame]	2910
				2911
Daniel Veillard	d8da01c	2003-03-24 15:58:23 +0000	[diff] [blame]	2912
Daniel Veillard	c2d4a93	2003-04-01 11:13:05 +0000	[diff] [blame^]	2913
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2914	} </pre>
				2915	</li>
				2916	<li>And then use it to save the document:
				2917	<pre>FILE *f;
				2918	xmlOutputBufferPtr output;
				2919	xmlDocPtr doc;
				2920	int res;
				2921
				2922	f = ...
				2923	doc = ....
				2924
				2925	output = xmlOutputBufferCreateOwn(f, NULL);
				2926	res = xmlSaveFileTo(output, doc, NULL);
				2927	</pre>
				2928	</li>
				2929	</ol>
				2930
				2931	<h2><a name="Catalog">Catalog support</a></h2>
				2932
				2933	<p>Table of Content:</p>
				2934	<ol>
				2935	<li><a href="General2">General overview</a></li>
				2936	<li><a href="#definition">The definition</a></li>
				2937	<li><a href="#Simple">Using catalogs</a></li>
				2938	<li><a href="#Some">Some examples</a></li>
				2939	<li><a href="#reference">How to tune catalog usage</a></li>
				2940	<li><a href="#validate">How to debug catalog processing</a></li>
				2941	<li><a href="#Declaring">How to create and maintain catalogs</a></li>
				2942	<li><a href="#implemento">The implementor corner quick review of the
				2943	API</a></li>
				2944	<li><a href="#Other">Other resources</a></li>
				2945	</ol>
				2946
				2947	<h3><a name="General2">General overview</a></h3>
				2948
				2949	<p>What is a catalog? Basically it's a lookup mechanism used when an entity
				2950	(a file or a remote resource) references another entity. The catalog lookup
				2951	is inserted between the moment the reference is recognized by the software
				2952	(XML parser, stylesheet processing, or even images referenced for inclusion
				2953	in a rendering) and the time where loading that resource is actually
				2954	started.</p>
				2955
				2956	<p>It is basically used for 3 things:</p>
				2957	<ul>
				2958	<li>mapping from "logical" names, the public identifiers and a more
				2959	concrete name usable for download (and URI). For example it can associate
				2960	the logical name
				2961	<p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
				2962	<p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
				2963	downloaded</p>
				2964	<p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
				2965	</li>
				2966	<li>remapping from a given URL to another one, like an HTTP indirection
				2967	saying that
				2968	<p>"http://www.oasis-open.org/committes/tr.xsl"</p>
				2969	<p>should really be looked at</p>
				2970	<p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
				2971	</li>
				2972	<li>providing a local cache mechanism allowing to load the entities
				2973	associated to public identifiers or remote resources, this is a really
				2974	important feature for any significant deployment of XML or SGML since it
				2975	allows to avoid the aleas and delays associated to fetching remote
				2976	resources.</li>
				2977	</ul>
				2978
				2979	<h3><a name="definition">The definitions</a></h3>
				2980
				2981	<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
				2982	<ul>
				2983	<li>the older SGML catalogs, the official spec is SGML Open Technical
				2984	Resolution TR9401:1997, but is better understood by reading <a
				2985	href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
				2986	James Clark. This is relatively old and not the preferred mode of
				2987	operation of libxml.</li>
				2988	<li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2989	Catalogs</a> is far more flexible, more recent, uses an XML syntax and
				2990	should scale quite better. This is the default option of libxml.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2991	</ul>
				2992
				2993	<p></p>
				2994
				2995	<h3><a name="Simple">Using catalog</a></h3>
				2996
				2997	<p>In a normal environment libxml will by default check the presence of a
				2998	catalog in /etc/xml/catalog, and assuming it has been correctly populated,
				2999	the processing is completely transparent to the document user. To take a
				3000	concrete example, suppose you are authoring a DocBook document, this one
				3001	starts with the following DOCTYPE definition:</p>
				3002	<pre><?xml version='1.0'?>
				3003	<!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
				3004	"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"></pre>
				3005
				3006	<p>When validating the document with libxml, the catalog will be
				3007	automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
				3008	DocBk XML V3.1.4//EN" and the system identifier
				3009	"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
				3010	been installed on your system and the catalogs actually point to them, libxml
				3011	will fetch them from the local disk.</p>
				3012
				3013	<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
				3014	DOCTYPE example it's a really old version, but is fine as an example.</p>
				3015
				3016	<p>Libxml will check the catalog each time that it is requested to load an
				3017	entity, this includes DTD, external parsed entities, stylesheets, etc ... If
				3018	your system is correctly configured all the authoring phase and processing
				3019	should use only local files, even if your document stays portable because it
				3020	uses the canonical public and system ID, referencing the remote document.</p>
				3021
				3022	<h3><a name="Some">Some examples:</a></h3>
				3023
				3024	<p>Here is a couple of fragments from XML Catalogs used in libxml early
				3025	regression tests in <code>test/catalogs</code> :</p>
				3026	<pre><?xml version="1.0"?>
				3027	<!DOCTYPE catalog PUBLIC
				3028	"-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
				3029	"http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd">
				3030	<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog">
				3031	<public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
				3032	uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/>
				3033	...</pre>
				3034
				3035	<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
				3036	written in XML, there is a specific namespace for catalog elements
				3037	"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
				3038	catalog is a <code>public</code> mapping it allows to associate a Public
				3039	Identifier with an URI.</p>
				3040	<pre>...
				3041	<rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
				3042	rewritePrefix="file:///usr/share/xml/docbook/"/>
				3043	...</pre>
				3044
				3045	<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
				3046	any URI starting with a given prefix should be looked at another URI
				3047	constructed by replacing the prefix with an new one. In effect this acts like
				3048	a cache system for a full area of the Web. In practice it is extremely useful
				3049	with a file prefix if you have installed a copy of those resources on your
				3050	local system.</p>
				3051	<pre>...
