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Daniel Veillard09ab7e12001-07-10 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 Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3<html>
4<head>
Daniel Veillard598bec32003-07-06 10:02:03 +0000[diff] [blame]5 <title>The XML C parser and toolkit of Gnome</title>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]6 <meta name="GENERATOR" content="amaya 5.1">
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]7 <meta http-equiv="Content-Type" content="text/html">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]8</head>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]9
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]10<body bgcolor="#ffffff">
Daniel Veillard598bec32003-07-06 10:02:03 +0000[diff] [blame]11<h1 align="center">The XML C parser and toolkit of Gnome</h1>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]12
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]13<h1>Note: this is the flat content of the <a href="index.html">web
14site</a></h1>
15
Daniel Veillardc9484202001-10-24 12:35:52 +0000[diff] [blame]16<h1 style="text-align: center">libxml, a.k.a. gnome-xml</h1>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]17
18<p></p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]19
Daniel Veillard598bec32003-07-06 10:02:03 +0000[diff] [blame]20<p>Libxml2 is the XML C parser and toolkit developed for the Gnome project
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]21(but usable outside of the Gnome platform). XML itself is a metalanguage to
22design markup languages, i.e. text language where semantic and structure are
23added to the content using extra "markup" information enclosed between angle
24brackets. HTML is the most well-known markup language. Though the library is
25written in C <a href="python.html">a variety of language bindings</a> make it
26available in other environments.</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]27
Daniel Veillard710823b2003-03-04 10:05:52 +0000[diff] [blame]28<p>Libxml2 is known to be very portable, the library should build and work
29without serious troubles on a variety of systems (Linux, Unix, Windows,
30CygWin, MacOS, MacOS X, RISC Os, OS/2, VMS, QNX, MVS, ...)</p>
31
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]32<p>Libxml2 implements a number of existing standards related to markup
33languages:</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]34<ul>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]35 <li>the XML standard: <a
36 href="http://www.w3.org/TR/REC-xml">http://www.w3.org/TR/REC-xml</a></li>
37 <li>Namespaces in XML: <a
38 href="http://www.w3.org/TR/REC-xml-names/">http://www.w3.org/TR/REC-xml-names/</a></li>
39 <li>XML Base: <a
40 href="http://www.w3.org/TR/xmlbase/">http://www.w3.org/TR/xmlbase/</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]41 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc2396.txt">RFC 2396</a> :
42 Uniform Resource Identifiers <a
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]43 href="http://www.ietf.org/rfc/rfc2396.txt">http://www.ietf.org/rfc/rfc2396.txt</a></li>
44 <li>XML Path Language (XPath) 1.0: <a
45 href="http://www.w3.org/TR/xpath">http://www.w3.org/TR/xpath</a></li>
46 <li>HTML4 parser: <a
47 href="http://www.w3.org/TR/html401/">http://www.w3.org/TR/html401/</a></li>
48 <li>most of XML Pointer Language (XPointer) Version 1.0: <a
49 href="http://www.w3.org/TR/xptr">http://www.w3.org/TR/xptr</a></li>
50 <li>XML Inclusions (XInclude) Version 1.0: <a
51 href="http://www.w3.org/TR/xinclude/">http://www.w3.org/TR/xinclude/</a></li>
52 <li>[ISO-8859-1], <a
53 href="http://www.cis.ohio-state.edu/rfc/rfc2044.txt">rfc2044</a> [UTF-8]
54 and <a href="http://www.cis.ohio-state.edu/rfc/rfc2781.txt">rfc2781</a>
55 [UTF-16] core encodings</li>
56 <li>part of SGML Open Technical Resolution TR9401:1997</li>
57 <li>XML Catalogs Working Draft 06 August 2001: <a
58 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 Veillard5c396542002-03-15 07:57:50 +0000[diff] [blame]59 <li>Canonical XML Version 1.0: <a
60 href="http://www.w3.org/TR/xml-c14n">http://www.w3.org/TR/xml-c14n</a>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]61 and the Exclusive XML Canonicalization CR draft <a
62 href="http://www.w3.org/TR/xml-exc-c14n">http://www.w3.org/TR/xml-exc-c14n</a></li>
Daniel Veillard17bed982003-02-24 20:11:43 +0000[diff] [blame]63 <li>Relax NG Committee Specification 3 December 2001 <a
64 href="http://www.oasis-open.org/committees/relax-ng/spec-20011203.html">http://www.oasis-open.org/committees/relax-ng/spec-20011203.html</a></li>
Daniel Veillardf83a2c72003-04-08 13:48:40 +0000[diff] [blame]65 <li>W3C XML Schemas Part 2: Datatypes <a
66 href="http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/">REC 02 May
67 2001</a> except the base64Binary and hexBinary types</li>
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]68</ul>
69
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]70<p>In most cases libxml2 tries to implement the specifications in a
71relatively strictly compliant way. As of release 2.4.16, libxml2 passes all
721800+ tests from the <a
Daniel Veillarda5393562002-02-20 11:40:49 +0000[diff] [blame]73href="http://www.oasis-open.org/committees/xml-conformance/">OASIS XML Tests
74Suite</a>.</p>
Daniel Veillard5b16f582002-02-20 11:38:46 +0000[diff] [blame]75
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]76<p>To some extent libxml2 provides support for the following additional
77specifications but doesn't claim to implement them completely:</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]78<ul>
79 <li>Document Object Model (DOM) <a
80 href="http://www.w3.org/TR/DOM-Level-2-Core/">http://www.w3.org/TR/DOM-Level-2-Core/</a>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]81 it doesn't implement the API itself, gdome2 does this on top of
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]82 libxml2</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]83 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc959.txt">RFC 959</a> :
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]84 libxml2 implements a basic FTP client code</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]85 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc1945.txt">RFC 1945</a> :
86 HTTP/1.0, again a basic HTTP client code</li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]87 <li>SAX: a minimal SAX implementation compatible with early expat
88 versions</li>
89 <li>DocBook SGML v4: libxml2 includes a hackish parser to transition to
90 XML</li>
91</ul>
92
Daniel Veillardf83a2c72003-04-08 13:48:40 +0000[diff] [blame]93<p>A partial implementation of <a
94href="http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/">XML Schemas Part
951: Structure</a> is being worked on but it would be far too early to make any
96conformance statement about it at the moment.</p>
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]97
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]98<p>Separate documents:</p>
99<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]100 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a> providing an
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]101 implementation of XSLT 1.0 and common extensions like EXSLT for
102 libxml2</li>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]103 <li><a href="http://www.cs.unibo.it/~casarini/gdome2/">the gdome2 page</a>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]104 : a standard DOM2 implementation for libxml2</li>
105 <li><a href="http://www.aleksey.com/xmlsec/">the XMLSec page</a>: an
106 implementation of <a href="http://www.w3.org/TR/xmldsig-core/">W3C XML
107 Digital Signature</a> for libxml2</li>
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]108 <li>also check the related links section below for more related and active
109 projects.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]110</ul>
111
Daniel Veillard806cada2003-03-19 21:58:59 +0000[diff] [blame]112<p>Results of the <a
113href="http://xmlbench.sourceforge.net/results/benchmark/index.html">xmlbench
114benchmark</a> on sourceforge 19 March 2003 (smaller is better):</p>
Daniel Veillardd8da01c2003-03-24 15:58:23 +0000[diff] [blame]115
116<p align="center"><img src="benchmark.gif"
117alt="benchmark results for Expat Xerces libxml2 Oracle and Sun toolkits"></p>
Daniel Veillard806cada2003-03-19 21:58:59 +0000[diff] [blame]118
Daniel Veillarde1662542002-08-28 11:50:59 +0000[diff] [blame]119<p>Logo designed by <a href="mailto:liyanage@access.ch">Marc Liyanage</a>.</p>
120
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]121<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]122
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]123<p>This document describes libxml, the <a
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]124href="http://www.w3.org/XML/">XML</a> C parser and toolkit developed for the
125<a href="http://www.gnome.org/">Gnome</a> project. <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]126href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
127structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]128
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]129<p>Here are some key points about libxml:</p>
130<ul>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]131 <li>Libxml2 exports Push (progressive) and Pull (blocking) type parser
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]132 interfaces for both XML and HTML.</li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]133 <li>Libxml2 can do DTD validation at parse time, using a parsed document
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]134 instance, or with an arbitrary DTD.</li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]135 <li>Libxml2 includes complete <a
Daniel Veillard8c2ecaf2001-07-10 17:53:07 +0000[diff] [blame]136 href="http://www.w3.org/TR/xpath">XPath</a>, <a
137 href="http://www.w3.org/TR/xptr">XPointer</a> and <a
138 href="http://www.w3.org/TR/xinclude">XInclude</a> implementations.</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]139 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]140 sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]141 Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]142 <li>Basic support for HTTP and FTP client allowing applications to fetch
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]143 remote resources.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]144 <li>The design is modular, most of the extensions can be compiled out.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]145 <li>The internal document representation is as close as possible to the <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]146 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]147 <li>Libxml2 also has a <a
148 href="http://www.megginson.com/SAX/index.html">SAX like interface</a>;
149 the interface is designed to be compatible with <a
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]150 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]151 <li>This library is released under the <a
152 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]153 License</a>. See the Copyright file in the distribution for the precise
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]154 wording.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]155</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]156
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]157<p>Warning: unless you are forced to because your application links with a
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]158Gnome-1.X library requiring it, <strong><span
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]159style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
160libxml2</p>
161
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]162<h2><a name="FAQ">FAQ</a></h2>
163
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]164<p>Table of Contents:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]165<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]166 <li><a href="FAQ.html#License">License(s)</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]167 <li><a href="FAQ.html#Installati">Installation</a></li>
168 <li><a href="FAQ.html#Compilatio">Compilation</a></li>
169 <li><a href="FAQ.html#Developer">Developer corner</a></li>
170</ul>
171
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]172<h3><a name="License">License</a>(s)</h3>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]173<ol>
174 <li><em>Licensing Terms for libxml</em>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]175 <p>libxml2 is released under the <a
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]176 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]177 License</a>; see the file Copyright in the distribution for the precise
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]178 wording</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]179 </li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]180 <li><em>Can I embed libxml2 in a proprietary application ?</em>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]181 <p>Yes. The MIT License allows you to keep proprietary the changes you
182 made to libxml, but it would be graceful to send-back bug fixes and
183 improvements as patches for possible incorporation in the main
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]184 development tree.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]185 </li>
186</ol>
187
188<h3><a name="Installati">Installation</a></h3>
189<ol>
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]190 <li><strong><span style="background-color: #FF0000">Do Not Use
191 libxml1</span></strong>, use libxml2</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]192 <li><em>Where can I get libxml</em> ?
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]193 <p>The original distribution comes from <a
194 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a
Daniel Veillard6581e1b2003-02-09 22:21:43 +0000[diff] [blame]195 href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.5/">gnome.org</a></p>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]196 <p>Most Linux and BSD distributions include libxml, this is probably the
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]197 safer way for end-users to use libxml.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]198 <p>David Doolin provides precompiled Windows versions at <a
199 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
200 </li>
201 <li><em>I see libxml and libxml2 releases, which one should I install ?</em>
202 <ul>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]203 <li>If you are not constrained by backward compatibility issues with
204 existing applications, install libxml2 only</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]205 <li>If you are not doing development, you can safely install both.
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]206 Usually the packages <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]207 href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a
208 href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]209 compatible (this is not the case for development packages).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]210 <li>If you are a developer and your system provides separate packaging
211 for shared libraries and the development components, it is possible
212 to install libxml and libxml2, and also <a
213 href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
214 and <a
215 href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
216 too for libxml2 &gt;= 2.3.0</li>
217 <li>If you are developing a new application, please develop against
218 libxml2(-devel)</li>
219 </ul>
220 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]221 <li><em>I can't install the libxml package, it conflicts with libxml0</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]222 <p>You probably have an old libxml0 package used to provide the shared
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]223 library for libxml.so.0, you can probably safely remove it. The libxml
224 packages provided on <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]225 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provide
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]226 libxml.so.0</p>
227 </li>
228 <li><em>I can't install the libxml(2) RPM package due to failed
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]229 dependencies</em>
230 <p>The most generic solution is to re-fetch the latest src.rpm , and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]231 rebuild it locally with</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]232 <p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code>.</p>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]233 <p>If everything goes well it will generate two binary rpm packages (one
234 providing the shared libs and xmllint, and the other one, the -devel
235 package, providing includes, static libraries and scripts needed to build
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]236 applications with libxml(2)) that you can install locally.</p>
237 </li>
238</ol>
239
240<h3><a name="Compilatio">Compilation</a></h3>
241<ol>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]242 <li><em>What is the process to compile libxml2 ?</em>
243 <p>As most UNIX libraries libxml2 follows the "standard":</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]244 <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p>
245 <p><code>cd libxml-xxxx</code></p>
246 <p><code>./configure --help</code></p>
247 <p>to see the options, then the compilation/installation proper</p>
248 <p><code>./configure [possible options]</code></p>
249 <p><code>make</code></p>
250 <p><code>make install</code></p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]251 <p>At that point you may have to rerun ldconfig or a similar utility to
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]252 update your list of installed shared libs.</p>
253 </li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]254 <li><em>What other libraries are needed to compile/install libxml2 ?</em>
255 <p>Libxml2 does not require any other library, the normal C ANSI API
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]256 should be sufficient (please report any violation to this rule you may
257 find).</p>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]258 <p>However if found at configuration time libxml2 will detect and use the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]259 following libs:</p>
260 <ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]261 <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a> : a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]262 highly portable and available widely compression library.</li>
263 <li>iconv: a powerful character encoding conversion library. It is
264 included by default in recent glibc libraries, so it doesn't need to
265 be installed specifically on Linux. It now seems a <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]266 href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
267 of the official UNIX</a> specification. Here is one <a
Daniel Veillarddad3f682002-11-17 16:47:27 +0000[diff] [blame]268 href="http://www.gnu.org/software/libiconv/">implementation of the
269 library</a> which source can be found <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]270 href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
271 </ul>
272 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]273 <li><em>Make check fails on some platforms</em>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]274 <p>Sometimes the regression tests' results don't completely match the
275 value produced by the parser, and the makefile uses diff to print the
276 delta. On some platforms the diff return breaks the compilation process;
277 if the diff is small this is probably not a serious problem.</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]278 <p>Sometimes (especially on Solaris) make checks fail due to limitations
Daniel Veillarde46182c2002-02-12 14:29:11 +0000[diff] [blame]279 in make. Try using GNU-make instead.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]280 </li>
281 <li><em>I use the CVS version and there is no configure script</em>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]282 <p>The configure script (and other Makefiles) are generated. Use the
283 autogen.sh script to regenerate the configure script and Makefiles,
284 like:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]285 <p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
286 </li>
287 <li><em>I have troubles when running make tests with gcc-3.0</em>
288 <p>It seems the initial release of gcc-3.0 has a problem with the
289 optimizer which miscompiles the URI module. Please use another
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]290 compiler.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]291 </li>
292</ol>
293
294<h3><a name="Developer">Developer</a> corner</h3>
295<ol>
Daniel Veillard93d95252003-04-29 20:25:40 +0000[diff] [blame]296 <li><em>Troubles compiling or linking programs using libxml2</em>
297 <p>Usually the problem comes from the fact that the compiler doesn't get
298 the right compilation or linking flags. There is a small shell script
299 <code>xml2-config</code> which is installed as part of libxml2 usual
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]300 install process which provides those flags. Use</p>
Daniel Veillard93d95252003-04-29 20:25:40 +0000[diff] [blame]301 <p><code>xml2-config --cflags</code></p>
302 <p>to get the compilation flags and</p>
303 <p><code>xml2-config --libs</code></p>
304 <p>to get the linker flags. Usually this is done directly from the
305 Makefile as:</p>
306 <p><code>CFLAGS=`xml2-config --cflags`</code></p>
307 <p><code>LIBS=`xml2-config --libs`</code></p>
308 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]309 <li><em>xmlDocDump() generates output on one line.</em>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]310 <p>Libxml2 will not <strong>invent</strong> spaces in the content of a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]311 document since <strong>all spaces in the content of a document are
312 significant</strong>. If you build a tree from the API and want
313 indentation:</p>
314 <ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]315 <li>the correct way is to generate those yourself too.</li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]316 <li>the dangerous way is to ask libxml2 to add those blanks to your
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]317 content <strong>modifying the content of your document in the
318 process</strong>. The result may not be what you expect. There is
319 <strong>NO</strong> way to guarantee that such a modification won't
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]320 affect other parts of the content of your document. See <a
Daniel Veillard5373ea12003-07-24 13:09:13 +0000[diff] [blame]321 href="http://xmlsoft.org/html/libxml-parser.html#xmlKeepBlanksDefault">xmlKeepBlanksDefault
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]322 ()</a> and <a
Daniel Veillard5373ea12003-07-24 13:09:13 +0000[diff] [blame]323 href="http://xmlsoft.org/html/libxml-tree.html#xmlSaveFormatFile">xmlSaveFormatFile
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]324 ()</a></li>
325 </ol>
326 </li>
327 <li>Extra nodes in the document:
328 <p><em>For a XML file as below:</em></p>
329 <pre>&lt;?xml version="1.0"?&gt;
330&lt;PLAN xmlns="http://www.argus.ca/autotest/1.0/"&gt;
331&lt;NODE CommFlag="0"/&gt;
332&lt;NODE CommFlag="1"/&gt;
333&lt;/PLAN&gt;</pre>
334 <p><em>after parsing it with the function
335 pxmlDoc=xmlParseFile(...);</em></p>
336 <p><em>I want to the get the content of the first node (node with the
337 CommFlag="0")</em></p>
338 <p><em>so I did it as following;</em></p>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]339 <pre>xmlNodePtr pnode;
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]340pnode=pxmlDoc-&gt;children-&gt;children;</pre>
341 <p><em>but it does not work. If I change it to</em></p>
342 <pre>pnode=pxmlDoc-&gt;children-&gt;children-&gt;next;</pre>
343 <p><em>then it works. Can someone explain it to me.</em></p>
344 <p></p>
345 <p>In XML all characters in the content of the document are significant
346 <strong>including blanks and formatting line breaks</strong>.</p>
347 <p>The extra nodes you are wondering about are just that, text nodes with
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]348 the formatting spaces which are part of the document but that people tend
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]349 to forget. There is a function <a
350 href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
351 ()</a> to remove those at parse time, but that's an heuristic, and its
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]352 use should be limited to cases where you are certain there is no
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]353 mixed-content in the document.</p>
354 </li>
355 <li><em>I get compilation errors of existing code like when accessing
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]356 <strong>root</strong> or <strong>child fields</strong> of nodes.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]357 <p>You are compiling code developed for libxml version 1 and using a
358 libxml2 development environment. Either switch back to libxml v1 devel or
359 even better fix the code to compile with libxml2 (or both) by <a
360 href="upgrade.html">following the instructions</a>.</p>
361 </li>
362 <li><em>I get compilation errors about non existing
363 <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]364 fields.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]365 <p>The source code you are using has been <a
366 href="upgrade.html">upgraded</a> to be able to compile with both libxml
367 and libxml2, but you need to install a more recent version:
368 libxml(-devel) &gt;= 1.8.8 or libxml2(-devel) &gt;= 2.1.0</p>
369 </li>
370 <li><em>XPath implementation looks seriously broken</em>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]371 <p>XPath implementation prior to 2.3.0 was really incomplete. Upgrade to
372 a recent version, there are no known bugs in the current version.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]373 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]374 <li><em>The example provided in the web page does not compile.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]375 <p>It's hard to maintain the documentation in sync with the code
376 &lt;grin/&gt; ...</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]377 <p>Check the previous points 1/ and 2/ raised before, and please send
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]378 patches.</p>
379 </li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]380 <li><em>Where can I get more examples and information than privoded on the
381 web page?</em>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]382 <p>Ideally a libxml2 book would be nice. I have no such plan ... But you
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]383 can:</p>
384 <ul>
385 <li>check more deeply the <a href="html/libxml-lib.html">existing
386 generated doc</a></li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]387 <li>look for examples of use for libxml2 function using the Gnome code.
