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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	9698445	2000-08-31 13:50:12 +0000	[diff] [blame]	58	</ul>
				59
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	60	<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]	61	strictly compliant way. As of release 2.4.16, libxml2 passes all 1800+ tests
				62	from the <a
Daniel Veillard	a539356	2002-02-20 11:40:49 +0000	[diff] [blame]	63	href="http://www.oasis-open.org/committees/xml-conformance/">OASIS XML Tests
				64	Suite</a>.</p>
Daniel Veillard	5b16f58	2002-02-20 11:38:46 +0000	[diff] [blame]	65
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	66	<p>To some extent libxml2 provides support for the following additional
				67	specifications but doesn't claim to implement them completely:</p>
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	68	<ul>
				69	<li>Document Object Model (DOM) <a
				70	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]	71	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]	72	libxml2</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	73	<li><a href="http://www.cis.ohio-state.edu/rfc/rfc959.txt">RFC 959</a> :
				74	libxml implements a basic FTP client code</li>
				75	<li><a href="http://www.cis.ohio-state.edu/rfc/rfc1945.txt">RFC 1945</a> :
				76	HTTP/1.0, again a basic HTTP client code</li>
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	77	<li>SAX: a minimal SAX implementation compatible with early expat
				78	versions</li>
				79	<li>DocBook SGML v4: libxml2 includes a hackish parser to transition to
				80	XML</li>
				81	</ul>
				82
Daniel Veillard	e6d8e20	2002-05-02 06:11:10 +0000	[diff] [blame]	83	<p>XML Schemas is being worked on but it would be far too early to make any
				84	conformance statement about it at the moment.</p>
				85
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	86	<p>Libxml2 is known to be very portable, the library should build and work
				87	without serious troubles on a variety of systems (Linux, Unix, Windows,
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	88	CygWin, MacOS, MacOS X, RISC Os, OS/2, VMS, QNX, MVS, ...)</p>
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	89
Daniel Veillard	9698445	2000-08-31 13:50:12 +0000	[diff] [blame]	90	<p>Separate documents:</p>
				91	<ul>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	92	<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]	93	implementation of XSLT 1.0 and common extensions like EXSLT for
				94	libxml2</li>
Daniel Veillard	c6271d2	2001-10-27 07:50:58 +0000	[diff] [blame]	95	<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]	96	: a standard DOM2 implementation for libxml2</li>
				97	<li><a href="http://www.aleksey.com/xmlsec/">the XMLSec page</a>: an
				98	implementation of <a href="http://www.w3.org/TR/xmldsig-core/">W3C XML
				99	Digital Signature</a> for libxml2</li>
Daniel Veillard	e6d8e20	2002-05-02 06:11:10 +0000	[diff] [blame]	100	<li>also check the related links section below for more related and active
				101	projects.</li>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	102	</ul>
				103
Daniel Veillard	e166254	2002-08-28 11:50:59 +0000	[diff] [blame]	104	<p>Logo designed by <a href="mailto:liyanage@access.ch">Marc Liyanage</a>.</p>
				105
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	106	<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	107
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	108	<p>This document describes libxml, the <a
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	109	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]	110	href="http://www.gnome.org/">Gnome</a> project. <a
				111	href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
				112	structured documents/data.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	113
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	114	<p>Here are some key points about libxml:</p>
				115	<ul>
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	116	<li>Libxml exports Push (progressive) and Pull (blocking) type parser
				117	interfaces for both XML and HTML.</li>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	118	<li>Libxml can do DTD validation at parse time, using a parsed document
				119	instance, or with an arbitrary DTD.</li>
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	120	<li>Libxml includes complete <a
Daniel Veillard	8c2ecaf	2001-07-10 17:53:07 +0000	[diff] [blame]	121	href="http://www.w3.org/TR/xpath">XPath</a>, <a
				122	href="http://www.w3.org/TR/xptr">XPointer</a> and <a
				123	href="http://www.w3.org/TR/xinclude">XInclude</a> implementations.</li>
Daniel Veillard	ec78c0f	2000-08-25 10:25:23 +0000	[diff] [blame]	124	<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]	125	sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	126	Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	127	<li>Basic support for HTTP and FTP client allowing applications to fetch
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	128	remote resources.</li>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	129	<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]	130	<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]	131	href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
				132	<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]	133	like interface</a>; the interface is designed to be compatible with <a
				134	href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillard	c575b99	2002-02-08 13:28:40 +0000	[diff] [blame]	135	<li>This library is released under the <a
				136	href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	137	License</a>. See the Copyright file in the distribution for the precise
Daniel Veillard	c575b99	2002-02-08 13:28:40 +0000	[diff] [blame]	138	wording.</li>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	139	</ul>
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	140
Daniel Veillard	e0c1d72	2001-03-21 10:28:36 +0000	[diff] [blame]	141	<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]	142	Gnome-1.X library requiring it, <strong><span
Daniel Veillard	e0c1d72	2001-03-21 10:28:36 +0000	[diff] [blame]	143	style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
				144	libxml2</p>
				145
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	146	<h2><a name="FAQ">FAQ</a></h2>
				147
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	148	<p>Table of Contents:</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	149	<ul>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	150	<li><a href="FAQ.html#License">License(s)</a></li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	151	<li><a href="FAQ.html#Installati">Installation</a></li>
				152	<li><a href="FAQ.html#Compilatio">Compilation</a></li>
				153	<li><a href="FAQ.html#Developer">Developer corner</a></li>
				154	</ul>
				155
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	156	<h3><a name="License">License</a>(s)</h3>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	157	<ol>
				158	<li><em>Licensing Terms for libxml</em>
Daniel Veillard	c575b99	2002-02-08 13:28:40 +0000	[diff] [blame]	159	<p>libxml is released under the <a
				160	href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	161	License</a>; see the file Copyright in the distribution for the precise
Daniel Veillard	c575b99	2002-02-08 13:28:40 +0000	[diff] [blame]	162	wording</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	163	</li>
				164	<li><em>Can I embed libxml in a proprietary application ?</em>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	165	<p>Yes. The MIT License allows you to keep proprietary the changes you
				166	made to libxml, but it would be graceful to send-back bug fixes and
				167	improvements as patches for possible incorporation in the main
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	168	development tree.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	169	</li>
				170	</ol>
				171
				172	<h3><a name="Installati">Installation</a></h3>
				173	<ol>
				174	<li>Unless you are forced to because your application links with a Gnome
				175	library requiring it, <strong><span style="background-color: #FF0000">Do
				176	Not Use libxml1</span></strong>, use libxml2</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	177	<li><em>Where can I get libxml</em> ?
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	178	<p>The original distribution comes from <a
				179	href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a
MDT 2002 John Fleck	30c7054	2002-09-24 14:24:54 +0000	[diff] [blame]	180	href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.4/">gnome.org</a></p>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	181	<p>Most Linux and BSD distributions include libxml, this is probably the
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	182	safer way for end-users to use libxml.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	183	<p>David Doolin provides precompiled Windows versions at <a
				184	href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
				185	</li>
				186	<li><em>I see libxml and libxml2 releases, which one should I install ?</em>
				187	<ul>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	188	<li>If you are not constrained by backward compatibility issues with
				189	existing applications, install libxml2 only</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	190	<li>If you are not doing development, you can safely install both.
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	191	Usually the packages <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	192	href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a
				193	href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	194	compatible (this is not the case for development packages).</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	195	<li>If you are a developer and your system provides separate packaging
				196	for shared libraries and the development components, it is possible
				197	to install libxml and libxml2, and also <a
				198	href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
				199	and <a
				200	href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
				201	too for libxml2 >= 2.3.0</li>
				202	<li>If you are developing a new application, please develop against
				203	libxml2(-devel)</li>
				204	</ul>
				205	</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	206	<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]	207	<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]	208	library for libxml.so.0, you can probably safely remove it. The libxml
				209	packages provided on <a
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	210	href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provide
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	211	libxml.so.0</p>
				212	</li>
				213	<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]	214	dependencies</em>
				215	<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]	216	rebuild it locally with</p>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	217	<p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code>.</p>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	218	<p>If everything goes well it will generate two binary rpm packages (one
				219	providing the shared libs and xmllint, and the other one, the -devel
				220	package, providing includes, static libraries and scripts needed to build
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	221	applications with libxml(2)) that you can install locally.</p>
				222	</li>
				223	</ol>
				224
				225	<h3><a name="Compilatio">Compilation</a></h3>
				226	<ol>
				227	<li><em>What is the process to compile libxml ?</em>
				228	<p>As most UNIX libraries libxml follows the "standard":</p>
				229	<p><code>gunzip -c xxx.tar.gz \| tar xvf -</code></p>
				230	<p><code>cd libxml-xxxx</code></p>
				231	<p><code>./configure --help</code></p>
				232	<p>to see the options, then the compilation/installation proper</p>
				233	<p><code>./configure [possible options]</code></p>
				234	<p><code>make</code></p>
				235	<p><code>make install</code></p>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	236	<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]	237	update your list of installed shared libs.</p>
				238	</li>
				239	<li><em>What other libraries are needed to compile/install libxml ?</em>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	240	<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]	241	should be sufficient (please report any violation to this rule you may
				242	find).</p>
				243	<p>However if found at configuration time libxml will detect and use the
				244	following libs:</p>
				245	<ul>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	246	<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]	247	highly portable and available widely compression library.</li>
				248	<li>iconv: a powerful character encoding conversion library. It is
				249	included by default in recent glibc libraries, so it doesn't need to
				250	be installed specifically on Linux. It now seems a <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	251	href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
				252	of the official UNIX</a> specification. Here is one <a
Daniel Veillard	dad3f68	2002-11-17 16:47:27 +0000	[diff] [blame]	253	href="http://www.gnu.org/software/libiconv/">implementation of the
				254	library</a> which source can be found <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	255	href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
				256	</ul>
				257	</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	258	<li><em>Make check fails on some platforms</em>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	259	<p>Sometimes the regression tests' results don't completely match the
				260	value produced by the parser, and the makefile uses diff to print the
				261	delta. On some platforms the diff return breaks the compilation process;
				262	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]	263	<p>Sometimes (especially on Solaris) make checks fail due to limitations
Daniel Veillard	e46182c	2002-02-12 14:29:11 +0000	[diff] [blame]	264	in make. Try using GNU-make instead.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	265	</li>
				266	<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]	267	<p>The configure script (and other Makefiles) are generated. Use the
				268	autogen.sh script to regenerate the configure script and Makefiles,
				269	like:</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	270	<p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
				271	</li>
				272	<li><em>I have troubles when running make tests with gcc-3.0</em>
				273	<p>It seems the initial release of gcc-3.0 has a problem with the
				274	optimizer which miscompiles the URI module. Please use another
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	275	compiler.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	276	</li>
				277	</ol>
				278
				279	<h3><a name="Developer">Developer</a> corner</h3>
				280	<ol>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	281	<li><em>xmlDocDump() generates output on one line.</em>
				282	<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]	283	document since <strong>all spaces in the content of a document are
				284	significant</strong>. If you build a tree from the API and want
				285	indentation:</p>
				286	<ol>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	287	<li>the correct way is to generate those yourself too.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	288	<li>the dangerous way is to ask libxml to add those blanks to your
				289	content <strong>modifying the content of your document in the
				290	process</strong>. The result may not be what you expect. There is
				291	<strong>NO</strong> way to guarantee that such a modification won't
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	292	affect other parts of the content of your document. See <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	293	href="http://xmlsoft.org/html/libxml-parser.html#XMLKEEPBLANKSDEFAULT">xmlKeepBlanksDefault
				294	()</a> and <a
				295	href="http://xmlsoft.org/html/libxml-tree.html#XMLSAVEFORMATFILE">xmlSaveFormatFile
				296	()</a></li>
				297	</ol>
				298	</li>
				299	<li>Extra nodes in the document:
				300	<p><em>For a XML file as below:</em></p>
				301	<pre><?xml version="1.0"?>
				302	<PLAN xmlns="http://www.argus.ca/autotest/1.0/">
				303	<NODE CommFlag="0"/>
				304	<NODE CommFlag="1"/>
				305	</PLAN></pre>
				306	<p><em>after parsing it with the function
				307	pxmlDoc=xmlParseFile(...);</em></p>
				308	<p><em>I want to the get the content of the first node (node with the
				309	CommFlag="0")</em></p>
				310	<p><em>so I did it as following;</em></p>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	311	<pre>xmlNodePtr pnode;
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	312	pnode=pxmlDoc->children->children;</pre>
				313	<p><em>but it does not work. If I change it to</em></p>
				314	<pre>pnode=pxmlDoc->children->children->next;</pre>
				315	<p><em>then it works. Can someone explain it to me.</em></p>
				316	<p></p>
				317	<p>In XML all characters in the content of the document are significant
				318	<strong>including blanks and formatting line breaks</strong>.</p>
				319	<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]	320	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]	321	to forget. There is a function <a
				322	href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
				323	()</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]	324	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]	325	mixed-content in the document.</p>
				326	</li>
				327	<li><em>I get compilation errors of existing code like when accessing
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	328	<strong>root</strong> or <strong>child fields</strong> of nodes.</em>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	329	<p>You are compiling code developed for libxml version 1 and using a
				330	libxml2 development environment. Either switch back to libxml v1 devel or
				331	even better fix the code to compile with libxml2 (or both) by <a
				332	href="upgrade.html">following the instructions</a>.</p>
				333	</li>
				334	<li><em>I get compilation errors about non existing
				335	<strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	336	fields.</em>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	337	<p>The source code you are using has been <a
				338	href="upgrade.html">upgraded</a> to be able to compile with both libxml
				339	and libxml2, but you need to install a more recent version:
				340	libxml(-devel) >= 1.8.8 or libxml2(-devel) >= 2.1.0</p>
				341	</li>
				342	<li><em>XPath implementation looks seriously broken</em>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	343	<p>XPath implementation prior to 2.3.0 was really incomplete. Upgrade to
				344	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]	345	</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	346	<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]	347	<p>It's hard to maintain the documentation in sync with the code
				348	<grin/> ...</p>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	349	<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]	350	patches.</p>
				351	</li>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	352	<li><em>Where can I get more examples and information than privoded on the
				353	web page?</em>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	354	<p>Ideally a libxml book would be nice. I have no such plan ... But you
				355	can:</p>
				356	<ul>
				357	<li>check more deeply the <a href="html/libxml-lib.html">existing
				358	generated doc</a></li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	359	<li>look for examples of use for libxml function using the Gnome code.
				360	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]	361	use of the <strong>xmlAddChild()</strong> function:
				362	<p><a
				363	href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p>
				364	<p>This may be slow, a large hardware donation to the gnome project
				365	could cure this :-)</p>
				366	</li>
				367	<li><a
				368	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]	369	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]	370	as possible, so looking at it may be helpful. In particular the code
				371	of xmllint.c and of the various testXXX.c test programs should
				372	provide good examples of how to do things with the library.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	373	</ul>
				374	</li>
				375	<li>What about C++ ?
				376	<p>libxml is written in pure C in order to allow easy reuse on a number
				377	of platforms, including embedded systems. I don't intend to convert to
				378	C++.</p>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	379	<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]	380	<ul>
				381	<li>by Ari Johnson <ari@btigate.com>:
				382	<p>Website: <a
				383	href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
				384	<p>Download: <a
				385	href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
				386	</li>
				387	<li>by Peter Jones <pjones@pmade.org>
				388	<p>Website: <a
				389	href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
				390	</li>
				391	</ul>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	392	</li>
				393	<li>How to validate a document a posteriori ?
				394	<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]	395	initial parsing time or documents which have been built from scratch
				396	using the API. Use the <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	397	href="http://xmlsoft.org/html/libxml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	398	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]	399	document:</p>
				400	<pre>xmlDocPtr doc; /* your existing document */
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	401	xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
				402
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	403	dtd->name = xmlStrDup((xmlChar)"root_name"); / use the given root */
				404
				405	doc->intSubset = dtd;
				406	if (doc->children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
				407	else xmlAddPrevSibling(doc->children, (xmlNodePtr)dtd);
				408	</pre>
				409	</li>
Daniel Veillard	dad3f68	2002-11-17 16:47:27 +0000	[diff] [blame]	410	<li>So what is this funky "xmlChar" used all the time?
				411	<p>It is a null terminated sequence of utf-8 characters. And only utf-8!