				3052	<delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
				3053	catalog="file:///usr/share/xml/docbook.xml"/>
				3054	<delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
				3055	catalog="file:///usr/share/xml/docbook.xml"/>
				3056	<delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
				3057	catalog="file:///usr/share/xml/docbook.xml"/>
				3058	<delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
				3059	catalog="file:///usr/share/xml/docbook.xml"/>
				3060	<delegateURI uriStartString="http://www.oasis-open.org/docbook/"
				3061	catalog="file:///usr/share/xml/docbook.xml"/>
				3062	...</pre>
				3063
				3064	<p>Delegation is the core features which allows to build a tree of catalogs,
				3065	easier to maintain than a single catalog, based on Public Identifier, System
				3066	Identifier or URI prefixes it instructs the catalog software to look up
				3067	entries in another resource. This feature allow to build hierarchies of
				3068	catalogs, the set of entries presented should be sufficient to redirect the
				3069	resolution of all DocBook references to the specific catalog in
				3070	<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
				3071	references for DocBook 4.2.1 to a specific catalog installed at the same time
				3072	as the DocBook resources on the local machine.</p>
				3073
				3074	<h3><a name="reference">How to tune catalog usage:</a></h3>
				3075
				3076	<p>The user can change the default catalog behaviour by redirecting queries
				3077	to its own set of catalogs, this can be done by setting the
				3078	<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
				3079	empty one should deactivate loading the default <code>/etc/xml/catalog</code>
				3080	default catalog</p>
				3081
				3082	<h3><a name="validate">How to debug catalog processing:</a></h3>
				3083
				3084	<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
				3085	make libxml output debugging informations for each catalog operations, for
				3086	example:</p>
				3087	<pre>orchis:~/XML -> xmllint --memory --noout test/ent2
				3088	warning: failed to load external entity "title.xml"
				3089	orchis:~/XML -> export XML_DEBUG_CATALOG=
				3090	orchis:~/XML -> xmllint --memory --noout test/ent2
				3091	Failed to parse catalog /etc/xml/catalog
				3092	Failed to parse catalog /etc/xml/catalog
				3093	warning: failed to load external entity "title.xml"
				3094	Catalogs cleanup
				3095	orchis:~/XML -> </pre>
				3096
				3097	<p>The test/ent2 references an entity, running the parser from memory makes
				3098	the base URI unavailable and the the "title.xml" entity cannot be loaded.
				3099	Setting up the debug environment variable allows to detect that an attempt is
				3100	made to load the <code>/etc/xml/catalog</code> but since it's not present the
				3101	resolution fails.</p>
				3102
				3103	<p>But the most advanced way to debug XML catalog processing is to use the
				3104	<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
				3105	catalogs and make resolution queries to see what is going on. This is also
				3106	used for the regression tests:</p>
				3107	<pre>orchis:~/XML -> ./xmlcatalog test/catalogs/docbook.xml \
				3108	"-//OASIS//DTD DocBook XML V4.1.2//EN"
				3109	http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
				3110	orchis:~/XML -> </pre>
				3111
				3112	<p>For debugging what is going on, adding one -v flags increase the verbosity
				3113	level to indicate the processing done (adding a second flag also indicate
				3114	what elements are recognized at parsing):</p>
				3115	<pre>orchis:~/XML -> ./xmlcatalog -v test/catalogs/docbook.xml \
				3116	"-//OASIS//DTD DocBook XML V4.1.2//EN"
				3117	Parsing catalog test/catalogs/docbook.xml's content
				3118	Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
				3119	http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
				3120	Catalogs cleanup
				3121	orchis:~/XML -> </pre>
				3122
				3123	<p>A shell interface is also available to debug and process multiple queries
				3124	(and for regression tests):</p>
				3125	<pre>orchis:~/XML -> ./xmlcatalog -shell test/catalogs/docbook.xml \
				3126	"-//OASIS//DTD DocBook XML V4.1.2//EN"
				3127	> help
				3128	Commands available:
				3129	public PublicID: make a PUBLIC identifier lookup
				3130	system SystemID: make a SYSTEM identifier lookup
				3131	resolve PublicID SystemID: do a full resolver lookup
				3132	add 'type' 'orig' 'replace' : add an entry
				3133	del 'values' : remove values
				3134	dump: print the current catalog state
				3135	debug: increase the verbosity level
				3136	quiet: decrease the verbosity level
				3137	exit: quit the shell
				3138	> public "-//OASIS//DTD DocBook XML V4.1.2//EN"
				3139	http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
				3140	> quit
				3141	orchis:~/XML -> </pre>
				3142
				3143	<p>This should be sufficient for most debugging purpose, this was actually
				3144	used heavily to debug the XML Catalog implementation itself.</p>
				3145
				3146	<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
				3147
				3148	<p>Basically XML Catalogs are XML files, you can either use XML tools to
				3149	manage them or use <strong>xmlcatalog</strong> for this. The basic step is
				3150	to create a catalog the -create option provide this facility:</p>
				3151	<pre>orchis:~/XML -> ./xmlcatalog --create tst.xml
				3152	<?xml version="1.0"?>
				3153	<!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
				3154	"http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd">
				3155	<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/>
				3156	orchis:~/XML -> </pre>
				3157
				3158	<p>By default xmlcatalog does not overwrite the original catalog and save the
				3159	result on the standard output, this can be overridden using the -noout
				3160	option. The <code>-add</code> command allows to add entries in the
				3161	catalog:</p>
				3162	<pre>orchis:~/XML -> ./xmlcatalog --noout --create --add "public" \
				3163	"-//OASIS//DTD DocBook XML V4.1.2//EN" \
				3164	http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
				3165	orchis:~/XML -> cat tst.xml
				3166	<?xml version="1.0"?>
				3167	<!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
				3168	"http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd">
				3169	<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog">
				3170	<public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
				3171	uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/>
				3172	</catalog>
				3173	orchis:~/XML -> </pre>
				3174
				3175	<p>The <code>-add</code> option will always take 3 parameters even if some of
				3176	the XML Catalog constructs (like nextCatalog) will have only a single
				3177	argument, just pass a third empty string, it will be ignored.</p>
				3178
				3179	<p>Similarly the <code>-del</code> option remove matching entries from the
				3180	catalog:</p>
				3181	<pre>orchis:~/XML -> ./xmlcatalog --del \
				3182	"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
				3183	<?xml version="1.0"?>
				3184	<!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
				3185	"http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd">
				3186	<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/>
				3187	orchis:~/XML -> </pre>
				3188
				3189	<p>The catalog is now empty. Note that the matching of <code>-del</code> is
				3190	exact and would have worked in a similar fashion with the Public ID