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]388 For example the following will query the full Gnome CVS base for the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]389 use of the <strong>xmlAddChild()</strong> function:
390 <p><a
391 href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p>
392 <p>This may be slow, a large hardware donation to the gnome project
393 could cure this :-)</p>
394 </li>
395 <li><a
396 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gnome-xml">Browse
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]397 the libxml2 source</a> , I try to write code as clean and documented
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]398 as possible, so looking at it may be helpful. In particular the code
399 of xmllint.c and of the various testXXX.c test programs should
400 provide good examples of how to do things with the library.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]401 </ul>
402 </li>
403 <li>What about C++ ?
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]404 <p>libxml2 is written in pure C in order to allow easy reuse on a number
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]405 of platforms, including embedded systems. I don't intend to convert to
406 C++.</p>
Daniel Veillard91e69c52003-08-04 01:43:07 +0000[diff] [blame]407 <p>There is however a C++ wrapper which may fulfill your needs:</p>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]408 <ul>
409 <li>by Ari Johnson &lt;ari@btigate.com&gt;:
410 <p>Website: <a
Daniel Veillard91e69c52003-08-04 01:43:07 +0000[diff] [blame]411 href="http://libxmlplusplus.sourceforge.net/">http://libxmlplusplus.sourceforge.net/</a></p>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]412 <p>Download: <a
Daniel Veillard91e69c52003-08-04 01:43:07 +0000[diff] [blame]413 href="http://sourceforge.net/project/showfiles.php?group_id=12999">http://sourceforge.net/project/showfiles.php?group_id=12999</a></p>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]414 </li>
Daniel Veillard83ee40d2003-08-09 22:24:09 +0000[diff] [blame]415 <!-- Website is currently unavailable as of 2003-08-02
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]416 <li>by Peter Jones &lt;pjones@pmade.org&gt;
Daniel Veillard83ee40d2003-08-09 22:24:09 +0000[diff] [blame]417 <p>Website: <a
418 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]419 </li>
Daniel Veillard83ee40d2003-08-09 22:24:09 +0000[diff] [blame]420 -->
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]421 </ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]422 </li>
423 <li>How to validate a document a posteriori ?
424 <p>It is possible to validate documents which had not been validated at
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]425 initial parsing time or documents which have been built from scratch
426 using the API. Use the <a
Daniel Veillard5373ea12003-07-24 13:09:13 +0000[diff] [blame]427 href="http://xmlsoft.org/html/libxml-valid.html#xmlValidateDtd">xmlValidateDtd()</a>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]428 function. It is also possible to simply add a DTD to an existing
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]429 document:</p>
430 <pre>xmlDocPtr doc; /* your existing document */
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]431xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
432
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]433 dtd-&gt;name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */
434
435 doc-&gt;intSubset = dtd;
436 if (doc-&gt;children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
437 else xmlAddPrevSibling(doc-&gt;children, (xmlNodePtr)dtd);
438 </pre>
439 </li>
Daniel Veillarddad3f682002-11-17 16:47:27 +0000[diff] [blame]440 <li>So what is this funky "xmlChar" used all the time?
441 <p>It is a null terminated sequence of utf-8 characters. And only utf-8!
442 You need to convert strings encoded in different ways to utf-8 before
443 passing them to the API. This can be accomplished with the iconv library
444 for instance.</p>
John Fleck61f6fb62002-10-31 15:23:29 +0000[diff] [blame]445 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]446 <li>etc ...</li>
447</ol>
448
449<p></p>
450
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]451<h2><a name="Documentat">Developer Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]452
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]453<p>There are several on-line resources related to using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]454<ol>
Daniel Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame]455 <li>Use the <a href="search.php">search engine</a> to lookup
456 informations.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]457 <li>Check the <a href="FAQ.html">FAQ.</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]458 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]459 documentation</a> automatically extracted from code comments (using <a
460 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
461 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]462 <li>Look at the documentation about <a href="encoding.html">libxml
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]463 internationalization support</a>.</li>
Daniel Veillardbc66f852002-01-14 09:49:20 +0000[diff] [blame]464 <li>This page provides a global overview and <a href="example.html">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]465 examples</a> on how to use libxml.</li>
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]466 <li>John Fleck's libxml2 tutorial: <a href="tutorial/index.html">html</a>
467 or <a href="tutorial/xmltutorial.pdf">pdf</a>.</li>
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]468 <li>If you need to parse large files, check the <a
469 href="xmlreader.html">xmlReader</a> API tutorial</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]470 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]471 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
472 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]473 <li>George Lebl wrote <a
474 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]475 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]476 <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]477 file</a>.</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]478 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>
479 description. If you are starting a new project using libxml you should
480 really use the 2.x version.</li>
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]481 <li>And don't forget to look at the <a
482 href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]483</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]484
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]485<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]486
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]487<p>Well, bugs or missing features are always possible, and I will make a
488point of fixing them in a timely fashion. The best way to report a bug is to
Daniel Veillardccf996f2003-08-14 10:48:38 +0000[diff] [blame]489use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml2">Gnome
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]490bug tracking database</a> (make sure to use the "libxml2" module name). I
491look at reports there regularly and it's good to have a reminder when a bug
492is still open. Be sure to specify that the bug is for the package libxml2.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]493
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]494<p>There is also a mailing-list <a
Daniel Veillard3197f162001-04-04 00:40:08 +0000[diff] [blame]495href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
496href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]497href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
498please visit the <a
499href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
500follow the instructions. <strong>Do not send code, I won't debug it</strong>
501(but patches are really appreciated!).</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]502
Daniel Veillard008186f2001-09-13 14:24:44 +0000[diff] [blame]503<p>Check the following <strong><span style="color: #FF0000">before
504posting</span></strong>:</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]505<ul>
Daniel Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame]506 <li>Read the <a href="FAQ.html">FAQ</a> and <a href="search.php">use the
Daniel Veillarda37aab82003-06-09 09:10:36 +0000[diff] [blame]507 search engine</a> to get information related to your problem.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]508 <li>Make sure you are <a href="ftp://xmlsoft.org/">using a recent
509 version</a>, and that the problem still shows up in a recent version.</li>
510 <li>Check the <a href="http://mail.gnome.org/archives/xml/">list
511 archives</a> to see if the problem was reported already. In this case
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]512 there is probably a fix available, similarly check the <a
Daniel Veillardccf996f2003-08-14 10:48:38 +0000[diff] [blame]513 href="http://bugzilla.gnome.org/buglist.cgi?product=libxml2">registered
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]514 open bugs</a>.</li>
515 <li>Make sure you can reproduce the bug with xmllint or one of the test
516 programs found in source in the distribution.</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]517 <li>Please send the command showing the error as well as the input (as an
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]518 attachment)</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]519</ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]520
Daniel Veillarda37aab82003-06-09 09:10:36 +0000[diff] [blame]521<p>Then send the bug with associated information to reproduce it to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]522href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillard98d071d2003-01-10 09:22:44 +0000[diff] [blame]523related I will approve it. Please do not send mail to me directly, it makes
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]524things really hard to track and in some cases I am not the best person to
Daniel Veillard98d071d2003-01-10 09:22:44 +0000[diff] [blame]525answer a given question, ask on the list.</p>
526
527<p>To <span style="color: #E50000">be really clear about support</span>:</p>
528<ul>
Daniel Veillarda37aab82003-06-09 09:10:36 +0000[diff] [blame]529 <li>Support or help <span style="color: #E50000">requests MUST be sent to
Daniel Veillard98d071d2003-01-10 09:22:44 +0000[diff] [blame]530 the list or on bugzilla</span> in case of problems, so that the Question
531 and Answers can be shared publicly. Failing to do so carries the implicit
532 message "I want free support but I don't want to share the benefits with
Daniel Veillard831e8fd2003-01-25 11:45:34 +0000[diff] [blame]533 others" and is not welcome. I will automatically Carbon-Copy the
534 xml@gnome.org mailing list for any technical reply made about libxml2 or
535 libxslt.</li>
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]536 <li>There is <span style="color: #E50000">no garantee of support</span>, if
537 your question remains unanswered after a week, repost it, making sure you
538 gave all the detail needed and the information requested.</li>
Daniel Veillarda37aab82003-06-09 09:10:36 +0000[diff] [blame]539 <li>Failing to provide information as requested or double checking first
Daniel Veillard98d071d2003-01-10 09:22:44 +0000[diff] [blame]540 for prior feedback also carries the implicit message "the time of the
541 library maintainers is less valuable than my time" and might not be
542 welcome.</li>
543</ul>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]544
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]545<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]546probably be processed faster than those without.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]547
548<p>If you're looking for help, a quick look at <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]549href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]550provide the answer. I usually send source samples when answering libxml2
551usage questions. The <a
552href="http://xmlsoft.org/html/book1.html">auto-generated documentation</a> is
553not as polished as I would like (i need to learn more about DocBook), but
554it's a good starting point.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]555
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]556<h2><a name="help">How to help</a></h2>
557
558<p>You can help the project in various ways, the best thing to do first is to
559subscribe to the mailing-list as explained before, check the <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]560href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
Daniel Veillardccf996f2003-08-14 10:48:38 +0000[diff] [blame]561href="http://bugzilla.gnome.org/buglist.cgi?product=libxml2">Gnome bug
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]562database</a>:</p>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]563<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]564 <li>Provide patches when you find problems.</li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]565 <li>Provide the diffs when you port libxml2 to a new platform. They may not
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]566 be integrated in all cases but help pinpointing portability problems
567 and</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]568 <li>Provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]569 as HTML diffs).</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]570 <li>Provide new documentations pieces (translations, examples, etc
571 ...).</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]572 <li>Check the TODO file and try to close one of the items.</li>
573 <li>Take one of the points raised in the archive or the bug database and
Daniel Veillarde7ead2d2001-08-22 23:44:09 +0000[diff] [blame]574 provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me
575 </a>before to avoid synchronization problems and check that the suggested
576 fix will fit in nicely :-)</li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]577</ol>
578
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]579<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]580
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]581<p>The latest versions of libxml2 can be found on <a
Daniel Veillard20c8cf22001-06-26 22:47:36 +0000[diff] [blame]582href="ftp://xmlsoft.org/">xmlsoft.org</a> (<a
583href="ftp://speakeasy.rpmfind.net/pub/libxml/">Seattle</a>, <a
584href="ftp://fr.rpmfind.net/pub/libxml/">France</a>) or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]585href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard6581e1b2003-02-09 22:21:43 +0000[diff] [blame]586as a <a href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.5/">source
MDT 2002 John Fleck30c70542002-09-24 14:24:54 +0000[diff] [blame]587archive</a><!-- commenting this out because they seem to have disappeared or <a
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]588href="ftp://ftp.gnome.org/pub/GNOME/stable/redhat/i386/libxml/">RPM
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]589packages</a> -->
Daniel Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame]590 , Antonin Sprinzl also provide <a href="ftp://gd.tuwien.ac.at/pub/libxml/">a
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]591mirror in Austria</a>. (NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]592href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
593href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillardb46a5732003-04-08 13:35:48 +0000[diff] [blame]594packages installed to compile applications using libxml.)</p>
595
596<p>Binary ports:</p>
597<ul>
598 <li>Red Hat RPMs for i386 are available directly on <a
599 href="ftp://xmlsoft.org/">xmlsoft.org</a>, the source RPM will compile on
600 any architecture supported by Red Hat.</li>
Daniel Veillardf83a2c72003-04-08 13:48:40 +0000[diff] [blame]601 <li><p><a href="mailto:igor@zlatkovic.com">Igor Zlatkovic</a></p>
Daniel Veillardce192eb2003-04-16 15:58:05 +0000[diff] [blame]602 is now the maintainer of the Windows port, <a
Daniel Veillardb46a5732003-04-08 13:35:48 +0000[diff] [blame]603 href="http://www.zlatkovic.com/projects/libxml/index.html">he provides
604 binaries</a>.</li>
605 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
606 <a href="http://garypennington.net/libxml2/">Solaris binaries</a>.</li>
607 <li><a href="mailto:Steve.Ball@zveno.com">Steve Ball</a> provides <a
608 href="http://www.zveno.com/open_source/libxml2xslt.html">Mac Os X
609 binaries</a>.</li>
610 <li>The HP-UX porting center provides <a
611 href="http://hpux.connect.org.uk/hppd/hpux/Gnome/">HP-UX binaries</a></li>
612</ul>
613
614<p>If you know other supported binary ports, please <a
615href="http://veillard.com/">contact me</a>.</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]616
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]617<p><a name="Snapshot">Snapshot:</a></p>
618<ul>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]619 <li>Code from the W3C cvs base gnome-xml <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]620 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]621 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]622 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]623</ul>
624
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]625<p><a name="Contribs">Contributions:</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]626
627<p>I do accept external contributions, especially if compiling on another
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]628platform, get in touch with me to upload the package, wrappers for various
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]629languages have been provided, and can be found in the <a
630href="contribs.html">contrib section</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]631
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]632<p>Libxml2 is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]633<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]634 <li><p>The <a
635 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gnome-xml">Gnome
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]636 CVS base</a>. Check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]637 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a>
638 page; the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]639 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]640 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]641</ul>
642
643<h2><a name="News">News</a></h2>
644
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]645<h3>CVS only : check the <a
646href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]647for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]648
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]649<p>Items not finished and worked on, get in touch with the list if you want
650to test those</p>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]651<ul>
Daniel Veillard72fef162003-02-05 14:31:19 +0000[diff] [blame]652 <li>More testing on RelaxNG</li>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]653 <li>Finishing up <a href="http://www.w3.org/TR/xmlschema-1/">XML
Daniel Veillard72fef162003-02-05 14:31:19 +0000[diff] [blame]654 Schemas</a></li>
655</ul>
656
Daniel Veillardcfba2fe2003-08-15 00:33:43 +0000[diff] [blame^]657<h3>2.5.10: Aug 15 2003</h3>
658
659<p>A bugfixes only release</p>
660<ul>
661 <li>Windows Makefiles (William Brack)</li>
662 <li>UTF-16 support fixes (Mark Itzcovitz)</li>
663 <li>Makefile and portability (William Brack) automake, Linux alpha, Mingw
664 on Windows (Mikhail Grushinskiy) </li>
665 <li>HTML parser (Oliver Stoeneberg)</li>
666 <li>XInclude performance problem reported by Kevin Ruscoe</li>
667 <li>XML parser performance problem reported by Grant Goodale</li>
668 <li>xmlSAXParseDTD() bug fix from Malcolm Tredinnick</li>
669 <li>and a couple other cleanup </li>
670</ul>
671
Daniel Veillard83ee40d2003-08-09 22:24:09 +0000[diff] [blame]672<h3>2.5.9: Aug 9 2003</h3>
673<ul>
674 <li>bugfixes: IPv6 portability, xmlHasNsProp (Markus Keim), Windows build
675 (Wiliam Brake, Jesse Pelton, Igor), Schemas (Peter Sobisch), threading
676 (Rob Richards), hexBinary type (), UTF-16 BOM (Dodji Seketeli),
677 xmlReader, Relax-NG schemas compilation, namespace handling, EXSLT (Sean
678 Griffin), HTML parsing problem (William Brack), DTD validation for mixed
679 content + namespaces, HTML serialization, library initialization,
680 progressive HTML parser</li>
681 <li>better interfaces for Relax-NG error handling (Joachim Bauch, )</li>
682 <li>adding xmlXIncludeProcessTree() for XInclud'ing in a subtree</li>
683 <li>doc fixes and improvements (John Fleck)</li>
684 <li>configure flag for -with-fexceptions when embedding in C++</li>
685 <li>couple of new UTF-8 helper functions (William Brack)</li>
686 <li>general encoding cleanup + ISO-8859-x without iconv (Peter Jacobi)</li>
687 <li>xmlTextReader cleanup + enum for node types (Bjorn Reese)</li>
688 <li>general compilation/warning cleanup Solaris/HP-UX/... (William
689 Brack)</li>
690</ul>
691
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]692<h3>2.5.8: Jul 6 2003</h3>
693<ul>
694 <li>bugfixes: XPath, XInclude, file/URI mapping, UTF-16 save (Mark
695 Itzcovitz), UTF-8 checking, URI saving, error printing (William Brack),
696 PI related memleak, compilation without schemas or without xpath (Joerg
697 Schmitz-Linneweber/Garry Pennington), xmlUnlinkNode problem with DTDs,
698 rpm problem on , i86_64, removed a few compilation problems from 2.5.7,
699 xmlIOParseDTD, and xmlSAXParseDTD (Malcolm Tredinnick)</li>
700 <li>portability: DJGPP (MsDos) , OpenVMS (Craig A. Berry)</li>
701 <li>William Brack fixed multithreading lock problems</li>
702 <li>IPv6 patch for FTP and HTTP accesses (Archana Shah/Wipro)</li>
703 <li>Windows fixes (Igor Zlatkovic, Eric Zurcher), threading (Stéphane
704 Bidoul)</li>
705 <li>A few W3C Schemas Structure improvements</li>
706 <li>W3C Schemas Datatype improvements (Charlie Bozeman)</li>
707 <li>Python bindings for thread globals (Stéphane Bidoul), and method/class
Daniel Veillard83ee40d2003-08-09 22:24:09 +0000[diff] [blame]708 generator</li>
709 <li>added --nonet option to xmllint</li>
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]710 <li>documentation improvements (John Fleck)</li>
711</ul>
712
Daniel Veillard92fc02c2003-04-24 23:12:35 +0000[diff] [blame]713<h3>2.5.7: Apr 25 2003</h3>
714<ul>
715 <li>Relax-NG: Compiling to regexp and streaming validation on top of the
716 xmlReader interface, added to xmllint --stream</li>
717 <li>xmlReader: Expand(), Next() and DOM access glue, bug fixes</li>
718 <li>Support for large files: RGN validated a 4.5GB instance</li>
719 <li>Thread support is now configured in by default</li>
720 <li>Fixes: update of the Trio code (Bjorn), WXS Date and Duration fixes
721 (Charles Bozeman), DTD and namespaces (Brent Hendricks), HTML push parser
722 and zero bytes handling, some missing Windows file path conversions,
723 behaviour of the parser and validator in the presence of "out of memory"
Daniel Veillard93d95252003-04-29 20:25:40 +0000[diff] [blame]724 error conditions</li>
Daniel Veillard92fc02c2003-04-24 23:12:35 +0000[diff] [blame]725 <li>extended the API to be able to plug a garbage collecting memory
726 allocator, added xmlMallocAtomic() and modified the allocations
727 accordingly.</li>
728 <li>Performances: removed excessive malloc() calls, speedup of the push and