				412	You need to convert strings encoded in different ways to utf-8 before
				413	passing them to the API. This can be accomplished with the iconv library
				414	for instance.</p>
John Fleck	61f6fb6	2002-10-31 15:23:29 +0000	[diff] [blame]	415	</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	416	<li>etc ...</li>
				417	</ol>
				418
				419	<p></p>
				420
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	421	<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	422
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	423	<p>There are several on-line resources related to using libxml:</p>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	424	<ol>
Daniel Veillard	321be0c	2002-10-08 21:26:42 +0000	[diff] [blame]	425	<li>Use the <a href="search.php">search engine</a> to lookup
				426	informations.</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	427	<li>Check the <a href="FAQ.html">FAQ.</a></li>
Daniel Veillard	c19fccc	2000-07-03 11:52:01 +0000	[diff] [blame]	428	<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]	429	documentation</a> automatically extracted from code comments (using <a
				430	href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&dir=gtk-doc">gtk
				431	doc</a>).</li>
Daniel Veillard	8d86964	2000-07-14 12:12:59 +0000	[diff] [blame]	432	<li>Look at the documentation about <a href="encoding.html">libxml
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	433	internationalization support</a>.</li>
Daniel Veillard	bc66f85	2002-01-14 09:49:20 +0000	[diff] [blame]	434	<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]	435	examples</a> on how to use libxml.</li>
Daniel Veillard	dad3f68	2002-11-17 16:47:27 +0000	[diff] [blame]	436	<li>John Fleck's libxml tutorial: <a href="tutorial/index.html">html</a> or
				437	<a href="tutorial/xmltutorial.pdf">pdf</a>.</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	438	<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]	439	href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
				440	documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	441	<li>George Lebl wrote <a
				442	href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	443	for IBM developerWorks</a> about using libxml.</li>
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	444	<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]	445	file</a>.</li>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	446	<li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>
				447	description. If you are starting a new project using libxml you should
				448	really use the 2.x version.</li>
Daniel Veillard	845cce4	2002-01-09 11:51:37 +0000	[diff] [blame]	449	<li>And don't forget to look at the <a
				450	href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	451	</ol>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	452
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	453	<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard	4c3a203	1999-11-19 17:46:26 +0000	[diff] [blame]	454
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	455	<p>Well, bugs or missing features are always possible, and I will make a
				456	point of fixing them in a timely fashion. The best way to report a bug is to
				457	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]	458	bug tracking database</a> (make sure to use the "libxml2" module name). I
				459	look at reports there regularly and it's good to have a reminder when a bug
				460	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]	461
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	462	<p>There is also a mailing-list <a
Daniel Veillard	3197f16	2001-04-04 00:40:08 +0000	[diff] [blame]	463	href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
				464	href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	465	href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
				466	please visit the <a
				467	href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
				468	follow the instructions. <strong>Do not send code, I won't debug it</strong>
				469	(but patches are really appreciated!).</p>
Daniel Veillard	234547b	2001-07-05 09:46:10 +0000	[diff] [blame]	470
Daniel Veillard	008186f	2001-09-13 14:24:44 +0000	[diff] [blame]	471	<p>Check the following <strong><span style="color: #FF0000">before
				472	posting</span></strong>:</p>
Daniel Veillard	234547b	2001-07-05 09:46:10 +0000	[diff] [blame]	473	<ul>
Daniel Veillard	321be0c	2002-10-08 21:26:42 +0000	[diff] [blame]	474	<li>Read the <a href="FAQ.html">FAQ</a> and <a href="search.php">use the
				475	search engine</a> to get informations related to your problem.</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	476	<li>Make sure you are <a href="ftp://xmlsoft.org/">using a recent
				477	version</a>, and that the problem still shows up in a recent version.</li>
				478	<li>Check the <a href="http://mail.gnome.org/archives/xml/">list
				479	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]	480	there is probably a fix available, similarly check the <a
Daniel Veillard	e7ead2d	2001-08-22 23:44:09 +0000	[diff] [blame]	481	href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">registered
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	482	open bugs</a>.</li>
				483	<li>Make sure you can reproduce the bug with xmllint or one of the test
				484	programs found in source in the distribution.</li>
Daniel Veillard	234547b	2001-07-05 09:46:10 +0000	[diff] [blame]	485	<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]	486	attachment)</li>
Daniel Veillard	234547b	2001-07-05 09:46:10 +0000	[diff] [blame]	487	</ul>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	488
Daniel Veillard	dadd087	2001-09-15 09:21:44 +0000	[diff] [blame]	489	<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]	490	href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	491	related I will approve it.. Please do not send mail to me directly, it makes
				492	things really hard to track and in some cases I am not the best person to
				493	answer a given question. Ask the list instead.</p>
Daniel Veillard	4c3a203	1999-11-19 17:46:26 +0000	[diff] [blame]	494
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	495	<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]	496	probably be processed faster than those without.</p>
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	497
				498	<p>If you're looking for help, a quick look at <a
Daniel Veillard	f7ed336	2001-08-17 12:01:21 +0000	[diff] [blame]	499	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]	500	provide the answer. I usually send source samples when answering libxml usage
Daniel Veillard	6f0adb5	2000-07-03 11:41:26 +0000	[diff] [blame]	501	questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	502	documentation</a> is not as polished as I would like (i need to learn more
				503	about DocBook), but it's a good starting point.</p>
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	504
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	505	<h2><a name="help">How to help</a></h2>
				506
				507	<p>You can help the project in various ways, the best thing to do first is to
				508	subscribe to the mailing-list as explained before, check the <a
Daniel Veillard	f7ed336	2001-08-17 12:01:21 +0000	[diff] [blame]	509	href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
				510	href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	511	database</a>:</p>
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	512	<ol>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	513	<li>Provide patches when you find problems.</li>
				514	<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]	515	be integrated in all cases but help pinpointing portability problems
				516	and</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	517	<li>Provide documentation fixes (either as patches to the code comments or
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	518	as HTML diffs).</li>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	519	<li>Provide new documentations pieces (translations, examples, etc
				520	...).</li>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	521	<li>Check the TODO file and try to close one of the items.</li>
				522	<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]	523	provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me
				524	</a>before to avoid synchronization problems and check that the suggested
				525	fix will fit in nicely :-)</li>
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	526	</ol>
				527
Daniel Veillard	10a2c65	1999-12-12 13:03:50 +0000	[diff] [blame]	528	<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	529
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	530	<p>The latest versions of libxml can be found on <a
Daniel Veillard	20c8cf2	2001-06-26 22:47:36 +0000	[diff] [blame]	531	href="ftp://xmlsoft.org/">xmlsoft.org</a> (<a
				532	href="ftp://speakeasy.rpmfind.net/pub/libxml/">Seattle</a>, <a
				533	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]	534	href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
MDT 2002 John Fleck	30c7054	2002-09-24 14:24:54 +0000	[diff] [blame]	535	as a <a href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.4/">source
				536	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]	537	href="ftp://ftp.gnome.org/pub/GNOME/stable/redhat/i386/libxml/">RPM
Daniel Veillard	e16b574	2002-09-26 17:50:03 +0000	[diff] [blame]	538	packages</a> -->
Daniel Veillard	321be0c	2002-10-08 21:26:42 +0000	[diff] [blame]	539	, 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]	540	mirror in Austria</a>. (NOTE that you need both the <a
Daniel Veillard	c19fccc	2000-07-03 11:52:01 +0000	[diff] [blame]	541	href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
				542	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]	543	packages installed to compile applications using libxml.) <a
Daniel Veillard	b2fb8ed	2002-04-01 09:33:12 +0000	[diff] [blame]	544	href="mailto:igor@stud.fh-frankfurt.de">Igor Zlatkovic</a> is now the
				545	maintainer of the Windows port, <a
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	546	href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
Daniel Veillard	c6271d2	2001-10-27 07:50:58 +0000	[diff] [blame]	547	provides binaries</a>. <a href="mailto:Gary.Pennington@sun.com">Gary
Daniel Veillard	1aadc44	2001-11-28 13:10:32 +0000	[diff] [blame]	548	Pennington</a> provides <a href="http://garypennington.net/libxml2/">Solaris
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	549	binaries</a>. <a href="mailto:Steve.Ball@zveno.com">Steve Ball</a> provides
				550	<a href="http://www.zveno.com/open_source/libxml2xslt.html">Mac Os X
				551	binaries</a>.</p>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	552
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	553	<p><a name="Snapshot">Snapshot:</a></p>
				554	<ul>
				555	<li>Code from the W3C cvs base libxml <a
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	556	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]	557	<li>Docs, content of the web site, the list archive included <a
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	558	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]	559	</ul>
				560
Daniel Veillard	c6271d2	2001-10-27 07:50:58 +0000	[diff] [blame]	561	<p><a name="Contribs">Contributions:</a></p>
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	562
				563	<p>I do accept external contributions, especially if compiling on another
Daniel Veillard	c6271d2	2001-10-27 07:50:58 +0000	[diff] [blame]	564	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]	565	languages have been provided, and can be found in the <a
				566	href="contribs.html">contrib section</a></p>
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	567
Daniel Veillard	8268716	2001-01-22 15:32:01 +0000	[diff] [blame]	568	<p>Libxml is also available from CVS:</p>
Daniel Veillard	10a2c65	1999-12-12 13:03:50 +0000	[diff] [blame]	569	<ul>
Daniel Veillard	10a2c65	1999-12-12 13:03:50 +0000	[diff] [blame]	570	<li><p>The <a
				571	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]	572	CVS base</a>. Check the <a
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	573	href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a>
				574	page; the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard	10a2c65	1999-12-12 13:03:50 +0000	[diff] [blame]	575	</li>
Daniel Veillard	8268716	2001-01-22 15:32:01 +0000	[diff] [blame]	576	<li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard	10a2c65	1999-12-12 13:03:50 +0000	[diff] [blame]	577	</ul>
				578
				579	<h2><a name="News">News</a></h2>
				580
Daniel Veillard	944b5ff	1999-12-15 19:08:24 +0000	[diff] [blame]	581	<h3>CVS only : check the <a
				582	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]	583	for a really accurate description</h3>
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	584
Daniel Veillard	e6d8e20	2002-05-02 06:11:10 +0000	[diff] [blame]	585	<p>Items not finished and worked on, get in touch with the list if you want
				586	to test those</p>
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	587	<ul>
Daniel Veillard	cf27f7c	2002-04-30 07:12:39 +0000	[diff] [blame]	588	<li>Finishing up <a href="http://www.w3.org/TR/xmlschema-1/">XML
				589	Schemas</a> and <a href="http://www.w3.org/TR/xinclude">XInclude</a></li>
				590	</ul>
				591
Daniel Veillard	c1eed32	2002-12-12 11:01:32 +0000	[diff] [blame]	592	<h3>2.4.30: Dec 12 2002</h3>
				593	<ul>
				594	<li>2.4.29 broke the python bindings, rereleasing</li>
				595	<li>Improvement/fixes of the XML API generator, and couple of minor code
				596	fixes.</li>
				597	</ul>
				598
Daniel Veillard	9b4bb4d	2002-12-11 19:28:47 +0000	[diff] [blame]	599	<h3>2.4.29: Dec 11 2002</h3>
				600	<ul>
				601	<li>Windows fixes (Igor): Windows CE port, pthread linking, python bindings
				602	(Stéphane Bidoul), Mingw (Magnus Henoch), and export list updates</li>
				603	<li>Fix for prev in python bindings (ERDI Gergo)</li>
				604	<li>Fix for entities handling (Marcus Clarke)</li>
				605	<li>Refactored the XML and HTML dumps to a single code path, fixed XHTML1
				606	dump</li>
				607	<li>Fix for URI parsing when handling URNs with fragment identifiers</li>
				608	<li>Fix for HTTP URL escaping problem</li>
				609	<li>added an TextXmlReader (C#) like API (work in progress)</li>
				610	<li>Rewrote the API in XML generation script, includes a C parser and saves
				611	more informations needed for C# bindings</li>
				612	</ul>
				613
Daniel Veillard	f9c4cad	2002-11-22 15:57:07 +0000	[diff] [blame]	614	<h3>2.4.28: Nov 22 2002</h3>
				615	<ul>
				616	<li>a couple of python binding fixes</li>
				617	<li>2 bug fixes in the XML push parser</li>
				618	<li>potential memory leak removed (Martin Stoilov)</li>
				619	<li>fix to the configure script for Unix (Dimitri Papadopoulos)</li>
				620	<li>added encoding support for XInclude parse="text"</li>
				621	<li>autodetection of XHTML1 and specific serialization rules added</li>
Daniel Veillard	9b4bb4d	2002-12-11 19:28:47 +0000	[diff] [blame]	622	<li>nasty threading bug fixed (William Brack)</li>
Daniel Veillard	f9c4cad	2002-11-22 15:57:07 +0000	[diff] [blame]	623	</ul>
				624
Daniel Veillard	dad3f68	2002-11-17 16:47:27 +0000	[diff] [blame]	625	<h3>2.4.27: Nov 17 2002</h3>
				626	<ul>
				627	<li>fixes for the Python bindings</li>
				628	<li>a number of bug fixes: SGML catalogs, xmlParseBalancedChunkMemory(),
				629	HTML parser, Schemas (Charles Bozeman), document fragment support
				630	(Christian Glahn), xmlReconciliateNs (Brian Stafford), XPointer,
				631	xmlFreeNode(), xmlSAXParseMemory (Peter Jones), xmlGetNodePath (Petr
				632	Pajas), entities processing</li>
				633	<li>added grep to xmllint --shell</li>
				634	<li>VMS update patch from Craig A. Berry</li>
				635	<li>cleanup of the Windows build with support for more compilers (Igor),
				636	better thread support on Windows</li>
				637	<li>cleanup of Unix Makefiles and spec file</li>
				638	<li>Improvements to the documentation (John Fleck)</li>
				639	</ul>
				640
Daniel Veillard	4826743	2002-10-18 11:21:38 +0000	[diff] [blame]	641	<h3>2.4.26: Oct 18 2002</h3>
				642	<ul>
				643	<li>Patches for Windows CE port, improvements on Windows paths handling</li>
				644	<li>Fixes to the validation code (DTD and Schemas), xmlNodeGetPath() ,
				645	HTML serialization, Namespace compliance, and a number of small
				646	problems</li>
				647	</ul>
				648
Daniel Veillard	e16b574	2002-09-26 17:50:03 +0000	[diff] [blame]	649	<h3>2.4.25: Sep 26 2002</h3>
				650	<ul>
				651	<li>A number of bug fixes: XPath, validation, Python bindings, DOM and
				652	tree, xmlI/O, Html</li>
				653	<li>Serious rewrite of XInclude</li>
				654	<li>Made XML Schemas regexp part of the default build and APIs, small fix
				655	and improvement of the regexp core</li>
				656	<li>Changed the validation code to reuse XML Schemas regexp APIs</li>
				657	<li>Better handling of Windows file paths, improvement of Makefiles (Igor,
				658	Daniel Gehriger, Mark Vakoc)</li>
				659	<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]	660	APIs</li>
Daniel Veillard	e16b574	2002-09-26 17:50:03 +0000	[diff] [blame]	661	<li>New logos from Marc Liyanage</li>
				662	<li>Tutorial improvements: John Fleck, Christopher Harris</li>
				663	<li>Makefile: Fixes for AMD x86_64 (Mandrake), DESTDIR (Christophe
				664	Merlet)</li>
				665	<li>removal of all stderr/perror use for error reporting</li>
				666	<li>Better error reporting: XPath and DTD validation</li>
				667	<li>update of the trio portability layer (Bjorn Reese)</li>
				668	</ul>
				669
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	670	<p><strong>2.4.24: Aug 22 2002</strong></p>
				671	<ul>
				672	<li>XPath fixes (William), xf:escape-uri() (Wesley Terpstra)</li>
				673	<li>Python binding fixes: makefiles (William), generator, rpm build, x86-64
				674	(fcrozat)</li>
				675	<li>HTML <style> and boolean attributes serializer fixes</li>
				676	<li>C14N improvements by Aleksey</li>
Daniel Veillard	e166254	2002-08-28 11:50:59 +0000	[diff] [blame]	677	<li>doc cleanups: Rick Jones</li>
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	678	<li>Windows compiler makefile updates: Igor and Elizabeth Barham</li>
				679	<li>XInclude: implementation of fallback and xml:base fixup added</li>
				680	</ul>
				681
Daniel Veillard	782afda	2002-07-08 15:12:49 +0000	[diff] [blame]	682	<h3>2.4.23: July 6 2002</h3>
				683	<ul>
				684	<li>performances patches: Peter Jacobi</li>
				685	<li>c14n fixes, testsuite and performances: Aleksey Sanin</li>
				686	<li>added xmlDocFormatDump: Chema Celorio</li>
				687	<li>new tutorial: John Fleck</li>
				688	<li>new hash functions and performances: Sander Vesik, portability fix from
				689	Peter Jacobi</li>
				690	<li>a number of bug fixes: XPath (William Brack, Richard Jinks), XML and
				691	HTML parsers, ID lookup function</li>
				692	<li>removal of all remaining sprintf: Aleksey Sanin</li>
				693	</ul>
				694
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	695	<h3>2.4.22: May 27 2002</h3>
				696	<ul>
				697	<li>a number of bug fixes: configure scripts, base handling, parser, memory
				698	usage, HTML parser, XPath, documentation (Christian Cornelssen),
Daniel Veillard	2147367	2002-06-17 07:29:22 +0000	[diff] [blame]	699	indentation, URI parsing</li>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	700	<li>Optimizations for XMLSec, fixing and making public some of the network
				701	protocol handlers (Aleksey)</li>
				702	<li>performance patch from Gary Pennington</li>
				703	<li>Charles Bozeman provided date and time support for XML Schemas
				704	datatypes</li>
				705	</ul>
				706
Daniel Veillard	cf27f7c	2002-04-30 07:12:39 +0000	[diff] [blame]	707	<h3>2.4.21: Apr 29 2002</h3>
				708
				709	<p>This release is both a bug fix release and also contains the early XML
				710	Schemas <a href="http://www.w3.org/TR/xmlschema-1/">structures</a> and <a
				711	href="http://www.w3.org/TR/xmlschema-2/">datatypes</a> code, beware, all
				712	interfaces are likely to change, there is huge holes, it is clearly a work in
				713	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]	714	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]	715	<ul>
				716	<li>a couple of bugs or limitations introduced in 2.4.20</li>
				717	<li>patches for Borland C++ and MSC by Igor</li>
				718	<li>some fixes on XPath strings and conformance patches by Richard
				719	Jinks</li>
				720	<li>patch from Aleksey for the ExcC14N specification</li>
				721	<li>OSF/1 bug fix by Bjorn</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	722	</ul>
				723
Daniel Veillard	a7084cd	2002-04-15 17:12:47 +0000	[diff] [blame]	724	<h3>2.4.20: Apr 15 2002</h3>
				725	<ul>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	726	<li>bug fixes: file descriptor leak, XPath, HTML output, DTD validation</li>
Daniel Veillard	a7084cd	2002-04-15 17:12:47 +0000	[diff] [blame]	727	<li>XPath conformance testing by Richard Jinks</li>
				728	<li>Portability fixes: Solaris, MPE/iX, Windows, OSF/1, python bindings,
				729	libxml.m4</li>
				730	</ul>
				731
Daniel Veillard	1927409	2002-03-25 16:48:03 +0000	[diff] [blame]	732	<h3>2.4.19: Mar 25 2002</h3>
				733	<ul>
				734	<li>bug fixes: half a dozen XPath bugs, Validation, ISO-Latin to UTF8
				735	encoder</li>
				736	<li>portability fixes in the HTTP code</li>
Daniel Veillard	b2fb8ed	2002-04-01 09:33:12 +0000	[diff] [blame]	737	<li>memory allocation checks using valgrind, and profiling tests</li>
Daniel Veillard	1927409	2002-03-25 16:48:03 +0000	[diff] [blame]	738	<li>revamp of the Windows build and Makefiles</li>
				739	</ul>
				740
Daniel Veillard	34ce8be	2002-03-18 19:37:11 +0000	[diff] [blame]	741	<h3>2.4.18: Mar 18 2002</h3>
				742	<ul>
				743	<li>bug fixes: tree, SAX, canonicalization, validation, portability,
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	744	XPath</li>
Daniel Veillard	34ce8be	2002-03-18 19:37:11 +0000	[diff] [blame]	745	<li>removed the --with-buffer option it was becoming unmaintainable</li>
				746	<li>serious cleanup of the Python makefiles</li>
				747	<li>speedup patch to XPath very effective for DocBook stylesheets</li>
				748	<li>Fixes for Windows build, cleanup of the documentation</li>
				749	</ul>
				750
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	751	<h3>2.4.17: Mar 8 2002</h3>
				752	<ul>
				753	<li>a lot of bug fixes, including "namespace nodes have no parents in
				754	XPath"</li>
				755	<li>fixed/improved the Python wrappers, added more examples and more
				756	regression tests, XPath extension functions can now return node-sets</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	757	<li>added the XML Canonicalization support from Aleksey Sanin</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	758	</ul>
				759
Daniel Veillard	5f4b599	2002-02-20 10:22:49 +0000	[diff] [blame]	760	<h3>2.4.16: Feb 20 2002</h3>
				761	<ul>
				762	<li>a lot of bug fixes, most of them were triggered by the XML Testsuite
				763	from OASIS and W3C. Compliance has been significantly improved.</li>
				764	<li>a couple of portability fixes too.</li>
				765	</ul>
				766
Daniel Veillard	397ff11	2002-02-11 18:27:20 +0000	[diff] [blame]	767	<h3>2.4.15: Feb 11 2002</h3>
				768	<ul>
				769	<li>Fixed the Makefiles, especially the python module ones</li>
				770	<li>A few bug fixes and cleanup</li>
				771	<li>Includes cleanup</li>
				772	</ul>
				773
Daniel Veillard	b6c1e2f	2002-02-08 14:52:52 +0000	[diff] [blame]	774	<h3>2.4.14: Feb 8 2002</h3>
				775	<ul>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	776	<li>Change of License to the <a
Daniel Veillard	b6c1e2f	2002-02-08 14:52:52 +0000	[diff] [blame]	777	href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	778	License</a> basically for integration in XFree86 codebase, and removing
				779	confusion around the previous dual-licensing</li>
Daniel Veillard	b6c1e2f	2002-02-08 14:52:52 +0000	[diff] [blame]	780	<li>added Python bindings, beta software but should already be quite
				781	complete</li>
				782	<li>a large number of fixes and cleanups, especially for all tree
				783	manipulations</li>
				784	<li>cleanup of the headers, generation of a reference API definition in
				785	XML</li>
				786	</ul>
				787
				788	<h3>2.4.13: Jan 14 2002</h3>
Daniel Veillard	744683d	2002-01-14 17:30:20 +0000	[diff] [blame]	789	<ul>
				790	<li>update of the documentation: John Fleck and Charlie Bozeman</li>
				791	<li>cleanup of timing code from Justin Fletcher</li>
				792	<li>fixes for Windows and initial thread support on Win32: Igor and Serguei
				793	Narojnyi</li>
				794	<li>Cygwin patch from Robert Collins</li>
				795	<li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
				796	</ul>
				797
Daniel Veillard	ef90ba7	2001-12-07 14:24:22 +0000	[diff] [blame]	798	<h3>2.4.12: Dec 7 2001</h3>
				799	<ul>
				800	<li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
				801	XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
				802	(robert)</li>
				803	<li>Eric Lavigne contributed project files for MacOS</li>
				804	<li>some makefiles cleanups</li>
				805	</ul>
				806
Daniel Veillard	a487105	2001-11-26 13:19:48 +0000	[diff] [blame]	807	<h3>2.4.11: Nov 26 2001</h3>
				808	<ul>
				809	<li>fixed a couple of errors in the includes, fixed a few bugs, some code
				810	cleanups</li>
				811	<li>xmllint man pages improvement by Heiko Rupp</li>
				812	<li>updated VMS build instructions from John A Fotheringham</li>
				813	<li>Windows Makefiles updates from Igor</li>
				814	</ul>
				815
Daniel Veillard	43d3f61	2001-11-10 11:57:23 +0000	[diff] [blame]	816	<h3>2.4.10: Nov 10 2001</h3>
				817	<ul>
				818	<li>URI escaping fix (Joel Young)</li>
				819	<li>added xmlGetNodePath() (for paths or XPointers generation)</li>
				820	<li>Fixes namespace handling problems when using DTD and validation</li>
				821	<li>improvements on xmllint: Morus Walter patches for --format and
				822	--encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
				823	<li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
				824	<li>fixes to the HTML parser</li>
				825	</ul>
				826
				827	<h3>2.4.9: Nov 6 2001</h3>
				828	<ul>
				829	<li>fixes more catalog bugs</li>
				830	<li>avoid a compilation problem, improve xmlGetLineNo()</li>
				831	</ul>
				832
Daniel Veillard	ed421aa	2001-11-04 21:22:45 +0000	[diff] [blame]	833	<h3>2.4.8: Nov 4 2001</h3>
				834	<ul>
				835	<li>fixed SGML catalogs broken in previous release, updated xmlcatalog
				836	tool</li>
				837	<li>fixed a compile errors and some includes troubles.</li>
				838	</ul>
				839
Daniel Veillard	52dcab3	2001-10-30 12:51:17 +0000	[diff] [blame]	840	<h3>2.4.7: Oct 30 2001</h3>
				841	<ul>
				842	<li>exported some debugging interfaces</li>
				843	<li>serious rewrite of the catalog code</li>
				844	<li>integrated Gary Pennington thread safety patch, added configure option
				845	and regression tests</li>
				846	<li>removed an HTML parser bug</li>
				847	<li>fixed a couple of potentially serious validation bugs</li>
				848	<li>integrated the SGML DocBook support in xmllint</li>
				849	<li>changed the nanoftp anonymous login passwd</li>
				850	<li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
				851	<li>general bug fixes</li>
				852	<li>updated xmllint man page by John Fleck</li>
				853	<li>some VMS and Windows updates</li>
				854	</ul>
				855
Daniel Veillard	60087f3	2001-10-10 09:45:09 +0000	[diff] [blame]	856	<h3>2.4.6: Oct 10 2001</h3>
				857	<ul>
Daniel Veillard	52dcab3	2001-10-30 12:51:17 +0000	[diff] [blame]	858	<li>added an updated man pages by John Fleck</li>
Daniel Veillard	60087f3	2001-10-10 09:45:09 +0000	[diff] [blame]	859	<li>portability and configure fixes</li>
				860	<li>an infinite loop on the HTML parser was removed (William)</li>
				861	<li>Windows makefile patches from Igor</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	862	<li>fixed half a dozen bugs reported for libxml or libxslt</li>
Daniel Veillard	60087f3	2001-10-10 09:45:09 +0000	[diff] [blame]	863	<li>updated xmlcatalog to be able to modify SGML super catalogs</li>
				864	</ul>
				865
Daniel Veillard	dadd087	2001-09-15 09:21:44 +0000	[diff] [blame]	866	<h3>2.4.5: Sep 14 2001</h3>
				867	<ul>
				868	<li>Remove a few annoying bugs in 2.4.4</li>
				869	<li>forces the HTML serializer to output decimal charrefs since some
				870	version of Netscape can't handle hexadecimal ones</li>
				871	</ul>
				872
				873	<h3>1.8.16: Sep 14 2001</h3>
				874	<ul>
				875	<li>maintenance release of the old libxml1 branch, couple of bug and
				876	portability fixes</li>
				877	</ul>
				878
Daniel Veillard	04382ae	2001-09-12 18:51:30 +0000	[diff] [blame]	879	<h3>2.4.4: Sep 12 2001</h3>
				880	<ul>