				3191	string.</p>
				3192
				3193	<p>This is rudimentary but should be sufficient to manage a not too complex
				3194	catalog tree of resources.</p>
				3195
				3196	<h3><a name="implemento">The implementor corner quick review of the
				3197	API:</a></h3>
				3198
				3199	<p>First, and like for every other module of libxml, there is an
				3200	automatically generated <a href="html/libxml-catalog.html">API page for
				3201	catalog support</a>.</p>
				3202
				3203	<p>The header for the catalog interfaces should be included as:</p>
				3204	<pre>#include <libxml/catalog.h></pre>
				3205
				3206	<p>The API is voluntarily kept very simple. First it is not obvious that
				3207	applications really need access to it since it is the default behaviour of
				3208	libxml (Note: it is possible to completely override libxml default catalog by
				3209	using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
				3210	plug an application specific resolver).</p>
				3211
				3212	<p>Basically libxml support 2 catalog lists:</p>
				3213	<ul>
				3214	<li>the default one, global shared by all the application</li>
				3215	<li>a per-document catalog, this one is built if the document uses the
				3216	<code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
				3217	associated to the parser context and destroyed when the parsing context
				3218	is destroyed.</li>
				3219	</ul>
				3220
				3221	<p>the document one will be used first if it exists.</p>
				3222
				3223	<h4>Initialization routines:</h4>
				3224
				3225	<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
				3226	used at startup to initialize the catalog, if the catalog should be
				3227	initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
				3228	should be called before xmlInitializeCatalog() which would otherwise do a
				3229	default initialization first.</p>
				3230
				3231	<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
				3232	own catalog list if needed.</p>
				3233
				3234	<h4>Preferences setup:</h4>
				3235
				3236	<p>The XML Catalog spec requires the possibility to select default
				3237	preferences between public and system delegation,
				3238	xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
				3239	xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
				3240	be forbidden, allowed for global catalog, for document catalog or both, the
				3241	default is to allow both.</p>
				3242
				3243	<p>And of course xmlCatalogSetDebug() allows to generate debug messages
				3244	(through the xmlGenericError() mechanism).</p>
				3245
				3246	<h4>Querying routines:</h4>
				3247
				3248	<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
				3249	and xmlCatalogResolveURI() are relatively explicit if you read the XML
				3250	Catalog specification they correspond to section 7 algorithms, they should
				3251	also work if you have loaded an SGML catalog with a simplified semantic.</p>
				3252
				3253	<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
				3254	operate on the document catalog list</p>
				3255
				3256	<h4>Cleanup and Miscellaneous:</h4>
				3257
				3258	<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
				3259	the per-document equivalent.</p>
				3260
				3261	<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
				3262	first catalog in the global list, and xmlCatalogDump() allows to dump a
				3263	catalog state, those routines are primarily designed for xmlcatalog, I'm not
				3264	sure that exposing more complex interfaces (like navigation ones) would be
				3265	really useful.</p>
				3266
				3267	<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
				3268	it's similar as xmlParseFile() except it bypass all catalog lookups, it's
				3269	provided because this functionality may be useful for client tools.</p>
				3270
				3271	<h4>threaded environments:</h4>
				3272
				3273	<p>Since the catalog tree is built progressively, some care has been taken to
				3274	try to avoid troubles in multithreaded environments. The code is now thread
				3275	safe assuming that the libxml library has been compiled with threads
				3276	support.</p>
				3277
				3278	<p></p>
				3279
				3280	<h3><a name="Other">Other resources</a></h3>
				3281
				3282	<p>The XML Catalog specification is relatively recent so there isn't much
				3283	literature to point at:</p>
				3284	<ul>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3285	<li>You can find a good rant from Norm Walsh about <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3286	href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
				3287	need for catalogs</a>, it provides a lot of context informations even if
Daniel Veillard	93d3a47	2002-04-26 14:04:55 +0000	[diff] [blame]	3288	I don't agree with everything presented. Norm also wrote a more recent
				3289	article <a
				3290	href="http://wwws.sun.com/software/xml/developers/resolver/article/">XML
				3291	entities and URI resolvers</a> describing them.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3292	<li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
				3293	catalog proposal</a> from John Cowan</li>
				3294	<li>The <a href="http://www.rddl.org/">Resource Directory Description
				3295	Language</a> (RDDL) another catalog system but more oriented toward
				3296	providing metadata for XML namespaces.</li>
				3297	<li>the page from the OASIS Technical <a
				3298	href="http://www.oasis-open.org/committees/entity/">Committee on Entity
				3299	Resolution</a> who maintains XML Catalog, you will find pointers to the
				3300	specification update, some background and pointers to others tools
				3301	providing XML Catalog support</li>
Daniel Veillard	35e937a	2002-01-19 22:21:54 +0000	[diff] [blame]	3302	<li>Here is a <a href="buildDocBookCatalog">shell script</a> to generate
				3303	XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
				3304	directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
				3305	the resources found on the system. Otherwise it will just create
				3306	~/xmlcatalog and ~/dbkxmlcatalog and doing:
Daniel Veillard	c575b99	2002-02-08 13:28:40 +0000	[diff] [blame]	3307	<p><code>export XMLCATALOG=$HOME/xmlcatalog</code></p>
Daniel Veillard	35e937a	2002-01-19 22:21:54 +0000	[diff] [blame]	3308	<p>should allow to process DocBook documentations without requiring
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3309	network accesses for the DTD or stylesheets</p>
Daniel Veillard	35e937a	2002-01-19 22:21:54 +0000	[diff] [blame]	3310	</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3311	<li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a
Daniel Veillard	35e937a	2002-01-19 22:21:54 +0000	[diff] [blame]	3312	small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
				3313	to work fine for me too</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3314	<li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
				3315	manual page</a></li>
				3316	</ul>
				3317
				3318	<p>If you have suggestions for corrections or additions, simply contact
				3319	me:</p>
				3320
				3321	<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3322
				3323	<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3324	using the XML library from the C language. It is not intended to be
				3325	extensive. I hope the automatically generated documents will provide the
				3326	completeness required, but as a separate set of documents. The interfaces of
				3327	the XML library are by principle low level, there is nearly zero abstraction.