729 xmlReader interfaces, removed excessive thread locking</li>
730 <li>Documentation: man page (John Fleck), xmlReader documentation</li>
731 <li>Python: adding binding for xmlCatalogAddLocal (Brent M Hendricks)</li>
732</ul>
733
Daniel Veillardc2d4a932003-04-01 11:13:05 +0000[diff] [blame]734<h3>2.5.6: Apr 1 2003</h3>
735<ul>
736 <li>Fixed W3C XML Schemas datatype, should be compliant now except for
737 binHex and base64 which are not supported yet.</li>
738 <li>bug fixes: non-ASCII IDs, HTML output, XInclude on large docs and
739 XInclude entities handling, encoding detection on external subsets, XML
740 Schemas bugs and memory leaks, HTML parser (James Bursa)</li>
741 <li>portability: python/trio (Albert Chin), Sun compiler warnings</li>
742 <li>documentation: added --relaxng option to xmllint man page (John)</li>
743 <li>improved error reporting: xml:space, start/end tag mismatches, Relax NG
744 errors</li>
745</ul>
746
747<h3>2.5.5: Mar 24 2003</h3>
Daniel Veillardd8da01c2003-03-24 15:58:23 +0000[diff] [blame]748<ul>
749 <li>Lot of fixes on the Relax NG implementation. More testing including
750 DocBook and TEI examples.</li>
751 <li>Increased the support for W3C XML Schemas datatype</li>
752 <li>Several bug fixes in the URI handling layer</li>
753 <li>Bug fixes: HTML parser, xmlReader, DTD validation, XPath, encoding
754 conversion, line counting in the parser.</li>
755 <li>Added support for $XMLLINT_INDENT environment variable, FTP delete</li>
756 <li>Fixed the RPM spec file name</li>
757</ul>
758
Daniel Veillard17bed982003-02-24 20:11:43 +0000[diff] [blame]759<h3>2.5.4: Feb 20 2003</h3>
760<ul>
761 <li>Conformance testing and lot of fixes on Relax NG and XInclude
762 implementation</li>
763 <li>Implementation of XPointer element() scheme</li>
764 <li>Bug fixes: XML parser, XInclude entities merge, validity checking on
765 namespaces,
766 <p>2 serialization bugs, node info generation problems, a DTD regexp
767 generation problem.</p>
768 </li>
769 <li>Portability: windows updates and path canonicalization (Igor)</li>
770 <li>A few typo fixes (Kjartan Maraas)</li>
771 <li>Python bindings generator fixes (Stephane Bidoul)</li>
772</ul>
773
Daniel Veillard1d788d22003-02-10 16:21:58 +0000[diff] [blame]774<h3>2.5.3: Feb 10 2003</h3>
775<ul>
776 <li>RelaxNG and XML Schemas datatypes improvements, and added a first
777 version of RelaxNG Python bindings</li>
778 <li>Fixes: XLink (Sean Chittenden), XInclude (Sean Chittenden), API fix for
779 serializing namespace nodes, encoding conversion bug, XHTML1
780 serialization</li>
781 <li>Portability fixes: Windows (Igor), AMD 64bits RPM spec file</li>
782</ul>
783
Daniel Veillard72fef162003-02-05 14:31:19 +0000[diff] [blame]784<h3>2.5.2: Feb 5 2003</h3>
785<ul>
786 <li>First implementation of RelaxNG, added --relaxng flag to xmllint</li>
787 <li>Schemas support now compiled in by default.</li>
788 <li>Bug fixes: DTD validation, namespace checking, XInclude and entities,
789 delegateURI in XML Catalogs, HTML parser, XML reader (Stéphane Bidoul),
790 XPath parser and evaluation, UTF8ToUTF8 serialization, XML reader memory
791 consumption, HTML parser, HTML serialization in the presence of
792 namespaces</li>
793 <li>added an HTML API to check elements and attributes.</li>
794 <li>Documentation improvement, PDF for the tutorial (John Fleck), doc
795 patches (Stefan Kost)</li>
796 <li>Portability fixes: NetBSD (Julio Merino), Windows (Igor Zlatkovic)</li>
797 <li>Added python bindings for XPointer, contextual error reporting
798 (Stéphane Bidoul)</li>
799 <li>URI/file escaping problems (Stefano Zacchiroli)</li>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]800</ul>
801
Daniel Veillarde2830f12003-01-08 17:47:49 +0000[diff] [blame]802<h3>2.5.1: Jan 8 2003</h3>
803<ul>
804 <li>Fixes a memory leak and configuration/compilation problems in 2.5.0</li>
805 <li>documentation updates (John)</li>
806 <li>a couple of XmlTextReader fixes</li>
807</ul>
808
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000[diff] [blame]809<h3>2.5.0: Jan 6 2003</h3>
810<ul>
811 <li>New <a href="xmlreader.html">XmltextReader interface</a> based on C#
812 API (with help of Stéphane Bidoul)</li>
813 <li>Windows: more exports, including the new API (Igor)</li>
814 <li>XInclude fallback fix</li>
815 <li>Python: bindings for the new API, packaging (Stéphane Bidoul),
816 drv_libxml2.py Python xml.sax driver (Stéphane Bidoul), fixes, speedup
817 and iterators for Python-2.2 (Hannu Krosing)</li>
818 <li>Tutorial fixes (john Fleck and Niraj Tolia) xmllint man update
819 (John)</li>
820 <li>Fix an XML parser bug raised by Vyacheslav Pindyura</li>
821 <li>Fix for VMS serialization (Nigel Hall) and config (Craig A. Berry)</li>
822 <li>Entities handling fixes</li>
823 <li>new API to optionally track node creation and deletion (Lukas
824 Schroeder)</li>
825 <li>Added documentation for the XmltextReader interface and some <a
826 href="guidelines.html">XML guidelines</a></li>
827</ul>
828
Daniel Veillardc1eed322002-12-12 11:01:32 +0000[diff] [blame]829<h3>2.4.30: Dec 12 2002</h3>
830<ul>
831 <li>2.4.29 broke the python bindings, rereleasing</li>
832 <li>Improvement/fixes of the XML API generator, and couple of minor code
833 fixes.</li>
834</ul>
835
Daniel Veillard9b4bb4d2002-12-11 19:28:47 +0000[diff] [blame]836<h3>2.4.29: Dec 11 2002</h3>
837<ul>
838 <li>Windows fixes (Igor): Windows CE port, pthread linking, python bindings
839 (Stéphane Bidoul), Mingw (Magnus Henoch), and export list updates</li>
840 <li>Fix for prev in python bindings (ERDI Gergo)</li>
841 <li>Fix for entities handling (Marcus Clarke)</li>
842 <li>Refactored the XML and HTML dumps to a single code path, fixed XHTML1
843 dump</li>
844 <li>Fix for URI parsing when handling URNs with fragment identifiers</li>
845 <li>Fix for HTTP URL escaping problem</li>
846 <li>added an TextXmlReader (C#) like API (work in progress)</li>
847 <li>Rewrote the API in XML generation script, includes a C parser and saves
848 more informations needed for C# bindings</li>
849</ul>
850
Daniel Veillardf9c4cad2002-11-22 15:57:07 +0000[diff] [blame]851<h3>2.4.28: Nov 22 2002</h3>
852<ul>
853 <li>a couple of python binding fixes</li>
854 <li>2 bug fixes in the XML push parser</li>
855 <li>potential memory leak removed (Martin Stoilov)</li>
856 <li>fix to the configure script for Unix (Dimitri Papadopoulos)</li>
857 <li>added encoding support for XInclude parse="text"</li>
858 <li>autodetection of XHTML1 and specific serialization rules added</li>
Daniel Veillard9b4bb4d2002-12-11 19:28:47 +0000[diff] [blame]859 <li>nasty threading bug fixed (William Brack)</li>
Daniel Veillardf9c4cad2002-11-22 15:57:07 +0000[diff] [blame]860</ul>
861
Daniel Veillarddad3f682002-11-17 16:47:27 +0000[diff] [blame]862<h3>2.4.27: Nov 17 2002</h3>
863<ul>
864 <li>fixes for the Python bindings</li>
865 <li>a number of bug fixes: SGML catalogs, xmlParseBalancedChunkMemory(),
866 HTML parser, Schemas (Charles Bozeman), document fragment support
867 (Christian Glahn), xmlReconciliateNs (Brian Stafford), XPointer,
868 xmlFreeNode(), xmlSAXParseMemory (Peter Jones), xmlGetNodePath (Petr
869 Pajas), entities processing</li>
870 <li>added grep to xmllint --shell</li>
871 <li>VMS update patch from Craig A. Berry</li>
872 <li>cleanup of the Windows build with support for more compilers (Igor),
873 better thread support on Windows</li>
874 <li>cleanup of Unix Makefiles and spec file</li>
875 <li>Improvements to the documentation (John Fleck)</li>
876</ul>
877
Daniel Veillard48267432002-10-18 11:21:38 +0000[diff] [blame]878<h3>2.4.26: Oct 18 2002</h3>
879<ul>
880 <li>Patches for Windows CE port, improvements on Windows paths handling</li>
881 <li>Fixes to the validation code (DTD and Schemas), xmlNodeGetPath() ,
882 HTML serialization, Namespace compliance, and a number of small
883 problems</li>
884</ul>
885
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]886<h3>2.4.25: Sep 26 2002</h3>
887<ul>
888 <li>A number of bug fixes: XPath, validation, Python bindings, DOM and
889 tree, xmlI/O, Html</li>
890 <li>Serious rewrite of XInclude</li>
891 <li>Made XML Schemas regexp part of the default build and APIs, small fix
892 and improvement of the regexp core</li>
893 <li>Changed the validation code to reuse XML Schemas regexp APIs</li>
894 <li>Better handling of Windows file paths, improvement of Makefiles (Igor,
895 Daniel Gehriger, Mark Vakoc)</li>
896 <li>Improved the python I/O bindings, the tests, added resolver and regexp
Daniel Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame]897 APIs</li>
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]898 <li>New logos from Marc Liyanage</li>
899 <li>Tutorial improvements: John Fleck, Christopher Harris</li>
900 <li>Makefile: Fixes for AMD x86_64 (Mandrake), DESTDIR (Christophe
901 Merlet)</li>
902 <li>removal of all stderr/perror use for error reporting</li>
903 <li>Better error reporting: XPath and DTD validation</li>
904 <li>update of the trio portability layer (Bjorn Reese)</li>
905</ul>
906
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]907<p><strong>2.4.24: Aug 22 2002</strong></p>
908<ul>
909 <li>XPath fixes (William), xf:escape-uri() (Wesley Terpstra)</li>
910 <li>Python binding fixes: makefiles (William), generator, rpm build, x86-64
911 (fcrozat)</li>
912 <li>HTML &lt;style&gt; and boolean attributes serializer fixes</li>
913 <li>C14N improvements by Aleksey</li>
Daniel Veillarde1662542002-08-28 11:50:59 +0000[diff] [blame]914 <li>doc cleanups: Rick Jones</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]915 <li>Windows compiler makefile updates: Igor and Elizabeth Barham</li>
916 <li>XInclude: implementation of fallback and xml:base fixup added</li>
917</ul>
918
Daniel Veillard782afda2002-07-08 15:12:49 +0000[diff] [blame]919<h3>2.4.23: July 6 2002</h3>
920<ul>
921 <li>performances patches: Peter Jacobi</li>
922 <li>c14n fixes, testsuite and performances: Aleksey Sanin</li>
923 <li>added xmlDocFormatDump: Chema Celorio</li>
924 <li>new tutorial: John Fleck</li>
925 <li>new hash functions and performances: Sander Vesik, portability fix from
926 Peter Jacobi</li>
927 <li>a number of bug fixes: XPath (William Brack, Richard Jinks), XML and
928 HTML parsers, ID lookup function</li>
929 <li>removal of all remaining sprintf: Aleksey Sanin</li>
930</ul>
931
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]932<h3>2.4.22: May 27 2002</h3>
933<ul>
934 <li>a number of bug fixes: configure scripts, base handling, parser, memory
935 usage, HTML parser, XPath, documentation (Christian Cornelssen),
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]936 indentation, URI parsing</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]937 <li>Optimizations for XMLSec, fixing and making public some of the network
938 protocol handlers (Aleksey)</li>
939 <li>performance patch from Gary Pennington</li>
940 <li>Charles Bozeman provided date and time support for XML Schemas
941 datatypes</li>
942</ul>
943
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]944<h3>2.4.21: Apr 29 2002</h3>
945
946<p>This release is both a bug fix release and also contains the early XML
947Schemas <a href="http://www.w3.org/TR/xmlschema-1/">structures</a> and <a
948href="http://www.w3.org/TR/xmlschema-2/">datatypes</a> code, beware, all
949interfaces are likely to change, there is huge holes, it is clearly a work in
950progress and don't even think of putting this code in a production system,
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]951it's actually not compiled in by default. The real fixes are:</p>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]952<ul>
953 <li>a couple of bugs or limitations introduced in 2.4.20</li>
954 <li>patches for Borland C++ and MSC by Igor</li>
955 <li>some fixes on XPath strings and conformance patches by Richard
956 Jinks</li>
957 <li>patch from Aleksey for the ExcC14N specification</li>
958 <li>OSF/1 bug fix by Bjorn</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]959</ul>
960
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]961<h3>2.4.20: Apr 15 2002</h3>
962<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]963 <li>bug fixes: file descriptor leak, XPath, HTML output, DTD validation</li>
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]964 <li>XPath conformance testing by Richard Jinks</li>
965 <li>Portability fixes: Solaris, MPE/iX, Windows, OSF/1, python bindings,
966 libxml.m4</li>
967</ul>
968
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]969<h3>2.4.19: Mar 25 2002</h3>
970<ul>
971 <li>bug fixes: half a dozen XPath bugs, Validation, ISO-Latin to UTF8
972 encoder</li>
973 <li>portability fixes in the HTTP code</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]974 <li>memory allocation checks using valgrind, and profiling tests</li>
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]975 <li>revamp of the Windows build and Makefiles</li>
976</ul>
977
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]978<h3>2.4.18: Mar 18 2002</h3>
979<ul>
980 <li>bug fixes: tree, SAX, canonicalization, validation, portability,
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]981 XPath</li>
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]982 <li>removed the --with-buffer option it was becoming unmaintainable</li>
983 <li>serious cleanup of the Python makefiles</li>
984 <li>speedup patch to XPath very effective for DocBook stylesheets</li>
985 <li>Fixes for Windows build, cleanup of the documentation</li>
986</ul>
987
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]988<h3>2.4.17: Mar 8 2002</h3>
989<ul>
990 <li>a lot of bug fixes, including "namespace nodes have no parents in
991 XPath"</li>
992 <li>fixed/improved the Python wrappers, added more examples and more
993 regression tests, XPath extension functions can now return node-sets</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]994 <li>added the XML Canonicalization support from Aleksey Sanin</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]995</ul>
996
Daniel Veillard5f4b5992002-02-20 10:22:49 +0000[diff] [blame]997<h3>2.4.16: Feb 20 2002</h3>
998<ul>
999 <li>a lot of bug fixes, most of them were triggered by the XML Testsuite
1000 from OASIS and W3C. Compliance has been significantly improved.</li>
1001 <li>a couple of portability fixes too.</li>
1002</ul>
1003
Daniel Veillard397ff112002-02-11 18:27:20 +0000[diff] [blame]1004<h3>2.4.15: Feb 11 2002</h3>
1005<ul>
1006 <li>Fixed the Makefiles, especially the python module ones</li>
1007 <li>A few bug fixes and cleanup</li>
1008 <li>Includes cleanup</li>
1009</ul>
1010
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]1011<h3>2.4.14: Feb 8 2002</h3>
1012<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1013 <li>Change of License to the <a
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]1014 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1015 License</a> basically for integration in XFree86 codebase, and removing
1016 confusion around the previous dual-licensing</li>
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]1017 <li>added Python bindings, beta software but should already be quite
1018 complete</li>
1019 <li>a large number of fixes and cleanups, especially for all tree
1020 manipulations</li>
1021 <li>cleanup of the headers, generation of a reference API definition in
1022 XML</li>
1023</ul>
1024
1025<h3>2.4.13: Jan 14 2002</h3>
Daniel Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame]1026<ul>
1027 <li>update of the documentation: John Fleck and Charlie Bozeman</li>
1028 <li>cleanup of timing code from Justin Fletcher</li>
1029 <li>fixes for Windows and initial thread support on Win32: Igor and Serguei
1030 Narojnyi</li>
1031 <li>Cygwin patch from Robert Collins</li>
1032 <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
1033</ul>
1034
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]1035<h3>2.4.12: Dec 7 2001</h3>
1036<ul>
1037 <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
1038 XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
1039 (robert)</li>
1040 <li>Eric Lavigne contributed project files for MacOS</li>
1041 <li>some makefiles cleanups</li>
1042</ul>
1043
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]1044<h3>2.4.11: Nov 26 2001</h3>
1045<ul>
1046 <li>fixed a couple of errors in the includes, fixed a few bugs, some code
1047 cleanups</li>
1048 <li>xmllint man pages improvement by Heiko Rupp</li>
1049 <li>updated VMS build instructions from John A Fotheringham</li>
1050 <li>Windows Makefiles updates from Igor</li>
1051</ul>
1052
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]1053<h3>2.4.10: Nov 10 2001</h3>
1054<ul>
1055 <li>URI escaping fix (Joel Young)</li>
1056 <li>added xmlGetNodePath() (for paths or XPointers generation)</li>
1057 <li>Fixes namespace handling problems when using DTD and validation</li>
1058 <li>improvements on xmllint: Morus Walter patches for --format and
1059 --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
1060 <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
1061 <li>fixes to the HTML parser</li>
1062</ul>
1063
1064<h3>2.4.9: Nov 6 2001</h3>
1065<ul>
1066 <li>fixes more catalog bugs</li>
1067 <li>avoid a compilation problem, improve xmlGetLineNo()</li>
1068</ul>
1069
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]1070<h3>2.4.8: Nov 4 2001</h3>
1071<ul>
1072 <li>fixed SGML catalogs broken in previous release, updated xmlcatalog
1073 tool</li>
1074 <li>fixed a compile errors and some includes troubles.</li>
1075</ul>
1076
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]1077<h3>2.4.7: Oct 30 2001</h3>
1078<ul>
1079 <li>exported some debugging interfaces</li>
1080 <li>serious rewrite of the catalog code</li>
1081 <li>integrated Gary Pennington thread safety patch, added configure option
1082 and regression tests</li>
1083 <li>removed an HTML parser bug</li>
1084 <li>fixed a couple of potentially serious validation bugs</li>
1085 <li>integrated the SGML DocBook support in xmllint</li>
1086 <li>changed the nanoftp anonymous login passwd</li>
1087 <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
1088 <li>general bug fixes</li>
1089 <li>updated xmllint man page by John Fleck</li>
1090 <li>some VMS and Windows updates</li>
1091</ul>
1092
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]1093<h3>2.4.6: Oct 10 2001</h3>
1094<ul>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]1095 <li>added an updated man pages by John Fleck</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]1096 <li>portability and configure fixes</li>
1097 <li>an infinite loop on the HTML parser was removed (William)</li>
1098 <li>Windows makefile patches from Igor</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1099 <li>fixed half a dozen bugs reported for libxml or libxslt</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]1100 <li>updated xmlcatalog to be able to modify SGML super catalogs</li>
1101</ul>
1102
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]1103<h3>2.4.5: Sep 14 2001</h3>
1104<ul>
1105 <li>Remove a few annoying bugs in 2.4.4</li>
1106 <li>forces the HTML serializer to output decimal charrefs since some
1107 version of Netscape can't handle hexadecimal ones</li>
1108</ul>
1109
1110<h3>1.8.16: Sep 14 2001</h3>
1111<ul>
1112 <li>maintenance release of the old libxml1 branch, couple of bug and
1113 portability fixes</li>
1114</ul>
1115
Daniel Veillard04382ae2001-09-12 18:51:30 +0000[diff] [blame]1116<h3>2.4.4: Sep 12 2001</h3>
1117<ul>
1118 <li>added --convert to xmlcatalog, bug fixes and cleanups of XML
1119 Catalog</li>
1120 <li>a few bug fixes and some portability changes</li>
1121 <li>some documentation cleanups</li>
1122</ul>
1123
Daniel Veillard39936902001-08-24 00:49:01 +0000[diff] [blame]1124<h3>2.4.3: Aug 23 2001</h3>
1125<ul>
1126 <li>XML Catalog support see the doc</li>
1127 <li>New NaN/Infinity floating point code</li>
1128 <li>A few bug fixes</li>
1129</ul>
1130
1131<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1132<ul>
1133 <li>adds xmlLineNumbersDefault() to control line number generation</li>
1134 <li>lot of bug fixes</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1135 <li>the Microsoft MSC projects files should now be up to date</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1136 <li>inheritance of namespaces from DTD defaulted attributes</li>
1137 <li>fixes a serious potential security bug</li>
1138 <li>added a --format option to xmllint</li>
1139</ul>
1140
1141<h3>2.4.1: July 24 2001</h3>
1142<ul>
1143 <li>possibility to keep line numbers in the tree</li>
1144 <li>some computation NaN fixes</li>
1145 <li>extension of the XPath API</li>
1146 <li>cleanup for alpha and ia64 targets</li>
1147 <li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]1148</ul>
1149
1150<h3>2.4.0: July 10 2001</h3>
1151<ul>
1152 <li>Fixed a few bugs in XPath, validation, and tree handling.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1153 <li>Fixed XML Base implementation, added a couple of examples to the
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]1154 regression tests</li>
1155 <li>A bit of cleanup</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1156</ul>
1157
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]1158<h3>2.3.14: July 5 2001</h3>
1159<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1160 <li>fixed some entities problems and reduce memory requirement when
1161 substituting them</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]1162 <li>lots of improvements in the XPath queries interpreter can be
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1163 substantially faster</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]1164 <li>Makefiles and configure cleanups</li>
1165 <li>Fixes to XPath variable eval, and compare on empty node set</li>
1166 <li>HTML tag closing bug fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1167 <li>Fixed an URI reference computation problem when validating</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]1168</ul>
1169
Daniel Veillard2adbb512001-06-28 16:20:36 +0000[diff] [blame]1170<h3>2.3.13: June 28 2001</h3>
1171<ul>
1172 <li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
1173 <li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
1174</ul>
1175
1176<h3>1.8.14: June 28 2001</h3>
1177<ul>
1178 <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
1179 <li>Small Makefile fix</li>
1180</ul>
1181
Daniel Veillard11648102001-06-26 16:08:24 +0000[diff] [blame]1182<h3>2.3.12: June 26 2001</h3>
1183<ul>
1184 <li>lots of cleanup</li>
1185 <li>a couple of validation fix</li>
1186 <li>fixed line number counting</li>
1187 <li>fixed serious problems in the XInclude processing</li>
1188 <li>added support for UTF8 BOM at beginning of entities</li>
1189 <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
1190 miscompile uri.c (William), Thomas Leitner provided a fix for the
1191 optimizer on Tru64</li>
1192 <li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
1193 compilation on Windows MSC</li>
1194 <li>update of libxml-doc.el (Felix Natter)</li>
1195 <li>fixed 2 bugs in URI normalization code</li>
1196</ul>
1197
Daniel Veillarde3c81b52001-06-17 14:50:34 +0000[diff] [blame]1198<h3>2.3.11: June 17 2001</h3>
1199<ul>
1200 <li>updates to trio, Makefiles and configure should fix some portability
1201 problems (alpha)</li>
1202 <li>fixed some HTML serialization problems (pre, script, and block/inline
1203 handling), added encoding aware APIs, cleanup of this code</li>
1204 <li>added xmlHasNsProp()</li>
1205 <li>implemented a specific PI for encoding support in the DocBook SGML
1206 parser</li>
1207 <li>some XPath fixes (-Infinity, / as a function parameter and namespaces
1208 node selection)</li>
1209 <li>fixed a performance problem and an error in the validation code</li>