				881	<li>added --convert to xmlcatalog, bug fixes and cleanups of XML
				882	Catalog</li>
				883	<li>a few bug fixes and some portability changes</li>
				884	<li>some documentation cleanups</li>
				885	</ul>
				886
Daniel Veillard	3993690	2001-08-24 00:49:01 +0000	[diff] [blame]	887	<h3>2.4.3: Aug 23 2001</h3>
				888	<ul>
				889	<li>XML Catalog support see the doc</li>
				890	<li>New NaN/Infinity floating point code</li>
				891	<li>A few bug fixes</li>
				892	</ul>
				893
				894	<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	895	<ul>
				896	<li>adds xmlLineNumbersDefault() to control line number generation</li>
				897	<li>lot of bug fixes</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	898	<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]	899	<li>inheritance of namespaces from DTD defaulted attributes</li>
				900	<li>fixes a serious potential security bug</li>
				901	<li>added a --format option to xmllint</li>
				902	</ul>
				903
				904	<h3>2.4.1: July 24 2001</h3>
				905	<ul>
				906	<li>possibility to keep line numbers in the tree</li>
				907	<li>some computation NaN fixes</li>
				908	<li>extension of the XPath API</li>
				909	<li>cleanup for alpha and ia64 targets</li>
				910	<li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard	09ab7e1	2001-07-10 15:49:44 +0000	[diff] [blame]	911	</ul>
				912
				913	<h3>2.4.0: July 10 2001</h3>
				914	<ul>
				915	<li>Fixed a few bugs in XPath, validation, and tree handling.</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	916	<li>Fixed XML Base implementation, added a couple of examples to the
Daniel Veillard	09ab7e1	2001-07-10 15:49:44 +0000	[diff] [blame]	917	regression tests</li>
				918	<li>A bit of cleanup</li>
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	919	</ul>
				920
Daniel Veillard	5b43fde	2001-07-05 23:31:40 +0000	[diff] [blame]	921	<h3>2.3.14: July 5 2001</h3>
				922	<ul>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	923	<li>fixed some entities problems and reduce memory requirement when
				924	substituting them</li>
Daniel Veillard	5b43fde	2001-07-05 23:31:40 +0000	[diff] [blame]	925	<li>lots of improvements in the XPath queries interpreter can be
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	926	substantially faster</li>
Daniel Veillard	5b43fde	2001-07-05 23:31:40 +0000	[diff] [blame]	927	<li>Makefiles and configure cleanups</li>
				928	<li>Fixes to XPath variable eval, and compare on empty node set</li>
				929	<li>HTML tag closing bug fixed</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	930	<li>Fixed an URI reference computation problem when validating</li>
Daniel Veillard	5b43fde	2001-07-05 23:31:40 +0000	[diff] [blame]	931	</ul>
				932
Daniel Veillard	2adbb51	2001-06-28 16:20:36 +0000	[diff] [blame]	933	<h3>2.3.13: June 28 2001</h3>
				934	<ul>
				935	<li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
				936	<li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
				937	</ul>
				938
				939	<h3>1.8.14: June 28 2001</h3>
				940	<ul>
				941	<li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
				942	<li>Small Makefile fix</li>
				943	</ul>
				944
Daniel Veillard	1164810	2001-06-26 16:08:24 +0000	[diff] [blame]	945	<h3>2.3.12: June 26 2001</h3>
				946	<ul>
				947	<li>lots of cleanup</li>
				948	<li>a couple of validation fix</li>
				949	<li>fixed line number counting</li>
				950	<li>fixed serious problems in the XInclude processing</li>
				951	<li>added support for UTF8 BOM at beginning of entities</li>
				952	<li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
				953	miscompile uri.c (William), Thomas Leitner provided a fix for the
				954	optimizer on Tru64</li>
				955	<li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
				956	compilation on Windows MSC</li>
				957	<li>update of libxml-doc.el (Felix Natter)</li>
				958	<li>fixed 2 bugs in URI normalization code</li>
				959	</ul>
				960
Daniel Veillard	e3c81b5	2001-06-17 14:50:34 +0000	[diff] [blame]	961	<h3>2.3.11: June 17 2001</h3>
				962	<ul>
				963	<li>updates to trio, Makefiles and configure should fix some portability
				964	problems (alpha)</li>
				965	<li>fixed some HTML serialization problems (pre, script, and block/inline
				966	handling), added encoding aware APIs, cleanup of this code</li>
				967	<li>added xmlHasNsProp()</li>
				968	<li>implemented a specific PI for encoding support in the DocBook SGML
				969	parser</li>
				970	<li>some XPath fixes (-Infinity, / as a function parameter and namespaces
				971	node selection)</li>
				972	<li>fixed a performance problem and an error in the validation code</li>
				973	<li>fixed XInclude routine to implement the recursive behaviour</li>
				974	<li>fixed xmlFreeNode problem when libxml is included statically twice</li>
				975	<li>added --version to xmllint for bug reports</li>
				976	</ul>
				977
Daniel Veillard	2e4f188	2001-06-01 10:11:57 +0000	[diff] [blame]	978	<h3>2.3.10: June 1 2001</h3>
				979	<ul>
				980	<li>fixed the SGML catalog support</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	981	<li>a number of reported bugs got fixed, in XPath, iconv detection,
				982	XInclude processing</li>
Daniel Veillard	2e4f188	2001-06-01 10:11:57 +0000	[diff] [blame]	983	<li>XPath string function should now handle unicode correctly</li>
				984	</ul>
				985
Daniel Veillard	4623acd	2001-05-19 15:13:15 +0000	[diff] [blame]	986	<h3>2.3.9: May 19 2001</h3>
				987
				988	<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
				989	<ul>
				990	<li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	991	<li>some serious speed optimization again</li>
Daniel Veillard	4623acd	2001-05-19 15:13:15 +0000	[diff] [blame]	992	<li>some documentation cleanups</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	993	<li>trying to get better linking on Solaris (-R)</li>
Daniel Veillard	4623acd	2001-05-19 15:13:15 +0000	[diff] [blame]	994	<li>XPath API cleanup from Thomas Broyer</li>
				995	<li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
				996	xmlValidGetValidElements()</li>
				997	<li>Added an INSTALL file</li>
				998	<li>Attribute removal added to API: #54433</li>
				999	<li>added a basic support for SGML catalogs</li>
				1000	<li>fixed xmlKeepBlanksDefault(0) API</li>
				1001	<li>bugfix in xmlNodeGetLang()</li>
				1002	<li>fixed a small configure portability problem</li>
				1003	<li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
				1004	</ul>
				1005
Daniel Veillard	a265af7	2001-05-14 11:13:58 +0000	[diff] [blame]	1006	<h3>1.8.13: May 14 2001</h3>
				1007	<ul>
				1008	<li>bugfixes release of the old libxml1 branch used by Gnome</li>
				1009	</ul>
				1010
Daniel Veillard	3bbbe6f	2001-05-03 11:15:37 +0000	[diff] [blame]	1011	<h3>2.3.8: May 3 2001</h3>
				1012	<ul>
				1013	<li>Integrated an SGML DocBook parser for the Gnome project</li>
				1014	<li>Fixed a few things in the HTML parser</li>
				1015	<li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
				1016	point portability issue</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1017	<li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
				1018	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]	1019	<li>incorporated more Windows cleanup</li>
				1020	<li>added xmlSaveFormatFile()</li>
				1021	<li>fixed problems in copying nodes with entities references (gdome)</li>
				1022	<li>removed some troubles surrounding the new validation module</li>
				1023	</ul>
				1024
Daniel Veillard	a41123c	2001-04-22 19:31:20 +0000	[diff] [blame]	1025	<h3>2.3.7: April 22 2001</h3>
				1026	<ul>
				1027	<li>lots of small bug fixes, corrected XPointer</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1028	<li>Non deterministic content model validation support</li>
Daniel Veillard	a41123c	2001-04-22 19:31:20 +0000	[diff] [blame]	1029	<li>added xmlDocCopyNode for gdome2</li>
				1030	<li>revamped the way the HTML parser handles end of tags</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1031	<li>XPath: corrections of namespaces support and number formatting</li>
Daniel Veillard	a41123c	2001-04-22 19:31:20 +0000	[diff] [blame]	1032	<li>Windows: Igor Zlatkovic patches for MSC compilation</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1033	<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]	1034	<li>Improved validation speed sensible for DocBook</li>
				1035	<li>fixed a big bug with ID declared in external parsed entities</li>
				1036	<li>portability fixes, update of Trio from Bjorn Reese</li>
				1037	</ul>
				1038
Daniel Veillard	afc7311	2001-04-11 11:51:41 +0000	[diff] [blame]	1039	<h3>2.3.6: April 8 2001</h3>
				1040	<ul>
				1041	<li>Code cleanup using extreme gcc compiler warning options, found and
				1042	cleared half a dozen potential problem</li>
				1043	<li>the Eazel team found an XML parser bug</li>
				1044	<li>cleaned up the user of some of the string formatting function. used the
				1045	trio library code to provide the one needed when the platform is missing
				1046	them</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1047	<li>xpath: removed a memory leak and fixed the predicate evaluation
				1048	problem, extended the testsuite and cleaned up the result. XPointer seems
				1049	broken ...</li>
Daniel Veillard	afc7311	2001-04-11 11:51:41 +0000	[diff] [blame]	1050	</ul>
				1051
Daniel Veillard	56a4cb8	2001-03-24 17:00:36 +0000	[diff] [blame]	1052	<h3>2.3.5: Mar 23 2001</h3>
				1053	<ul>
				1054	<li>Biggest change is separate parsing and evaluation of XPath expressions,
				1055	there is some new APIs for this too</li>
				1056	<li>included a number of bug fixes(XML push parser, 51876, notations,
				1057	52299)</li>
				1058	<li>Fixed some portability issues</li>
				1059	</ul>
				1060
Daniel Veillard	e356c28	2001-03-10 12:32:04 +0000	[diff] [blame]	1061	<h3>2.3.4: Mar 10 2001</h3>
				1062	<ul>
				1063	<li>Fixed bugs #51860 and #51861</li>
				1064	<li>Added a global variable xmlDefaultBufferSize to allow default buffer
				1065	size to be application tunable.</li>
				1066	<li>Some cleanup in the validation code, still a bug left and this part
				1067	should probably be rewritten to support ambiguous content model :-\</li>
				1068	<li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
				1069	parser</li>
				1070	<li>Fixed another bug in xmlNodeGetContent()</li>
				1071	<li>Bjorn fixed XPath node collection and Number formatting</li>
				1072	<li>Fixed a loop reported in the HTML parsing</li>
				1073	<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]	1074	are formatting spaces, this is for XML conformance</li>
Daniel Veillard	e356c28	2001-03-10 12:32:04 +0000	[diff] [blame]	1075	</ul>
				1076
Daniel Veillard	b402c07	2001-03-01 17:28:58 +0000	[diff] [blame]	1077	<h3>2.3.3: Mar 1 2001</h3>
				1078	<ul>
				1079	<li>small change in XPath for XSLT</li>
				1080	<li>documentation cleanups</li>
				1081	<li>fix in validation by Gary Pennington</li>
				1082	<li>serious parsing performances improvements</li>
				1083	</ul>
				1084
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	1085	<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard	7168110	2001-02-24 17:48:53 +0000	[diff] [blame]	1086	<ul>
				1087	<li>chasing XPath bugs, found a bunch, completed some TODO</li>
				1088	<li>fixed a Dtd parsing bug</li>
				1089	<li>fixed a bug in xmlNodeGetContent</li>
				1090	<li>ID/IDREF support partly rewritten by Gary Pennington</li>
				1091	</ul>
				1092
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	1093	<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard	6e6a6cc	2001-02-15 15:55:44 +0000	[diff] [blame]	1094	<ul>
				1095	<li>some XPath and HTML bug fixes for XSLT</li>
				1096	<li>small extension of the hash table interfaces for DOM gdome2
				1097	implementation</li>
				1098	<li>A few bug fixes</li>
				1099	</ul>
				1100
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	1101	<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]	1102	<ul>
				1103	<li>Lots of XPath bug fixes</li>
				1104	<li>Add a mode with Dtd lookup but without validation error reporting for
				1105	XSLT</li>
				1106	<li>Add support for text node without escaping (XSLT)</li>
				1107	<li>bug fixes for xmlCheckFilename</li>
				1108	<li>validation code bug fixes from Gary Pennington</li>
				1109	<li>Patch from Paul D. Smith correcting URI path normalization</li>
				1110	<li>Patch to allow simultaneous install of libxml-devel and
				1111	libxml2-devel</li>
				1112	<li>the example Makefile is now fixed</li>
				1113	<li>added HTML to the RPM packages</li>
				1114	<li>tree copying bugfixes</li>
				1115	<li>updates to Windows makefiles</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1116	<li>optimization patch from Bjorn Reese</li>
Daniel Veillard	6e6a6cc	2001-02-15 15:55:44 +0000	[diff] [blame]	1117	</ul>
				1118
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	1119	<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard	503b893	2001-01-05 06:36:31 +0000	[diff] [blame]	1120	<ul>
				1121	<li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
				1122	<li>added htmlHandleOmittedElem()</li>
				1123	<li>Applied Bjorn Reese's IPV6 first patch</li>
				1124	<li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard	8268716	2001-01-22 15:32:01 +0000	[diff] [blame]	1125	<li>added XPointer xmlns() new scheme support</li>
Daniel Veillard	503b893	2001-01-05 06:36:31 +0000	[diff] [blame]	1126	</ul>
				1127
Daniel Veillard	2ddd23d	2000-11-25 10:42:19 +0000	[diff] [blame]	1128	<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard	9d343c4	2000-11-25 10:12:43 +0000	[diff] [blame]	1129	<ul>
				1130	<li>Fix the Windows problems of 2.2.8</li>
				1131	<li>integrate OpenVMS patches</li>
				1132	<li>better handling of some nasty HTML input</li>
				1133	<li>Improved the XPointer implementation</li>
				1134	<li>integrate a number of provided patches</li>
				1135	</ul>
				1136
Daniel Veillard	2ddd23d	2000-11-25 10:42:19 +0000	[diff] [blame]	1137	<h3>2.2.9: Nov 25 2000</h3>
				1138	<ul>
				1139	<li>erroneous release :-(</li>
				1140	</ul>
				1141
Daniel Veillard	28929b2	2000-11-13 18:22:49 +0000	[diff] [blame]	1142	<h3>2.2.8: Nov 13 2000</h3>
				1143	<ul>
				1144	<li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
				1145	support</li>
				1146	<li>Patch in conditional section handling</li>
				1147	<li>updated MS compiler project</li>
				1148	<li>fixed some XPath problems</li>
				1149	<li>added an URI escaping function</li>
				1150	<li>some other bug fixes</li>
				1151	</ul>
				1152
				1153	<h3>2.2.7: Oct 31 2000</h3>
				1154	<ul>
				1155	<li>added message redirection</li>
				1156	<li>XPath improvements (thanks TOM !)</li>
				1157	<li>xmlIOParseDTD() added</li>
				1158	<li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
				1159	<li>some cleanup of the Makefile, autoconf and the distribution content</li>
				1160	</ul>
				1161
Daniel Veillard	29a11cc	2000-10-25 13:32:39 +0000	[diff] [blame]	1162	<h3>2.2.6: Oct 25 2000:</h3>
				1163	<ul>
				1164	<li>Added an hash table module, migrated a number of internal structure to
				1165	those</li>
				1166	<li>Fixed a posteriori validation problems</li>
				1167	<li>HTTP module cleanups</li>
				1168	<li>HTML parser improvements (tag errors, script/style handling, attribute
				1169	normalization)</li>
				1170	<li>coalescing of adjacent text nodes</li>
				1171	<li>couple of XPath bug fixes, exported the internal API</li>
				1172	</ul>
				1173
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	1174	<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard	4c3a203	1999-11-19 17:46:26 +0000	[diff] [blame]	1175	<ul>
Daniel Veillard	189446d	2000-10-13 10:23:06 +0000	[diff] [blame]	1176	<li>XPointer implementation and testsuite</li>
				1177	<li>Lot of XPath fixes, added variable and functions registration, more
				1178	tests</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1179	<li>Portability fixes, lots of enhancements toward an easy Windows build
				1180	and release</li>
Daniel Veillard	189446d	2000-10-13 10:23:06 +0000	[diff] [blame]	1181	<li>Late validation fixes</li>
				1182	<li>Integrated a lot of contributed patches</li>
				1183	<li>added memory management docs</li>
Daniel Veillard	ab8500d	2000-10-15 21:06:19 +0000	[diff] [blame]	1184	<li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard	189446d	2000-10-13 10:23:06 +0000	[diff] [blame]	1185	</ul>
				1186
				1187	<h3>2.2.4: Oct 1 2000:</h3>
				1188	<ul>
				1189	<li>main XPath problem fixed</li>
				1190	<li>Integrated portability patches for Windows</li>
				1191	<li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	1192	</ul>
				1193
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	1194	<h3>2.2.3: Sep 17 2000</h3>
				1195	<ul>
				1196	<li>bug fixes</li>
				1197	<li>cleanup of entity handling code</li>
				1198	<li>overall review of all loops in the parsers, all sprintf usage has been
				1199	checked too</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1200	<li>Far better handling of larges Dtd. Validating against DocBook XML Dtd
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	1201	works smoothly now.</li>
				1202	</ul>
				1203
				1204	<h3>1.8.10: Sep 6 2000</h3>
				1205	<ul>
				1206	<li>bug fix release for some Gnome projects</li>
				1207	</ul>
				1208
				1209	<h3>2.2.2: August 12 2000</h3>
Daniel Veillard	786d7c8	2000-08-12 23:38:57 +0000	[diff] [blame]	1210	<ul>
				1211	<li>mostly bug fixes</li>
Daniel Veillard	ec78c0f	2000-08-25 10:25:23 +0000	[diff] [blame]	1212	<li>started adding routines to access xml parser context options</li>
Daniel Veillard	786d7c8	2000-08-12 23:38:57 +0000	[diff] [blame]	1213	</ul>
				1214
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	1215	<h3>2.2.1: July 21 2000</h3>
Daniel Veillard	a2679fa	2000-07-22 02:38:15 +0000	[diff] [blame]	1216	<ul>
				1217	<li>a purely bug fixes release</li>
				1218	<li>fixed an encoding support problem when parsing from a memory block</li>
				1219	<li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1220	<li>removed a bug in the function allowing to override the memory
				1221	allocation routines</li>
Daniel Veillard	a2679fa	2000-07-22 02:38:15 +0000	[diff] [blame]	1222	</ul>
				1223
Daniel Veillard	d5f97f8	2000-09-17 16:38:14 +0000	[diff] [blame]	1224	<h3>2.2.0: July 14 2000</h3>
Daniel Veillard	94e9060	2000-07-17 14:38:19 +0000	[diff] [blame]	1225	<ul>
				1226	<li>applied a lot of portability fixes</li>
				1227	<li>better encoding support/cleanup and saving (content is now always
				1228	encoded in UTF-8)</li>
				1229	<li>the HTML parser now correctly handles encodings</li>
				1230	<li>added xmlHasProp()</li>
				1231	<li>fixed a serious problem with &#38;</li>
				1232	<li>propagated the fix to FTP client</li>
				1233	<li>cleanup, bugfixes, etc ...</li>
				1234	<li>Added a page about <a href="encoding.html">libxml Internationalization
				1235	support</a></li>
				1236	</ul>
				1237
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	1238	<h3>1.8.9: July 9 2000</h3>
				1239	<ul>
				1240	<li>fixed the spec the RPMs should be better</li>
				1241	<li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
				1242	rpmfind users problem</li>
				1243	</ul>
				1244
Daniel Veillard	6388e17	2000-07-03 16:07:19 +0000	[diff] [blame]	1245	<h3>2.1.1: July 1 2000</h3>
				1246	<ul>
				1247	<li>fixes a couple of bugs in the 2.1.0 packaging</li>
				1248	<li>improvements on the HTML parser</li>
				1249	</ul>
				1250
Daniel Veillard	3f6f7f6	2000-06-30 17:58:25 +0000	[diff] [blame]	1251	<h3>2.1.0 and 1.8.8: June 29 2000</h3>
				1252	<ul>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	1253	<li>1.8.8 is mostly a commodity package for upgrading to libxml2 according
				1254	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]	1255	about &#38; charref parsing</li>
				1256	<li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
				1257	also contains numerous fixes and enhancements:
				1258	<ul>
				1259	<li>added xmlStopParser() to stop parsing</li>
				1260	<li>improved a lot parsing speed when there is large CDATA blocs</li>
				1261	<li>includes XPath patches provided by Picdar Technology</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1262	<li>tried to fix as much as possible DTD validation and namespace
Daniel Veillard	3f6f7f6	2000-06-30 17:58:25 +0000	[diff] [blame]	1263	related problems</li>
				1264	<li>output to a given encoding has been added/tested</li>
				1265	<li>lot of various fixes</li>
				1266	</ul>
				1267	</li>
				1268	</ul>
				1269
Daniel Veillard	e0aed30	2000-04-16 08:52:20 +0000	[diff] [blame]	1270	<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	1271	<ul>
				1272	<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]	1273	idea to check the 1.x to 2.x upgrade instructions. NOTE: while initially
				1274	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]	1275	workload.</li>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	1276	<li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillard	e0aed30	2000-04-16 08:52:20 +0000	[diff] [blame]	1277	$prefix/include/gnome-xml), they also are referenced by
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	1278	<pre>#include <libxml/xxx.h></pre>
Daniel Veillard	e0aed30	2000-04-16 08:52:20 +0000	[diff] [blame]	1279	<p>instead of</p>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	1280	<pre>#include "xxx.h"</pre>
				1281	</li>
Daniel Veillard	8f62198	2000-03-20 13:07:15 +0000	[diff] [blame]	1282	<li>a new URI module for parsing URIs and following strictly RFC 2396</li>
				1283	<li>the memory allocation routines used by libxml can now be overloaded
				1284	dynamically by using xmlMemSetup()</li>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	1285	<li>The previously CVS only tool tester has been renamed
				1286	<strong>xmllint</strong> and is now installed as part of the libxml2
				1287	package</li>
Daniel Veillard	e0aed30	2000-04-16 08:52:20 +0000	[diff] [blame]	1288	<li>The I/O interface has been revamped. There is now ways to plug in
				1289	specific I/O modules, either at the URI scheme detection level using
				1290	xmlRegisterInputCallbacks() or by passing I/O functions when creating a
				1291	parser context using xmlCreateIOParserCtxt()</li>
				1292	<li>there is a C preprocessor macro LIBXML_VERSION providing the version
				1293	number of the libxml module in use</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1294	<li>a number of optional features of libxml can now be excluded at
				1295	configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillard	edfb29b	2000-03-14 19:59:05 +0000	[diff] [blame]	1296	</ul>
				1297
				1298	<h3>2.0.0beta: Mar 14 2000</h3>
				1299	<ul>
				1300	<li>This is a first Beta release of libxml version 2</li>
Daniel Veillard	e356c28	2001-03-10 12:32:04 +0000	[diff] [blame]	1301	<li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
				1302	FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
				1303	RPMs</li>
Daniel Veillard	edfb29b	2000-03-14 19:59:05 +0000	[diff] [blame]	1304	<li>This version is now the head in the Gnome CVS base, the old one is
				1305	available under the tag LIB_XML_1_X</li>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	1306	<li>This includes a very large set of changes. From a programmatic point
				1307	of view applications should not have to be modified too much, check the
				1308	<a href="upgrade.html">upgrade page</a></li>
Daniel Veillard	edfb29b	2000-03-14 19:59:05 +0000	[diff] [blame]	1309	<li>Some interfaces may changes (especially a bit about encoding).</li>
				1310	<li>the updates includes:
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	1311	<ul>
Daniel Veillard	edfb29b	2000-03-14 19:59:05 +0000	[diff] [blame]	1312	<li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
				1313	handled now</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1314	<li>Better handling of entities, especially well-formedness checking
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1315	and proper PEref extensions in external subsets</li>
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	1316	<li>DTD conditional sections</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1317	<li>Validation now correctly handle entities content</li>
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	1318	<li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1319	structures to accommodate DOM</a></li>
Daniel Veillard	6c8b117	2000-03-01 00:40:41 +0000	[diff] [blame]	1320	</ul>
				1321	</li>
Daniel Veillard	edfb29b	2000-03-14 19:59:05 +0000	[diff] [blame]	1322	<li>Serious progress were made toward compliance, <a
				1323	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]	1324	OASIS testsuite (except the Japanese tests since I don't support that
Daniel Veillard	edfb29b	2000-03-14 19:59:05 +0000	[diff] [blame]	1325	encoding yet). This URL is rebuilt every couple of hours using the CVS
				1326	head version.</li>
Daniel Veillard	e41f2b7	2000-01-30 20:00:07 +0000	[diff] [blame]	1327	</ul>
				1328
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	1329	<h3>1.8.7: Mar 6 2000</h3>
				1330	<ul>
				1331	<li>This is a bug fix release:</li>
				1332	<li>It is possible to disable the ignorable blanks heuristic used by
				1333	libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1334	that for adherence to XML spec, this behaviour will be disabled by
				1335	default in 2.x . The same function will allow to keep compatibility for
				1336	old code.</li>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	1337	<li>Blanks in <a> </a> constructs are not ignored anymore,
				1338	avoiding heuristic is really the Right Way :-\</li>
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	1339	<li>The unchecked use of snprintf which was breaking libxml-1.8.6
				1340	compilation on some platforms has been fixed</li>
				1341	<li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
				1342	URIs</li>
				1343	</ul>
				1344
Daniel Veillard	e41f2b7	2000-01-30 20:00:07 +0000	[diff] [blame]	1345	<h3>1.8.6: Jan 31 2000</h3>
				1346	<ul>
				1347	<li>added a nanoFTP transport module, debugged until the new version of <a
				1348	href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
				1349	it without troubles</li>
Daniel Veillard	da07c34	2000-01-25 18:31:22 +0000	[diff] [blame]	1350	</ul>
				1351
				1352	<h3>1.8.5: Jan 21 2000</h3>
				1353	<ul>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	1354	<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]	1355	href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
				1356	XML spec)</li>
Daniel Veillard	461a66c	2000-01-18 18:01:01 +0000	[diff] [blame]	1357	<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]	1358	<li>Jody Goldberg <jgoldberg@home.com> provided another patch trying
				1359	to solve the zlib checks problems</li>
Daniel Veillard	461a66c	2000-01-18 18:01:01 +0000	[diff] [blame]	1360	<li>The current state in gnome CVS base is expected to ship as 1.8.5 with
				1361	gnumeric soon</li>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	1362	</ul>
				1363
				1364	<h3>1.8.4: Jan 13 2000</h3>
				1365	<ul>
				1366	<li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
				1367	<li>all exit() call should have been removed from libxml</li>
				1368	<li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
				1369	<li>added newDocFragment()</li>
Daniel Veillard	f84f71f	2000-01-05 19:54:23 +0000	[diff] [blame]	1370	</ul>
				1371
				1372	<h3>1.8.3: Jan 5 2000</h3>
				1373	<ul>
				1374	<li>a Push interface for the XML and HTML parsers</li>
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	1375	<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]	1376	<li>lots of bug fixes and improvement added over XMas holidays</li>
Daniel Veillard	437b87b	2000-01-03 17:30:46 +0000	[diff] [blame]	1377	<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]	1378	<li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
				1379	<li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard	437b87b	2000-01-03 17:30:46 +0000	[diff] [blame]	1380	<li>External entity loading code has been revamped, now it uses
Daniel Veillard	f84f71f	2000-01-05 19:54:23 +0000	[diff] [blame]	1381	xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard	437b87b	2000-01-03 17:30:46 +0000	[diff] [blame]	1382	<li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard	5cb5ab8	1999-12-21 15:35:29 +0000	[diff] [blame]	1383	</ul>
				1384
				1385	<h3>1.8.2: Dec 21 1999</h3>
				1386	<ul>
Daniel Veillard	b24054a	1999-12-18 15:32:46 +0000	[diff] [blame]	1387	<li>I got another problem with includes and C++, I hope this issue is fixed
				1388	for good this time</li>
Daniel Veillard	5cb5ab8	1999-12-21 15:35:29 +0000	[diff] [blame]	1389	<li>Added a few tree modification functions: xmlReplaceNode,