				3328	Those interested in a higher level API should <a href="#DOM">look at
				3329	DOM</a>.</p>
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	3330
Daniel Veillard	9cb5ff4	2001-01-29 08:22:21 +0000	[diff] [blame]	3331	<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
				3332	separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3333	interfaces</a>. Let's have a look at how the XML parser can be called:</p>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3334
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3335	<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3336
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3337	<p>Usually, the first thing to do is to read an XML input. The parser accepts
				3338	documents either from in-memory strings or from files. The functions are
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3339	defined in "parser.h":</p>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3340	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3341	<dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3342	<dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3343	</dd>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3344	</dl>
				3345	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3346	<dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3347	<dd><p>Parse an XML document contained in a (possibly compressed)
				3348	file.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3349	</dd>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3350	</dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3351
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3352	<p>The parser returns a pointer to the document structure (or NULL in case of
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3353	failure).</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3354
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3355	<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3356
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3357	<p>In order for the application to keep the control when the document is
				3358	being fetched (which is common for GUI based programs) libxml provides a push
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3359	interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3360	<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
				3361	void *user_data,
				3362	const char *chunk,
				3363	int size,
				3364	const char *filename);
				3365	int xmlParseChunk (xmlParserCtxtPtr ctxt,
				3366	const char *chunk,
				3367	int size,
				3368	int terminate);</pre>
				3369
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3370	<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3371	<pre> FILE *f;
				3372
				3373	f = fopen(filename, "r");
				3374	if (f != NULL) {
				3375	int res, size = 1024;
				3376	char chars[1024];
				3377	xmlParserCtxtPtr ctxt;
				3378
				3379	res = fread(chars, 1, 4, f);
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3380	if (res > 0) {
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3381	ctxt = xmlCreatePushParserCtxt(NULL, NULL,
				3382	chars, res, filename);
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3383	while ((res = fread(chars, 1, size, f)) > 0) {
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3384	xmlParseChunk(ctxt, chars, res, 0);
				3385	}
				3386	xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3387	doc = ctxt->myDoc;
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3388	xmlFreeParserCtxt(ctxt);
				3389	}
				3390	}</pre>
				3391
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3392	<p>The HTML parser embedded into libxml also has a push interface; the
				3393	functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3394
				3395	<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
				3396
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3397	<p>The tree-building interface makes the parser memory-hungry, first loading
				3398	the document in memory and then building the tree itself. Reading a document
				3399	without building the tree is possible using the SAX interfaces (see SAX.h and
				3400	<a href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">James
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3401	Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3402	limited to SAX: just use the two first arguments of
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3403	<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	3404
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3405	<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3406
				3407	<p>The other way to get an XML tree in memory is by building it. Basically
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3408	there is a set of functions dedicated to building new elements. (These are
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3409	also described in <libxml/tree.h>.) For example, here is a piece of
				3410	code that produces the XML document used in the previous examples:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3411	<pre> #include <libxml/tree.h>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	3412	xmlDocPtr doc;
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3413	xmlNodePtr tree, subtree;
				3414
				3415	doc = xmlNewDoc("1.0");
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3416	doc->children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
				3417	xmlSetProp(doc->children, "prop1", "gnome is great");
				3418	xmlSetProp(doc->children, "prop2", "& linux too");
				3419	tree = xmlNewChild(doc->children, NULL, "head", NULL);
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3420	subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3421	tree = xmlNewChild(doc->children, NULL, "chapter", NULL);
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3422	subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
				3423	subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
				3424	subtree = xmlNewChild(tree, NULL, "image", NULL);
				3425	xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3426
				3427	<p>Not really rocket science ...</p>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3428
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3429	<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3430
Daniel Veillard	9cb5ff4	2001-01-29 08:22:21 +0000	[diff] [blame]	3431	<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3432	code has access to the internal structure of all the elements of the tree.
				3433	The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard	306be99	2000-07-03 12:38:45 +0000	[diff] [blame]	3434	<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3435	<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3436	example:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3437	<pre><code>doc->children->children->children</code></pre>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3438
				3439	<p>points to the title element,</p>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3440	<pre>doc->children->children->next->children->children</pre>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3441
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3442	<p>points to the text node containing the chapter title "The Linux
				3443	adventure".</p>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3444
Daniel Veillard	b24054a	1999-12-18 15:32:46 +0000	[diff] [blame]	3445	<p><strong>NOTE</strong>: XML allows <em>PI</em>s and <em>comments</em> to be
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3446	present before the document root, so <code>doc->children</code> may point
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3447	to an element which is not the document Root Element; a function
Daniel Veillard	5cb5ab8	1999-12-21 15:35:29 +0000	[diff] [blame]	3448	<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillard	b24054a	1999-12-18 15:32:46 +0000	[diff] [blame]	3449
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3450	<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3451
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3452	<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard	9cb5ff4	2001-01-29 08:22:21 +0000	[diff] [blame]	3453	is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3454	<dl>
Daniel Veillard	dd6b367	1999-09-23 22:19:22 +0000	[diff] [blame]	3455	<dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
				3456	xmlChar *value);</code></dt>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3457	<dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
				3458	The value can be NULL.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3459	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3460	</dl>
				3461	<dl>
Daniel Veillard	dd6b367	1999-09-23 22:19:22 +0000	[diff] [blame]	3462	<dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3463	*name);</code></dt>
Daniel Veillard	c92c304	2000-09-29 02:42:04 +0000	[diff] [blame]	3464	<dd><p>This function returns a pointer to new copy of the property
				3465	content. Note that the user must deallocate the result.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3466	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3467	</dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3468
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3469	<p>Two functions are provided for reading and writing the text associated
				3470	with elements:</p>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3471	<dl>
Daniel Veillard	dd6b367	1999-09-23 22:19:22 +0000	[diff] [blame]	3472	<dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3473	*value);</code></dt>
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3474	<dd><p>This function takes an "external" string and converts it to one
				3475	text node or possibly to a list of entity and text nodes. All
				3476	non-predefined entity references like &Gnome; will be stored
				3477	internally as entity nodes, hence the result of the function may not be
				3478	a single node.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3479	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3480	</dl>
				3481	<dl>
Daniel Veillard	dd6b367	1999-09-23 22:19:22 +0000	[diff] [blame]	3482	<dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3483	inLine);</code></dt>
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3484	<dd><p>This function is the inverse of
				3485	<code>xmlStringGetNodeList()</code>. It generates a new string
				3486	containing the content of the text and entity nodes. Note the extra
				3487	argument inLine. If this argument is set to 1, the function will expand
				3488	entity references. For example, instead of returning the &Gnome;
				3489	XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3490	"GNU Network Object Model Environment").</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3491	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3492	</dl>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3493
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3494	<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3495
				3496	<p>Basically 3 options are possible:</p>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3497	<dl>