1210 <li>fixed XInclude routine to implement the recursive behaviour</li>
1211 <li>fixed xmlFreeNode problem when libxml is included statically twice</li>
1212 <li>added --version to xmllint for bug reports</li>
1213</ul>
1214
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]1215<h3>2.3.10: June 1 2001</h3>
1216<ul>
1217 <li>fixed the SGML catalog support</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1218 <li>a number of reported bugs got fixed, in XPath, iconv detection,
1219 XInclude processing</li>
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]1220 <li>XPath string function should now handle unicode correctly</li>
1221</ul>
1222
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]1223<h3>2.3.9: May 19 2001</h3>
1224
1225<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
1226<ul>
1227 <li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1228 <li>some serious speed optimization again</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]1229 <li>some documentation cleanups</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1230 <li>trying to get better linking on Solaris (-R)</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]1231 <li>XPath API cleanup from Thomas Broyer</li>
1232 <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
1233 xmlValidGetValidElements()</li>
1234 <li>Added an INSTALL file</li>
1235 <li>Attribute removal added to API: #54433</li>
1236 <li>added a basic support for SGML catalogs</li>
1237 <li>fixed xmlKeepBlanksDefault(0) API</li>
1238 <li>bugfix in xmlNodeGetLang()</li>
1239 <li>fixed a small configure portability problem</li>
1240 <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
1241</ul>
1242
Daniel Veillarda265af72001-05-14 11:13:58 +0000[diff] [blame]1243<h3>1.8.13: May 14 2001</h3>
1244<ul>
1245 <li>bugfixes release of the old libxml1 branch used by Gnome</li>
1246</ul>
1247
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]1248<h3>2.3.8: May 3 2001</h3>
1249<ul>
1250 <li>Integrated an SGML DocBook parser for the Gnome project</li>
1251 <li>Fixed a few things in the HTML parser</li>
1252 <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
1253 point portability issue</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1254 <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
1255 DOM+validation using the XML REC as input and a 700MHz celeron).</li>
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]1256 <li>incorporated more Windows cleanup</li>
1257 <li>added xmlSaveFormatFile()</li>
1258 <li>fixed problems in copying nodes with entities references (gdome)</li>
1259 <li>removed some troubles surrounding the new validation module</li>
1260</ul>
1261
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]1262<h3>2.3.7: April 22 2001</h3>
1263<ul>
1264 <li>lots of small bug fixes, corrected XPointer</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1265 <li>Non deterministic content model validation support</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]1266 <li>added xmlDocCopyNode for gdome2</li>
1267 <li>revamped the way the HTML parser handles end of tags</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1268 <li>XPath: corrections of namespaces support and number formatting</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]1269 <li>Windows: Igor Zlatkovic patches for MSC compilation</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1270 <li>HTML output fixes from P C Chow and William M. Brack</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]1271 <li>Improved validation speed sensible for DocBook</li>
1272 <li>fixed a big bug with ID declared in external parsed entities</li>
1273 <li>portability fixes, update of Trio from Bjorn Reese</li>
1274</ul>
1275
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]1276<h3>2.3.6: April 8 2001</h3>
1277<ul>
1278 <li>Code cleanup using extreme gcc compiler warning options, found and
1279 cleared half a dozen potential problem</li>
1280 <li>the Eazel team found an XML parser bug</li>
1281 <li>cleaned up the user of some of the string formatting function. used the
1282 trio library code to provide the one needed when the platform is missing
1283 them</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1284 <li>xpath: removed a memory leak and fixed the predicate evaluation
1285 problem, extended the testsuite and cleaned up the result. XPointer seems
1286 broken ...</li>
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]1287</ul>
1288
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame]1289<h3>2.3.5: Mar 23 2001</h3>
1290<ul>
1291 <li>Biggest change is separate parsing and evaluation of XPath expressions,
1292 there is some new APIs for this too</li>
1293 <li>included a number of bug fixes(XML push parser, 51876, notations,
1294 52299)</li>
1295 <li>Fixed some portability issues</li>
1296</ul>
1297
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1298<h3>2.3.4: Mar 10 2001</h3>
1299<ul>
1300 <li>Fixed bugs #51860 and #51861</li>
1301 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
1302 size to be application tunable.</li>
1303 <li>Some cleanup in the validation code, still a bug left and this part
1304 should probably be rewritten to support ambiguous content model :-\</li>
1305 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
1306 parser</li>
1307 <li>Fixed another bug in xmlNodeGetContent()</li>
1308 <li>Bjorn fixed XPath node collection and Number formatting</li>
1309 <li>Fixed a loop reported in the HTML parsing</li>
1310 <li>blank space are reported even if the Dtd content model proves that they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1311 are formatting spaces, this is for XML conformance</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1312</ul>
1313
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]1314<h3>2.3.3: Mar 1 2001</h3>
1315<ul>
1316 <li>small change in XPath for XSLT</li>
1317 <li>documentation cleanups</li>
1318 <li>fix in validation by Gary Pennington</li>
1319 <li>serious parsing performances improvements</li>
1320</ul>
1321
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1322<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]1323<ul>
1324 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
1325 <li>fixed a Dtd parsing bug</li>
1326 <li>fixed a bug in xmlNodeGetContent</li>
1327 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
1328</ul>
1329
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1330<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1331<ul>
1332 <li>some XPath and HTML bug fixes for XSLT</li>
1333 <li>small extension of the hash table interfaces for DOM gdome2
1334 implementation</li>
1335 <li>A few bug fixes</li>
1336</ul>
1337
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1338<h3>2.3.0: Feb 8 2001 (2.2.12 was on 25 Jan but I didn't kept track)</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1339<ul>
1340 <li>Lots of XPath bug fixes</li>
1341 <li>Add a mode with Dtd lookup but without validation error reporting for
1342 XSLT</li>
1343 <li>Add support for text node without escaping (XSLT)</li>
1344 <li>bug fixes for xmlCheckFilename</li>
1345 <li>validation code bug fixes from Gary Pennington</li>
1346 <li>Patch from Paul D. Smith correcting URI path normalization</li>
1347 <li>Patch to allow simultaneous install of libxml-devel and
1348 libxml2-devel</li>
1349 <li>the example Makefile is now fixed</li>
1350 <li>added HTML to the RPM packages</li>
1351 <li>tree copying bugfixes</li>
1352 <li>updates to Windows makefiles</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1353 <li>optimization patch from Bjorn Reese</li>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1354</ul>
1355
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1356<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]1357<ul>
1358 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
1359 <li>added htmlHandleOmittedElem()</li>
1360 <li>Applied Bjorn Reese's IPV6 first patch</li>
1361 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1362 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]1363</ul>
1364
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]1365<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]1366<ul>
1367 <li>Fix the Windows problems of 2.2.8</li>
1368 <li>integrate OpenVMS patches</li>
1369 <li>better handling of some nasty HTML input</li>
1370 <li>Improved the XPointer implementation</li>
1371 <li>integrate a number of provided patches</li>
1372</ul>
1373
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]1374<h3>2.2.9: Nov 25 2000</h3>
1375<ul>
1376 <li>erroneous release :-(</li>
1377</ul>
1378
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]1379<h3>2.2.8: Nov 13 2000</h3>
1380<ul>
1381 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
1382 support</li>
1383 <li>Patch in conditional section handling</li>
1384 <li>updated MS compiler project</li>
1385 <li>fixed some XPath problems</li>
1386 <li>added an URI escaping function</li>
1387 <li>some other bug fixes</li>
1388</ul>
1389
1390<h3>2.2.7: Oct 31 2000</h3>
1391<ul>
1392 <li>added message redirection</li>
1393 <li>XPath improvements (thanks TOM !)</li>
1394 <li>xmlIOParseDTD() added</li>
1395 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
1396 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
1397</ul>
1398
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]1399<h3>2.2.6: Oct 25 2000:</h3>
1400<ul>
1401 <li>Added an hash table module, migrated a number of internal structure to
1402 those</li>
1403 <li>Fixed a posteriori validation problems</li>
1404 <li>HTTP module cleanups</li>
1405 <li>HTML parser improvements (tag errors, script/style handling, attribute
1406 normalization)</li>
1407 <li>coalescing of adjacent text nodes</li>
1408 <li>couple of XPath bug fixes, exported the internal API</li>
1409</ul>
1410
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1411<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1412<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1413 <li>XPointer implementation and testsuite</li>
1414 <li>Lot of XPath fixes, added variable and functions registration, more
1415 tests</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1416 <li>Portability fixes, lots of enhancements toward an easy Windows build
1417 and release</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1418 <li>Late validation fixes</li>
1419 <li>Integrated a lot of contributed patches</li>
1420 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1421 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1422</ul>
1423
1424<h3>2.2.4: Oct 1 2000:</h3>
1425<ul>
1426 <li>main XPath problem fixed</li>
1427 <li>Integrated portability patches for Windows</li>
1428 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1429</ul>
1430
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1431<h3>2.2.3: Sep 17 2000</h3>
1432<ul>
1433 <li>bug fixes</li>
1434 <li>cleanup of entity handling code</li>
1435 <li>overall review of all loops in the parsers, all sprintf usage has been
1436 checked too</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1437 <li>Far better handling of larges Dtd. Validating against DocBook XML Dtd
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1438 works smoothly now.</li>
1439</ul>
1440
1441<h3>1.8.10: Sep 6 2000</h3>
1442<ul>
1443 <li>bug fix release for some Gnome projects</li>
1444</ul>
1445
1446<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1447<ul>
1448 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]1449 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1450</ul>
1451
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1452<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1453<ul>
1454 <li>a purely bug fixes release</li>
1455 <li>fixed an encoding support problem when parsing from a memory block</li>
1456 <li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1457 <li>removed a bug in the function allowing to override the memory
1458 allocation routines</li>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1459</ul>
1460
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1461<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]1462<ul>
1463 <li>applied a lot of portability fixes</li>
1464 <li>better encoding support/cleanup and saving (content is now always
1465 encoded in UTF-8)</li>
1466 <li>the HTML parser now correctly handles encodings</li>
1467 <li>added xmlHasProp()</li>
1468 <li>fixed a serious problem with &amp;#38;</li>
1469 <li>propagated the fix to FTP client</li>
1470 <li>cleanup, bugfixes, etc ...</li>
1471 <li>Added a page about <a href="encoding.html">libxml Internationalization
1472 support</a></li>
1473</ul>
1474
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1475<h3>1.8.9: July 9 2000</h3>
1476<ul>
1477 <li>fixed the spec the RPMs should be better</li>
1478 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
1479 rpmfind users problem</li>
1480</ul>
1481
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]1482<h3>2.1.1: July 1 2000</h3>
1483<ul>
1484 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
1485 <li>improvements on the HTML parser</li>
1486</ul>
1487
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1488<h3>2.1.0 and 1.8.8: June 29 2000</h3>
1489<ul>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1490 <li>1.8.8 is mostly a commodity package for upgrading to libxml2 according
1491 to <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1492 about &amp;#38; charref parsing</li>
1493 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
1494 also contains numerous fixes and enhancements:
1495 <ul>
1496 <li>added xmlStopParser() to stop parsing</li>
1497 <li>improved a lot parsing speed when there is large CDATA blocs</li>
1498 <li>includes XPath patches provided by Picdar Technology</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1499 <li>tried to fix as much as possible DTD validation and namespace
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1500 related problems</li>
1501 <li>output to a given encoding has been added/tested</li>
1502 <li>lot of various fixes</li>
1503 </ul>
1504 </li>
1505</ul>
1506
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1507<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1508<ul>
1509 <li>First public release of libxml2. If you are using libxml, it's a good
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1510 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initially
1511 scheduled for Apr 3 the release occurred only on Apr 12 due to massive
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1512 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1513 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1514 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1515 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1516 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1517 <pre>#include "xxx.h"</pre>
1518 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]1519 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
1520 <li>the memory allocation routines used by libxml can now be overloaded
1521 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1522 <li>The previously CVS only tool tester has been renamed
1523 <strong>xmllint</strong> and is now installed as part of the libxml2
1524 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1525 <li>The I/O interface has been revamped. There is now ways to plug in
1526 specific I/O modules, either at the URI scheme detection level using
1527 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
1528 parser context using xmlCreateIOParserCtxt()</li>
1529 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
1530 number of the libxml module in use</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1531 <li>a number of optional features of libxml can now be excluded at
1532 configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1533</ul>
1534
1535<h3>2.0.0beta: Mar 14 2000</h3>
1536<ul>
1537 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1538 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
1539 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
1540 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1541 <li>This version is now the head in the Gnome CVS base, the old one is
1542 available under the tag LIB_XML_1_X</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1543 <li>This includes a very large set of changes. From a programmatic point
1544 of view applications should not have to be modified too much, check the
1545 <a href="upgrade.html">upgrade page</a></li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1546 <li>Some interfaces may changes (especially a bit about encoding).</li>
1547 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1548 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1549 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
1550 handled now</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1551 <li>Better handling of entities, especially well-formedness checking
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1552 and proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1553 <li>DTD conditional sections</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1554 <li>Validation now correctly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1555 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1556 structures to accommodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1557 </ul>
1558 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1559 <li>Serious progress were made toward compliance, <a
1560 href="conf/result.html">here are the result of the test</a> against the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1561 OASIS testsuite (except the Japanese tests since I don't support that
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1562 encoding yet). This URL is rebuilt every couple of hours using the CVS
1563 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1564</ul>
1565
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1566<h3>1.8.7: Mar 6 2000</h3>
1567<ul>
1568 <li>This is a bug fix release:</li>
1569 <li>It is possible to disable the ignorable blanks heuristic used by
1570 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1571 that for adherence to XML spec, this behaviour will be disabled by
1572 default in 2.x . The same function will allow to keep compatibility for
1573 old code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1574 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
1575 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1576 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
1577 compilation on some platforms has been fixed</li>
1578 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
1579 URIs</li>
1580</ul>
1581
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1582<h3>1.8.6: Jan 31 2000</h3>
1583<ul>
1584 <li>added a nanoFTP transport module, debugged until the new version of <a
1585 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
1586 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]1587</ul>
1588
1589<h3>1.8.5: Jan 21 2000</h3>
1590<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1591 <li>adding APIs to parse a well balanced chunk of XML (production <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1592 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
1593 XML spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1594 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1595 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
1596 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1597 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
1598 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1599</ul>
1600
1601<h3>1.8.4: Jan 13 2000</h3>
1602<ul>
1603 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
1604 <li>all exit() call should have been removed from libxml</li>
1605 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
1606 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1607</ul>
1608
1609<h3>1.8.3: Jan 5 2000</h3>
1610<ul>
1611 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1612 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1613 <li>lots of bug fixes and improvement added over XMas holidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1614 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1615 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
1616 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1617 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1618 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1619 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1620</ul>
1621
1622<h3>1.8.2: Dec 21 1999</h3>
1623<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1624 <li>I got another problem with includes and C++, I hope this issue is fixed
1625 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1626 <li>Added a few tree modification functions: xmlReplaceNode,
1627 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
1628 xmlDocSetRootElement</li>
1629 <li>Tried to improve the HTML output with help from <a
1630 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1631</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1632
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1633<h3>1.8.1: Dec 18 1999</h3>
1634<ul>
1635 <li>various patches to avoid troubles when using libxml with C++ compilers
1636 the "namespace" keyword and C escaping in include files</li>
1637 <li>a problem in one of the core macros IS_CHAR was corrected</li>
1638 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
1639 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]1640 <li>fixed a posteriori validation (validation after parsing, or by using a
1641 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1642 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]1643</ul>
1644
1645<h3>1.8.0: Dec 12 1999</h3>
1646<ul>
1647 <li>cleanup, especially memory wise</li>
1648 <li>the parser should be more reliable, especially the HTML one, it should
1649 not crash, whatever the input !</li>
1650 <li>Integrated various patches, especially a speedup improvement for large
1651 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
1652 configure with --with-buffers to enable them.</li>
1653 <li>attribute normalization, oops should have been added long ago !</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1654 <li>attributes defaulted from DTDs should be available, xmlSetProp() now
1655 does entities escaping by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1656</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1657
1658<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1659<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1660 <li>Lots of HTML improvement</li>
1661 <li>Fixed some errors when saving both XML and HTML</li>
1662 <li>More examples, the regression tests should now look clean</li>
1663 <li>Fixed a bug with contiguous charref</li>
1664</ul>
1665
1666<h3>1.7.3: Sep 29 1999</h3>
1667<ul>
1668 <li>portability problems fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1669 <li>snprintf was used unconditionally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1670 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1671</ul>
1672
1673<h3>1.7.1: Sep 24 1999</h3>
1674<ul>
1675 <li>The basic type for strings manipulated by libxml has been renamed in
1676 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1677 is that CHAR was conflicting with a predefined type on Windows. However
1678 on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1679 <strong>#define </strong>.</li>
1680 <li>Changed another error : the use of a structure field called errno, and
1681 leading to troubles on platforms where it's a macro</li>
1682</ul>