				1390	xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
				1391	xmlDocSetRootElement</li>
				1392	<li>Tried to improve the HTML output with help from <a
				1393	href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillard	e4e5131	1999-12-18 15:32:46 +0000	[diff] [blame]	1394	</ul>
Daniel Veillard	b24054a	1999-12-18 15:32:46 +0000	[diff] [blame]	1395
Daniel Veillard	e4e5131	1999-12-18 15:32:46 +0000	[diff] [blame]	1396	<h3>1.8.1: Dec 18 1999</h3>
				1397	<ul>
				1398	<li>various patches to avoid troubles when using libxml with C++ compilers
				1399	the "namespace" keyword and C escaping in include files</li>
				1400	<li>a problem in one of the core macros IS_CHAR was corrected</li>
				1401	<li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
				1402	and more specifically the Dia application</li>
Daniel Veillard	944b5ff	1999-12-15 19:08:24 +0000	[diff] [blame]	1403	<li>fixed a posteriori validation (validation after parsing, or by using a
				1404	Dtd not specified in the original document)</li>
Daniel Veillard	b24054a	1999-12-18 15:32:46 +0000	[diff] [blame]	1405	<li>fixed a bug in</li>
Daniel Veillard	10a2c65	1999-12-12 13:03:50 +0000	[diff] [blame]	1406	</ul>
				1407
				1408	<h3>1.8.0: Dec 12 1999</h3>
				1409	<ul>
				1410	<li>cleanup, especially memory wise</li>
				1411	<li>the parser should be more reliable, especially the HTML one, it should
				1412	not crash, whatever the input !</li>
				1413	<li>Integrated various patches, especially a speedup improvement for large
				1414	dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
				1415	configure with --with-buffers to enable them.</li>
				1416	<li>attribute normalization, oops should have been added long ago !</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1417	<li>attributes defaulted from DTDs should be available, xmlSetProp() now
				1418	does entities escaping by default.</li>
Daniel Veillard	4c3a203	1999-11-19 17:46:26 +0000	[diff] [blame]	1419	</ul>
Daniel Veillard	3500838	1999-10-25 13:15:52 +0000	[diff] [blame]	1420
				1421	<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1422	<ul>
Daniel Veillard	3500838	1999-10-25 13:15:52 +0000	[diff] [blame]	1423	<li>Lots of HTML improvement</li>
				1424	<li>Fixed some errors when saving both XML and HTML</li>
				1425	<li>More examples, the regression tests should now look clean</li>
				1426	<li>Fixed a bug with contiguous charref</li>
				1427	</ul>
				1428
				1429	<h3>1.7.3: Sep 29 1999</h3>
				1430	<ul>
				1431	<li>portability problems fixed</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1432	<li>snprintf was used unconditionally, leading to link problems on system
Daniel Veillard	3500838	1999-10-25 13:15:52 +0000	[diff] [blame]	1433	were it's not available, fixed</li>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1434	</ul>
				1435
				1436	<h3>1.7.1: Sep 24 1999</h3>
				1437	<ul>
				1438	<li>The basic type for strings manipulated by libxml has been renamed in
				1439	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]	1440	is that CHAR was conflicting with a predefined type on Windows. However
				1441	on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1442	<strong>#define </strong>.</li>
				1443	<li>Changed another error : the use of a structure field called errno, and
				1444	leading to troubles on platforms where it's a macro</li>
				1445	</ul>
				1446
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1447	<h3>1.7.0: Sep 23 1999</h3>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1448	<ul>
				1449	<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]	1450	href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1451	<li>Added an errno to report errors by another mean than a simple printf
				1452	like callback</li>
				1453	<li>Finished ID/IDREF support and checking when validation</li>
				1454	<li>Serious memory leaks fixed (there is now a <a
Daniel Veillard	9cb5ff4	2001-01-29 08:22:21 +0000	[diff] [blame]	1455	href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1456	<li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
				1457	implementation</li>
				1458	<li>Added an HTML parser front-end</li>
				1459	</ul>
				1460
				1461	<h2><a name="XML">XML</a></h2>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	1462
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	1463	<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]	1464	markup-based structured documents. Here is <a name="example">an example XML
				1465	document</a>:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	1466	<pre><?xml version="1.0"?>
				1467	<EXAMPLE prop1="gnome is great" prop2="&amp; linux too">
				1468	<head>
				1469	<title>Welcome to Gnome</title>
				1470	</head>
				1471	<chapter>
				1472	<title>The Linux adventure</title>
				1473	<p>bla bla bla ...</p>
				1474	<image href="linus.gif"/>
				1475	<p>...</p>
				1476	</chapter>
				1477	</EXAMPLE></pre>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	1478
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1479	<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]	1480	information about its encoding. Then the rest of the document is a text
				1481	format whose structure is specified by tags between brackets. <strong>Each
				1482	tag opened has to be closed</strong>. XML is pedantic about this. However, if
				1483	a tag is empty (no content), a single tag can serve as both the opening and
				1484	closing tag if it ends with <code>/></code> rather than with
				1485	<code>></code>. Note that, for example, the image tag has no content (just
				1486	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]	1487
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	1488	<p>XML can be applied successfully to a wide range of tasks, ranging from
				1489	long term structured document maintenance (where it follows the steps of
				1490	SGML) to simple data encoding mechanisms like configuration file formatting
				1491	(glade), spreadsheets (gnumeric), or even shorter lived documents such as
				1492	WebDAV where it is used to encode remote calls between a client and a
				1493	server.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	1494
Daniel Veillard	8268716	2001-01-22 15:32:01 +0000	[diff] [blame]	1495	<h2><a name="XSLT">XSLT</a></h2>
				1496
Daniel Veillard	6e6a6cc	2001-02-15 15:55:44 +0000	[diff] [blame]	1497	<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
				1498
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1499	<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
				1500	language for transforming XML documents into other XML documents (or
				1501	HTML/textual output).</p>
Daniel Veillard	8268716	2001-01-22 15:32:01 +0000	[diff] [blame]	1502
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	1503	<p>A separate library called libxslt is being developed on top of libxml2.
				1504	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]	1505
Daniel Veillard	383b147	2001-01-23 11:39:52 +0000	[diff] [blame]	1506	<p>You can check the <a
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	1507	href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
				1508	supported and the progresses on the <a
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1509	href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog"
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1510	name="Changelog">Changelog</a>.</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1511
				1512	<h2><a name="Python">Python and bindings</a></h2>
				1513
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	1514	<p>There are a number of language bindings and wrappers available for
				1515	libxml2, the list below is not exhaustive. Please contact the <a
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1516	href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a>
				1517	(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in
				1518	order to get updates to this list or to discuss the specific topic of libxml2
				1519	or libxslt wrappers or bindings:</p>
				1520	<ul>
Daniel Veillard	c14401e	2002-11-20 14:28:17 +0000	[diff] [blame]	1521	<li><a href="http://libxmlplusplus.sourceforge.net/">Libxml++</a> seems the
				1522	most up-to-date C++ bindings for libxml2, check the <a
				1523	href="http://libxmlplusplus.sourceforge.net/reference/html/hierarchy.html">documentation</a>
				1524	and the <a
				1525	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]	1526	<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]	1527	based on the gdome2 bindings</a> maintained by Tobias Peters.</li>
Daniel Veillard	9b6fd30	2002-05-13 12:06:47 +0000	[diff] [blame]	1528	<li>and a third C++ wrapper by Peter Jones <pjones@pmade.org>
				1529	<p>Website: <a
				1530	href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
				1531	</li>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1532	<li><a
				1533	href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1534	Sergeant</a> developed <a
				1535	href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1536	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]	1537	application server</a>.</li>
Daniel Veillard	2147367	2002-06-17 07:29:22 +0000	[diff] [blame]	1538	<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]	1539	earlier version of the libxml/libxslt <a
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1540	href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li>
Daniel Veillard	2147367	2002-06-17 07:29:22 +0000	[diff] [blame]	1541	<li>Gopal.V and Peter Minten develop <a
				1542	href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1543	C# libxml2 bindings.</li>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1544	<li>Petr Kozelka provides <a
				1545	href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1546	libxml2</a> with Kylix, Delphi and other Pascal compilers.</li>
Daniel Veillard	b2fb8ed	2002-04-01 09:33:12 +0000	[diff] [blame]	1547	<li>Uwe Fechner also provides <a
				1548	href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1549	implementation for Kylix2/D5/D6 from Borland.</li>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1550	<li>Wai-Sun "Squidster" Chia provides <a
				1551	href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and
				1552	libxml2 bindings are also available in Ruby through the <a
				1553	href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module
				1554	maintained by Tobias Peters.</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1555	<li>Steve Ball and contributors maintains <a
				1556	href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1557	Tcl</a>.</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1558	<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]	1559	</ul>
				1560
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	1561	<p>The distribution includes a set of Python bindings, which are guaranteed
				1562	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]	1563	interface have not yet reached the maturity of the C API.</p>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1564
Daniel Veillard	7ef0fcb	2002-12-14 10:38:55 +0000	[diff] [blame^]	1565	<p>Note to people interested in building bindings, the API is formalized as
				1566	<a href="libxml2-api.xml">an XML API description file</a> which allows to
				1567	automate a large part of the Python bindings, this includes function
				1568	descriptions, enums, structures, typedefs, etc... The Python script used
				1569	to build the bindings is python/generator.py in the source distribution.</p>
				1570
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1571	<p>To install the Python bindings there are 2 options:</p>
Daniel Veillard	0b79dfe	2002-02-23 13:02:31 +0000	[diff] [blame]	1572	<ul>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1573	<li>If you use an RPM based distribution, simply install the <a
				1574	href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python
				1575	RPM</a> (and if needed the <a
				1576	href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python
				1577	RPM</a>).</li>
				1578	<li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python
				1579	module distribution</a> corresponding to your installed version of
				1580	libxml2 and libxslt. Note that to install it you will need both libxml2
				1581	and libxslt installed and run "python setup.py build install" in the
				1582	module tree.</li>
Daniel Veillard	0b79dfe	2002-02-23 13:02:31 +0000	[diff] [blame]	1583	</ul>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1584
				1585	<p>The distribution includes a set of examples and regression tests for the
				1586	python bindings in the <code>python/tests</code> directory. Here are some
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1587	excerpts from those tests:</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1588
				1589	<h3>tst.py:</h3>
				1590
				1591	<p>This is a basic test of the file interface and DOM navigation:</p>
				1592	<pre>import libxml2
				1593
				1594	doc = libxml2.parseFile("tst.xml")
				1595	if doc.name != "tst.xml":
				1596	print "doc.name failed"
				1597	sys.exit(1)
				1598	root = doc.children
				1599	if root.name != "doc":
				1600	print "root.name failed"
				1601	sys.exit(1)
				1602	child = root.children
				1603	if child.name != "foo":
				1604	print "child.name failed"
				1605	sys.exit(1)
				1606	doc.freeDoc()</pre>
				1607
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	1608	<p>The Python module is called libxml2; parseFile is the equivalent of
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1609	xmlParseFile (most of the bindings are automatically generated, and the xml
				1610	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]	1611	binding level share the same subset of accessors:</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1612	<ul>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1613	<li><code>name</code> : returns the node name</li>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	1614	<li><code>type</code> : returns a string indicating the node type</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1615	<li><code>content</code> : returns the content of the node, it is based on
				1616	xmlNodeGetContent() and hence is recursive.</li>
				1617	<li><code>parent</code> , <code>children</code>, <code>last</code>,
				1618	<code>next</code>, <code>prev</code>, <code>doc</code>,
				1619	<code>properties</code>: pointing to the associated element in the tree,
				1620	those may return None in case no such link exists.</li>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1621	</ul>
				1622
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1623	<p>Also note the need to explicitly deallocate documents with freeDoc() .
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1624	Reference counting for libxml2 trees would need quite a lot of work to
				1625	function properly, and rather than risk memory leaks if not implemented
				1626	correctly it sounds safer to have an explicit function to free a tree. The
				1627	wrapper python objects like doc, root or child are them automatically garbage
				1628	collected.</p>
				1629
				1630	<h3>validate.py:</h3>
				1631
				1632	<p>This test check the validation interfaces and redirection of error
				1633	messages:</p>
				1634	<pre>import libxml2
				1635
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1636	#deactivate error messages from the validation
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1637	def noerr(ctx, str):
				1638	pass
				1639
				1640	libxml2.registerErrorHandler(noerr, None)
				1641
				1642	ctxt = libxml2.createFileParserCtxt("invalid.xml")
				1643	ctxt.validate(1)
				1644	ctxt.parseDocument()
				1645	doc = ctxt.doc()
				1646	valid = ctxt.isValid()
				1647	doc.freeDoc()
				1648	if valid != 0:
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1649	print "validity check failed"</pre>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1650
				1651	<p>The first thing to notice is the call to registerErrorHandler(), it
				1652	defines a new error handler global to the library. It is used to avoid seeing
				1653	the error messages when trying to validate the invalid document.</p>
				1654
				1655	<p>The main interest of that test is the creation of a parser context with
				1656	createFileParserCtxt() and how the behaviour can be changed before calling
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1657	parseDocument() . Similarly the informations resulting from the parsing phase
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1658	are also available using context methods.</p>
				1659
				1660	<p>Contexts like nodes are defined as class and the libxml2 wrappers maps the
				1661	C function interfaces in terms of objects method as much as possible. The
				1662	best to get a complete view of what methods are supported is to look at the
				1663	libxml2.py module containing all the wrappers.</p>
				1664
				1665	<h3>push.py:</h3>
				1666
				1667	<p>This test show how to activate the push parser interface:</p>
				1668	<pre>import libxml2
				1669
				1670	ctxt = libxml2.createPushParser(None, "<foo", 4, "test.xml")
				1671	ctxt.parseChunk("/>", 2, 1)
				1672	doc = ctxt.doc()
				1673
				1674	doc.freeDoc()</pre>
				1675
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1676	<p>The context is created with a special call based on the
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1677	xmlCreatePushParser() from the C library. The first argument is an optional
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1678	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]	1679	the resource in case URI-References need to be computed by the parser.</p>
				1680
				1681	<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]	1682	setting the third argument terminate to 1.</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1683
				1684	<h3>pushSAX.py:</h3>
				1685
				1686	<p>this test show the use of the event based parsing interfaces. In this case
				1687	the parser does not build a document, but provides callback information as
				1688	the parser makes progresses analyzing the data being provided:</p>
				1689	<pre>import libxml2
				1690	log = ""
				1691
				1692	class callback:
				1693	def startDocument(self):
				1694	global log
				1695	log = log + "startDocument:"
				1696
				1697	def endDocument(self):
				1698	global log
				1699	log = log + "endDocument:"
				1700
				1701	def startElement(self, tag, attrs):
				1702	global log
				1703	log = log + "startElement %s %s:" % (tag, attrs)
				1704
				1705	def endElement(self, tag):
				1706	global log
				1707	log = log + "endElement %s:" % (tag)
				1708
				1709	def characters(self, data):
				1710	global log
				1711	log = log + "characters: %s:" % (data)
				1712
				1713	def warning(self, msg):
				1714	global log
				1715	log = log + "warning: %s:" % (msg)
				1716
				1717	def error(self, msg):
				1718	global log
				1719	log = log + "error: %s:" % (msg)
				1720
				1721	def fatalError(self, msg):
				1722	global log
				1723	log = log + "fatalError: %s:" % (msg)
				1724
				1725	handler = callback()
				1726
				1727	ctxt = libxml2.createPushParser(handler, "<foo", 4, "test.xml")
				1728	chunk = " url='tst'>b"
				1729	ctxt.parseChunk(chunk, len(chunk), 0)
				1730	chunk = "ar</foo>"
				1731	ctxt.parseChunk(chunk, len(chunk), 1)
				1732
Daniel Veillard	fcbfa2d	2002-02-21 17:54:27 +0000	[diff] [blame]	1733	reference = "startDocument:startElement foo {'url': 'tst'}:" + \
				1734	"characters: bar:endElement foo:endDocument:"
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1735	if log != reference:
				1736	print "Error got: %s" % log
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1737	print "Expected: %s" % reference</pre>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1738
				1739	<p>The key object in that test is the handler, it provides a number of entry
				1740	points which can be called by the parser as it makes progresses to indicate
				1741	the information set obtained. The full set of callback is larger than what
				1742	the callback class in that specific example implements (see the SAX
				1743	definition for a complete list). The wrapper will only call those supplied by
				1744	the object when activated. The startElement receives the names of the element
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1745	and a dictionary containing the attributes carried by this element.</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1746
				1747	<p>Also note that the reference string generated from the callback shows a
				1748	single character call even though the string "bar" is passed to the parser
				1749	from 2 different call to parseChunk()</p>
				1750
				1751	<h3>xpath.py:</h3>
				1752
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1753	<p>This is a basic test of XPath wrappers support</p>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1754	<pre>import libxml2
				1755
				1756	doc = libxml2.parseFile("tst.xml")
				1757	ctxt = doc.xpathNewContext()
				1758	res = ctxt.xpathEval("//*")
				1759	if len(res) != 2:
				1760	print "xpath query: wrong node set size"
				1761	sys.exit(1)
				1762	if res[0].name != "doc" or res[1].name != "foo":
				1763	print "xpath query: wrong node set value"
				1764	sys.exit(1)
				1765	doc.freeDoc()
				1766	ctxt.xpathFreeContext()</pre>
				1767
				1768	<p>This test parses a file, then create an XPath context to evaluate XPath
				1769	expression on it. The xpathEval() method execute an XPath query and returns
				1770	the result mapped in a Python way. String and numbers are natively converted,
				1771	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]	1772	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]	1773	the result of the XPath query may point back to the document tree and hence
				1774	the document must be freed after the result of the query is used.</p>
				1775
				1776	<h3>xpathext.py:</h3>
				1777
				1778	<p>This test shows how to extend the XPath engine with functions written in
				1779	python:</p>
				1780	<pre>import libxml2
				1781
				1782	def foo(ctx, x):
				1783	return x + 1
				1784
				1785	doc = libxml2.parseFile("tst.xml")
				1786	ctxt = doc.xpathNewContext()
				1787	libxml2.registerXPathFunction(ctxt._o, "foo", None, foo)
				1788	res = ctxt.xpathEval("foo(1)")
				1789	if res != 2:
				1790	print "xpath extension failure"
				1791	doc.freeDoc()
				1792	ctxt.xpathFreeContext()</pre>
				1793
				1794	<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]	1795	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]	1796
				1797	<h3>tstxpath.py:</h3>
				1798
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1799	<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]	1800	function can access the XPath evaluation context:</p>
				1801	<pre>def foo(ctx, x):
				1802	global called
				1803
				1804	#
				1805	# test that access to the XPath evaluation contexts
				1806	#
				1807	pctxt = libxml2.xpathParserContext(_obj=ctx)
				1808	ctxt = pctxt.context()
				1809	called = ctxt.function()
				1810	return x + 1</pre>
				1811
				1812	<p>All the interfaces around the XPath parser(or rather evaluation) context
				1813	are not finalized, but it should be sufficient to do contextual work at the
				1814	evaluation point.</p>
				1815
				1816	<h3>Memory debugging:</h3>
				1817
				1818	<p>last but not least, all tests starts with the following prologue:</p>
				1819	<pre>#memory debug specific
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	1820	libxml2.debugMemory(1)</pre>
Daniel Veillard	6dbcaf8	2002-02-20 14:37:47 +0000	[diff] [blame]	1821
				1822	<p>and ends with the following epilogue:</p>
				1823	<pre>#memory debug specific
				1824	libxml2.cleanupParser()
				1825	if libxml2.debugMemory(1) == 0:
				1826	print "OK"
				1827	else:
				1828	print "Memory leak %d bytes" % (libxml2.debugMemory(1))
				1829	libxml2.dumpMemory()</pre>
				1830
				1831	<p>Those activate the memory debugging interface of libxml2 where all
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	1832	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]	1833	library state and checks that all allocated memory has been freed. If not it
				1834	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]	1835
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	1836	<h2><a name="architecture">libxml architecture</a></h2>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1837
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	1838	<p>Libxml is made of multiple components; some of them are optional, and most
				1839	of the block interfaces are public. The main components are:</p>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1840	<ul>
				1841	<li>an Input/Output layer</li>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	1842	<li>FTP and HTTP client layers (optional)</li>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1843	<li>an Internationalization layer managing the encodings support</li>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	1844	<li>a URI module</li>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1845	<li>the XML parser and its basic SAX interface</li>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	1846	<li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1847	<li>a SAX tree module to build an in-memory DOM representation</li>
				1848	<li>a tree module to manipulate the DOM representation</li>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	1849	<li>a validation module using the DOM representation (optional)</li>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1850	<li>an XPath module for global lookup in a DOM representation
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	1851	(optional)</li>
				1852	<li>a debug module (optional)</li>
Daniel Veillard	4540be4	2000-08-19 16:40:28 +0000	[diff] [blame]	1853	</ul>
				1854
				1855	<p>Graphically this gives the following:</p>
				1856
				1857	<p><img src="libxml.gif" alt="a graphical view of the various"></p>
				1858
				1859	<p></p>
				1860
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1861	<h2><a name="tree">The tree output</a></h2>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	1862
				1863	<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]	1864	returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	1865	<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard	306be99	2000-07-03 12:38:45 +0000	[diff] [blame]	1866	as the file name, the document type, and a <strong>children</strong> pointer
				1867	which is the root of the document (or more exactly the first child under the
				1868	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]	1869	chained in double-linked lists of siblings and with a children<->parent
Daniel Veillard	306be99	2000-07-03 12:38:45 +0000	[diff] [blame]	1870	relationship. An xmlNode can also carry properties (a chain of xmlAttr
				1871	structures). An attribute may have a value which is a list of TEXT or
				1872	ENTITY_REF nodes.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	1873
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	1874	<p>Here is an example (erroneous with respect to the XML spec since there
				1875	should be only one ELEMENT under the root):</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	1876
				1877	<p><img src="structure.gif" alt=" structure.gif "></p>
				1878
				1879	<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]	1880	called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	1881	prints them back as parsed. This is useful for detecting errors both in XML
				1882	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]	1883	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]	1884	result with the <a href="#example">example</a> given before:</p>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	1885	<pre>DOCUMENT
				1886	version=1.0
				1887	standalone=true
				1888	ELEMENT EXAMPLE
				1889	ATTRIBUTE prop1
				1890	TEXT
				1891	content=gnome is great
				1892	ATTRIBUTE prop2
				1893	ENTITY_REF
				1894	TEXT
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	1895	content= linux too
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	1896	ELEMENT head
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	1897	ELEMENT title
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	1898	TEXT
				1899	content=Welcome to Gnome
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	1900	ELEMENT chapter
				1901	ELEMENT title
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	1902	TEXT
				1903	content=The Linux adventure
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	1904	ELEMENT p
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	1905	TEXT
				1906	content=bla bla bla ...
