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