1683
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1684<h3>1.7.0: Sep 23 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1685<ul>
1686 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1687 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1688 <li>Added an errno to report errors by another mean than a simple printf
1689 like callback</li>
1690 <li>Finished ID/IDREF support and checking when validation</li>
1691 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1692 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1693 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
1694 implementation</li>
1695 <li>Added an HTML parser front-end</li>
1696</ul>
1697
1698<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1699
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1700<p><a href="http://www.w3.org/TR/REC-xml">XML is a standard</a> for
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1701markup-based structured documents. Here is <a name="example">an example XML
1702document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1703<pre>&lt;?xml version="1.0"?&gt;
1704&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
1705 &lt;head&gt;
1706 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
1707 &lt;/head&gt;
1708 &lt;chapter&gt;
1709 &lt;title&gt;The Linux adventure&lt;/title&gt;
1710 &lt;p&gt;bla bla bla ...&lt;/p&gt;
1711 &lt;image href="linus.gif"/&gt;
1712 &lt;p&gt;...&lt;/p&gt;
1713 &lt;/chapter&gt;
1714&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1715
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1716<p>The first line specifies that it is an XML document and gives useful
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1717information about its encoding. Then the rest of the document is a text
1718format whose structure is specified by tags between brackets. <strong>Each
1719tag opened has to be closed</strong>. XML is pedantic about this. However, if
1720a tag is empty (no content), a single tag can serve as both the opening and
1721closing tag if it ends with <code>/&gt;</code> rather than with
1722<code>&gt;</code>. Note that, for example, the image tag has no content (just
1723an attribute) and is closed by ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1724
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1725<p>XML can be applied successfully to a wide range of tasks, ranging from
1726long term structured document maintenance (where it follows the steps of
1727SGML) to simple data encoding mechanisms like configuration file formatting
1728(glade), spreadsheets (gnumeric), or even shorter lived documents such as
1729WebDAV where it is used to encode remote calls between a client and a
1730server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1731
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1732<h2><a name="XSLT">XSLT</a></h2>
1733
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1734<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
1735
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1736<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
1737language for transforming XML documents into other XML documents (or
1738HTML/textual output).</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1739
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]1740<p>A separate library called libxslt is available implementing XSLT-1.0 for
1741libxml2. This module "libxslt" too can be found in the Gnome CVS base.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1742
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]1743<p>You can check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1744href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
1745supported and the progresses on the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1746href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog"
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1747name="Changelog">Changelog</a>.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1748
1749<h2><a name="Python">Python and bindings</a></h2>
1750
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1751<p>There are a number of language bindings and wrappers available for
1752libxml2, the list below is not exhaustive. Please contact the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1753href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a>
1754(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in
1755order to get updates to this list or to discuss the specific topic of libxml2
1756or libxslt wrappers or bindings:</p>
1757<ul>
Daniel Veillardc14401e2002-11-20 14:28:17 +0000[diff] [blame]1758 <li><a href="http://libxmlplusplus.sourceforge.net/">Libxml++</a> seems the
1759 most up-to-date C++ bindings for libxml2, check the <a
1760 href="http://libxmlplusplus.sourceforge.net/reference/html/hierarchy.html">documentation</a>
1761 and the <a
1762 href="http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/libxmlplusplus/libxml%2b%2b/examples/">examples</a>.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1763 <li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1764 based on the gdome2 bindings</a> maintained by Tobias Peters.</li>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]1765 <li>and a third C++ wrapper by Peter Jones &lt;pjones@pmade.org&gt;
1766 <p>Website: <a
1767 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
1768 </li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1769 <li><a
1770 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1771 Sergeant</a> developed <a
1772 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1773 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1774 application server</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]1775 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides an
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1776 earlier version of the libxml/libxslt <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1777 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]1778 <li>Gopal.V and Peter Minten develop <a
1779 href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1780 C# libxml2 bindings.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1781 <li>Petr Kozelka provides <a
1782 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1783 libxml2</a> with Kylix, Delphi and other Pascal compilers.</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]1784 <li>Uwe Fechner also provides <a
1785 href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1786 implementation for Kylix2/D5/D6 from Borland.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1787 <li>Wai-Sun "Squidster" Chia provides <a
1788 href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and
1789 libxml2 bindings are also available in Ruby through the <a
1790 href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module
1791 maintained by Tobias Peters.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1792 <li>Steve Ball and contributors maintains <a
1793 href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1794 Tcl</a>.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1795 <li>There is support for libxml2 in the DOM module of PHP.</li>
Daniel Veillard41b01a82003-02-27 11:09:06 +0000[diff] [blame]1796 <li><a href="http://savannah.gnu.org/projects/classpathx/">LibxmlJ</a> is
Daniel Veillard806cada2003-03-19 21:58:59 +0000[diff] [blame]1797 an effort to create a 100% JAXP-compatible Java wrapper for libxml2 and
1798 libxslt as part of GNU ClasspathX project.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1799</ul>
1800
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1801<p>The distribution includes a set of Python bindings, which are guaranteed
1802to be maintained as part of the library in the future, though the Python
Daniel Veillard41b01a82003-02-27 11:09:06 +0000[diff] [blame]1803interface have not yet reached the completeness of the C API.</p>
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000[diff] [blame]1804
Daniel Veillard27907c72002-12-16 16:05:58 +0000[diff] [blame]1805<p><a href="mailto:stephane.bidoul@softwareag.com">Stéphane Bidoul</a>
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000[diff] [blame]1806maintains <a href="http://users.skynet.be/sbi/libxml-python/">a Windows port
1807of the Python bindings</a>.</p>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1808
Daniel Veillard7ef0fcb2002-12-14 10:38:55 +0000[diff] [blame]1809<p>Note to people interested in building bindings, the API is formalized as
1810<a href="libxml2-api.xml">an XML API description file</a> which allows to
1811automate a large part of the Python bindings, this includes function
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000[diff] [blame]1812descriptions, enums, structures, typedefs, etc... The Python script used to
1813build the bindings is python/generator.py in the source distribution.</p>
Daniel Veillard7ef0fcb2002-12-14 10:38:55 +0000[diff] [blame]1814
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1815<p>To install the Python bindings there are 2 options:</p>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1816<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1817 <li>If you use an RPM based distribution, simply install the <a
1818 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python
1819 RPM</a> (and if needed the <a
1820 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python
1821 RPM</a>).</li>
1822 <li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python
1823 module distribution</a> corresponding to your installed version of
1824 libxml2 and libxslt. Note that to install it you will need both libxml2
1825 and libxslt installed and run "python setup.py build install" in the
1826 module tree.</li>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1827</ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1828
1829<p>The distribution includes a set of examples and regression tests for the
1830python bindings in the <code>python/tests</code> directory. Here are some
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1831excerpts from those tests:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1832
1833<h3>tst.py:</h3>
1834
1835<p>This is a basic test of the file interface and DOM navigation:</p>
1836<pre>import libxml2
1837
1838doc = libxml2.parseFile("tst.xml")
1839if doc.name != "tst.xml":
1840 print "doc.name failed"
1841 sys.exit(1)
1842root = doc.children
1843if root.name != "doc":
1844 print "root.name failed"
1845 sys.exit(1)
1846child = root.children
1847if child.name != "foo":
1848 print "child.name failed"
1849 sys.exit(1)
1850doc.freeDoc()</pre>
1851
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1852<p>The Python module is called libxml2; parseFile is the equivalent of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1853xmlParseFile (most of the bindings are automatically generated, and the xml
1854prefix is removed and the casing convention are kept). All node seen at the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1855binding level share the same subset of accessors:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1856<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1857 <li><code>name</code> : returns the node name</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1858 <li><code>type</code> : returns a string indicating the node type</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1859 <li><code>content</code> : returns the content of the node, it is based on
1860 xmlNodeGetContent() and hence is recursive.</li>
1861 <li><code>parent</code> , <code>children</code>, <code>last</code>,
1862 <code>next</code>, <code>prev</code>, <code>doc</code>,
1863 <code>properties</code>: pointing to the associated element in the tree,
1864 those may return None in case no such link exists.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1865</ul>
1866
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1867<p>Also note the need to explicitly deallocate documents with freeDoc() .
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1868Reference counting for libxml2 trees would need quite a lot of work to
1869function properly, and rather than risk memory leaks if not implemented
1870correctly it sounds safer to have an explicit function to free a tree. The
1871wrapper python objects like doc, root or child are them automatically garbage
1872collected.</p>
1873
1874<h3>validate.py:</h3>
1875
1876<p>This test check the validation interfaces and redirection of error
1877messages:</p>
1878<pre>import libxml2
1879
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1880#deactivate error messages from the validation
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1881def noerr(ctx, str):
1882 pass
1883
1884libxml2.registerErrorHandler(noerr, None)
1885
1886ctxt = libxml2.createFileParserCtxt("invalid.xml")
1887ctxt.validate(1)
1888ctxt.parseDocument()
1889doc = ctxt.doc()
1890valid = ctxt.isValid()
1891doc.freeDoc()
1892if valid != 0:
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1893 print "validity check failed"</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1894
1895<p>The first thing to notice is the call to registerErrorHandler(), it
1896defines a new error handler global to the library. It is used to avoid seeing
1897the error messages when trying to validate the invalid document.</p>
1898
1899<p>The main interest of that test is the creation of a parser context with
1900createFileParserCtxt() and how the behaviour can be changed before calling
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1901parseDocument() . Similarly the informations resulting from the parsing phase
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1902are also available using context methods.</p>
1903
1904<p>Contexts like nodes are defined as class and the libxml2 wrappers maps the
1905C function interfaces in terms of objects method as much as possible. The
1906best to get a complete view of what methods are supported is to look at the
1907libxml2.py module containing all the wrappers.</p>
1908
1909<h3>push.py:</h3>
1910
1911<p>This test show how to activate the push parser interface:</p>
1912<pre>import libxml2
1913
1914ctxt = libxml2.createPushParser(None, "&lt;foo", 4, "test.xml")
1915ctxt.parseChunk("/&gt;", 2, 1)
1916doc = ctxt.doc()
1917
1918doc.freeDoc()</pre>
1919
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1920<p>The context is created with a special call based on the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1921xmlCreatePushParser() from the C library. The first argument is an optional
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1922SAX callback object, then the initial set of data, the length and the name of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1923the resource in case URI-References need to be computed by the parser.</p>
1924
1925<p>Then the data are pushed using the parseChunk() method, the last call
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1926setting the third argument terminate to 1.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1927
1928<h3>pushSAX.py:</h3>
1929
1930<p>this test show the use of the event based parsing interfaces. In this case
1931the parser does not build a document, but provides callback information as
1932the parser makes progresses analyzing the data being provided:</p>
1933<pre>import libxml2
1934log = ""
1935
1936class callback:
1937 def startDocument(self):
1938 global log
1939 log = log + "startDocument:"
1940
1941 def endDocument(self):
1942 global log
1943 log = log + "endDocument:"
1944
1945 def startElement(self, tag, attrs):
1946 global log
1947 log = log + "startElement %s %s:" % (tag, attrs)
1948
1949 def endElement(self, tag):
1950 global log
1951 log = log + "endElement %s:" % (tag)
1952
1953 def characters(self, data):
1954 global log
1955 log = log + "characters: %s:" % (data)
1956
1957 def warning(self, msg):
1958 global log
1959 log = log + "warning: %s:" % (msg)
1960
1961 def error(self, msg):
1962 global log
1963 log = log + "error: %s:" % (msg)
1964
1965 def fatalError(self, msg):
1966 global log
1967 log = log + "fatalError: %s:" % (msg)
1968
1969handler = callback()
1970
1971ctxt = libxml2.createPushParser(handler, "&lt;foo", 4, "test.xml")
1972chunk = " url='tst'&gt;b"
1973ctxt.parseChunk(chunk, len(chunk), 0)
1974chunk = "ar&lt;/foo&gt;"
1975ctxt.parseChunk(chunk, len(chunk), 1)
1976
Daniel Veillardfcbfa2d2002-02-21 17:54:27 +0000[diff] [blame]1977reference = "startDocument:startElement foo {'url': 'tst'}:" + \
1978 "characters: bar:endElement foo:endDocument:"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1979if log != reference:
1980 print "Error got: %s" % log
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1981 print "Expected: %s" % reference</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1982
1983<p>The key object in that test is the handler, it provides a number of entry
1984points which can be called by the parser as it makes progresses to indicate
1985the information set obtained. The full set of callback is larger than what
1986the callback class in that specific example implements (see the SAX
1987definition for a complete list). The wrapper will only call those supplied by
1988the object when activated. The startElement receives the names of the element
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1989and a dictionary containing the attributes carried by this element.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1990
1991<p>Also note that the reference string generated from the callback shows a
1992single character call even though the string "bar" is passed to the parser
1993from 2 different call to parseChunk()</p>
1994
1995<h3>xpath.py:</h3>
1996
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1997<p>This is a basic test of XPath wrappers support</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1998<pre>import libxml2
1999
2000doc = libxml2.parseFile("tst.xml")
2001ctxt = doc.xpathNewContext()
2002res = ctxt.xpathEval("//*")
2003if len(res) != 2:
2004 print "xpath query: wrong node set size"
2005 sys.exit(1)
2006if res[0].name != "doc" or res[1].name != "foo":
2007 print "xpath query: wrong node set value"
2008 sys.exit(1)
2009doc.freeDoc()
2010ctxt.xpathFreeContext()</pre>
2011
2012<p>This test parses a file, then create an XPath context to evaluate XPath
2013expression on it. The xpathEval() method execute an XPath query and returns
2014the result mapped in a Python way. String and numbers are natively converted,
2015and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2016the document, the XPath context need to be freed explicitly, also not that
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]2017the result of the XPath query may point back to the document tree and hence
2018the document must be freed after the result of the query is used.</p>
2019
2020<h3>xpathext.py:</h3>
2021
2022<p>This test shows how to extend the XPath engine with functions written in
2023python:</p>
2024<pre>import libxml2
2025
2026def foo(ctx, x):
2027 return x + 1
2028
2029doc = libxml2.parseFile("tst.xml")
2030ctxt = doc.xpathNewContext()
2031libxml2.registerXPathFunction(ctxt._o, "foo", None, foo)
2032res = ctxt.xpathEval("foo(1)")
2033if res != 2:
2034 print "xpath extension failure"
2035doc.freeDoc()
2036ctxt.xpathFreeContext()</pre>
2037
2038<p>Note how the extension function is registered with the context (but that
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2039part is not yet finalized, this may change slightly in the future).</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]2040
2041<h3>tstxpath.py:</h3>
2042
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2043<p>This test is similar to the previous one but shows how the extension
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]2044function can access the XPath evaluation context:</p>
2045<pre>def foo(ctx, x):
2046 global called
2047
2048 #
2049 # test that access to the XPath evaluation contexts
2050 #
2051 pctxt = libxml2.xpathParserContext(_obj=ctx)
2052 ctxt = pctxt.context()
2053 called = ctxt.function()
2054 return x + 1</pre>
2055
2056<p>All the interfaces around the XPath parser(or rather evaluation) context
2057are not finalized, but it should be sufficient to do contextual work at the
2058evaluation point.</p>
2059
2060<h3>Memory debugging:</h3>
2061
2062<p>last but not least, all tests starts with the following prologue:</p>
2063<pre>#memory debug specific
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2064libxml2.debugMemory(1)</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]2065
2066<p>and ends with the following epilogue:</p>
2067<pre>#memory debug specific
2068libxml2.cleanupParser()
2069if libxml2.debugMemory(1) == 0:
2070 print "OK"
2071else:
2072 print "Memory leak %d bytes" % (libxml2.debugMemory(1))
2073 libxml2.dumpMemory()</pre>
2074
2075<p>Those activate the memory debugging interface of libxml2 where all
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2076allocated block in the library are tracked. The prologue then cleans up the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]2077library state and checks that all allocated memory has been freed. If not it
2078calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]2079
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2080<h2><a name="architecture">libxml2 architecture</a></h2>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2081
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]2082<p>Libxml2 is made of multiple components; some of them are optional, and
2083most of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2084<ul>
2085 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2086 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2087 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2088 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2089 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2090 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2091 <li>a SAX tree module to build an in-memory DOM representation</li>
2092 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2093 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2094 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2095 (optional)</li>
2096 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2097</ul>
2098
2099<p>Graphically this gives the following:</p>
2100
2101<p><img src="libxml.gif" alt="a graphical view of the various"></p>
2102
2103<p></p>
2104
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2105<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2106
2107<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]2108returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2109<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]2110as the file name, the document type, and a <strong>children</strong> pointer
2111which is the root of the document (or more exactly the first child under the
2112root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2113chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]2114relationship. An xmlNode can also carry properties (a chain of xmlAttr
2115structures). An attribute may have a value which is a list of TEXT or
2116ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2117
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2118<p>Here is an example (erroneous with respect to the XML spec since there
2119should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2120
2121<p><img src="structure.gif" alt=" structure.gif "></p>
2122
2123<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]2124called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2125prints them back as parsed. This is useful for detecting errors both in XML
