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

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