Daniel Veillard	dd6b367	1999-09-23 22:19:22 +0000	[diff] [blame]	3498	<dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3499	*size);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3500	<dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3501	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3502	</dl>
				3503	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3504	<dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3505	<dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3506	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3507	</dl>
				3508	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3509	<dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3510	<dd><p>Saves the document to a file. In this case, the compression
				3511	interface is triggered if it has been turned on.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3512	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3513	</dl>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3514
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3515	<h3><a name="Compressio">Compression</a></h3>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3516
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3517	<p>The library transparently handles compression when doing file-based
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3518	accesses. The level of compression on saves can be turned on either globally
				3519	or individually for one file:</p>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3520	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3521	<dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3522	<dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3523	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3524	</dl>
				3525	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3526	<dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3527	<dd><p>Sets the document compression ratio.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3528	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3529	</dl>
				3530	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3531	<dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3532	<dd><p>Gets the default compression ratio.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3533	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3534	</dl>
				3535	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3536	<dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3537	<dd><p>Sets the default compression ratio.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3538	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3539	</dl>
				3540
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3541	<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3542
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3543	<p>Entities in principle are similar to simple C macros. An entity defines an
				3544	abbreviation for a given string that you can reuse many times throughout the
				3545	content of your document. Entities are especially useful when a given string
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3546	may occur frequently within a document, or to confine the change needed to a
				3547	document to a restricted area in the internal subset of the document (at the
				3548	beginning). Example:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3549	<pre>1 <?xml version="1.0"?>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3550	2 <!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3551	3 <!ENTITY xml "Extensible Markup Language">
				3552	4 ]>
				3553	5 <EXAMPLE>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3554	6 &xml;
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3555	7 </EXAMPLE></pre>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3556
				3557	<p>Line 3 declares the xml entity. Line 6 uses the xml entity, by prefixing
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3558	its name with '&' and following it by ';' without any spaces added. There
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3559	are 5 predefined entities in libxml allowing you to escape characters with
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3560	predefined meaning in some parts of the xml document content:
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3561	<strong>&lt;</strong> for the character '<', <strong>&gt;</strong>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3562	for the character '>', <strong>&apos;</strong> for the character ''',
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3563	<strong>&quot;</strong> for the character '"', and
				3564	<strong>&amp;</strong> for the character '&'.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3565
				3566	<p>One of the problems related to entities is that you may want the parser to
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3567	substitute an entity's content so that you can see the replacement text in
				3568	your application. Or you may prefer to keep entity references as such in the
				3569	content to be able to save the document back without losing this usually
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3570	precious information (if the user went through the pain of explicitly
				3571	defining entities, he may have a a rather negative attitude if you blindly
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3572	substitute them as saving time). The <a
Daniel Veillard	9cb5ff4	2001-01-29 08:22:21 +0000	[diff] [blame]	3573	href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3574	function allows you to check and change the behaviour, which is to not
				3575	substitute entities by default.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3576
				3577	<p>Here is the DOM tree built by libxml for the previous document in the
				3578	default case:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3579	<pre>/gnome/src/gnome-xml -> ./xmllint --debug test/ent1
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3580	DOCUMENT
				3581	version=1.0
				3582	ELEMENT EXAMPLE
				3583	TEXT
				3584	content=
				3585	ENTITY_REF
				3586	INTERNAL_GENERAL_ENTITY xml
				3587	content=Extensible Markup Language
				3588	TEXT
				3589	content=</pre>
				3590
				3591	<p>And here is the result when substituting entities:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3592	<pre>/gnome/src/gnome-xml -> ./tester --debug --noent test/ent1
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3593	DOCUMENT
				3594	version=1.0
				3595	ELEMENT EXAMPLE
				3596	TEXT
				3597	content= Extensible Markup Language</pre>
				3598
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3599	<p>So, entities or no entities? Basically, it depends on your use case. I
				3600	suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3601	entities in your XML document or data if you are not willing to handle the
				3602	entity references elements in the DOM tree.</p>
				3603
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3604	<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3605	entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3606	transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3607	reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3608	finding them in the input).</p>
				3609
Daniel Veillard	7b9c4b7	2000-08-25 16:26:50 +0000	[diff] [blame]	3610	<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3611	on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3612	non-predefined entities in your documents, then the learning curve to handle
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3613	then using the SAX API may be long. If you plan to use complex documents, I
Daniel Veillard	7b9c4b7	2000-08-25 16:26:50 +0000	[diff] [blame]	3614	strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard	8c6d6af	2000-08-25 17:14:13 +0000	[diff] [blame]	3615	deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard	7b9c4b7	2000-08-25 16:26:50 +0000	[diff] [blame]	3616
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3617	<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3618
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	3619	<p>The libxml library implements <a
				3620	href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3621	recognizing namespace constructs in the input, and does namespace lookup
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	3622	automatically when building the DOM tree. A namespace declaration is
				3623	associated with an in-memory structure and all elements or attributes within
				3624	that namespace point to it. Hence testing the namespace is a simple and fast
				3625	equality operation at the user level.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3626
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3627	<p>I suggest that people using libxml use a namespace, and declare it in the
				3628	root element of their document as the default namespace. Then they don't need
				3629	to use the prefix in the content but we will have a basis for future semantic
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3630	refinement and merging of data from different sources. This doesn't increase
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3631	the size of the XML output significantly, but significantly increases its
				3632	value in the long-term. Example:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3633	<pre><mydoc xmlns="http://mydoc.example.org/schemas/">
				3634	<elem1>...</elem1>
				3635	<elem2>...</elem2>
				3636	</mydoc></pre>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3637
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3638	<p>The namespace value has to be an absolute URL, but the URL doesn't have to
				3639	point to any existing resource on the Web. It will bind all the element and
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	3640	attributes with that URL. I suggest to use an URL within a domain you
				3641	control, and that the URL should contain some kind of version information if
				3642	possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a
				3643	good namespace scheme.</p>
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	3644
				3645	<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3646	version-independent prefix is installed on the root element of your document,
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3647	and if the version information don't match something you know, warn the user
				3648	and be liberal in what you accept as the input. Also do not try to base
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3649	namespace checking on the prefix value. <foo:text> may be exactly the
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3650	same as <bar:text> in another document. What really matters is the URI
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3651	associated with the element or the attribute, not the prefix string (which is
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3652	just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	3653	<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3654	prefix and its URI.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3655
				3656	<p>@@Interfaces@@</p>
				3657
				3658	<p>@@Examples@@</p>
				3659
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3660	<p>Usually people object to using namespaces together with validity checking.