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	1907	ELEMENT image
				1908	ATTRIBUTE href
				1909	TEXT
				1910	content=linus.gif
				1911	ELEMENT p
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	1912	TEXT
				1913	content=...</pre>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	1914
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	1915	<p>This should be useful for learning the internal representation model.</p>
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	1916
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	1917	<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	1918
Daniel Veillard	402e8c8	2000-02-29 22:57:47 +0000	[diff] [blame]	1919	<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]	1920	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]	1921	loaded using libxml), it's better to use the SAX interface of libxml. SAX is
				1922	a <strong>callback-based interface</strong> to the parser. Before parsing,
				1923	the application layer registers a customized set of callbacks which are
				1924	called by the library as it progresses through the XML input.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	1925
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	1926	<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]	1927	libxml, see the <a
				1928	href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
				1929	documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	1930	Henstridge</a>.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	1931
				1932	<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
				1933	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]	1934	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]	1935	distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	1936	testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	1937	<pre>SAX.setDocumentLocator()
				1938	SAX.startDocument()
				1939	SAX.getEntity(amp)
				1940	SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp; linux too')
				1941	SAX.characters( , 3)
				1942	SAX.startElement(head)
				1943	SAX.characters( , 4)
				1944	SAX.startElement(title)
				1945	SAX.characters(Welcome to Gnome, 16)
				1946	SAX.endElement(title)
				1947	SAX.characters( , 3)
				1948	SAX.endElement(head)
				1949	SAX.characters( , 3)
				1950	SAX.startElement(chapter)
				1951	SAX.characters( , 4)
				1952	SAX.startElement(title)
				1953	SAX.characters(The Linux adventure, 19)
				1954	SAX.endElement(title)
				1955	SAX.characters( , 4)
				1956	SAX.startElement(p)
				1957	SAX.characters(bla bla bla ..., 15)
				1958	SAX.endElement(p)
				1959	SAX.characters( , 4)
				1960	SAX.startElement(image, href='linus.gif')
				1961	SAX.endElement(image)
				1962	SAX.characters( , 4)
				1963	SAX.startElement(p)
				1964	SAX.characters(..., 3)
				1965	SAX.endElement(p)
				1966	SAX.characters( , 3)
				1967	SAX.endElement(chapter)
				1968	SAX.characters( , 1)
				1969	SAX.endElement(EXAMPLE)
				1970	SAX.endDocument()</pre>
				1971
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	1972	<p>Most of the other interfaces of libxml are based on the DOM tree-building
				1973	facility, so nearly everything up to the end of this document presupposes the
				1974	use of the standard DOM tree build. Note that the DOM tree itself is built by
				1975	a set of registered default callbacks, without internal specific
				1976	interface.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	1977
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	1978	<h2><a name="Validation">Validation & DTDs</a></h2>
				1979
				1980	<p>Table of Content:</p>
				1981	<ol>
				1982	<li><a href="#General5">General overview</a></li>
				1983	<li><a href="#definition">The definition</a></li>
				1984	<li><a href="#Simple">Simple rules</a>
				1985	<ol>
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	1986	<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]	1987	<li><a href="#Declaring">Declaring elements</a></li>
				1988	<li><a href="#Declaring1">Declaring attributes</a></li>
				1989	</ol>
				1990	</li>
				1991	<li><a href="#Some">Some examples</a></li>
				1992	<li><a href="#validate">How to validate</a></li>
				1993	<li><a href="#Other">Other resources</a></li>
				1994	</ol>
				1995
				1996	<h3><a name="General5">General overview</a></h3>
				1997
				1998	<p>Well what is validation and what is a DTD ?</p>
				1999
				2000	<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]	2001	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]	2002	specification, and allows one to describe and verify that a given document
				2003	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]	2004
				2005	<p>Validation is the process of checking a document against a DTD (more
				2006	generally against a set of construction rules).</p>
				2007
				2008	<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]	2009	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]	2010	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]	2011	(by defining the allowed content of an element; either text, a regular
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2012	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]	2013	and children). The DTD also defines the valid attributes for all elements and
				2014	the types of those attributes.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2015
				2016	<h3><a name="definition1">The definition</a></h3>
				2017
				2018	<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
				2019	href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
				2020	Rev1</a>):</p>
				2021	<ul>
				2022	<li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
				2023	elements</a></li>
				2024	<li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
				2025	attributes</a></li>
				2026	</ul>
				2027
				2028	<p>(unfortunately) all this is inherited from the SGML world, the syntax is
				2029	ancient...</p>
				2030
				2031	<h3><a name="Simple1">Simple rules</a></h3>
				2032
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	2033	<p>Writing DTDs can be done in many ways. The rules to build them if you need
				2034	something permanent or something which can evolve over time can be radically
				2035	different. Really complex DTDs like DocBook ones are flexible but quite
				2036	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]	2037	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]	2038	usable for complex DTD design.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2039
				2040	<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
				2041
				2042	<p>Assuming the top element of the document is <code>spec</code> and the dtd
				2043	is placed in the file <code>mydtd</code> in the subdirectory
				2044	<code>dtds</code> of the directory from where the document were loaded:</p>
				2045
				2046	<p><code><!DOCTYPE spec SYSTEM "dtds/mydtd"></code></p>
				2047
				2048	<p>Notes:</p>
				2049	<ul>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2050	<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]	2051	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]	2052	full URL string indicating the location of your DTD on the Web. This is a
				2053	really good thing to do if you want others to validate your document.</li>
				2054	<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]	2055	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]	2056	without having to locate it on the web.</li>
				2057	<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]	2058	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]	2059	told to the parser/validator as the first element of the
				2060	<code>DOCTYPE</code> declaration.</li>
				2061	</ul>
				2062
				2063	<h4><a name="Declaring2">Declaring elements</a>:</h4>
				2064
				2065	<p>The following declares an element <code>spec</code>:</p>
				2066
				2067	<p><code><!ELEMENT spec (front, body, back?)></code></p>
				2068
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2069	<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]	2070	one <code>body</code> and one optional <code>back</code> children elements in
				2071	this order. The declaration of one element of the structure and its content
				2072	are done in a single declaration. Similarly the following declares
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2073	<code>div1</code> elements:</p>
				2074
Daniel Veillard	5173727	2002-01-23 23:10:38 +0000	[diff] [blame]	2075	<p><code><!ELEMENT div1 (head, (p \| list \| note)*, div2?)></code></p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2076
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2077	<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]	2078	<code>p</code>, <code>list</code>s and <code>note</code>s and then an
				2079	optional <code>div2</code>. And last but not least an element can contain
				2080	text:</p>
				2081
				2082	<p><code><!ELEMENT b (#PCDATA)></code></p>
				2083
				2084	<p><code>b</code> contains text or being of mixed content (text and elements
				2085	in no particular order):</p>
				2086
				2087	<p><code><!ELEMENT p (#PCDATA\|a\|ul\|b\|i\|em)*></code></p>
				2088
				2089	<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
				2090	<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
				2091	order.</p>
				2092
				2093	<h4><a name="Declaring1">Declaring attributes</a>:</h4>
				2094
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2095	<p>Again the attributes declaration includes their content definition:</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2096
				2097	<p><code><!ATTLIST termdef name CDATA #IMPLIED></code></p>
				2098
				2099	<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]	2100	attribute containing text (<code>CDATA</code>) and which is optional
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2101	(<code>#IMPLIED</code>). The attribute value can also be defined within a
				2102	set:</p>
				2103
				2104	<p><code><!ATTLIST list type (bullets\|ordered\|glossary)
				2105	"ordered"></code></p>
				2106
				2107	<p>means <code>list</code> element have a <code>type</code> attribute with 3
				2108	allowed values "bullets", "ordered" or "glossary" and which default to
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2109	"ordered" if the attribute is not explicitly specified.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2110
				2111	<p>The content type of an attribute can be text (<code>CDATA</code>),
				2112	anchor/reference/references
				2113	(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
				2114	(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
				2115	(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
				2116	<code>chapter</code> element can have an optional <code>id</code> attribute
				2117	of type <code>ID</code>, usable for reference from attribute of type
				2118	IDREF:</p>
				2119
				2120	<p><code><!ATTLIST chapter id ID #IMPLIED></code></p>
				2121
				2122	<p>The last value of an attribute definition can be <code>#REQUIRED
				2123	</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
				2124	meaning that it is optional, or the default value (possibly prefixed by
				2125	<code>#FIXED</code> if it is the only allowed).</p>
				2126
				2127	<p>Notes:</p>
				2128	<ul>
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2129	<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]	2130	single expression, but it is just a convention adopted by a lot of DTD
				2131	writers:
				2132	<pre><!ATTLIST termdef
				2133	id ID #REQUIRED
				2134	name CDATA #IMPLIED></pre>
				2135	<p>The previous construct defines both <code>id</code> and
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2136	<code>name</code> attributes for the element <code>termdef</code>.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2137	</li>
				2138	</ul>
				2139
				2140	<h3><a name="Some1">Some examples</a></h3>
				2141
				2142	<p>The directory <code>test/valid/dtds/</code> in the libxml distribution
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	2143	contains some complex DTD examples. The example in the file
				2144	<code>test/valid/dia.xml</code> shows an XML file where the simple DTD is
				2145	directly included within the document.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2146
				2147	<h3><a name="validate1">How to validate</a></h3>
				2148
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2149	<p>The simplest way is to use the xmllint program included with libxml. The
				2150	<code>--valid</code> option turns-on validation of the files given as input.
				2151	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]	2152	1.0 specification:</p>
				2153
				2154	<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
				2155
Daniel Veillard	0b28e88	2002-07-24 23:47:05 +0000	[diff] [blame]	2156	<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]	2157
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	2158	<p>The <code>--dtdvalid dtd</code> allows validation of the document(s)
				2159	against a given DTD.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2160
				2161	<p>Libxml exports an API to handle DTDs and validation, check the <a
				2162	href="http://xmlsoft.org/html/libxml-valid.html">associated
				2163	description</a>.</p>
				2164
				2165	<h3><a name="Other1">Other resources</a></h3>
				2166
				2167	<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
				2168	will just list one for now, others pointers welcome:</p>
				2169	<ul>
				2170	<li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
				2171	</ul>
				2172
				2173	<p>I suggest looking at the examples found under test/valid/dtd and any of
				2174	the large number of books available on XML. The dia example in test/valid
				2175	should be both simple and complete enough to allow you to build your own.</p>
				2176
				2177	<p></p>
				2178
				2179	<h2><a name="Memory">Memory Management</a></h2>
				2180
				2181	<p>Table of Content:</p>
				2182	<ol>
				2183	<li><a href="#General3">General overview</a></li>
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	2184	<li><a href="#setting">Setting libxml set of memory routines</a></li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2185	<li><a href="#cleanup">Cleaning up after parsing</a></li>
				2186	<li><a href="#Debugging">Debugging routines</a></li>
				2187	<li><a href="#General4">General memory requirements</a></li>
				2188	</ol>
				2189
				2190	<h3><a name="General3">General overview</a></h3>
				2191
				2192	<p>The module <code><a
				2193	href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
				2194	provides the interfaces to the libxml memory system:</p>
				2195	<ul>
				2196	<li>libxml does not use the libc memory allocator directly but xmlFree(),
				2197	xmlMalloc() and xmlRealloc()</li>
				2198	<li>those routines can be reallocated to a specific set of routine, by
				2199	default the libc ones i.e. free(), malloc() and realloc()</li>
				2200	<li>the xmlmemory.c module includes a set of debugging routine</li>
				2201	</ul>
				2202
				2203	<h3><a name="setting">Setting libxml set of memory routines</a></h3>
				2204
				2205	<p>It is sometimes useful to not use the default memory allocator, either for
				2206	debugging, analysis or to implement a specific behaviour on memory management
				2207	(like on embedded systems). Two function calls are available to do so:</p>
				2208	<ul>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2209	<li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet
				2210	()</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]	2211	<li><a
				2212	href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2213	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]	2214	</ul>
				2215
				2216	<p>Of course a call to xmlMemSetup() should probably be done before calling
				2217	any other libxml routines (unless you are sure your allocations routines are
				2218	compatibles).</p>
				2219
				2220	<h3><a name="cleanup">Cleaning up after parsing</a></h3>
				2221
				2222	<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]	2223	allocation before the parser is fully functional (some encoding structures
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2224	for example). This also mean that once parsing is finished there is a tiny
				2225	amount of memory (a few hundred bytes) which can be recollected if you don't
				2226	reuse the parser immediately:</p>
				2227	<ul>
				2228	<li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2229	()</a> is a centralized routine to free the parsing states. Note that it
				2230	won't deallocate any produced tree if any (use the xmlFreeDoc() and
				2231	related routines for this).</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2232	<li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2233	()</a> is the dual routine allowing to preallocate the parsing state
				2234	which can be useful for example to avoid initialization reentrancy
				2235	problems when using libxml in multithreaded applications</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2236	</ul>
				2237
				2238	<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
				2239	at the next invocation of parser routines, but be careful of the consequences
				2240	in multithreaded applications.</p>
				2241
				2242	<h3><a name="Debugging">Debugging routines</a></h3>
				2243
				2244	<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]	2245	a set of memory allocation debugging routines keeping track of all allocated
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2246	blocks and the location in the code where the routine was called. A couple of
				2247	other debugging routines allow to dump the memory allocated infos to a file
				2248	or call a specific routine when a given block number is allocated:</p>
				2249	<ul>
				2250	<li><a
				2251	href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2252	<a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2253	href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
				2254	and <a
				2255	href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
				2256	are the memory debugging replacement allocation routines</li>
				2257	<li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	2258	()</a> dumps all the informations about the allocated memory block lefts
				2259	in the <code>.memdump</code> file</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2260	</ul>
				2261
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2262	<p>When developing libxml memory debug is enabled, the tests programs call
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2263	xmlMemoryDump () and the "make test" regression tests will check for any
				2264	memory leak during the full regression test sequence, this helps a lot
				2265	ensuring that libxml does not leak memory and bullet proof memory
				2266	allocations use (some libc implementations are known to be far too permissive
				2267	resulting in major portability problems!).</p>
				2268
				2269	<p>If the .memdump reports a leak, it displays the allocation function and
				2270	also tries to give some informations about the content and structure of the
				2271	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]	2272	but not always. Assuming the allocation problem is reproducible, it is
				2273	possible to find more easily:</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2274	<ol>
				2275	<li>write down the block number xxxx not allocated</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2276	<li>export the environment variable XML_MEM_BREAKPOINT=xxxx , the easiest
Daniel Veillard	7579482	2002-04-11 16:24:32 +0000	[diff] [blame]	2277	when using GDB is to simply give the command
				2278	<p><code>set environment XML_MEM_BREAKPOINT xxxx</code></p>
				2279	<p>before running the program.</p>
				2280	</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2281	<li>run the program under a debugger and set a breakpoint on
				2282	xmlMallocBreakpoint() a specific function called when this precise block
				2283	is allocated</li>
				2284	<li>when the breakpoint is reached you can then do a fine analysis of the
				2285	allocation an step to see the condition resulting in the missing
				2286	deallocation.</li>
				2287	</ol>
				2288
				2289	<p>I used to use a commercial tool to debug libxml memory problems but after
				2290	noticing that it was not detecting memory leaks that simple mechanism was
Daniel Veillard	7579482	2002-04-11 16:24:32 +0000	[diff] [blame]	2291	used and proved extremely efficient until now. Lately I have also used <a
				2292	href="http://developer.kde.org/~sewardj/">valgrind</a> with quite some
				2293	success, it is tied to the i386 architecture since it works by emulating the
				2294	processor and instruction set, it is slow but extremely efficient, i.e. it
				2295	spot memory usage errors in a very precise way.</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2296
				2297	<h3><a name="General4">General memory requirements</a></h3>
				2298
				2299	<p>How much libxml memory require ? It's hard to tell in average it depends
				2300	of a number of things:</p>
				2301	<ul>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2302	<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]	2303	information maintained about the stacks of names and entities locations.
				2304	The I/O and encoding handlers will probably account for a few KBytes.
				2305	This is true for both the XML and HTML parser (though the HTML parser
				2306	need more state).</li>
				2307	<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]	2308	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]	2309	textual document the internal memory requirement is about 4 times the
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2310	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]	2311	recommendation is a bit more of 150KBytes and takes 650KBytes of main
				2312	memory when parsed). Validation will add a amount of memory required for
				2313	maintaining the external Dtd state which should be linear with the
				2314	complexity of the content model defined by the Dtd</li>
				2315	<li>If you don't care about the advanced features of libxml like
				2316	validation, DOM, XPath or XPointer, but really need to work fixed memory
				2317	requirements, then the SAX interface should be used.</li>
				2318	</ul>
				2319
				2320	<p></p>
				2321
				2322	<h2><a name="Encodings">Encodings support</a></h2>
				2323
				2324	<p>Table of Content:</p>
				2325	<ol>
				2326	<li><a href="encoding.html#What">What does internationalization support
				2327	mean ?</a></li>
				2328	<li><a href="encoding.html#internal">The internal encoding, how and
				2329	why</a></li>
				2330	<li><a href="encoding.html#implemente">How is it implemented ?</a></li>
				2331	<li><a href="encoding.html#Default">Default supported encodings</a></li>
				2332	<li><a href="encoding.html#extend">How to extend the existing
				2333	support</a></li>
				2334	</ol>
				2335
				2336	<h3><a name="What">What does internationalization support mean ?</a></h3>
				2337
				2338	<p>XML was designed from the start to allow the support of any character set
				2339	by using Unicode. Any conformant XML parser has to support the UTF-8 and
				2340	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]	2341	is a variable length encoding whose greatest points are to reuse the same
				2342	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]	2343	more complex to handle in practice. UTF-16 use 2 bytes per characters (and
				2344	sometimes combines two pairs), it makes implementation easier, but looks a
				2345	bit overkill for Western languages encoding. Moreover the XML specification
				2346	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]	2347	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]	2348	document encoded in ISO-8859 1 and using accentuated letter that we French
				2349	likes for both markup and content:</p>
				2350	<pre><?xml version="1.0" encoding="ISO-8859-1"?>
				2351	<très>là</très></pre>
				2352
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2353	<p>Having internationalization support in libxml means the following:</p>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2354	<ul>
				2355	<li>the document is properly parsed</li>
				2356	<li>informations about it's encoding are saved</li>
				2357	<li>it can be modified</li>
				2358	<li>it can be saved in its original encoding</li>
				2359	<li>it can also be saved in another encoding supported by libxml (for
				2360	example straight UTF8 or even an ASCII form)</li>
				2361	</ul>
				2362
				2363	<p>Another very important point is that the whole libxml API, with the
				2364	exception of a few routines to read with a specific encoding or save to a
				2365	specific encoding, is completely agnostic about the original encoding of the
				2366	document.</p>
				2367
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2368	<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]	2369	the same rules too, the following document will be (as of 2.2.2) handled in
				2370	an internationalized fashion by libxml too:</p>
				2371	<pre><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
				2372	"http://www.w3.org/TR/REC-html40/loose.dtd">
				2373	<html lang="fr">
				2374	<head>
				2375	<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1">
				2376	</head>
				2377	<body>
				2378	<p>W3C crée des standards pour le Web.</body>
				2379	</html></pre>
				2380
				2381	<h3><a name="internal">The internal encoding, how and why</a></h3>
				2382
				2383	<p>One of the core decision was to force all documents to be converted to a
				2384	default internal encoding, and that encoding to be UTF-8, here are the
				2385	rationale for those choices:</p>
				2386	<ul>
				2387	<li>keeping the native encoding in the internal form would force the libxml
				2388	users (or the code associated) to be fully aware of the encoding of the
				2389	original document, for examples when adding a text node to a document,
				2390	the content would have to be provided in the document encoding, i.e. the
				2391	client code would have to check it before hand, make sure it's conformant
				2392	to the encoding, etc ... Very hard in practice, though in some specific
				2393	cases this may make sense.</li>
				2394	<li>the second decision was which encoding. From the XML spec only UTF8 and
				2395	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]	2396	is mandatory support. UCS-4 (32 bits fixed size encoding) could be
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2397	considered an intelligent choice too since it's a direct Unicode mapping
				2398	support. I selected UTF-8 on the basis of efficiency and compatibility
				2399	with surrounding software:
				2400	<ul>
				2401	<li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
				2402	more costly to import and export CPU wise) is also far more compact
				2403	than UTF-16 (and UCS-4) for a majority of the documents I see it used
				2404	for right now (RPM RDF catalogs, advogato data, various configuration
				2405	file formats, etc.) and the key point for today's computer
				2406	architecture is efficient uses of caches. If one nearly double the
				2407	memory requirement to store the same amount of data, this will trash
				2408	caches (main memory/external caches/internal caches) and my take is
				2409	that this harms the system far more than the CPU requirements needed
				2410	for the conversion to UTF-8</li>
				2411	<li>Most of libxml version 1 users were using it with straight ASCII
				2412	most of the time, doing the conversion with an internal encoding
				2413	requiring all their code to be rewritten was a serious show-stopper
				2414	for using UTF-16 or UCS-4.</li>
				2415	<li>UTF-8 is being used as the de-facto internal encoding standard for
				2416	related code like the <a href="http://www.pango.org/">pango</a>
				2417	upcoming Gnome text widget, and a lot of Unix code (yep another place
				2418	where Unix programmer base takes a different approach from Microsoft
				2419	- they are using UTF-16)</li>
				2420	</ul>
				2421	</li>
				2422	</ul>
				2423
				2424	<p>What does this mean in practice for the libxml user:</p>
				2425	<ul>
				2426	<li>xmlChar, the libxml data type is a byte, those bytes must be assembled
				2427	as UTF-8 valid strings. The proper way to terminate an xmlChar * string
				2428	is simply to append 0 byte, as usual.</li>
				2429	<li>One just need to make sure that when using chars outside the ASCII set,
				2430	the values has been properly converted to UTF-8</li>
				2431	</ul>
				2432
				2433	<h3><a name="implemente">How is it implemented ?</a></h3>
				2434
				2435	<p>Let's describe how all this works within libxml, basically the I18N
				2436	(internationalization) support get triggered only during I/O operation, i.e.