2126code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2127which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2128result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2129<pre>DOCUMENT
2130version=1.0
2131standalone=true
2132 ELEMENT EXAMPLE
2133 ATTRIBUTE prop1
2134 TEXT
2135 content=gnome is great
2136 ATTRIBUTE prop2
2137 ENTITY_REF
2138 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2139 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]2140 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2141 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2142 TEXT
2143 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2144 ELEMENT chapter
2145 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2146 TEXT
2147 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2148 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2149 TEXT
2150 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2151 ELEMENT image
2152 ATTRIBUTE href
2153 TEXT
2154 content=linus.gif
2155 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2156 TEXT
2157 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2158
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2159<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]2160
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2161<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2162
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]2163<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2164memory. In that case (and if you don't expect to save back the XML document
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2165loaded using libxml), it's better to use the SAX interface of libxml. SAX is
2166a <strong>callback-based interface</strong> to the parser. Before parsing,
2167the application layer registers a customized set of callbacks which are
2168called by the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2169
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2170<p>To get more detailed step-by-step guidance on using the SAX interface of
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2171libxml, see the <a
2172href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
2173documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2174Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2175
2176<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
2177program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2178binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]2179distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2180testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2181<pre>SAX.setDocumentLocator()
2182SAX.startDocument()
2183SAX.getEntity(amp)
2184SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
2185SAX.characters( , 3)
2186SAX.startElement(head)
2187SAX.characters( , 4)
2188SAX.startElement(title)
2189SAX.characters(Welcome to Gnome, 16)
2190SAX.endElement(title)
2191SAX.characters( , 3)
2192SAX.endElement(head)
2193SAX.characters( , 3)
2194SAX.startElement(chapter)
2195SAX.characters( , 4)
2196SAX.startElement(title)
2197SAX.characters(The Linux adventure, 19)
2198SAX.endElement(title)
2199SAX.characters( , 4)
2200SAX.startElement(p)
2201SAX.characters(bla bla bla ..., 15)
2202SAX.endElement(p)
2203SAX.characters( , 4)
2204SAX.startElement(image, href='linus.gif')
2205SAX.endElement(image)
2206SAX.characters( , 4)
2207SAX.startElement(p)
2208SAX.characters(..., 3)
2209SAX.endElement(p)
2210SAX.characters( , 3)
2211SAX.endElement(chapter)
2212SAX.characters( , 1)
2213SAX.endElement(EXAMPLE)
2214SAX.endDocument()</pre>
2215
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2216<p>Most of the other interfaces of libxml2 are based on the DOM tree-building
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2217facility, so nearly everything up to the end of this document presupposes the
2218use of the standard DOM tree build. Note that the DOM tree itself is built by
2219a set of registered default callbacks, without internal specific
2220interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2221
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2222<h2><a name="Validation">Validation &amp; DTDs</a></h2>
2223
2224<p>Table of Content:</p>
2225<ol>
2226 <li><a href="#General5">General overview</a></li>
2227 <li><a href="#definition">The definition</a></li>
2228 <li><a href="#Simple">Simple rules</a>
2229 <ol>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2230 <li><a href="#reference">How to reference a DTD from a document</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2231 <li><a href="#Declaring">Declaring elements</a></li>
2232 <li><a href="#Declaring1">Declaring attributes</a></li>
2233 </ol>
2234 </li>
2235 <li><a href="#Some">Some examples</a></li>
2236 <li><a href="#validate">How to validate</a></li>
2237 <li><a href="#Other">Other resources</a></li>
2238</ol>
2239
2240<h3><a name="General5">General overview</a></h3>
2241
2242<p>Well what is validation and what is a DTD ?</p>
2243
2244<p>DTD is the acronym for Document Type Definition. This is a description of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2245the content for a family of XML files. This is part of the XML 1.0
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2246specification, and allows one to describe and verify that a given document
2247instance conforms to the set of rules detailing its structure and content.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2248
2249<p>Validation is the process of checking a document against a DTD (more
2250generally against a set of construction rules).</p>
2251
2252<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2253of the XML life cycle. Briefly a DTD defines all the possible elements to be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2254found within your document, what is the formal shape of your document tree
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2255(by defining the allowed content of an element; either text, a regular
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2256expression for the allowed list of children, or mixed content i.e. both text
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2257and children). The DTD also defines the valid attributes for all elements and
2258the types of those attributes.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2259
2260<h3><a name="definition1">The definition</a></h3>
2261
2262<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
2263href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
2264Rev1</a>):</p>
2265<ul>
2266 <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
2267 elements</a></li>
2268 <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
2269 attributes</a></li>
2270</ul>
2271
2272<p>(unfortunately) all this is inherited from the SGML world, the syntax is
2273ancient...</p>
2274
2275<h3><a name="Simple1">Simple rules</a></h3>
2276
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2277<p>Writing DTDs can be done in many ways. The rules to build them if you need
2278something permanent or something which can evolve over time can be radically
2279different. Really complex DTDs like DocBook ones are flexible but quite
2280harder to design. I will just focus on DTDs for a formats with a fixed simple
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2281structure. It is just a set of basic rules, and definitely not exhaustive nor
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2282usable for complex DTD design.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2283
2284<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
2285
2286<p>Assuming the top element of the document is <code>spec</code> and the dtd
2287is placed in the file <code>mydtd</code> in the subdirectory
2288<code>dtds</code> of the directory from where the document were loaded:</p>
2289
2290<p><code>&lt;!DOCTYPE spec SYSTEM "dtds/mydtd"&gt;</code></p>
2291
2292<p>Notes:</p>
2293<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2294 <li>The system string is actually an URI-Reference (as defined in <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2295 href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396</a>) so you can use a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2296 full URL string indicating the location of your DTD on the Web. This is a
2297 really good thing to do if you want others to validate your document.</li>
2298 <li>It is also possible to associate a <code>PUBLIC</code> identifier (a
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2299 magic string) so that the DTD is looked up in catalogs on the client side
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2300 without having to locate it on the web.</li>
2301 <li>A DTD contains a set of element and attribute declarations, but they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2302 don't define what the root of the document should be. This is explicitly
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2303 told to the parser/validator as the first element of the
2304 <code>DOCTYPE</code> declaration.</li>
2305</ul>
2306
2307<h4><a name="Declaring2">Declaring elements</a>:</h4>
2308
2309<p>The following declares an element <code>spec</code>:</p>
2310
2311<p><code>&lt;!ELEMENT spec (front, body, back?)&gt;</code></p>
2312
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2313<p>It also expresses that the spec element contains one <code>front</code>,
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2314one <code>body</code> and one optional <code>back</code> children elements in
2315this order. The declaration of one element of the structure and its content
2316are done in a single declaration. Similarly the following declares
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2317<code>div1</code> elements:</p>
2318
Daniel Veillard51737272002-01-23 23:10:38 +0000[diff] [blame]2319<p><code>&lt;!ELEMENT div1 (head, (p | list | note)*, div2?)&gt;</code></p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2320
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2321<p>which means div1 contains one <code>head</code> then a series of optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2322<code>p</code>, <code>list</code>s and <code>note</code>s and then an
2323optional <code>div2</code>. And last but not least an element can contain
2324text:</p>
2325
2326<p><code>&lt;!ELEMENT b (#PCDATA)&gt;</code></p>
2327
2328<p><code>b</code> contains text or being of mixed content (text and elements
2329in no particular order):</p>
2330
2331<p><code>&lt;!ELEMENT p (#PCDATA|a|ul|b|i|em)*&gt;</code></p>
2332
2333<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
2334<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
2335order.</p>
2336
2337<h4><a name="Declaring1">Declaring attributes</a>:</h4>
2338
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2339<p>Again the attributes declaration includes their content definition:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2340
2341<p><code>&lt;!ATTLIST termdef name CDATA #IMPLIED&gt;</code></p>
2342
2343<p>means that the element <code>termdef</code> can have a <code>name</code>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2344attribute containing text (<code>CDATA</code>) and which is optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2345(<code>#IMPLIED</code>). The attribute value can also be defined within a
2346set:</p>
2347
2348<p><code>&lt;!ATTLIST list type (bullets|ordered|glossary)
2349"ordered"&gt;</code></p>
2350
2351<p>means <code>list</code> element have a <code>type</code> attribute with 3
2352allowed values "bullets", "ordered" or "glossary" and which default to
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2353"ordered" if the attribute is not explicitly specified.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2354
2355<p>The content type of an attribute can be text (<code>CDATA</code>),
2356anchor/reference/references
2357(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
2358(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
2359(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
2360<code>chapter</code> element can have an optional <code>id</code> attribute
2361of type <code>ID</code>, usable for reference from attribute of type
2362IDREF:</p>
2363
2364<p><code>&lt;!ATTLIST chapter id ID #IMPLIED&gt;</code></p>
2365
2366<p>The last value of an attribute definition can be <code>#REQUIRED
2367</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
2368meaning that it is optional, or the default value (possibly prefixed by
2369<code>#FIXED</code> if it is the only allowed).</p>
2370
2371<p>Notes:</p>
2372<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2373 <li>Usually the attributes pertaining to a given element are declared in a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2374 single expression, but it is just a convention adopted by a lot of DTD
2375 writers:
2376 <pre>&lt;!ATTLIST termdef
2377 id ID #REQUIRED
2378 name CDATA #IMPLIED&gt;</pre>
2379 <p>The previous construct defines both <code>id</code> and
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2380 <code>name</code> attributes for the element <code>termdef</code>.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2381 </li>
2382</ul>
2383
2384<h3><a name="Some1">Some examples</a></h3>
2385
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2386<p>The directory <code>test/valid/dtds/</code> in the libxml2 distribution
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2387contains some complex DTD examples. The example in the file
2388<code>test/valid/dia.xml</code> shows an XML file where the simple DTD is
2389directly included within the document.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2390
2391<h3><a name="validate1">How to validate</a></h3>
2392
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2393<p>The simplest way is to use the xmllint program included with libxml. The
2394<code>--valid</code> option turns-on validation of the files given as input.
2395For example the following validates a copy of the first revision of the XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]23961.0 specification:</p>
2397
2398<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
2399
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2400<p>the -- noout is used to disable output of the resulting tree.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2401
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2402<p>The <code>--dtdvalid dtd</code> allows validation of the document(s)
2403against a given DTD.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2404
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2405<p>Libxml2 exports an API to handle DTDs and validation, check the <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2406href="http://xmlsoft.org/html/libxml-valid.html">associated
2407description</a>.</p>
2408
2409<h3><a name="Other1">Other resources</a></h3>
2410
2411<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
2412will just list one for now, others pointers welcome:</p>
2413<ul>
2414 <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
2415</ul>
2416
2417<p>I suggest looking at the examples found under test/valid/dtd and any of
2418the large number of books available on XML. The dia example in test/valid
2419should be both simple and complete enough to allow you to build your own.</p>
2420
2421<p></p>
2422
2423<h2><a name="Memory">Memory Management</a></h2>
2424
2425<p>Table of Content:</p>
2426<ol>
2427 <li><a href="#General3">General overview</a></li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2428 <li><a href="#setting">Setting libxml2 set of memory routines</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2429 <li><a href="#cleanup">Cleaning up after parsing</a></li>
2430 <li><a href="#Debugging">Debugging routines</a></li>
2431 <li><a href="#General4">General memory requirements</a></li>
2432</ol>
2433
2434<h3><a name="General3">General overview</a></h3>
2435
2436<p>The module <code><a
2437href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2438provides the interfaces to the libxml2 memory system:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2439<ul>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2440 <li>libxml2 does not use the libc memory allocator directly but xmlFree(),
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2441 xmlMalloc() and xmlRealloc()</li>
2442 <li>those routines can be reallocated to a specific set of routine, by
2443 default the libc ones i.e. free(), malloc() and realloc()</li>
2444 <li>the xmlmemory.c module includes a set of debugging routine</li>
2445</ul>
2446
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2447<h3><a name="setting">Setting libxml2 set of memory routines</a></h3>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2448
2449<p>It is sometimes useful to not use the default memory allocator, either for
2450debugging, analysis or to implement a specific behaviour on memory management
2451(like on embedded systems). Two function calls are available to do so:</p>
2452<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2453 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet
2454 ()</a> which return the current set of functions in use by the parser</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2455 <li><a
2456 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2457 which allow to set up a new set of memory allocation functions</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2458</ul>
2459
2460<p>Of course a call to xmlMemSetup() should probably be done before calling
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2461any other libxml2 routines (unless you are sure your allocations routines are
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2462compatibles).</p>
2463
2464<h3><a name="cleanup">Cleaning up after parsing</a></h3>
2465
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2466<p>Libxml2 is not stateless, there is a few set of memory structures needing
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2467allocation before the parser is fully functional (some encoding structures
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2468for example). This also mean that once parsing is finished there is a tiny
2469amount of memory (a few hundred bytes) which can be recollected if you don't
2470reuse the parser immediately:</p>
2471<ul>
2472 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2473 ()</a> is a centralized routine to free the parsing states. Note that it
2474 won't deallocate any produced tree if any (use the xmlFreeDoc() and
2475 related routines for this).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2476 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2477 ()</a> is the dual routine allowing to preallocate the parsing state
2478 which can be useful for example to avoid initialization reentrancy
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2479 problems when using libxml2 in multithreaded applications</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2480</ul>
2481
2482<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
2483at the next invocation of parser routines, but be careful of the consequences
2484in multithreaded applications.</p>
2485
2486<h3><a name="Debugging">Debugging routines</a></h3>
2487
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2488<p>When configured using --with-mem-debug flag (off by default), libxml2 uses
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2489a set of memory allocation debugging routines keeping track of all allocated
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2490blocks and the location in the code where the routine was called. A couple of
2491other debugging routines allow to dump the memory allocated infos to a file
2492or call a specific routine when a given block number is allocated:</p>
2493<ul>
2494 <li><a
2495 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2496 <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2497 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
2498 and <a
2499 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
2500 are the memory debugging replacement allocation routines</li>
2501 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2502 ()</a> dumps all the informations about the allocated memory block lefts
2503 in the <code>.memdump</code> file</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2504</ul>
2505
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2506<p>When developing libxml2 memory debug is enabled, the tests programs call
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2507xmlMemoryDump () and the "make test" regression tests will check for any
2508memory leak during the full regression test sequence, this helps a lot
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2509ensuring that libxml2 does not leak memory and bullet proof memory
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2510allocations use (some libc implementations are known to be far too permissive
2511resulting in major portability problems!).</p>
2512
2513<p>If the .memdump reports a leak, it displays the allocation function and
2514also tries to give some informations about the content and structure of the
2515allocated blocks left. This is sufficient in most cases to find the culprit,
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2516but not always. Assuming the allocation problem is reproducible, it is
2517possible to find more easily:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2518<ol>
2519 <li>write down the block number xxxx not allocated</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2520 <li>export the environment variable XML_MEM_BREAKPOINT=xxxx , the easiest
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2521 when using GDB is to simply give the command
2522 <p><code>set environment XML_MEM_BREAKPOINT xxxx</code></p>
2523 <p>before running the program.</p>
2524 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2525 <li>run the program under a debugger and set a breakpoint on
2526 xmlMallocBreakpoint() a specific function called when this precise block
2527 is allocated</li>
2528 <li>when the breakpoint is reached you can then do a fine analysis of the
2529 allocation an step to see the condition resulting in the missing
2530 deallocation.</li>
2531</ol>
2532
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2533<p>I used to use a commercial tool to debug libxml2 memory problems but after
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2534noticing that it was not detecting memory leaks that simple mechanism was
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2535used and proved extremely efficient until now. Lately I have also used <a
2536href="http://developer.kde.org/~sewardj/">valgrind</a> with quite some
2537success, it is tied to the i386 architecture since it works by emulating the
2538processor and instruction set, it is slow but extremely efficient, i.e. it
2539spot memory usage errors in a very precise way.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2540
2541<h3><a name="General4">General memory requirements</a></h3>
2542
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2543<p>How much libxml2 memory require ? It's hard to tell in average it depends
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2544of a number of things:</p>
2545<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2546 <li>the parser itself should work in a fixed amount of memory, except for
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2547 information maintained about the stacks of names and entities locations.