				3661	I will try to make sure that using namespaces won't break validity checking,
				3662	so even if you plan to use or currently are using validation I strongly
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3663	suggest adding namespaces to your document. A default namespace scheme
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3664	<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3665	flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3666	from multiple DTDs will certainly break current validation schemes. I will
				3667	try to provide ways to do this, but this may not be portable or
				3668	standardized.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3669
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3670	<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3671
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3672	<p>Incompatible changes:</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3673
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3674	<p>Version 2 of libxml is the first version introducing serious backward
				3675	incompatible changes. The main goals were:</p>
				3676	<ul>
				3677	<li>a general cleanup. A number of mistakes inherited from the very early
				3678	versions couldn't be changed due to compatibility constraints. Example
				3679	the "childs" element in the nodes.</li>
				3680	<li>Uniformization of the various nodes, at least for their header and link
				3681	parts (doc, parent, children, prev, next), the goal is a simpler
				3682	programming model and simplifying the task of the DOM implementors.</li>
				3683	<li>better conformances to the XML specification, for example version 1.x
				3684	had an heuristic to try to detect ignorable white spaces. As a result the
				3685	SAX event generated were ignorableWhitespace() while the spec requires
				3686	character() in that case. This also mean that a number of DOM node
				3687	containing blank text may populate the DOM tree which were not present
				3688	before.</li>
				3689	</ul>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3690
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3691	<h3>How to fix libxml-1.x code:</h3>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3692
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3693	<p>So client code of libxml designed to run with version 1.x may have to be
				3694	changed to compile against version 2.x of libxml. Here is a list of changes
				3695	that I have collected, they may not be sufficient, so in case you find other
				3696	change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
				3697	mail</a>:</p>
				3698	<ol>
				3699	<li>The package name have changed from libxml to libxml2, the library name
				3700	is now -lxml2 . There is a new xml2-config script which should be used to
				3701	select the right parameters libxml2</li>
				3702	<li>Node <strong>childs</strong> field has been renamed
				3703	<strong>children</strong> so s/childs/children/g should be applied
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3704	(probability of having "childs" anywhere else is close to 0+</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3705	<li>The document don't have anymore a <strong>root</strong> element it has
				3706	been replaced by <strong>children</strong> and usually you will get a
				3707	list of element here. For example a Dtd element for the internal subset
				3708	and it's declaration may be found in that list, as well as processing
				3709	instructions or comments found before or after the document root element.
				3710	Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3711	a document. Alternatively if you are sure to not reference DTDs nor have
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3712	PIs or comments before or after the root element
				3713	s/->root/->children/g will probably do it.</li>
				3714	<li>The white space issue, this one is more complex, unless special case of
				3715	validating parsing, the line breaks and spaces usually used for indenting
				3716	and formatting the document content becomes significant. So they are
				3717	reported by SAX and if your using the DOM tree, corresponding nodes are
				3718	generated. Too approach can be taken:
				3719	<ol>
				3720	<li>lazy one, use the compatibility call
				3721	<strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
				3722	relying on a special (and possibly broken) set of heuristics of
				3723	libxml to detect ignorable blanks. Don't complain if it breaks or
				3724	make your application not 100% clean w.r.t. to it's input.</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3725	<li>the Right Way: change you code to accept possibly insignificant
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3726	blanks characters, or have your tree populated with weird blank text
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3727	nodes. You can spot them using the commodity function
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3728	<strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
				3729	nodes.</li>
				3730	</ol>
				3731	<p>Note also that with the new default the output functions don't add any
				3732	extra indentation when saving a tree in order to be able to round trip
				3733	(read and save) without inflating the document with extra formatting
				3734	chars.</p>
				3735	</li>
				3736	<li>The include path has changed to $prefix/libxml/ and the includes
				3737	themselves uses this new prefix in includes instructions... If you are
				3738	using (as expected) the
				3739	<pre>xml2-config --cflags</pre>
				3740	<p>output to generate you compile commands this will probably work out of
				3741	the box</p>
				3742	</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3743	<li>xmlDetectCharEncoding takes an extra argument indicating the length in
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3744	byte of the head of the document available for character detection.</li>
				3745	</ol>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3746
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3747	<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3748
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3749	<p>Two new version of libxml (1.8.11) and libxml2 (2.3.4) have been released
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3750	to allow smooth upgrade of existing libxml v1code while retaining
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3751	compatibility. They offers the following:</p>
				3752	<ol>
				3753	<li>similar include naming, one should use
				3754	<strong>#include<libxml/...></strong> in both cases.</li>
				3755	<li>similar identifiers defined via macros for the child and root fields:
				3756	respectively <strong>xmlChildrenNode</strong> and
				3757	<strong>xmlRootNode</strong></li>
				3758	<li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
				3759	inserted once in the client code</li>
				3760	</ol>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3761
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3762	<p>So the roadmap to upgrade your existing libxml applications is the
				3763	following:</p>
				3764	<ol>
				3765	<li>install the libxml-1.8.8 (and libxml-devel-1.8.8) packages</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3766	<li>find all occurrences where the xmlDoc <strong>root</strong> field is
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3767	used and change it to <strong>xmlRootNode</strong></li>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	3768	<li>similarly find all occurrences where the xmlNode
				3769	<strong>childs</strong> field is used and change it to
				3770	<strong>xmlChildrenNode</strong></li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3771	<li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
				3772	<strong>main()</strong> or in the library init entry point</li>
				3773	<li>Recompile, check compatibility, it should still work</li>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	3774	<li>Change your configure script to look first for xml2-config and fall
				3775	back using xml-config . Use the --cflags and --libs output of the command
				3776	as the Include and Linking parameters needed to use libxml.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3777	<li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
				3778	libxml-devel-1.8.y can be kept simultaneously)</li>
				3779	<li>remove your config.cache, relaunch your configuration mechanism, and
				3780	recompile, if steps 2 and 3 were done right it should compile as-is</li>
				3781	<li>Test that your application is still running correctly, if not this may
				3782	be due to extra empty nodes due to formating spaces being kept in libxml2
				3783	contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
				3784	code before calling the parser (next to
				3785	<strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
				3786	</ol>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3787
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3788	<p>Following those steps should work. It worked for some of my own code.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3789
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3790	<p>Let me put some emphasis on the fact that there is far more changes from
				3791	libxml 1.x to 2.x than the ones you may have to patch for. The overall code
				3792	has been considerably cleaned up and the conformance to the XML specification
				3793	has been drastically improved too. Don't take those changes as an excuse to
				3794	not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3795
Daniel Veillard	52dcab3	2001-10-30 12:51:17 +0000	[diff] [blame]	3796	<h2><a name="Thread">Thread safety</a></h2>
				3797
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3798	<p>Starting with 2.4.7, libxml makes provisions to ensure that concurrent
Daniel Veillard	52dcab3	2001-10-30 12:51:17 +0000	[diff] [blame]	3799	threads can safely work in parallel parsing different documents. There is
				3800	however a couple of things to do to ensure it:</p>
				3801	<ul>
				3802	<li>configure the library accordingly using the --with-threads options</li>
				3803	<li>call xmlInitParser() in the "main" thread before using any of the
				3804	libxml API (except possibly selecting a different memory allocator)</li>
				3805	</ul>
				3806
				3807	<p>Note that the thread safety cannot be ensured for multiple threads sharing
				3808	the same document, the locking must be done at the application level, libxml
				3809	exports a basic mutex and reentrant mutexes API in <libxml/threads.h>.