				2437	when reading a document or saving one. Let's look first at the reading
				2438	sequence:</p>
				2439	<ol>
				2440	<li>when a document is processed, we usually don't know the encoding, a
				2441	simple heuristic allows to detect UTF-18 and UCS-4 from whose where the
				2442	ASCII range (0-0x7F) maps with ASCII</li>
				2443	<li>the xml declaration if available is parsed, including the encoding
				2444	declaration. At that point, if the autodetected encoding is different
				2445	from the one declared a call to xmlSwitchEncoding() is issued.</li>
				2446	<li>If there is no encoding declaration, then the input has to be in either
				2447	UTF-8 or UTF-16, if it is not then at some point when processing the
				2448	input, the converter/checker of UTF-8 form will raise an encoding error.
				2449	You may end-up with a garbled document, or no document at all ! Example:
				2450	<pre>~/XML -> ./xmllint err.xml
				2451	err.xml:1: error: Input is not proper UTF-8, indicate encoding !
				2452	<très>là</très>
				2453	^
				2454	err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
				2455	<très>là</très>
				2456	^</pre>
				2457	</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2458	<li>xmlSwitchEncoding() does an encoding name lookup, canonicalize it, and
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2459	then search the default registered encoding converters for that encoding.
				2460	If it's not within the default set and iconv() support has been compiled
				2461	it, it will ask iconv for such an encoder. If this fails then the parser
				2462	will report an error and stops processing:
				2463	<pre>~/XML -> ./xmllint err2.xml
				2464	err2.xml:1: error: Unsupported encoding UnsupportedEnc
				2465	<?xml version="1.0" encoding="UnsupportedEnc"?>
				2466	^</pre>
				2467	</li>
Daniel Veillard	46c5c1d	2002-05-20 07:15:54 +0000	[diff] [blame]	2468	<li>From that point the encoder processes progressively the input (it is
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2469	plugged as a front-end to the I/O module) for that entity. It captures
				2470	and convert on-the-fly the document to be parsed to UTF-8. The parser
				2471	itself just does UTF-8 checking of this input and process it
				2472	transparently. The only difference is that the encoding information has
				2473	been added to the parsing context (more precisely to the input
				2474	corresponding to this entity).</li>
				2475	<li>The result (when using DOM) is an internal form completely in UTF-8
				2476	with just an encoding information on the document node.</li>
				2477	</ol>
				2478
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2479	<p>Ok then what happens when saving the document (assuming you
				2480	collected/built an xmlDoc DOM like structure) ? It depends on the function
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2481	called, xmlSaveFile() will just try to save in the original encoding, while
				2482	xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
				2483	encoding:</p>
				2484	<ol>
				2485	<li>if no encoding is given, libxml will look for an encoding value
				2486	associated to the document and if it exists will try to save to that
				2487	encoding,
				2488	<p>otherwise everything is written in the internal form, i.e. UTF-8</p>
				2489	</li>
				2490	<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]	2491	document, libxml will again canonicalize the encoding name, lookup for a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2492	converter in the registered set or through iconv. If not found the
				2493	function will return an error code</li>
				2494	<li>the converter is placed before the I/O buffer layer, as another kind of
				2495	buffer, then libxml will simply push the UTF-8 serialization to through
				2496	that buffer, which will then progressively be converted and pushed onto
				2497	the I/O layer.</li>
				2498	<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]	2499	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]	2500	ISO-8859-1 converter won't work. Since the encoders are progressive they
				2501	will just report the error and the number of bytes converted, at that
				2502	point libxml will decode the offending character, remove it from the
				2503	buffer and replace it with the associated charRef encoding &#123; and
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2504	resume the conversion. This guarantees that any document will be saved
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2505	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]	2506	a problem in the current version, in practice avoid using non-ascii
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2507	characters for tags or attributes names @@). A special "ascii" encoding
				2508	name is used to save documents to a pure ascii form can be used when
				2509	portability is really crucial</li>
				2510	</ol>
				2511
				2512	<p>Here is a few examples based on the same test document:</p>
				2513	<pre>~/XML -> ./xmllint isolat1
				2514	<?xml version="1.0" encoding="ISO-8859-1"?>
				2515	<très>là</très>
				2516	~/XML -> ./xmllint --encode UTF-8 isolat1
				2517	<?xml version="1.0" encoding="UTF-8"?>
				2518	<trÃ¨s>lÃ </trÃ¨s>
				2519	~/XML -> </pre>
				2520
				2521	<p>The same processing is applied (and reuse most of the code) for HTML I18N
				2522	processing. Looking up and modifying the content encoding is a bit more
				2523	difficult since it is located in a <meta> tag under the <head>,
				2524	so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
				2525	been provided. The parser also attempts to switch encoding on the fly when
				2526	detecting such a tag on input. Except for that the processing is the same
				2527	(and again reuses the same code).</p>
				2528
				2529	<h3><a name="Default">Default supported encodings</a></h3>
				2530
				2531	<p>libxml has a set of default converters for the following encodings
				2532	(located in encoding.c):</p>
				2533	<ol>
				2534	<li>UTF-8 is supported by default (null handlers)</li>
				2535	<li>UTF-16, both little and big endian</li>
				2536	<li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
				2537	<li>ASCII, useful mostly for saving</li>
				2538	<li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
				2539	predefined entities like &copy; for the Copyright sign.</li>
				2540	</ol>
				2541
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	2542	<p>More over when compiled on an Unix platform with iconv support the full
				2543	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]	2544	linux machine with glibc-2.1 the list of supported encodings and aliases fill
				2545	3 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
				2546	various Japanese ones.</p>
				2547
				2548	<h4>Encoding aliases</h4>
				2549
				2550	<p>From 2.2.3, libxml has support to register encoding names aliases. The
				2551	goal is to be able to parse document whose encoding is supported but where
				2552	the name differs (for example from the default set of names accepted by
				2553	iconv). The following functions allow to register and handle new aliases for
				2554	existing encodings. Once registered libxml will automatically lookup the
				2555	aliases when handling a document:</p>
				2556	<ul>
				2557	<li>int xmlAddEncodingAlias(const char name, const char alias);</li>
				2558	<li>int xmlDelEncodingAlias(const char *alias);</li>
				2559	<li>const char * xmlGetEncodingAlias(const char *alias);</li>
				2560	<li>void xmlCleanupEncodingAliases(void);</li>
				2561	</ul>
				2562
				2563	<h3><a name="extend">How to extend the existing support</a></h3>
				2564
				2565	<p>Well adding support for new encoding, or overriding one of the encoders
				2566	(assuming it is buggy) should not be hard, just write an input and output
				2567	conversion routines to/from UTF-8, and register them using
				2568	xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
				2569	called automatically if the parser(s) encounter such an encoding name
				2570	(register it uppercase, this will help). The description of the encoders,
				2571	their arguments and expected return values are described in the encoding.h
				2572	header.</p>
				2573
				2574	<p>A quick note on the topic of subverting the parser to use a different
				2575	internal encoding than UTF-8, in some case people will absolutely want to
				2576	keep the internal encoding different, I think it's still possible (but the
				2577	encoding must be compliant with ASCII on the same subrange) though I didn't
				2578	tried it. The key is to override the default conversion routines (by
				2579	registering null encoders/decoders for your charsets), and bypass the UTF-8
				2580	checking of the parser by setting the parser context charset
				2581	(ctxt->charset) to something different than XML_CHAR_ENCODING_UTF8, but
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2582	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]	2583	saving back.</p>
				2584
				2585	<p>Basically proper I18N support is important, this requires at least
				2586	libxml-2.0.0, but a lot of features and corrections are really available only
				2587	starting 2.2.</p>
				2588
				2589	<h2><a name="IO">I/O Interfaces</a></h2>
				2590
				2591	<p>Table of Content:</p>
				2592	<ol>
				2593	<li><a href="#General1">General overview</a></li>
				2594	<li><a href="#basic">The basic buffer type</a></li>
				2595	<li><a href="#Input">Input I/O handlers</a></li>
				2596	<li><a href="#Output">Output I/O handlers</a></li>
				2597	<li><a href="#entities">The entities loader</a></li>
				2598	<li><a href="#Example2">Example of customized I/O</a></li>
				2599	</ol>
				2600
				2601	<h3><a name="General1">General overview</a></h3>
				2602
				2603	<p>The module <code><a
				2604	href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
				2605	the interfaces to the libxml I/O system. This consists of 4 main parts:</p>
				2606	<ul>
				2607	<li>Entities loader, this is a routine which tries to fetch the entities
				2608	(files) based on their PUBLIC and SYSTEM identifiers. The default loader
				2609	don't look at the public identifier since libxml do not maintain a
				2610	catalog. You can redefine you own entity loader by using
				2611	<code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard	9c46682	2001-10-25 12:03:39 +0000	[diff] [blame]	2612	<code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
				2613	example</a>.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2614	<li>Input I/O buffers which are a commodity structure used by the parser(s)
				2615	input layer to handle fetching the informations to feed the parser. This
				2616	provides buffering and is also a placeholder where the encoding
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	2617	converters to UTF8 are piggy-backed.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2618	<li>Output I/O buffers are similar to the Input ones and fulfill similar
				2619	task but when generating a serialization from a tree.</li>
				2620	<li>A mechanism to register sets of I/O callbacks and associate them with
				2621	specific naming schemes like the protocol part of the URIs.
				2622	<p>This affect the default I/O operations and allows to use specific I/O
				2623	handlers for certain names.</p>
				2624	</li>
				2625	</ul>
				2626
				2627	<p>The general mechanism used when loading http://rpmfind.net/xml.html for
				2628	example in the HTML parser is the following:</p>
				2629	<ol>
				2630	<li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
				2631	the parsing context and the URI string.</li>
				2632	<li>the URI string is checked against the existing registered handlers
				2633	using their match() callback function, if the HTTP module was compiled
				2634	in, it is registered and its match() function will succeeds</li>
				2635	<li>the open() function of the handler is called and if successful will
				2636	return an I/O Input buffer</li>
				2637	<li>the parser will the start reading from this buffer and progressively
				2638	fetch information from the resource, calling the read() function of the
				2639	handler until the resource is exhausted</li>
				2640	<li>if an encoding change is detected it will be installed on the input
				2641	buffer, providing buffering and efficient use of the conversion
				2642	routines</li>
				2643	<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]	2644	called once and the Input buffer and associated resources are
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2645	deallocated.</li>
				2646	</ol>
				2647
				2648	<p>The user defined callbacks are checked first to allow overriding of the
				2649	default libxml I/O routines.</p>
				2650
				2651	<h3><a name="basic">The basic buffer type</a></h3>
				2652
				2653	<p>All the buffer manipulation handling is done using the
				2654	<code>xmlBuffer</code> type define in <code><a
				2655	href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
				2656	resizable memory buffer. The buffer allocation strategy can be selected to be
				2657	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]	2658	trade-off). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2659	<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
				2660	system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
				2661	of functions allows to manipulate buffers with names starting with the
				2662	<code>xmlBuffer...</code> prefix.</p>
				2663
				2664	<h3><a name="Input">Input I/O handlers</a></h3>
				2665
				2666	<p>An Input I/O handler is a simple structure
				2667	<code>xmlParserInputBuffer</code> containing a context associated to the
				2668	resource (file descriptor, or pointer to a protocol handler), the read() and
				2669	close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
				2670	encoding handler are also present to support charset conversion when
				2671	needed.</p>
				2672
				2673	<h3><a name="Output">Output I/O handlers</a></h3>
				2674
				2675	<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
				2676	Input one except the callbacks are write() and close().</p>
				2677
				2678	<h3><a name="entities">The entities loader</a></h3>
				2679
				2680	<p>The entity loader resolves requests for new entities and create inputs for
				2681	the parser. Creating an input from a filename or an URI string is done
				2682	through the xmlNewInputFromFile() routine. The default entity loader do not
				2683	handle the PUBLIC identifier associated with an entity (if any). So it just
				2684	calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
				2685	XML).</p>
				2686
				2687	<p>If you want to hook up a catalog mechanism then you simply need to
				2688	override the default entity loader, here is an example:</p>
				2689	<pre>#include <libxml/xmlIO.h>
				2690
				2691	xmlExternalEntityLoader defaultLoader = NULL;
				2692
				2693	xmlParserInputPtr
				2694	xmlMyExternalEntityLoader(const char URL, const char ID,
				2695	xmlParserCtxtPtr ctxt) {
				2696	xmlParserInputPtr ret;
				2697	const char *fileID = NULL;
				2698	/* lookup for the fileID depending on ID */
				2699
				2700	ret = xmlNewInputFromFile(ctxt, fileID);
				2701	if (ret != NULL)
				2702	return(ret);
				2703	if (defaultLoader != NULL)
				2704	ret = defaultLoader(URL, ID, ctxt);
				2705	return(ret);
				2706	}
				2707
				2708	int main(..) {
				2709	...
				2710
				2711	/*
				2712	* Install our own entity loader
				2713	*/
				2714	defaultLoader = xmlGetExternalEntityLoader();
				2715	xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
				2716
				2717	...
				2718	}</pre>
				2719
				2720	<h3><a name="Example2">Example of customized I/O</a></h3>
				2721
				2722	<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
				2723	real use case</a>, xmlDocDump() closes the FILE * passed by the application
				2724	and this was a problem. The <a
				2725	href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
				2726	new output handler with the closing call deactivated:</p>
				2727	<ol>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	2728	<li>First define a new I/O output allocator where the output don't close
				2729	the file:
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2730	<pre>xmlOutputBufferPtr
				2731	xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
				2732	xmlOutputBufferPtr ret;
				2733
				2734	if (xmlOutputCallbackInitialized == 0)
				2735	xmlRegisterDefaultOutputCallbacks();
				2736
				2737	if (file == NULL) return(NULL);
				2738	ret = xmlAllocOutputBuffer(encoder);
				2739	if (ret != NULL) {
				2740	ret->context = file;
				2741	ret->writecallback = xmlFileWrite;
				2742	ret->closecallback = NULL; /* No close callback */
				2743	}
				2744	return(ret); <br>
Daniel Veillard	1eb2424	2002-03-18 11:33:03 +0000	[diff] [blame]	2745
Daniel Veillard	34ce8be	2002-03-18 19:37:11 +0000	[diff] [blame]	2746
				2747
Daniel Veillard	1927409	2002-03-25 16:48:03 +0000	[diff] [blame]	2748
Daniel Veillard	b2fb8ed	2002-04-01 09:33:12 +0000	[diff] [blame]	2749
Daniel Veillard	7579482	2002-04-11 16:24:32 +0000	[diff] [blame]	2750
Daniel Veillard	a7084cd	2002-04-15 17:12:47 +0000	[diff] [blame]	2751
Daniel Veillard	0bfbb42	2002-04-26 09:21:45 +0000	[diff] [blame]	2752
Daniel Veillard	93d3a47	2002-04-26 14:04:55 +0000	[diff] [blame]	2753
Daniel Veillard	cf27f7c	2002-04-30 07:12:39 +0000	[diff] [blame]	2754
Daniel Veillard	e6d8e20	2002-05-02 06:11:10 +0000	[diff] [blame]	2755
Daniel Veillard	9b6fd30	2002-05-13 12:06:47 +0000	[diff] [blame]	2756
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	2757
Daniel Veillard	2147367	2002-06-17 07:29:22 +0000	[diff] [blame]	2758
Daniel Veillard	782afda	2002-07-08 15:12:49 +0000	[diff] [blame]	2759
Daniel Veillard	42766c0	2002-08-22 20:52:17 +0000	[diff] [blame]	2760
Daniel Veillard	e166254	2002-08-28 11:50:59 +0000	[diff] [blame]	2761
Daniel Veillard	e16b574	2002-09-26 17:50:03 +0000	[diff] [blame]	2762
Daniel Veillard	321be0c	2002-10-08 21:26:42 +0000	[diff] [blame]	2763
Daniel Veillard	4826743	2002-10-18 11:21:38 +0000	[diff] [blame]	2764
Daniel Veillard	dad3f68	2002-11-17 16:47:27 +0000	[diff] [blame]	2765
Daniel Veillard	c14401e	2002-11-20 14:28:17 +0000	[diff] [blame]	2766
Daniel Veillard	f9c4cad	2002-11-22 15:57:07 +0000	[diff] [blame]	2767
Daniel Veillard	9b4bb4d	2002-12-11 19:28:47 +0000	[diff] [blame]	2768
Daniel Veillard	c1eed32	2002-12-12 11:01:32 +0000	[diff] [blame]	2769
Daniel Veillard	7ef0fcb	2002-12-14 10:38:55 +0000	[diff] [blame^]	2770
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2771	} </pre>
				2772	</li>
				2773	<li>And then use it to save the document:
				2774	<pre>FILE *f;
				2775	xmlOutputBufferPtr output;
				2776	xmlDocPtr doc;
				2777	int res;
				2778
				2779	f = ...
				2780	doc = ....
				2781
				2782	output = xmlOutputBufferCreateOwn(f, NULL);
				2783	res = xmlSaveFileTo(output, doc, NULL);
				2784	</pre>
				2785	</li>
				2786	</ol>
				2787
				2788	<h2><a name="Catalog">Catalog support</a></h2>
				2789
				2790	<p>Table of Content:</p>
				2791	<ol>
				2792	<li><a href="General2">General overview</a></li>
				2793	<li><a href="#definition">The definition</a></li>
				2794	<li><a href="#Simple">Using catalogs</a></li>
				2795	<li><a href="#Some">Some examples</a></li>
				2796	<li><a href="#reference">How to tune catalog usage</a></li>
				2797	<li><a href="#validate">How to debug catalog processing</a></li>
				2798	<li><a href="#Declaring">How to create and maintain catalogs</a></li>
				2799	<li><a href="#implemento">The implementor corner quick review of the
				2800	API</a></li>
				2801	<li><a href="#Other">Other resources</a></li>
				2802	</ol>
				2803
				2804	<h3><a name="General2">General overview</a></h3>
				2805
				2806	<p>What is a catalog? Basically it's a lookup mechanism used when an entity
				2807	(a file or a remote resource) references another entity. The catalog lookup
				2808	is inserted between the moment the reference is recognized by the software
				2809	(XML parser, stylesheet processing, or even images referenced for inclusion
				2810	in a rendering) and the time where loading that resource is actually
				2811	started.</p>
				2812
				2813	<p>It is basically used for 3 things:</p>
				2814	<ul>
				2815	<li>mapping from "logical" names, the public identifiers and a more
				2816	concrete name usable for download (and URI). For example it can associate
				2817	the logical name
				2818	<p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
				2819	<p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
				2820	downloaded</p>
				2821	<p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
				2822	</li>
				2823	<li>remapping from a given URL to another one, like an HTTP indirection
				2824	saying that
				2825	<p>"http://www.oasis-open.org/committes/tr.xsl"</p>
				2826	<p>should really be looked at</p>
				2827	<p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
				2828	</li>
				2829	<li>providing a local cache mechanism allowing to load the entities
				2830	associated to public identifiers or remote resources, this is a really
				2831	important feature for any significant deployment of XML or SGML since it
				2832	allows to avoid the aleas and delays associated to fetching remote
				2833	resources.</li>
				2834	</ul>
				2835
				2836	<h3><a name="definition">The definitions</a></h3>
				2837
				2838	<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
				2839	<ul>
				2840	<li>the older SGML catalogs, the official spec is SGML Open Technical
				2841	Resolution TR9401:1997, but is better understood by reading <a
				2842	href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
				2843	James Clark. This is relatively old and not the preferred mode of
				2844	operation of libxml.</li>
				2845	<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]	2846	Catalogs</a> is far more flexible, more recent, uses an XML syntax and
				2847	should scale quite better. This is the default option of libxml.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	2848	</ul>
				2849
				2850	<p></p>
				2851
				2852	<h3><a name="Simple">Using catalog</a></h3>
				2853
				2854	<p>In a normal environment libxml will by default check the presence of a
				2855	catalog in /etc/xml/catalog, and assuming it has been correctly populated,
				2856	the processing is completely transparent to the document user. To take a
				2857	concrete example, suppose you are authoring a DocBook document, this one
				2858	starts with the following DOCTYPE definition:</p>
				2859	<pre><?xml version='1.0'?>
				2860	<!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
				2861	"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"></pre>
				2862
				2863	<p>When validating the document with libxml, the catalog will be
				2864	automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
				2865	DocBk XML V3.1.4//EN" and the system identifier
				2866	"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
				2867	been installed on your system and the catalogs actually point to them, libxml
				2868	will fetch them from the local disk.</p>
				2869
				2870	<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
				2871	DOCTYPE example it's a really old version, but is fine as an example.</p>
				2872
				2873	<p>Libxml will check the catalog each time that it is requested to load an
				2874	entity, this includes DTD, external parsed entities, stylesheets, etc ... If
				2875	your system is correctly configured all the authoring phase and processing
				2876	should use only local files, even if your document stays portable because it
				2877	uses the canonical public and system ID, referencing the remote document.</p>
				2878
				2879	<h3><a name="Some">Some examples:</a></h3>
				2880
				2881	<p>Here is a couple of fragments from XML Catalogs used in libxml early
				2882	regression tests in <code>test/catalogs</code> :</p>
				2883	<pre><?xml version="1.0"?>
				2884	<!DOCTYPE catalog PUBLIC
				2885	"-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
				2886	"http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd">
				2887	<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog">
				2888	<public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
				2889	uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/>
				2890	...</pre>
				2891
				2892	<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
				2893	written in XML, there is a specific namespace for catalog elements
				2894	"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
				2895	catalog is a <code>public</code> mapping it allows to associate a Public
				2896	Identifier with an URI.</p>
				2897	<pre>...