2548 The I/O and encoding handlers will probably account for a few KBytes.
2549 This is true for both the XML and HTML parser (though the HTML parser
2550 need more state).</li>
2551 <li>If you are generating the DOM tree then memory requirements will grow
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2552 nearly linear with the size of the data. In general for a balanced
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2553 textual document the internal memory requirement is about 4 times the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2554 size of the UTF8 serialization of this document (example the XML-1.0
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2555 recommendation is a bit more of 150KBytes and takes 650KBytes of main
2556 memory when parsed). Validation will add a amount of memory required for
2557 maintaining the external Dtd state which should be linear with the
2558 complexity of the content model defined by the Dtd</li>
Daniel Veillardce192eb2003-04-16 15:58:05 +0000[diff] [blame]2559 <li>If you need to work with fixed memory requirements or don't need the
2560 full DOM tree then using the <a href="xmlreader.html">xmlReader
2561 interface</a> is probably the best way to proceed, it still allows to
2562 validate or operate on subset of the tree if needed.</li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2563 <li>If you don't care about the advanced features of libxml2 like
Daniel Veillardce192eb2003-04-16 15:58:05 +0000[diff] [blame]2564 validation, DOM, XPath or XPointer, don't use entities, need to work with
2565 fixed memory requirements, and try to get the fastest parsing possible
2566 then the SAX interface should be used, but it has known restrictions.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2567</ul>
2568
2569<p></p>
2570
2571<h2><a name="Encodings">Encodings support</a></h2>
2572
2573<p>Table of Content:</p>
2574<ol>
2575 <li><a href="encoding.html#What">What does internationalization support
2576 mean ?</a></li>
2577 <li><a href="encoding.html#internal">The internal encoding, how and
2578 why</a></li>
2579 <li><a href="encoding.html#implemente">How is it implemented ?</a></li>
2580 <li><a href="encoding.html#Default">Default supported encodings</a></li>
2581 <li><a href="encoding.html#extend">How to extend the existing
2582 support</a></li>
2583</ol>
2584
2585<h3><a name="What">What does internationalization support mean ?</a></h3>
2586
Daniel Veillard238836e2003-04-07 22:57:29 +0000[diff] [blame]2587<p>If you are not really familiar with Internationalization (usual shorcut is
2588I18N) , Unicode, characters and glyphs, I suggest you read a <a
2589href="http://www.tbray.org/ongoing/When/200x/2003/04/06/Unicode">presentation</a>
2590by Tim Bray on Unicode and why you should care about it.</p>
2591
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2592<p>XML was designed from the start to allow the support of any character set
2593by using Unicode. Any conformant XML parser has to support the UTF-8 and
2594UTF-16 default encodings which can both express the full unicode ranges. UTF8
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2595is a variable length encoding whose greatest points are to reuse the same
2596encoding for ASCII and to save space for Western encodings, but it is a bit
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2597more complex to handle in practice. UTF-16 use 2 bytes per characters (and
2598sometimes combines two pairs), it makes implementation easier, but looks a
2599bit overkill for Western languages encoding. Moreover the XML specification
2600allows document to be encoded in other encodings at the condition that they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2601are clearly labeled as such. For example the following is a wellformed XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2602document encoded in ISO-8859 1 and using accentuated letter that we French
2603likes for both markup and content:</p>
2604<pre>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2605&lt;très&gt;là&lt;/très&gt;</pre>
2606
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2607<p>Having internationalization support in libxml2 means the following:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2608<ul>
2609 <li>the document is properly parsed</li>
2610 <li>informations about it's encoding are saved</li>
2611 <li>it can be modified</li>
2612 <li>it can be saved in its original encoding</li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2613 <li>it can also be saved in another encoding supported by libxml2 (for
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2614 example straight UTF8 or even an ASCII form)</li>
2615</ul>
2616
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2617<p>Another very important point is that the whole libxml2 API, with the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2618exception of a few routines to read with a specific encoding or save to a
2619specific encoding, is completely agnostic about the original encoding of the
2620document.</p>
2621
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2622<p>It should be noted too that the HTML parser embedded in libxml2 now obey
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2623the same rules too, the following document will be (as of 2.2.2) handled in
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2624an internationalized fashion by libxml2 too:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2625<pre>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
2626 "http://www.w3.org/TR/REC-html40/loose.dtd"&gt;
2627&lt;html lang="fr"&gt;
2628&lt;head&gt;
2629 &lt;META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&gt;
2630&lt;/head&gt;
2631&lt;body&gt;
2632&lt;p&gt;W3C crée des standards pour le Web.&lt;/body&gt;
2633&lt;/html&gt;</pre>
2634
2635<h3><a name="internal">The internal encoding, how and why</a></h3>
2636
2637<p>One of the core decision was to force all documents to be converted to a
2638default internal encoding, and that encoding to be UTF-8, here are the
2639rationale for those choices:</p>
2640<ul>
2641 <li>keeping the native encoding in the internal form would force the libxml
2642 users (or the code associated) to be fully aware of the encoding of the
2643 original document, for examples when adding a text node to a document,
2644 the content would have to be provided in the document encoding, i.e. the
2645 client code would have to check it before hand, make sure it's conformant
2646 to the encoding, etc ... Very hard in practice, though in some specific
2647 cases this may make sense.</li>
2648 <li>the second decision was which encoding. From the XML spec only UTF8 and
2649 UTF16 really makes sense as being the two only encodings for which there
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2650 is mandatory support. UCS-4 (32 bits fixed size encoding) could be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2651 considered an intelligent choice too since it's a direct Unicode mapping
2652 support. I selected UTF-8 on the basis of efficiency and compatibility
2653 with surrounding software:
2654 <ul>
2655 <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
2656 more costly to import and export CPU wise) is also far more compact
2657 than UTF-16 (and UCS-4) for a majority of the documents I see it used
2658 for right now (RPM RDF catalogs, advogato data, various configuration
2659 file formats, etc.) and the key point for today's computer
2660 architecture is efficient uses of caches. If one nearly double the
2661 memory requirement to store the same amount of data, this will trash
2662 caches (main memory/external caches/internal caches) and my take is
2663 that this harms the system far more than the CPU requirements needed
2664 for the conversion to UTF-8</li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2665 <li>Most of libxml2 version 1 users were using it with straight ASCII
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2666 most of the time, doing the conversion with an internal encoding
2667 requiring all their code to be rewritten was a serious show-stopper
2668 for using UTF-16 or UCS-4.</li>
2669 <li>UTF-8 is being used as the de-facto internal encoding standard for
2670 related code like the <a href="http://www.pango.org/">pango</a>
2671 upcoming Gnome text widget, and a lot of Unix code (yep another place
2672 where Unix programmer base takes a different approach from Microsoft
2673 - they are using UTF-16)</li>
2674 </ul>
2675 </li>
2676</ul>
2677
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2678<p>What does this mean in practice for the libxml2 user:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2679<ul>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2680 <li>xmlChar, the libxml2 data type is a byte, those bytes must be assembled
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2681 as UTF-8 valid strings. The proper way to terminate an xmlChar * string
2682 is simply to append 0 byte, as usual.</li>
2683 <li>One just need to make sure that when using chars outside the ASCII set,
2684 the values has been properly converted to UTF-8</li>
2685</ul>
2686
2687<h3><a name="implemente">How is it implemented ?</a></h3>
2688
2689<p>Let's describe how all this works within libxml, basically the I18N
2690(internationalization) support get triggered only during I/O operation, i.e.
2691when reading a document or saving one. Let's look first at the reading
2692sequence:</p>
2693<ol>
2694 <li>when a document is processed, we usually don't know the encoding, a
Daniel Veillard7b68df92003-08-03 22:58:54 +0000[diff] [blame]2695 simple heuristic allows to detect UTF-16 and UCS-4 from whose where the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2696 ASCII range (0-0x7F) maps with ASCII</li>
2697 <li>the xml declaration if available is parsed, including the encoding
2698 declaration. At that point, if the autodetected encoding is different
2699 from the one declared a call to xmlSwitchEncoding() is issued.</li>
2700 <li>If there is no encoding declaration, then the input has to be in either
2701 UTF-8 or UTF-16, if it is not then at some point when processing the
2702 input, the converter/checker of UTF-8 form will raise an encoding error.
2703 You may end-up with a garbled document, or no document at all ! Example:
2704 <pre>~/XML -&gt; ./xmllint err.xml
2705err.xml:1: error: Input is not proper UTF-8, indicate encoding !
2706&lt;très&gt;là&lt;/très&gt;
2707 ^
2708err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
2709&lt;très&gt;là&lt;/très&gt;
2710 ^</pre>
2711 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2712 <li>xmlSwitchEncoding() does an encoding name lookup, canonicalize it, and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2713 then search the default registered encoding converters for that encoding.
2714 If it's not within the default set and iconv() support has been compiled
2715 it, it will ask iconv for such an encoder. If this fails then the parser
2716 will report an error and stops processing:
2717 <pre>~/XML -&gt; ./xmllint err2.xml
2718err2.xml:1: error: Unsupported encoding UnsupportedEnc
2719&lt;?xml version="1.0" encoding="UnsupportedEnc"?&gt;
2720 ^</pre>
2721 </li>
Daniel Veillard46c5c1d2002-05-20 07:15:54 +0000[diff] [blame]2722 <li>From that point the encoder processes progressively the input (it is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2723 plugged as a front-end to the I/O module) for that entity. It captures
2724 and convert on-the-fly the document to be parsed to UTF-8. The parser
2725 itself just does UTF-8 checking of this input and process it
2726 transparently. The only difference is that the encoding information has
2727 been added to the parsing context (more precisely to the input
2728 corresponding to this entity).</li>
2729 <li>The result (when using DOM) is an internal form completely in UTF-8
2730 with just an encoding information on the document node.</li>
2731</ol>
2732
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2733<p>Ok then what happens when saving the document (assuming you
2734collected/built an xmlDoc DOM like structure) ? It depends on the function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2735called, xmlSaveFile() will just try to save in the original encoding, while
2736xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
2737encoding:</p>
2738<ol>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2739 <li>if no encoding is given, libxml2 will look for an encoding value
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2740 associated to the document and if it exists will try to save to that
2741 encoding,
2742 <p>otherwise everything is written in the internal form, i.e. UTF-8</p>
2743 </li>
2744 <li>so if an encoding was specified, either at the API level or on the
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2745 document, libxml2 will again canonicalize the encoding name, lookup for a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2746 converter in the registered set or through iconv. If not found the
2747 function will return an error code</li>
2748 <li>the converter is placed before the I/O buffer layer, as another kind of
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2749 buffer, then libxml2 will simply push the UTF-8 serialization to through
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2750 that buffer, which will then progressively be converted and pushed onto
2751 the I/O layer.</li>
2752 <li>It is possible that the converter code fails on some input, for example
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2753 trying to push an UTF-8 encoded Chinese character through the UTF-8 to
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2754 ISO-8859-1 converter won't work. Since the encoders are progressive they
2755 will just report the error and the number of bytes converted, at that
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2756 point libxml2 will decode the offending character, remove it from the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2757 buffer and replace it with the associated charRef encoding &amp;#123; and
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2758 resume the conversion. This guarantees that any document will be saved
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2759 without losses (except for markup names where this is not legal, this is
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2760 a problem in the current version, in practice avoid using non-ascii
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2761 characters for tags or attributes names @@). A special "ascii" encoding
2762 name is used to save documents to a pure ascii form can be used when
2763 portability is really crucial</li>
2764</ol>
2765
2766<p>Here is a few examples based on the same test document:</p>
2767<pre>~/XML -&gt; ./xmllint isolat1
2768&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2769&lt;très&gt;là&lt;/très&gt;
2770~/XML -&gt; ./xmllint --encode UTF-8 isolat1
2771&lt;?xml version="1.0" encoding="UTF-8"?&gt;
2772&lt;très&gt;là  &lt;/très&gt;
2773~/XML -&gt; </pre>
2774
2775<p>The same processing is applied (and reuse most of the code) for HTML I18N
2776processing. Looking up and modifying the content encoding is a bit more
2777difficult since it is located in a &lt;meta&gt; tag under the &lt;head&gt;,
2778so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
2779been provided. The parser also attempts to switch encoding on the fly when
2780detecting such a tag on input. Except for that the processing is the same
2781(and again reuses the same code).</p>
2782
2783<h3><a name="Default">Default supported encodings</a></h3>
2784
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2785<p>libxml2 has a set of default converters for the following encodings
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2786(located in encoding.c):</p>
2787<ol>
2788 <li>UTF-8 is supported by default (null handlers)</li>
2789 <li>UTF-16, both little and big endian</li>
2790 <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
2791 <li>ASCII, useful mostly for saving</li>
2792 <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
2793 predefined entities like &amp;copy; for the Copyright sign.</li>
2794</ol>
2795
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2796<p>More over when compiled on an Unix platform with iconv support the full
2797set of encodings supported by iconv can be instantly be used by libxml. On a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2798linux machine with glibc-2.1 the list of supported encodings and aliases fill
27993 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
2800various Japanese ones.</p>
2801
2802<h4>Encoding aliases</h4>
2803
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2804<p>From 2.2.3, libxml2 has support to register encoding names aliases. The
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2805goal is to be able to parse document whose encoding is supported but where
2806the name differs (for example from the default set of names accepted by
2807iconv). The following functions allow to register and handle new aliases for
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2808existing encodings. Once registered libxml2 will automatically lookup the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2809aliases when handling a document:</p>
2810<ul>
2811 <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li>
2812 <li>int xmlDelEncodingAlias(const char *alias);</li>
2813 <li>const char * xmlGetEncodingAlias(const char *alias);</li>
2814 <li>void xmlCleanupEncodingAliases(void);</li>
2815</ul>
2816
2817<h3><a name="extend">How to extend the existing support</a></h3>
2818
2819<p>Well adding support for new encoding, or overriding one of the encoders
2820(assuming it is buggy) should not be hard, just write an input and output
2821conversion routines to/from UTF-8, and register them using
2822xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
2823called automatically if the parser(s) encounter such an encoding name
2824(register it uppercase, this will help). The description of the encoders,
2825their arguments and expected return values are described in the encoding.h
2826header.</p>
2827
2828<p>A quick note on the topic of subverting the parser to use a different
2829internal encoding than UTF-8, in some case people will absolutely want to
2830keep the internal encoding different, I think it's still possible (but the
2831encoding must be compliant with ASCII on the same subrange) though I didn't
2832tried it. The key is to override the default conversion routines (by
2833registering null encoders/decoders for your charsets), and bypass the UTF-8
2834checking of the parser by setting the parser context charset
2835(ctxt-&gt;charset) to something different than XML_CHAR_ENCODING_UTF8, but
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2836there is no guarantee that this will work. You may also have some troubles
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2837saving back.</p>
2838
2839<p>Basically proper I18N support is important, this requires at least
2840libxml-2.0.0, but a lot of features and corrections are really available only
2841starting 2.2.</p>
2842
2843<h2><a name="IO">I/O Interfaces</a></h2>
2844
2845<p>Table of Content:</p>
2846<ol>
2847 <li><a href="#General1">General overview</a></li>
2848 <li><a href="#basic">The basic buffer type</a></li>
2849 <li><a href="#Input">Input I/O handlers</a></li>
2850 <li><a href="#Output">Output I/O handlers</a></li>
2851 <li><a href="#entities">The entities loader</a></li>
2852 <li><a href="#Example2">Example of customized I/O</a></li>
2853</ol>
2854
2855<h3><a name="General1">General overview</a></h3>
2856
2857<p>The module <code><a
2858href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2859the interfaces to the libxml2 I/O system. This consists of 4 main parts:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2860<ul>
2861 <li>Entities loader, this is a routine which tries to fetch the entities
2862 (files) based on their PUBLIC and SYSTEM identifiers. The default loader
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2863 don't look at the public identifier since libxml2 do not maintain a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2864 catalog. You can redefine you own entity loader by using
2865 <code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2866 <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
2867 example</a>.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2868 <li>Input I/O buffers which are a commodity structure used by the parser(s)
2869 input layer to handle fetching the informations to feed the parser. This
2870 provides buffering and is also a placeholder where the encoding
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2871 converters to UTF8 are piggy-backed.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2872 <li>Output I/O buffers are similar to the Input ones and fulfill similar
2873 task but when generating a serialization from a tree.</li>
2874 <li>A mechanism to register sets of I/O callbacks and associate them with
2875 specific naming schemes like the protocol part of the URIs.
2876 <p>This affect the default I/O operations and allows to use specific I/O
2877 handlers for certain names.</p>
2878 </li>
2879</ul>
2880
2881<p>The general mechanism used when loading http://rpmfind.net/xml.html for
2882example in the HTML parser is the following:</p>
2883<ol>
2884 <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
2885 the parsing context and the URI string.</li>
2886 <li>the URI string is checked against the existing registered handlers
2887 using their match() callback function, if the HTTP module was compiled
2888 in, it is registered and its match() function will succeeds</li>
2889 <li>the open() function of the handler is called and if successful will
2890 return an I/O Input buffer</li>
2891 <li>the parser will the start reading from this buffer and progressively
2892 fetch information from the resource, calling the read() function of the
2893 handler until the resource is exhausted</li>
2894 <li>if an encoding change is detected it will be installed on the input
2895 buffer, providing buffering and efficient use of the conversion
2896 routines</li>
2897 <li>once the parser has finished, the close() function of the handler is
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2898 called once and the Input buffer and associated resources are
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2899 deallocated.</li>
2900</ol>
2901
2902<p>The user defined callbacks are checked first to allow overriding of the
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2903default libxml2 I/O routines.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2904
2905<h3><a name="basic">The basic buffer type</a></h3>
2906
2907<p>All the buffer manipulation handling is done using the
2908<code>xmlBuffer</code> type define in <code><a
2909href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
2910resizable memory buffer. The buffer allocation strategy can be selected to be
2911either best-fit or use an exponential doubling one (CPU vs. memory use
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2912trade-off). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2913<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
2914system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
2915of functions allows to manipulate buffers with names starting with the
2916<code>xmlBuffer...</code> prefix.</p>
2917
2918<h3><a name="Input">Input I/O handlers</a></h3>
2919
2920<p>An Input I/O handler is a simple structure
2921<code>xmlParserInputBuffer</code> containing a context associated to the
2922resource (file descriptor, or pointer to a protocol handler), the read() and
2923close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
2924encoding handler are also present to support charset conversion when
2925needed.</p>
2926
2927<h3><a name="Output">Output I/O handlers</a></h3>
2928
2929<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
2930Input one except the callbacks are write() and close().</p>
2931
2932<h3><a name="entities">The entities loader</a></h3>
2933
2934<p>The entity loader resolves requests for new entities and create inputs for
2935the parser. Creating an input from a filename or an URI string is done
2936through the xmlNewInputFromFile() routine. The default entity loader do not
2937handle the PUBLIC identifier associated with an entity (if any). So it just
2938calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
2939XML).</p>
2940
2941<p>If you want to hook up a catalog mechanism then you simply need to
2942override the default entity loader, here is an example:</p>
2943<pre>#include &lt;libxml/xmlIO.h&gt;
2944
2945xmlExternalEntityLoader defaultLoader = NULL;
2946
2947xmlParserInputPtr
2948xmlMyExternalEntityLoader(const char *URL, const char *ID,
2949 xmlParserCtxtPtr ctxt) {
2950 xmlParserInputPtr ret;
2951 const char *fileID = NULL;
2952 /* lookup for the fileID depending on ID */
2953
2954 ret = xmlNewInputFromFile(ctxt, fileID);
2955 if (ret != NULL)
2956 return(ret);
2957 if (defaultLoader != NULL)
2958 ret = defaultLoader(URL, ID, ctxt);
2959 return(ret);
2960}
2961
2962int main(..) {
2963 ...
2964
2965 /*
2966 * Install our own entity loader
2967 */
2968 defaultLoader = xmlGetExternalEntityLoader();
2969 xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
2970
2971 ...
2972}</pre>
2973
2974<h3><a name="Example2">Example of customized I/O</a></h3>
2975
2976<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
2977real use case</a>, xmlDocDump() closes the FILE * passed by the application
2978and this was a problem. The <a
2979href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
2980new output handler with the closing call deactivated:</p>
2981<ol>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2982 <li>First define a new I/O output allocator where the output don't close
2983 the file:
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2984 <pre>xmlOutputBufferPtr
2985xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
2986    xmlOutputBufferPtr ret;
2987    
2988    if (xmlOutputCallbackInitialized == 0)
2989        xmlRegisterDefaultOutputCallbacks();
2990
2991    if (file == NULL) return(NULL);
2992    ret = xmlAllocOutputBuffer(encoder);
2993    if (ret != NULL) {
2994        ret-&gt;context = file;
2995        ret-&gt;writecallback = xmlFileWrite;
2996        ret-&gt;closecallback = NULL; /* No close callback */
2997    }
Daniel Veillardf83a2c72003-04-08 13:48:40 +0000[diff] [blame]2998    return(ret);
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2999} </pre>
3000 </li>
3001 <li>And then use it to save the document:
3002 <pre>FILE *f;
3003xmlOutputBufferPtr output;
3004xmlDocPtr doc;
3005int res;
3006
3007f = ...