				3810	The parts of the library checked for thread safety are:</p>
				3811	<ul>
				3812	<li>concurrent loading</li>
				3813	<li>file access resolution</li>
				3814	<li>catalog access</li>
				3815	<li>catalog building</li>
				3816	<li>entities lookup/accesses</li>
				3817	<li>validation</li>
				3818	<li>global variables per-thread override</li>
				3819	<li>memory handling</li>
				3820	</ul>
				3821
				3822	<p>XPath is supposed to be thread safe now, but this wasn't tested
				3823	seriously.</p>
				3824
Daniel Veillard	3500838	1999-10-25 13:15:52 +0000	[diff] [blame]	3825	<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3826
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3827	<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
				3828	Object Model</em>; this is an API for accessing XML or HTML structured
				3829	documents. Native support for DOM in Gnome is on the way (module gnome-dom),
				3830	and will be based on gnome-xml. This will be a far cleaner interface to
				3831	manipulate XML files within Gnome since it won't expose the internal
				3832	structure.</p>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3833
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3834	<p>The current DOM implementation on top of libxml is the <a
Daniel Veillard	a47fb3d	2001-03-25 17:23:49 +0000	[diff] [blame]	3835	href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
				3836	is a full DOM interface, thanks to Paolo Casarini, check the <a
				3837	href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
				3838	informations.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3839
Daniel Veillard	3500838	1999-10-25 13:15:52 +0000	[diff] [blame]	3840	<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3841
				3842	<p>Here is a real size example, where the actual content of the application
				3843	data is not kept in the DOM tree but uses internal structures. It is based on
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3844	a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3845	storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
				3846	base</a>:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3847	<pre><?xml version="1.0"?>
				3848	<gjob:Helping xmlns:gjob="http://www.gnome.org/some-location">
				3849	<gjob:Jobs>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3850
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3851	<gjob:Job>
				3852	<gjob:Project ID="3"/>
				3853	<gjob:Application>GBackup</gjob:Application>
				3854	<gjob:Category>Development</gjob:Category>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3855
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3856	<gjob:Update>
				3857	<gjob:Status>Open</gjob:Status>
				3858	<gjob:Modified>Mon, 07 Jun 1999 20:27:45 -0400 MET DST</gjob:Modified>
				3859	<gjob:Salary>USD 0.00</gjob:Salary>
				3860	</gjob:Update>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3861
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3862	<gjob:Developers>
				3863	<gjob:Developer>
				3864	</gjob:Developer>
				3865	</gjob:Developers>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3866
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3867	<gjob:Contact>
				3868	<gjob:Person>Nathan Clemons</gjob:Person>
				3869	<gjob:Email>nathan@windsofstorm.net</gjob:Email>
				3870	<gjob:Company>
				3871	</gjob:Company>
				3872	<gjob:Organisation>
				3873	</gjob:Organisation>
				3874	<gjob:Webpage>
				3875	</gjob:Webpage>
				3876	<gjob:Snailmail>
				3877	</gjob:Snailmail>
				3878	<gjob:Phone>
				3879	</gjob:Phone>
				3880	</gjob:Contact>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3881
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3882	<gjob:Requirements>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3883	The program should be released as free software, under the GPL.
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3884	</gjob:Requirements>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3885
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3886	<gjob:Skills>
				3887	</gjob:Skills>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3888
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3889	<gjob:Details>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3890	A GNOME based system that will allow a superuser to configure
				3891	compressed and uncompressed files and/or file systems to be backed
				3892	up with a supported media in the system. This should be able to
				3893	perform via find commands generating a list of files that are passed
				3894	to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
				3895	or via operations performed on the filesystem itself. Email
				3896	notification and GUI status display very important.
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3897	</gjob:Details>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3898
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3899	</gjob:Job>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3900
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3901	</gjob:Jobs>
				3902	</gjob:Helping></pre>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3903
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3904	<p>While loading the XML file into an internal DOM tree is a matter of
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3905	calling only a couple of functions, browsing the tree to gather the data and
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3906	generate the internal structures is harder, and more error prone.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3907
				3908	<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3909	structure. For example, the ordering of the attributes is not significant,
				3910	the XML specification is clear about it. It's also usually a good idea not to
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3911	depend on the order of the children of a given node, unless it really makes
				3912	things harder. Here is some code to parse the information for a person:</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3913	<pre>/*
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3914	* A person record
				3915	*/
				3916	typedef struct person {
				3917	char *name;
				3918	char *email;
				3919	char *company;
				3920	char *organisation;
				3921	char *smail;
				3922	char *webPage;
				3923	char *phone;
				3924	} person, *personPtr;
				3925
				3926	/*
				3927	* And the code needed to parse it
				3928	*/
				3929	personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
				3930	personPtr ret = NULL;
				3931
				3932	DEBUG("parsePerson\n");
				3933	/*
				3934	* allocate the struct
				3935	*/
				3936	ret = (personPtr) malloc(sizeof(person));
				3937	if (ret == NULL) {
				3938	fprintf(stderr,"out of memory\n");
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3939	return(NULL);
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3940	}
				3941	memset(ret, 0, sizeof(person));
				3942
				3943	/* We don't care what the top level element name is */
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3944	cur = cur->xmlChildrenNode;
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3945	while (cur != NULL) {
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3946	if ((!strcmp(cur->name, "Person")) && (cur->ns == ns))
				3947	ret->name = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1);
				3948	if ((!strcmp(cur->name, "Email")) && (cur->ns == ns))
				3949	ret->email = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1);
				3950	cur = cur->next;
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3951	}
				3952
				3953	return(ret);
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3954	}</pre>
				3955
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3956	<p>Here are a couple of things to notice:</p>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3957	<ul>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3958	<li>Usually a recursive parsing style is the more convenient one: XML data