				2898	<rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
				2899	rewritePrefix="file:///usr/share/xml/docbook/"/>
				2900	...</pre>
				2901
				2902	<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
				2903	any URI starting with a given prefix should be looked at another URI
				2904	constructed by replacing the prefix with an new one. In effect this acts like
				2905	a cache system for a full area of the Web. In practice it is extremely useful
				2906	with a file prefix if you have installed a copy of those resources on your
				2907	local system.</p>
				2908	<pre>...
				2909	<delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
				2910	catalog="file:///usr/share/xml/docbook.xml"/>
				2911	<delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
				2912	catalog="file:///usr/share/xml/docbook.xml"/>
				2913	<delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
				2914	catalog="file:///usr/share/xml/docbook.xml"/>
				2915	<delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
				2916	catalog="file:///usr/share/xml/docbook.xml"/>
				2917	<delegateURI uriStartString="http://www.oasis-open.org/docbook/"
				2918	catalog="file:///usr/share/xml/docbook.xml"/>
				2919	...</pre>
				2920
				2921	<p>Delegation is the core features which allows to build a tree of catalogs,
				2922	easier to maintain than a single catalog, based on Public Identifier, System
				2923	Identifier or URI prefixes it instructs the catalog software to look up
				2924	entries in another resource. This feature allow to build hierarchies of
				2925	catalogs, the set of entries presented should be sufficient to redirect the
				2926	resolution of all DocBook references to the specific catalog in
				2927	<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
				2928	references for DocBook 4.2.1 to a specific catalog installed at the same time
				2929	as the DocBook resources on the local machine.</p>
				2930
				2931	<h3><a name="reference">How to tune catalog usage:</a></h3>
				2932
				2933	<p>The user can change the default catalog behaviour by redirecting queries
				2934	to its own set of catalogs, this can be done by setting the
				2935	<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
				2936	empty one should deactivate loading the default <code>/etc/xml/catalog</code>
				2937	default catalog</p>
				2938
				2939	<h3><a name="validate">How to debug catalog processing:</a></h3>
				2940
				2941	<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
				2942	make libxml output debugging informations for each catalog operations, for
				2943	example:</p>
				2944	<pre>orchis:~/XML -> xmllint --memory --noout test/ent2
				2945	warning: failed to load external entity "title.xml"
				2946	orchis:~/XML -> export XML_DEBUG_CATALOG=
				2947	orchis:~/XML -> xmllint --memory --noout test/ent2
				2948	Failed to parse catalog /etc/xml/catalog
				2949	Failed to parse catalog /etc/xml/catalog
				2950	warning: failed to load external entity "title.xml"
				2951	Catalogs cleanup
				2952	orchis:~/XML -> </pre>
				2953
				2954	<p>The test/ent2 references an entity, running the parser from memory makes
				2955	the base URI unavailable and the the "title.xml" entity cannot be loaded.
				2956	Setting up the debug environment variable allows to detect that an attempt is
				2957	made to load the <code>/etc/xml/catalog</code> but since it's not present the
				2958	resolution fails.</p>
				2959
				2960	<p>But the most advanced way to debug XML catalog processing is to use the
				2961	<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
				2962	catalogs and make resolution queries to see what is going on. This is also
				2963	used for the regression tests:</p>
				2964	<pre>orchis:~/XML -> ./xmlcatalog test/catalogs/docbook.xml \
				2965	"-//OASIS//DTD DocBook XML V4.1.2//EN"
				2966	http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
				2967	orchis:~/XML -> </pre>
				2968
				2969	<p>For debugging what is going on, adding one -v flags increase the verbosity
				2970	level to indicate the processing done (adding a second flag also indicate
				2971	what elements are recognized at parsing):</p>
				2972	<pre>orchis:~/XML -> ./xmlcatalog -v test/catalogs/docbook.xml \
				2973	"-//OASIS//DTD DocBook XML V4.1.2//EN"
				2974	Parsing catalog test/catalogs/docbook.xml's content
				2975	Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
				2976	http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
				2977	Catalogs cleanup
				2978	orchis:~/XML -> </pre>
				2979
				2980	<p>A shell interface is also available to debug and process multiple queries
				2981	(and for regression tests):</p>
				2982	<pre>orchis:~/XML -> ./xmlcatalog -shell test/catalogs/docbook.xml \
				2983	"-//OASIS//DTD DocBook XML V4.1.2//EN"
				2984	> help
				2985	Commands available:
				2986	public PublicID: make a PUBLIC identifier lookup
				2987	system SystemID: make a SYSTEM identifier lookup
				2988	resolve PublicID SystemID: do a full resolver lookup
				2989	add 'type' 'orig' 'replace' : add an entry
				2990	del 'values' : remove values
				2991	dump: print the current catalog state
				2992	debug: increase the verbosity level
				2993	quiet: decrease the verbosity level
				2994	exit: quit the shell
				2995	> public "-//OASIS//DTD DocBook XML V4.1.2//EN"
				2996	http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
				2997	> quit
				2998	orchis:~/XML -> </pre>
				2999
				3000	<p>This should be sufficient for most debugging purpose, this was actually
				3001	used heavily to debug the XML Catalog implementation itself.</p>
				3002
				3003	<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
				3004
				3005	<p>Basically XML Catalogs are XML files, you can either use XML tools to
				3006	manage them or use <strong>xmlcatalog</strong> for this. The basic step is
				3007	to create a catalog the -create option provide this facility:</p>
				3008	<pre>orchis:~/XML -> ./xmlcatalog --create tst.xml
				3009	<?xml version="1.0"?>
				3010	<!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
				3011	"http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd">
				3012	<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/>
				3013	orchis:~/XML -> </pre>
				3014
				3015	<p>By default xmlcatalog does not overwrite the original catalog and save the
				3016	result on the standard output, this can be overridden using the -noout
				3017	option. The <code>-add</code> command allows to add entries in the
				3018	catalog:</p>
				3019	<pre>orchis:~/XML -> ./xmlcatalog --noout --create --add "public" \
				3020	"-//OASIS//DTD DocBook XML V4.1.2//EN" \
				3021	http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
				3022	orchis:~/XML -> cat tst.xml
				3023	<?xml version="1.0"?>
				3024	<!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
				3025	"http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd">
				3026	<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog">
				3027	<public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
				3028	uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/>
				3029	</catalog>
				3030	orchis:~/XML -> </pre>
				3031
				3032	<p>The <code>-add</code> option will always take 3 parameters even if some of
				3033	the XML Catalog constructs (like nextCatalog) will have only a single
				3034	argument, just pass a third empty string, it will be ignored.</p>
				3035
				3036	<p>Similarly the <code>-del</code> option remove matching entries from the
				3037	catalog:</p>
				3038	<pre>orchis:~/XML -> ./xmlcatalog --del \
				3039	"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
				3040	<?xml version="1.0"?>
				3041	<!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
				3042	"http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd">
				3043	<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/>
				3044	orchis:~/XML -> </pre>
				3045
				3046	<p>The catalog is now empty. Note that the matching of <code>-del</code> is
				3047	exact and would have worked in a similar fashion with the Public ID
				3048	string.</p>
				3049
				3050	<p>This is rudimentary but should be sufficient to manage a not too complex
				3051	catalog tree of resources.</p>
				3052
				3053	<h3><a name="implemento">The implementor corner quick review of the
				3054	API:</a></h3>
				3055
				3056	<p>First, and like for every other module of libxml, there is an
				3057	automatically generated <a href="html/libxml-catalog.html">API page for
				3058	catalog support</a>.</p>
				3059
				3060	<p>The header for the catalog interfaces should be included as:</p>
				3061	<pre>#include <libxml/catalog.h></pre>
				3062
				3063	<p>The API is voluntarily kept very simple. First it is not obvious that
				3064	applications really need access to it since it is the default behaviour of
				3065	libxml (Note: it is possible to completely override libxml default catalog by
				3066	using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
				3067	plug an application specific resolver).</p>
				3068
				3069	<p>Basically libxml support 2 catalog lists:</p>
				3070	<ul>
				3071	<li>the default one, global shared by all the application</li>
				3072	<li>a per-document catalog, this one is built if the document uses the
				3073	<code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
				3074	associated to the parser context and destroyed when the parsing context
				3075	is destroyed.</li>
				3076	</ul>
				3077
				3078	<p>the document one will be used first if it exists.</p>
				3079
				3080	<h4>Initialization routines:</h4>
				3081
				3082	<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
				3083	used at startup to initialize the catalog, if the catalog should be
				3084	initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
				3085	should be called before xmlInitializeCatalog() which would otherwise do a
				3086	default initialization first.</p>
				3087
				3088	<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
				3089	own catalog list if needed.</p>
				3090
				3091	<h4>Preferences setup:</h4>
				3092
				3093	<p>The XML Catalog spec requires the possibility to select default
				3094	preferences between public and system delegation,
				3095	xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
				3096	xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
				3097	be forbidden, allowed for global catalog, for document catalog or both, the
				3098	default is to allow both.</p>
				3099
				3100	<p>And of course xmlCatalogSetDebug() allows to generate debug messages
				3101	(through the xmlGenericError() mechanism).</p>
				3102
				3103	<h4>Querying routines:</h4>
				3104
				3105	<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
				3106	and xmlCatalogResolveURI() are relatively explicit if you read the XML
				3107	Catalog specification they correspond to section 7 algorithms, they should
				3108	also work if you have loaded an SGML catalog with a simplified semantic.</p>
				3109
				3110	<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
				3111	operate on the document catalog list</p>
				3112
				3113	<h4>Cleanup and Miscellaneous:</h4>
				3114
				3115	<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
				3116	the per-document equivalent.</p>
				3117
				3118	<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
				3119	first catalog in the global list, and xmlCatalogDump() allows to dump a
				3120	catalog state, those routines are primarily designed for xmlcatalog, I'm not
				3121	sure that exposing more complex interfaces (like navigation ones) would be
				3122	really useful.</p>
				3123
				3124	<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
				3125	it's similar as xmlParseFile() except it bypass all catalog lookups, it's
				3126	provided because this functionality may be useful for client tools.</p>
				3127
				3128	<h4>threaded environments:</h4>
				3129
				3130	<p>Since the catalog tree is built progressively, some care has been taken to
				3131	try to avoid troubles in multithreaded environments. The code is now thread
				3132	safe assuming that the libxml library has been compiled with threads
				3133	support.</p>
				3134
				3135	<p></p>
				3136
				3137	<h3><a name="Other">Other resources</a></h3>
				3138
				3139	<p>The XML Catalog specification is relatively recent so there isn't much
				3140	literature to point at:</p>
				3141	<ul>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3142	<li>You can find a good rant from Norm Walsh about <a
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3143	href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
				3144	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]	3145	I don't agree with everything presented. Norm also wrote a more recent
				3146	article <a
				3147	href="http://wwws.sun.com/software/xml/developers/resolver/article/">XML
				3148	entities and URI resolvers</a> describing them.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3149	<li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
				3150	catalog proposal</a> from John Cowan</li>
				3151	<li>The <a href="http://www.rddl.org/">Resource Directory Description
				3152	Language</a> (RDDL) another catalog system but more oriented toward
				3153	providing metadata for XML namespaces.</li>
				3154	<li>the page from the OASIS Technical <a
				3155	href="http://www.oasis-open.org/committees/entity/">Committee on Entity
				3156	Resolution</a> who maintains XML Catalog, you will find pointers to the
				3157	specification update, some background and pointers to others tools
				3158	providing XML Catalog support</li>
Daniel Veillard	35e937a	2002-01-19 22:21:54 +0000	[diff] [blame]	3159	<li>Here is a <a href="buildDocBookCatalog">shell script</a> to generate
				3160	XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
				3161	directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
				3162	the resources found on the system. Otherwise it will just create
				3163	~/xmlcatalog and ~/dbkxmlcatalog and doing:
Daniel Veillard	c575b99	2002-02-08 13:28:40 +0000	[diff] [blame]	3164	<p><code>export XMLCATALOG=$HOME/xmlcatalog</code></p>
Daniel Veillard	35e937a	2002-01-19 22:21:54 +0000	[diff] [blame]	3165	<p>should allow to process DocBook documentations without requiring
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3166	network accesses for the DTD or stylesheets</p>
Daniel Veillard	35e937a	2002-01-19 22:21:54 +0000	[diff] [blame]	3167	</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3168	<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]	3169	small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
				3170	to work fine for me too</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3171	<li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
				3172	manual page</a></li>
				3173	</ul>
				3174
				3175	<p>If you have suggestions for corrections or additions, simply contact
				3176	me:</p>
				3177
				3178	<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3179
				3180	<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3181	using the XML library from the C language. It is not intended to be
				3182	extensive. I hope the automatically generated documents will provide the
				3183	completeness required, but as a separate set of documents. The interfaces of
				3184	the XML library are by principle low level, there is nearly zero abstraction.
				3185	Those interested in a higher level API should <a href="#DOM">look at
				3186	DOM</a>.</p>
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	3187
Daniel Veillard	9cb5ff4	2001-01-29 08:22:21 +0000	[diff] [blame]	3188	<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
				3189	separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3190	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]	3191
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3192	<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3193
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3194	<p>Usually, the first thing to do is to read an XML input. The parser accepts
				3195	documents either from in-memory strings or from files. The functions are
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3196	defined in "parser.h":</p>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3197	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3198	<dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3199	<dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3200	</dd>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3201	</dl>
				3202	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3203	<dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3204	<dd><p>Parse an XML document contained in a (possibly compressed)
				3205	file.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3206	</dd>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3207	</dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3208
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3209	<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]	3210	failure).</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3211
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3212	<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3213
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3214	<p>In order for the application to keep the control when the document is
				3215	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]	3216	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]	3217	<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
				3218	void *user_data,
				3219	const char *chunk,
				3220	int size,
				3221	const char *filename);
				3222	int xmlParseChunk (xmlParserCtxtPtr ctxt,
				3223	const char *chunk,
				3224	int size,
				3225	int terminate);</pre>
				3226
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3227	<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]	3228	<pre> FILE *f;
				3229
				3230	f = fopen(filename, "r");
				3231	if (f != NULL) {
				3232	int res, size = 1024;
				3233	char chars[1024];
				3234	xmlParserCtxtPtr ctxt;
				3235
				3236	res = fread(chars, 1, 4, f);
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3237	if (res > 0) {
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3238	ctxt = xmlCreatePushParserCtxt(NULL, NULL,
				3239	chars, res, filename);
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3240	while ((res = fread(chars, 1, size, f)) > 0) {
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3241	xmlParseChunk(ctxt, chars, res, 0);
				3242	}
				3243	xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3244	doc = ctxt->myDoc;
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3245	xmlFreeParserCtxt(ctxt);
				3246	}
				3247	}</pre>
				3248
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3249	<p>The HTML parser embedded into libxml also has a push interface; the
				3250	functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3251
				3252	<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
				3253
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3254	<p>The tree-building interface makes the parser memory-hungry, first loading
				3255	the document in memory and then building the tree itself. Reading a document
				3256	without building the tree is possible using the SAX interfaces (see SAX.h and
				3257	<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]	3258	Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3259	limited to SAX: just use the two first arguments of
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3260	<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	3261
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3262	<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3263
				3264	<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]	3265	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]	3266	also described in <libxml/tree.h>.) For example, here is a piece of
				3267	code that produces the XML document used in the previous examples:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3268	<pre> #include <libxml/tree.h>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	3269	xmlDocPtr doc;
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3270	xmlNodePtr tree, subtree;
				3271
				3272	doc = xmlNewDoc("1.0");
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3273	doc->children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
				3274	xmlSetProp(doc->children, "prop1", "gnome is great");
				3275	xmlSetProp(doc->children, "prop2", "& linux too");
				3276	tree = xmlNewChild(doc->children, NULL, "head", NULL);
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3277	subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3278	tree = xmlNewChild(doc->children, NULL, "chapter", NULL);
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3279	subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
				3280	subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
				3281	subtree = xmlNewChild(tree, NULL, "image", NULL);
				3282	xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3283
				3284	<p>Not really rocket science ...</p>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3285
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3286	<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3287
Daniel Veillard	9cb5ff4	2001-01-29 08:22:21 +0000	[diff] [blame]	3288	<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]	3289	code has access to the internal structure of all the elements of the tree.
				3290	The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard	306be99	2000-07-03 12:38:45 +0000	[diff] [blame]	3291	<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3292	<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard	0142b84	2000-01-14 14:45:24 +0000	[diff] [blame]	3293	example:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3294	<pre><code>doc->children->children->children</code></pre>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3295
				3296	<p>points to the title element,</p>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3297	<pre>doc->children->children->next->children->children</pre>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3298
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3299	<p>points to the text node containing the chapter title "The Linux
				3300	adventure".</p>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3301
Daniel Veillard	b24054a	1999-12-18 15:32:46 +0000	[diff] [blame]	3302	<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]	3303	present before the document root, so <code>doc->children</code> may point
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3304	to an element which is not the document Root Element; a function
Daniel Veillard	5cb5ab8	1999-12-21 15:35:29 +0000	[diff] [blame]	3305	<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillard	b24054a	1999-12-18 15:32:46 +0000	[diff] [blame]	3306
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3307	<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3308
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3309	<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard	9cb5ff4	2001-01-29 08:22:21 +0000	[diff] [blame]	3310	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]	3311	<dl>
Daniel Veillard	dd6b367	1999-09-23 22:19:22 +0000	[diff] [blame]	3312	<dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
				3313	xmlChar *value);</code></dt>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3314	<dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
				3315	The value can be NULL.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3316	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3317	</dl>
				3318	<dl>
Daniel Veillard	dd6b367	1999-09-23 22:19:22 +0000	[diff] [blame]	3319	<dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3320	*name);</code></dt>
Daniel Veillard	c92c304	2000-09-29 02:42:04 +0000	[diff] [blame]	3321	<dd><p>This function returns a pointer to new copy of the property
				3322	content. Note that the user must deallocate the result.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3323	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3324	</dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3325
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3326	<p>Two functions are provided for reading and writing the text associated
				3327	with elements:</p>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3328	<dl>
Daniel Veillard	dd6b367	1999-09-23 22:19:22 +0000	[diff] [blame]	3329	<dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3330	*value);</code></dt>
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3331	<dd><p>This function takes an "external" string and converts it to one
				3332	text node or possibly to a list of entity and text nodes. All
				3333	non-predefined entity references like &Gnome; will be stored
				3334	internally as entity nodes, hence the result of the function may not be
				3335	a single node.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3336	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3337	</dl>
				3338	<dl>
Daniel Veillard	dd6b367	1999-09-23 22:19:22 +0000	[diff] [blame]	3339	<dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3340	inLine);</code></dt>
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3341	<dd><p>This function is the inverse of
				3342	<code>xmlStringGetNodeList()</code>. It generates a new string
				3343	containing the content of the text and entity nodes. Note the extra
				3344	argument inLine. If this argument is set to 1, the function will expand
				3345	entity references. For example, instead of returning the &Gnome;
				3346	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]	3347	"GNU Network Object Model Environment").</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3348	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3349	</dl>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3350
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3351	<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3352
				3353	<p>Basically 3 options are possible:</p>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3354	<dl>
Daniel Veillard	dd6b367	1999-09-23 22:19:22 +0000	[diff] [blame]	3355	<dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3356	*size);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3357	<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]	3358	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3359	</dl>
				3360	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3361	<dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3362	<dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3363	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3364	</dl>
				3365	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3366	<dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3367	<dd><p>Saves the document to a file. In this case, the compression
				3368	interface is triggered if it has been turned on.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3369	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3370	</dl>
Daniel Veillard	10c6a8f	1998-10-28 01:00:12 +0000	[diff] [blame]	3371
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3372	<h3><a name="Compressio">Compression</a></h3>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3373
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3374	<p>The library transparently handles compression when doing file-based
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3375	accesses. The level of compression on saves can be turned on either globally
				3376	or individually for one file:</p>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3377	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3378	<dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3379	<dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3380	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3381	</dl>
				3382	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3383	<dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3384	<dd><p>Sets the document compression ratio.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3385	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3386	</dl>
				3387	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3388	<dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3389	<dd><p>Gets the default compression ratio.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3390	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3391	</dl>
				3392	<dl>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3393	<dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3394	<dd><p>Sets the default compression ratio.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3395	</dd>
Daniel Veillard	25940b7	1998-10-29 05:51:30 +0000	[diff] [blame]	3396	</dl>
				3397
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3398	<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3399
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3400	<p>Entities in principle are similar to simple C macros. An entity defines an
				3401	abbreviation for a given string that you can reuse many times throughout the
				3402	content of your document. Entities are especially useful when a given string
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3403	may occur frequently within a document, or to confine the change needed to a
				3404	document to a restricted area in the internal subset of the document (at the
				3405	beginning). Example:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3406	<pre>1 <?xml version="1.0"?>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3407	2 <!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3408	3 <!ENTITY xml "Extensible Markup Language">
				3409	4 ]>
				3410	5 <EXAMPLE>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3411	6 &xml;
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3412	7 </EXAMPLE></pre>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3413
				3414	<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]	3415	its name with '&' and following it by ';' without any spaces added. There
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3416	are 5 predefined entities in libxml allowing you to escape characters with
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3417	predefined meaning in some parts of the xml document content:
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3418	<strong>&lt;</strong> for the character '<', <strong>&gt;</strong>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3419	for the character '>', <strong>&apos;</strong> for the character ''',
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3420	<strong>&quot;</strong> for the character '"', and
				3421	<strong>&amp;</strong> for the character '&'.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3422
				3423	<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]	3424	substitute an entity's content so that you can see the replacement text in
				3425	your application. Or you may prefer to keep entity references as such in the
				3426	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]	3427	precious information (if the user went through the pain of explicitly
				3428	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]	3429	substitute them as saving time). The <a
Daniel Veillard	9cb5ff4	2001-01-29 08:22:21 +0000	[diff] [blame]	3430	href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3431	function allows you to check and change the behaviour, which is to not
				3432	substitute entities by default.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3433
				3434	<p>Here is the DOM tree built by libxml for the previous document in the
				3435	default case:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3436	<pre>/gnome/src/gnome-xml -> ./xmllint --debug test/ent1
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3437	DOCUMENT
				3438	version=1.0
				3439	ELEMENT EXAMPLE
				3440	TEXT
				3441	content=
				3442	ENTITY_REF
				3443	INTERNAL_GENERAL_ENTITY xml
				3444	content=Extensible Markup Language
				3445	TEXT
				3446	content=</pre>
				3447
				3448	<p>And here is the result when substituting entities:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3449	<pre>/gnome/src/gnome-xml -> ./tester --debug --noent test/ent1
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3450	DOCUMENT
				3451	version=1.0
				3452	ELEMENT EXAMPLE
				3453	TEXT
				3454	content= Extensible Markup Language</pre>
				3455
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3456	<p>So, entities or no entities? Basically, it depends on your use case. I
				3457	suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3458	entities in your XML document or data if you are not willing to handle the
				3459	entity references elements in the DOM tree.</p>
				3460
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3461	<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]	3462	entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3463	transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard	88f00ae	2000-03-02 00:15:55 +0000	[diff] [blame]	3464	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]	3465	finding them in the input).</p>
				3466
Daniel Veillard	7b9c4b7	2000-08-25 16:26:50 +0000	[diff] [blame]	3467	<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3468	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]	3469	non-predefined entities in your documents, then the learning curve to handle
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3470	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]	3471	strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard	8c6d6af	2000-08-25 17:14:13 +0000	[diff] [blame]	3472	deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard	7b9c4b7	2000-08-25 16:26:50 +0000	[diff] [blame]	3473
Daniel Veillard	2f4dfc4	1999-09-24 14:03:48 +0000	[diff] [blame]	3474	<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3475
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	3476	<p>The libxml library implements <a
				3477	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]	3478	recognizing namespace constructs in the input, and does namespace lookup
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	3479	automatically when building the DOM tree. A namespace declaration is
				3480	associated with an in-memory structure and all elements or attributes within
				3481	that namespace point to it. Hence testing the namespace is a simple and fast
				3482	equality operation at the user level.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3483
Daniel Veillard	f13e1ed	2000-03-06 07:41:49 +0000	[diff] [blame]	3484	<p>I suggest that people using libxml use a namespace, and declare it in the
				3485	root element of their document as the default namespace. Then they don't need
				3486	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]	3487	refinement and merging of data from different sources. This doesn't increase
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3488	the size of the XML output significantly, but significantly increases its
				3489	value in the long-term. Example:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3490	<pre><mydoc xmlns="http://mydoc.example.org/schemas/">
				3491	<elem1>...</elem1>
				3492	<elem2>...</elem2>
				3493	</mydoc></pre>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3494
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3495	<p>The namespace value has to be an absolute URL, but the URL doesn't have to
				3496	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]	3497	attributes with that URL. I suggest to use an URL within a domain you
				3498	control, and that the URL should contain some kind of version information if
				3499	possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a
				3500	good namespace scheme.</p>
Daniel Veillard	ec30341	2000-03-24 13:41:54 +0000	[diff] [blame]	3501
				3502	<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]	3503	version-independent prefix is installed on the root element of your document,
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3504	and if the version information don't match something you know, warn the user
				3505	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]	3506	namespace checking on the prefix value. <foo:text> may be exactly the
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3507	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]	3508	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]	3509	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]	3510	<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3511	prefix and its URI.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3512
				3513	<p>@@Interfaces@@</p>
				3514
				3515	<p>@@Examples@@</p>
				3516
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3517	<p>Usually people object to using namespaces together with validity checking.
