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