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3959	is by nature subject to repetitive constructs and usually exhibits highly
				3960	structured patterns.</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3961	<li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
				3962	i.e. the pointer to the global XML document and the namespace reserved to
				3963	the application. Document wide information are needed for example to
				3964	decode entities and it's a good coding practice to define a namespace for
				3965	your application set of data and test that the element and attributes
				3966	you're analyzing actually pertains to your application space. This is
				3967	done by a simple equality test (cur->ns == ns).</li>
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3968	<li>To retrieve text and attributes value, you can use the function
				3969	<em>xmlNodeListGetString</em> to gather all the text and entity reference
				3970	nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3971	</ul>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3972
				3973	<p>Here is another piece of code used to parse another level of the
				3974	structure:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3975	<pre>#include <libxml/tree.h>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	3976	/*
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3977	* a Description for a Job
				3978	*/
				3979	typedef struct job {
				3980	char *projectID;
				3981	char *application;
				3982	char *category;
				3983	personPtr contact;
				3984	int nbDevelopers;
				3985	personPtr developers[100]; /* using dynamic alloc is left as an exercise */
				3986	} job, *jobPtr;
				3987
				3988	/*
				3989	* And the code needed to parse it
				3990	*/
				3991	jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
				3992	jobPtr ret = NULL;
				3993
				3994	DEBUG("parseJob\n");
				3995	/*
				3996	* allocate the struct
				3997	*/
				3998	ret = (jobPtr) malloc(sizeof(job));
				3999	if (ret == NULL) {
				4000	fprintf(stderr,"out of memory\n");
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	4001	return(NULL);
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	4002	}
				4003	memset(ret, 0, sizeof(job));
				4004
				4005	/* We don't care what the top level element name is */
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	4006	cur = cur->xmlChildrenNode;
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	4007	while (cur != NULL) {
				4008
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	4009	if ((!strcmp(cur->name, "Project")) && (cur->ns == ns)) {
				4010	ret->projectID = xmlGetProp(cur, "ID");
				4011	if (ret->projectID == NULL) {
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	4012	fprintf(stderr, "Project has no ID\n");
				4013	}
				4014	}
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	4015	if ((!strcmp(cur->name, "Application")) && (cur->ns == ns))
				4016	ret->application = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1);
				4017	if ((!strcmp(cur->name, "Category")) && (cur->ns == ns))
				4018	ret->category = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1);
				4019	if ((!strcmp(cur->name, "Contact")) && (cur->ns == ns))
				4020	ret->contact = parsePerson(doc, ns, cur);
				4021	cur = cur->next;
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	4022	}
				4023
				4024	return(ret);
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	4025	}</pre>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	4026
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	4027	<p>Once you are used to it, writing this kind of code is quite simple, but
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	4028	boring. Ultimately, it could be possible to write stubbers taking either C
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	4029	data structure definitions, a set of XML examples or an XML DTD and produce
				4030	the code needed to import and export the content between C data and XML
				4031	storage. This is left as an exercise to the reader :-)</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	4032
Daniel Veillard	6f0adb5	2000-07-03 11:41:26 +0000	[diff] [blame]	4033	<p>Feel free to use <a href="example/gjobread.c">the code for the full C
				4034	parsing example</a> as a template, it is also available with Makefile in the
				4035	Gnome CVS base under gnome-xml/example</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	4036
Daniel Veillard	c310d56	2000-06-23 18:32:15 +0000	[diff] [blame]	4037	<h2><a name="Contributi">Contributions</a></h2>
				4038	<ul>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	4039	<li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
				4040	patches, Gary Pennington worked on the validation API, threading support
				4041	and Solaris port.</li>
				4042	<li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillard	7b4b2f9	2003-01-06 13:11:20 +0000	[diff] [blame]	4043	<li><a href="mailto:igor@zlatkovic.com">Igor Zlatkovic</a> is now the
				4044	maintainer of the Windows port, <a
				4045	href="http://www.zlatkovic.com/projects/libxml/index.html">he provides
				4046	binaries</a></li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	4047	<li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
				4048	<a href="http://garypennington.net/libxml2/">Solaris binaries</a></li>
Daniel Veillard	e356c28	2001-03-10 12:32:04 +0000	[diff] [blame]	4049	<li><a
				4050	href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	4051	Sergeant</a> developed <a
				4052	href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	4053	libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
				4054	application server</a></li>
				4055	<li><a href="mailto:fnatter@gmx.net">Felix Natter</a> and <a
				4056	href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillard	ca98976	2001-06-23 17:39:29 +0000	[diff] [blame]	4057	href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
Daniel Veillard	3f6f7f6	2000-06-30 17:58:25 +0000	[diff] [blame]	4058	documentation</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	4059	<li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
				4060	href="http://xmlsoft.org/messages/0488.html">man pages</a></li>
Daniel Veillard	5168dbf	2001-07-07 00:18:23 +0000	[diff] [blame]	4061	<li>there is a module for <a
				4062	href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
				4063	in OpenNSD/AOLServer</a></li>
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	4064	<li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provided the
				4065	first version of libxml/libxslt <a
				4066	href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li>
Daniel Veillard	1aadc44	2001-11-28 13:10:32 +0000	[diff] [blame]	4067	<li>Petr Kozelka provides <a
				4068	href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
				4069	libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	4070	<li><a href="mailto:aleksey@aleksey.com">Aleksey Sanin</a> implemented the
				4071	<a href="http://www.w3.org/Signature/">XML Canonicalization and XML
				4072	Digital Signature</a> <a
				4073	href="http://www.aleksey.com/xmlsec/">implementations for libxml2</a></li>
Daniel Veillard	17bed98	2003-02-24 20:11:43 +0000	[diff] [blame]	4074	<li><a href="mailto:Steve.Ball@zveno.com">Steve Ball</a>, <a
				4075	href="http://www.zveno.com/">Zveno</a> and contributors maintain <a
				4076	href="http://tclxml.sourceforge.net/">tcl bindings for libxml2 and
				4077	libxslt</a>, as well as <a
				4078	href="http://tclxml.sf.net/tkxmllint.html">tkxmllint</a> a GUI for
				4079	xmllint and <a href="http://tclxml.sf.net/tkxsltproc.html">tkxsltproc</a>
				4080	a GUI for xsltproc.</li>
Daniel Veillard	c310d56	2000-06-23 18:32:15 +0000	[diff] [blame]	4081	</ul>
				4082
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	4083	<p></p>
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	4084	</body>
				4085	</html>