				3518	I will try to make sure that using namespaces won't break validity checking,
				3519	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]	3520	suggest adding namespaces to your document. A default namespace scheme
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3521	<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3522	flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3523	from multiple DTDs will certainly break current validation schemes. I will
				3524	try to provide ways to do this, but this may not be portable or
				3525	standardized.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3526
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3527	<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3528
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3529	<p>Incompatible changes:</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3530
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3531	<p>Version 2 of libxml is the first version introducing serious backward
				3532	incompatible changes. The main goals were:</p>
				3533	<ul>
				3534	<li>a general cleanup. A number of mistakes inherited from the very early
				3535	versions couldn't be changed due to compatibility constraints. Example
				3536	the "childs" element in the nodes.</li>
				3537	<li>Uniformization of the various nodes, at least for their header and link
				3538	parts (doc, parent, children, prev, next), the goal is a simpler
				3539	programming model and simplifying the task of the DOM implementors.</li>
				3540	<li>better conformances to the XML specification, for example version 1.x
				3541	had an heuristic to try to detect ignorable white spaces. As a result the
				3542	SAX event generated were ignorableWhitespace() while the spec requires
				3543	character() in that case. This also mean that a number of DOM node
				3544	containing blank text may populate the DOM tree which were not present
				3545	before.</li>
				3546	</ul>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3547
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3548	<h3>How to fix libxml-1.x code:</h3>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3549
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3550	<p>So client code of libxml designed to run with version 1.x may have to be
				3551	changed to compile against version 2.x of libxml. Here is a list of changes
				3552	that I have collected, they may not be sufficient, so in case you find other
				3553	change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
				3554	mail</a>:</p>
				3555	<ol>
				3556	<li>The package name have changed from libxml to libxml2, the library name
				3557	is now -lxml2 . There is a new xml2-config script which should be used to
				3558	select the right parameters libxml2</li>
				3559	<li>Node <strong>childs</strong> field has been renamed
				3560	<strong>children</strong> so s/childs/children/g should be applied
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3561	(probability of having "childs" anywhere else is close to 0+</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3562	<li>The document don't have anymore a <strong>root</strong> element it has
				3563	been replaced by <strong>children</strong> and usually you will get a
				3564	list of element here. For example a Dtd element for the internal subset
				3565	and it's declaration may be found in that list, as well as processing
				3566	instructions or comments found before or after the document root element.
				3567	Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3568	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]	3569	PIs or comments before or after the root element
				3570	s/->root/->children/g will probably do it.</li>
				3571	<li>The white space issue, this one is more complex, unless special case of
				3572	validating parsing, the line breaks and spaces usually used for indenting
				3573	and formatting the document content becomes significant. So they are
				3574	reported by SAX and if your using the DOM tree, corresponding nodes are
				3575	generated. Too approach can be taken:
				3576	<ol>
				3577	<li>lazy one, use the compatibility call
				3578	<strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
				3579	relying on a special (and possibly broken) set of heuristics of
				3580	libxml to detect ignorable blanks. Don't complain if it breaks or
				3581	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]	3582	<li>the Right Way: change you code to accept possibly insignificant
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3583	blanks characters, or have your tree populated with weird blank text
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3584	nodes. You can spot them using the commodity function
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3585	<strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
				3586	nodes.</li>
				3587	</ol>
				3588	<p>Note also that with the new default the output functions don't add any
				3589	extra indentation when saving a tree in order to be able to round trip
				3590	(read and save) without inflating the document with extra formatting
				3591	chars.</p>
				3592	</li>
				3593	<li>The include path has changed to $prefix/libxml/ and the includes
				3594	themselves uses this new prefix in includes instructions... If you are
				3595	using (as expected) the
				3596	<pre>xml2-config --cflags</pre>
				3597	<p>output to generate you compile commands this will probably work out of
				3598	the box</p>
				3599	</li>
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3600	<li>xmlDetectCharEncoding takes an extra argument indicating the length in
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3601	byte of the head of the document available for character detection.</li>
				3602	</ol>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3603
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3604	<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3605
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3606	<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]	3607	to allow smooth upgrade of existing libxml v1code while retaining
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3608	compatibility. They offers the following:</p>
				3609	<ol>
				3610	<li>similar include naming, one should use
				3611	<strong>#include<libxml/...></strong> in both cases.</li>
				3612	<li>similar identifiers defined via macros for the child and root fields:
				3613	respectively <strong>xmlChildrenNode</strong> and
				3614	<strong>xmlRootNode</strong></li>
				3615	<li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
				3616	inserted once in the client code</li>
				3617	</ol>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3618
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3619	<p>So the roadmap to upgrade your existing libxml applications is the
				3620	following:</p>
				3621	<ol>
				3622	<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]	3623	<li>find all occurrences where the xmlDoc <strong>root</strong> field is
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3624	used and change it to <strong>xmlRootNode</strong></li>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	3625	<li>similarly find all occurrences where the xmlNode
				3626	<strong>childs</strong> field is used and change it to
				3627	<strong>xmlChildrenNode</strong></li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3628	<li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
				3629	<strong>main()</strong> or in the library init entry point</li>
				3630	<li>Recompile, check compatibility, it should still work</li>
Daniel Veillard	c0801af	2002-05-28 16:28:42 +0000	[diff] [blame]	3631	<li>Change your configure script to look first for xml2-config and fall
				3632	back using xml-config . Use the --cflags and --libs output of the command
				3633	as the Include and Linking parameters needed to use libxml.</li>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3634	<li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
				3635	libxml-devel-1.8.y can be kept simultaneously)</li>
				3636	<li>remove your config.cache, relaunch your configuration mechanism, and
				3637	recompile, if steps 2 and 3 were done right it should compile as-is</li>
				3638	<li>Test that your application is still running correctly, if not this may
				3639	be due to extra empty nodes due to formating spaces being kept in libxml2
				3640	contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
				3641	code before calling the parser (next to
				3642	<strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
				3643	</ol>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3644
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3645	<p>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]	3646
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3647	<p>Let me put some emphasis on the fact that there is far more changes from
				3648	libxml 1.x to 2.x than the ones you may have to patch for. The overall code
				3649	has been considerably cleaned up and the conformance to the XML specification
				3650	has been drastically improved too. Don't take those changes as an excuse to
				3651	not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3652
Daniel Veillard	52dcab3	2001-10-30 12:51:17 +0000	[diff] [blame]	3653	<h2><a name="Thread">Thread safety</a></h2>
				3654
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3655	<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]	3656	threads can safely work in parallel parsing different documents. There is
				3657	however a couple of things to do to ensure it:</p>
				3658	<ul>
				3659	<li>configure the library accordingly using the --with-threads options</li>
				3660	<li>call xmlInitParser() in the "main" thread before using any of the
				3661	libxml API (except possibly selecting a different memory allocator)</li>
				3662	</ul>
				3663
				3664	<p>Note that the thread safety cannot be ensured for multiple threads sharing
				3665	the same document, the locking must be done at the application level, libxml
				3666	exports a basic mutex and reentrant mutexes API in <libxml/threads.h>.
				3667	The parts of the library checked for thread safety are:</p>
				3668	<ul>
				3669	<li>concurrent loading</li>
				3670	<li>file access resolution</li>
				3671	<li>catalog access</li>
				3672	<li>catalog building</li>
				3673	<li>entities lookup/accesses</li>
				3674	<li>validation</li>
				3675	<li>global variables per-thread override</li>
				3676	<li>memory handling</li>
				3677	</ul>
				3678
				3679	<p>XPath is supposed to be thread safe now, but this wasn't tested
				3680	seriously.</p>
				3681
Daniel Veillard	3500838	1999-10-25 13:15:52 +0000	[diff] [blame]	3682	<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3683
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3684	<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
				3685	Object Model</em>; this is an API for accessing XML or HTML structured
				3686	documents. Native support for DOM in Gnome is on the way (module gnome-dom),
				3687	and will be based on gnome-xml. This will be a far cleaner interface to
				3688	manipulate XML files within Gnome since it won't expose the internal
				3689	structure.</p>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3690
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3691	<p>The current DOM implementation on top of libxml is the <a
Daniel Veillard	a47fb3d	2001-03-25 17:23:49 +0000	[diff] [blame]	3692	href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
				3693	is a full DOM interface, thanks to Paolo Casarini, check the <a
				3694	href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
				3695	informations.</p>
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3696
Daniel Veillard	3500838	1999-10-25 13:15:52 +0000	[diff] [blame]	3697	<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]	3698
				3699	<p>Here is a real size example, where the actual content of the application
				3700	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]	3701	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]	3702	storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
				3703	base</a>:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3704	<pre><?xml version="1.0"?>
				3705	<gjob:Helping xmlns:gjob="http://www.gnome.org/some-location">
				3706	<gjob:Jobs>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3707
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3708	<gjob:Job>
				3709	<gjob:Project ID="3"/>
				3710	<gjob:Application>GBackup</gjob:Application>
				3711	<gjob:Category>Development</gjob:Category>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3712
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3713	<gjob:Update>
				3714	<gjob:Status>Open</gjob:Status>
				3715	<gjob:Modified>Mon, 07 Jun 1999 20:27:45 -0400 MET DST</gjob:Modified>
				3716	<gjob:Salary>USD 0.00</gjob:Salary>
				3717	</gjob:Update>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3718
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3719	<gjob:Developers>
				3720	<gjob:Developer>
				3721	</gjob:Developer>
				3722	</gjob:Developers>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3723
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3724	<gjob:Contact>
				3725	<gjob:Person>Nathan Clemons</gjob:Person>
				3726	<gjob:Email>nathan@windsofstorm.net</gjob:Email>
				3727	<gjob:Company>
				3728	</gjob:Company>
				3729	<gjob:Organisation>
				3730	</gjob:Organisation>
				3731	<gjob:Webpage>
				3732	</gjob:Webpage>
				3733	<gjob:Snailmail>
				3734	</gjob:Snailmail>
				3735	<gjob:Phone>
				3736	</gjob:Phone>
				3737	</gjob:Contact>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3738
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3739	<gjob:Requirements>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3740	The program should be released as free software, under the GPL.
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3741	</gjob:Requirements>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3742
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3743	<gjob:Skills>
				3744	</gjob:Skills>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3745
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3746	<gjob:Details>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3747	A GNOME based system that will allow a superuser to configure
				3748	compressed and uncompressed files and/or file systems to be backed
				3749	up with a supported media in the system. This should be able to
				3750	perform via find commands generating a list of files that are passed
				3751	to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
				3752	or via operations performed on the filesystem itself. Email
				3753	notification and GUI status display very important.
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3754	</gjob:Details>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3755
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3756	</gjob:Job>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3757
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3758	</gjob:Jobs>
				3759	</gjob:Helping></pre>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3760
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3761	<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]	3762	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]	3763	generate the internal structures is harder, and more error prone.</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3764
				3765	<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]	3766	structure. For example, the ordering of the attributes is not significant,
				3767	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]	3768	depend on the order of the children of a given node, unless it really makes
				3769	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]	3770	<pre>/*
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3771	* A person record
				3772	*/
				3773	typedef struct person {
				3774	char *name;
				3775	char *email;
				3776	char *company;
				3777	char *organisation;
				3778	char *smail;
				3779	char *webPage;
				3780	char *phone;
				3781	} person, *personPtr;
				3782
				3783	/*
				3784	* And the code needed to parse it
				3785	*/
				3786	personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
				3787	personPtr ret = NULL;
				3788
				3789	DEBUG("parsePerson\n");
				3790	/*
				3791	* allocate the struct
				3792	*/
				3793	ret = (personPtr) malloc(sizeof(person));
				3794	if (ret == NULL) {
				3795	fprintf(stderr,"out of memory\n");
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3796	return(NULL);
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3797	}
				3798	memset(ret, 0, sizeof(person));
				3799
				3800	/* We don't care what the top level element name is */
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3801	cur = cur->xmlChildrenNode;
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3802	while (cur != NULL) {
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3803	if ((!strcmp(cur->name, "Person")) && (cur->ns == ns))
				3804	ret->name = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1);
				3805	if ((!strcmp(cur->name, "Email")) && (cur->ns == ns))
				3806	ret->email = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1);
				3807	cur = cur->next;
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3808	}
				3809
				3810	return(ret);
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3811	}</pre>
				3812
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3813	<p>Here are a couple of things to notice:</p>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3814	<ul>
Daniel Veillard	91e9d58	2001-02-26 07:31:12 +0000	[diff] [blame]	3815	<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]	3816	is by nature subject to repetitive constructs and usually exhibits highly
				3817	structured patterns.</li>
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3818	<li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
				3819	i.e. the pointer to the global XML document and the namespace reserved to
				3820	the application. Document wide information are needed for example to
				3821	decode entities and it's a good coding practice to define a namespace for
				3822	your application set of data and test that the element and attributes
				3823	you're analyzing actually pertains to your application space. This is
				3824	done by a simple equality test (cur->ns == ns).</li>
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3825	<li>To retrieve text and attributes value, you can use the function
				3826	<em>xmlNodeListGetString</em> to gather all the text and entity reference
				3827	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]	3828	</ul>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3829
				3830	<p>Here is another piece of code used to parse another level of the
				3831	structure:</p>
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3832	<pre>#include <libxml/tree.h>
Daniel Veillard	361d845	2000-04-03 19:48:13 +0000	[diff] [blame]	3833	/*
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3834	* a Description for a Job
				3835	*/
				3836	typedef struct job {
				3837	char *projectID;
				3838	char *application;
				3839	char *category;
				3840	personPtr contact;
				3841	int nbDevelopers;
				3842	personPtr developers[100]; /* using dynamic alloc is left as an exercise */
				3843	} job, *jobPtr;
				3844
				3845	/*
				3846	* And the code needed to parse it
				3847	*/
				3848	jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
				3849	jobPtr ret = NULL;
				3850
				3851	DEBUG("parseJob\n");
				3852	/*
				3853	* allocate the struct
				3854	*/
				3855	ret = (jobPtr) malloc(sizeof(job));
				3856	if (ret == NULL) {
				3857	fprintf(stderr,"out of memory\n");
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3858	return(NULL);
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3859	}
				3860	memset(ret, 0, sizeof(job));
				3861
				3862	/* We don't care what the top level element name is */
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3863	cur = cur->xmlChildrenNode;
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3864	while (cur != NULL) {
				3865
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3866	if ((!strcmp(cur->name, "Project")) && (cur->ns == ns)) {
				3867	ret->projectID = xmlGetProp(cur, "ID");
				3868	if (ret->projectID == NULL) {
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3869	fprintf(stderr, "Project has no ID\n");
				3870	}
				3871	}
Daniel Veillard	60979bd	2000-07-10 12:17:33 +0000	[diff] [blame]	3872	if ((!strcmp(cur->name, "Application")) && (cur->ns == ns))
				3873	ret->application = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1);
				3874	if ((!strcmp(cur->name, "Category")) && (cur->ns == ns))
				3875	ret->category = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1);
				3876	if ((!strcmp(cur->name, "Contact")) && (cur->ns == ns))
				3877	ret->contact = parsePerson(doc, ns, cur);
				3878	cur = cur->next;
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3879	}
				3880
				3881	return(ret);
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3882	}</pre>
Daniel Veillard	14fff06	1999-06-22 21:49:07 +0000	[diff] [blame]	3883
Daniel Veillard	ec70e91	2001-02-26 20:10:45 +0000	[diff] [blame]	3884	<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]	3885	boring. Ultimately, it could be possible to write stubbers taking either C
Daniel Veillard	3d6ae1c	2001-08-15 13:12:39 +0000	[diff] [blame]	3886	data structure definitions, a set of XML examples or an XML DTD and produce
				3887	the code needed to import and export the content between C data and XML
				3888	storage. This is left as an exercise to the reader :-)</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3889
Daniel Veillard	6f0adb5	2000-07-03 11:41:26 +0000	[diff] [blame]	3890	<p>Feel free to use <a href="example/gjobread.c">the code for the full C
				3891	parsing example</a> as a template, it is also available with Makefile in the
				3892	Gnome CVS base under gnome-xml/example</p>
Daniel Veillard	b05deb7	1999-08-10 19:04:08 +0000	[diff] [blame]	3893
Daniel Veillard	c310d56	2000-06-23 18:32:15 +0000	[diff] [blame]	3894	<h2><a name="Contributi">Contributions</a></h2>
				3895	<ul>
Daniel Veillard	b8cfbd1	2001-10-25 10:53:28 +0000	[diff] [blame]	3896	<li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
				3897	patches, Gary Pennington worked on the validation API, threading support
				3898	and Solaris port.</li>
				3899	<li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillard	b2fb8ed	2002-04-01 09:33:12 +0000	[diff] [blame]	3900	<li><a href="mailto:igor@stud.fh-frankfurt.de">Igor Zlatkovic</a> is now
				3901	the maintainer of the Windows port, <a
Daniel Veillard	9518953	2001-07-26 18:30:26 +0000	[diff] [blame]	3902	href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
				3903	provides binaries</a></li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	3904	<li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
				3905	<a href="http://garypennington.net/libxml2/">Solaris binaries</a></li>
Daniel Veillard	e356c28	2001-03-10 12:32:04 +0000	[diff] [blame]	3906	<li><a
				3907	href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard	63d8314	2002-05-20 06:51:05 +0000	[diff] [blame]	3908	Sergeant</a> developed <a
				3909	href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	3910	libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
				3911	application server</a></li>
				3912	<li><a href="mailto:fnatter@gmx.net">Felix Natter</a> and <a
				3913	href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillard	ca98976	2001-06-23 17:39:29 +0000	[diff] [blame]	3914	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]	3915	documentation</li>
Daniel Veillard	af43f63	2002-03-08 15:05:20 +0000	[diff] [blame]	3916	<li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
				3917	href="http://xmlsoft.org/messages/0488.html">man pages</a></li>
Daniel Veillard	5168dbf	2001-07-07 00:18:23 +0000	[diff] [blame]	3918	<li>there is a module for <a
				3919	href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
				3920	in OpenNSD/AOLServer</a></li>
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	3921	<li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provided the
				3922	first version of libxml/libxslt <a
				3923	href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li>
Daniel Veillard	1aadc44	2001-11-28 13:10:32 +0000	[diff] [blame]	3924	<li>Petr Kozelka provides <a
				3925	href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
				3926	libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillard	2d347fa	2002-03-17 10:34:11 +0000	[diff] [blame]	3927	<li><a href="mailto:aleksey@aleksey.com">Aleksey Sanin</a> implemented the
				3928	<a href="http://www.w3.org/Signature/">XML Canonicalization and XML
				3929	Digital Signature</a> <a
				3930	href="http://www.aleksey.com/xmlsec/">implementations for libxml2</a></li>
Daniel Veillard	c310d56	2000-06-23 18:32:15 +0000	[diff] [blame]	3931	</ul>
				3932
Daniel Veillard	c8eab3a	1999-09-04 18:27:23 +0000	[diff] [blame]	3933	<p></p>
Daniel Veillard	ccb0963	1998-10-27 06:21:04 +0000	[diff] [blame]	3934	</body>
				3935	</html>