3008doc = ....
3009
3010output = xmlOutputBufferCreateOwn(f, NULL);
3011res = xmlSaveFileTo(output, doc, NULL);
3012 </pre>
3013 </li>
3014</ol>
3015
3016<h2><a name="Catalog">Catalog support</a></h2>
3017
3018<p>Table of Content:</p>
3019<ol>
3020 <li><a href="General2">General overview</a></li>
3021 <li><a href="#definition">The definition</a></li>
3022 <li><a href="#Simple">Using catalogs</a></li>
3023 <li><a href="#Some">Some examples</a></li>
3024 <li><a href="#reference">How to tune catalog usage</a></li>
3025 <li><a href="#validate">How to debug catalog processing</a></li>
3026 <li><a href="#Declaring">How to create and maintain catalogs</a></li>
3027 <li><a href="#implemento">The implementor corner quick review of the
3028 API</a></li>
3029 <li><a href="#Other">Other resources</a></li>
3030</ol>
3031
3032<h3><a name="General2">General overview</a></h3>
3033
3034<p>What is a catalog? Basically it's a lookup mechanism used when an entity
3035(a file or a remote resource) references another entity. The catalog lookup
3036is inserted between the moment the reference is recognized by the software
3037(XML parser, stylesheet processing, or even images referenced for inclusion
3038in a rendering) and the time where loading that resource is actually
3039started.</p>
3040
3041<p>It is basically used for 3 things:</p>
3042<ul>
3043 <li>mapping from "logical" names, the public identifiers and a more
3044 concrete name usable for download (and URI). For example it can associate
3045 the logical name
3046 <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
3047 <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
3048 downloaded</p>
3049 <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
3050 </li>
3051 <li>remapping from a given URL to another one, like an HTTP indirection
3052 saying that
3053 <p>"http://www.oasis-open.org/committes/tr.xsl"</p>
3054 <p>should really be looked at</p>
3055 <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
3056 </li>
3057 <li>providing a local cache mechanism allowing to load the entities
3058 associated to public identifiers or remote resources, this is a really
3059 important feature for any significant deployment of XML or SGML since it
3060 allows to avoid the aleas and delays associated to fetching remote
3061 resources.</li>
3062</ul>
3063
3064<h3><a name="definition">The definitions</a></h3>
3065
3066<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
3067<ul>
3068 <li>the older SGML catalogs, the official spec is SGML Open Technical
3069 Resolution TR9401:1997, but is better understood by reading <a
3070 href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
3071 James Clark. This is relatively old and not the preferred mode of
3072 operation of libxml.</li>
3073 <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3074 Catalogs</a> is far more flexible, more recent, uses an XML syntax and
3075 should scale quite better. This is the default option of libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3076</ul>
3077
3078<p></p>
3079
3080<h3><a name="Simple">Using catalog</a></h3>
3081
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3082<p>In a normal environment libxml2 will by default check the presence of a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3083catalog in /etc/xml/catalog, and assuming it has been correctly populated,
3084the processing is completely transparent to the document user. To take a
3085concrete example, suppose you are authoring a DocBook document, this one
3086starts with the following DOCTYPE definition:</p>
3087<pre>&lt;?xml version='1.0'?&gt;
3088&lt;!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
3089 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"&gt;</pre>
3090
3091<p>When validating the document with libxml, the catalog will be
3092automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
3093DocBk XML V3.1.4//EN" and the system identifier
3094"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
3095been installed on your system and the catalogs actually point to them, libxml
3096will fetch them from the local disk.</p>
3097
3098<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
3099DOCTYPE example it's a really old version, but is fine as an example.</p>
3100
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3101<p>Libxml2 will check the catalog each time that it is requested to load an
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3102entity, this includes DTD, external parsed entities, stylesheets, etc ... If
3103your system is correctly configured all the authoring phase and processing
3104should use only local files, even if your document stays portable because it
3105uses the canonical public and system ID, referencing the remote document.</p>
3106
3107<h3><a name="Some">Some examples:</a></h3>
3108
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3109<p>Here is a couple of fragments from XML Catalogs used in libxml2 early
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3110regression tests in <code>test/catalogs</code> :</p>
3111<pre>&lt;?xml version="1.0"?&gt;
3112&lt;!DOCTYPE catalog PUBLIC
3113 "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
3114 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
3115&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
3116 &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
3117 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
3118...</pre>
3119
3120<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
3121written in XML, there is a specific namespace for catalog elements
3122"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
3123catalog is a <code>public</code> mapping it allows to associate a Public
3124Identifier with an URI.</p>
3125<pre>...
3126 &lt;rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
3127 rewritePrefix="file:///usr/share/xml/docbook/"/&gt;
3128...</pre>
3129
3130<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
3131any URI starting with a given prefix should be looked at another URI
3132constructed by replacing the prefix with an new one. In effect this acts like
3133a cache system for a full area of the Web. In practice it is extremely useful
3134with a file prefix if you have installed a copy of those resources on your
3135local system.</p>
3136<pre>...
3137&lt;delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
3138 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3139&lt;delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
3140 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3141&lt;delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
3142 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3143&lt;delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
3144 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3145&lt;delegateURI uriStartString="http://www.oasis-open.org/docbook/"
3146 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3147...</pre>
3148
3149<p>Delegation is the core features which allows to build a tree of catalogs,
3150easier to maintain than a single catalog, based on Public Identifier, System
3151Identifier or URI prefixes it instructs the catalog software to look up
3152entries in another resource. This feature allow to build hierarchies of
3153catalogs, the set of entries presented should be sufficient to redirect the
3154resolution of all DocBook references to the specific catalog in
3155<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
3156references for DocBook 4.2.1 to a specific catalog installed at the same time
3157as the DocBook resources on the local machine.</p>
3158
3159<h3><a name="reference">How to tune catalog usage:</a></h3>
3160
3161<p>The user can change the default catalog behaviour by redirecting queries
3162to its own set of catalogs, this can be done by setting the
3163<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
3164empty one should deactivate loading the default <code>/etc/xml/catalog</code>
3165default catalog</p>
3166
3167<h3><a name="validate">How to debug catalog processing:</a></h3>
3168
3169<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3170make libxml2 output debugging informations for each catalog operations, for
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3171example:</p>
3172<pre>orchis:~/XML -&gt; xmllint --memory --noout test/ent2
3173warning: failed to load external entity "title.xml"
3174orchis:~/XML -&gt; export XML_DEBUG_CATALOG=
3175orchis:~/XML -&gt; xmllint --memory --noout test/ent2
3176Failed to parse catalog /etc/xml/catalog
3177Failed to parse catalog /etc/xml/catalog
3178warning: failed to load external entity "title.xml"
3179Catalogs cleanup
3180orchis:~/XML -&gt; </pre>
3181
3182<p>The test/ent2 references an entity, running the parser from memory makes
3183the base URI unavailable and the the "title.xml" entity cannot be loaded.
3184Setting up the debug environment variable allows to detect that an attempt is
3185made to load the <code>/etc/xml/catalog</code> but since it's not present the
3186resolution fails.</p>
3187
3188<p>But the most advanced way to debug XML catalog processing is to use the
3189<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
3190catalogs and make resolution queries to see what is going on. This is also
3191used for the regression tests:</p>
3192<pre>orchis:~/XML -&gt; ./xmlcatalog test/catalogs/docbook.xml \
3193 "-//OASIS//DTD DocBook XML V4.1.2//EN"
3194http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
3195orchis:~/XML -&gt; </pre>
3196
3197<p>For debugging what is going on, adding one -v flags increase the verbosity
3198level to indicate the processing done (adding a second flag also indicate
3199what elements are recognized at parsing):</p>
3200<pre>orchis:~/XML -&gt; ./xmlcatalog -v test/catalogs/docbook.xml \
3201 "-//OASIS//DTD DocBook XML V4.1.2//EN"
3202Parsing catalog test/catalogs/docbook.xml's content
3203Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
3204http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
3205Catalogs cleanup
3206orchis:~/XML -&gt; </pre>
3207
3208<p>A shell interface is also available to debug and process multiple queries
3209(and for regression tests):</p>
3210<pre>orchis:~/XML -&gt; ./xmlcatalog -shell test/catalogs/docbook.xml \
3211 "-//OASIS//DTD DocBook XML V4.1.2//EN"
3212&gt; help
3213Commands available:
3214public PublicID: make a PUBLIC identifier lookup
3215system SystemID: make a SYSTEM identifier lookup
3216resolve PublicID SystemID: do a full resolver lookup
3217add 'type' 'orig' 'replace' : add an entry
3218del 'values' : remove values
3219dump: print the current catalog state
3220debug: increase the verbosity level
3221quiet: decrease the verbosity level
3222exit: quit the shell
3223&gt; public "-//OASIS//DTD DocBook XML V4.1.2//EN"
3224http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
3225&gt; quit
3226orchis:~/XML -&gt; </pre>
3227
3228<p>This should be sufficient for most debugging purpose, this was actually
3229used heavily to debug the XML Catalog implementation itself.</p>
3230
3231<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
3232
3233<p>Basically XML Catalogs are XML files, you can either use XML tools to
3234manage them or use <strong>xmlcatalog</strong> for this. The basic step is
3235to create a catalog the -create option provide this facility:</p>
3236<pre>orchis:~/XML -&gt; ./xmlcatalog --create tst.xml
3237&lt;?xml version="1.0"?&gt;
3238&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
3239 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
3240&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
3241orchis:~/XML -&gt; </pre>
3242
3243<p>By default xmlcatalog does not overwrite the original catalog and save the
3244result on the standard output, this can be overridden using the -noout
3245option. The <code>-add</code> command allows to add entries in the
3246catalog:</p>
3247<pre>orchis:~/XML -&gt; ./xmlcatalog --noout --create --add "public" \
3248 "-//OASIS//DTD DocBook XML V4.1.2//EN" \
3249 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
3250orchis:~/XML -&gt; cat tst.xml
3251&lt;?xml version="1.0"?&gt;
3252&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
3253 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
3254&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
3255&lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
3256 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
3257&lt;/catalog&gt;
3258orchis:~/XML -&gt; </pre>
3259
3260<p>The <code>-add</code> option will always take 3 parameters even if some of
3261the XML Catalog constructs (like nextCatalog) will have only a single
3262argument, just pass a third empty string, it will be ignored.</p>
3263
3264<p>Similarly the <code>-del</code> option remove matching entries from the
3265catalog:</p>
3266<pre>orchis:~/XML -&gt; ./xmlcatalog --del \
3267 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
3268&lt;?xml version="1.0"?&gt;
3269&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
3270 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
3271&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
3272orchis:~/XML -&gt; </pre>
3273
3274<p>The catalog is now empty. Note that the matching of <code>-del</code> is
3275exact and would have worked in a similar fashion with the Public ID
3276string.</p>
3277
3278<p>This is rudimentary but should be sufficient to manage a not too complex
3279catalog tree of resources.</p>
3280
3281<h3><a name="implemento">The implementor corner quick review of the
3282API:</a></h3>
3283
3284<p>First, and like for every other module of libxml, there is an
3285automatically generated <a href="html/libxml-catalog.html">API page for
3286catalog support</a>.</p>
3287
3288<p>The header for the catalog interfaces should be included as:</p>
3289<pre>#include &lt;libxml/catalog.h&gt;</pre>
3290
3291<p>The API is voluntarily kept very simple. First it is not obvious that
3292applications really need access to it since it is the default behaviour of
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]3293libxml2 (Note: it is possible to completely override libxml2 default catalog
3294by using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3295plug an application specific resolver).</p>
3296
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3297<p>Basically libxml2 support 2 catalog lists:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3298<ul>
3299 <li>the default one, global shared by all the application</li>
3300 <li>a per-document catalog, this one is built if the document uses the
3301 <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
3302 associated to the parser context and destroyed when the parsing context
3303 is destroyed.</li>
3304</ul>
3305
3306<p>the document one will be used first if it exists.</p>
3307
3308<h4>Initialization routines:</h4>
3309
3310<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
3311used at startup to initialize the catalog, if the catalog should be
3312initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
3313should be called before xmlInitializeCatalog() which would otherwise do a
3314default initialization first.</p>
3315
3316<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
3317own catalog list if needed.</p>
3318
3319<h4>Preferences setup:</h4>
3320
3321<p>The XML Catalog spec requires the possibility to select default
3322preferences between public and system delegation,
3323xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
3324xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
3325be forbidden, allowed for global catalog, for document catalog or both, the
3326default is to allow both.</p>
3327
3328<p>And of course xmlCatalogSetDebug() allows to generate debug messages
3329(through the xmlGenericError() mechanism).</p>
3330
3331<h4>Querying routines:</h4>
3332
3333<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
3334and xmlCatalogResolveURI() are relatively explicit if you read the XML
3335Catalog specification they correspond to section 7 algorithms, they should
3336also work if you have loaded an SGML catalog with a simplified semantic.</p>
3337
3338<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
3339operate on the document catalog list</p>
3340
3341<h4>Cleanup and Miscellaneous:</h4>
3342
3343<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
3344the per-document equivalent.</p>
3345
3346<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
3347first catalog in the global list, and xmlCatalogDump() allows to dump a
3348catalog state, those routines are primarily designed for xmlcatalog, I'm not
3349sure that exposing more complex interfaces (like navigation ones) would be
3350really useful.</p>
3351
3352<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
3353it's similar as xmlParseFile() except it bypass all catalog lookups, it's
3354provided because this functionality may be useful for client tools.</p>
3355
3356<h4>threaded environments:</h4>
3357
3358<p>Since the catalog tree is built progressively, some care has been taken to
3359try to avoid troubles in multithreaded environments. The code is now thread
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3360safe assuming that the libxml2 library has been compiled with threads
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3361support.</p>
3362
3363<p></p>
3364
3365<h3><a name="Other">Other resources</a></h3>
3366
3367<p>The XML Catalog specification is relatively recent so there isn't much
3368literature to point at:</p>
3369<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3370 <li>You can find a good rant from Norm Walsh about <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3371 href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
3372 need for catalogs</a>, it provides a lot of context informations even if
Daniel Veillard93d3a472002-04-26 14:04:55 +0000[diff] [blame]3373 I don't agree with everything presented. Norm also wrote a more recent
3374 article <a
3375 href="http://wwws.sun.com/software/xml/developers/resolver/article/">XML
3376 entities and URI resolvers</a> describing them.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3377 <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
3378 catalog proposal</a> from John Cowan</li>
3379 <li>The <a href="http://www.rddl.org/">Resource Directory Description
3380 Language</a> (RDDL) another catalog system but more oriented toward
3381 providing metadata for XML namespaces.</li>
3382 <li>the page from the OASIS Technical <a
3383 href="http://www.oasis-open.org/committees/entity/">Committee on Entity
3384 Resolution</a> who maintains XML Catalog, you will find pointers to the
3385 specification update, some background and pointers to others tools
3386 providing XML Catalog support</li>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3387 <li>Here is a <a href="buildDocBookCatalog">shell script</a> to generate
3388 XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
3389 directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
3390 the resources found on the system. Otherwise it will just create
3391 ~/xmlcatalog and ~/dbkxmlcatalog and doing:
Daniel Veillard8594de92003-04-25 10:08:44 +0000[diff] [blame]3392 <p><code>export XML_CATALOG_FILES=$HOME/xmlcatalog</code></p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3393 <p>should allow to process DocBook documentations without requiring
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3394 network accesses for the DTD or stylesheets</p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3395 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3396 <li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3397 small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
3398 to work fine for me too</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3399 <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
3400 manual page</a></li>
3401</ul>
3402
3403<p>If you have suggestions for corrections or additions, simply contact
3404me:</p>
3405
3406<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3407
3408<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3409using the XML tollkit from the C language. It is not intended to be
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3410extensive. I hope the automatically generated documents will provide the
3411completeness required, but as a separate set of documents. The interfaces of
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]3412the XML parser are by principle low level, Those interested in a higher level
3413API should <a href="#DOM">look at DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3414
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3415<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
3416separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3417interfaces</a>. Let's have a look at how the XML parser can be called:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3418
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3419<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3420
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3421<p>Usually, the first thing to do is to read an XML input. The parser accepts
3422documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3423defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3424<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3425 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3426 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3427 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3428</dl>
3429<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3430 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3431 <dd><p>Parse an XML document contained in a (possibly compressed)
3432 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3433 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3434</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3435
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3436<p>The parser returns a pointer to the document structure (or NULL in case of
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3437failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3438
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3439<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3440
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3441<p>In order for the application to keep the control when the document is
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]3442being fetched (which is common for GUI based programs) libxml2 provides a
3443push interface, too, as of version 1.8.3. Here are the interface
3444functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3445<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
3446 void *user_data,
3447 const char *chunk,
3448 int size,
3449 const char *filename);
3450int xmlParseChunk (xmlParserCtxtPtr ctxt,
3451 const char *chunk,
3452 int size,
3453 int terminate);</pre>
3454
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3455<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3456<pre> FILE *f;
3457
3458 f = fopen(filename, "r");
3459 if (f != NULL) {
3460 int res, size = 1024;
3461 char chars[1024];
3462 xmlParserCtxtPtr ctxt;
3463
3464 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3465 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3466 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
3467 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3468 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3469 xmlParseChunk(ctxt, chars, res, 0);
3470 }
3471 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3472 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3473 xmlFreeParserCtxt(ctxt);
3474 }
3475 }</pre>
3476
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3477<p>The HTML parser embedded into libxml2 also has a push interface; the
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3478functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3479
3480<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
3481
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3482<p>The tree-building interface makes the parser memory-hungry, first loading
3483the document in memory and then building the tree itself. Reading a document
3484without building the tree is possible using the SAX interfaces (see SAX.h and
3485<a href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3486Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3487limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3488<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3489
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3490<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3491
3492<p>The other way to get an XML tree in memory is by building it. Basically
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3493there is a set of functions dedicated to building new elements. (These are
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3494also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of
3495code that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3496<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3497 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3498 xmlNodePtr tree, subtree;
3499
3500 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3501 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
3502 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
3503 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
3504 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3505 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3506 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3507 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
3508 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
3509 subtree = xmlNewChild(tree, NULL, "image", NULL);
3510 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3511
3512<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3513
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3514<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3515
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3516<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3517code has access to the internal structure of all the elements of the tree.
3518The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]3519<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3520<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3521example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3522<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3523
3524<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3525<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3526
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3527<p>points to the text node containing the chapter title "The Linux
3528adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3529
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3530<p><strong>NOTE</strong>: XML allows <em>PI</em>s and <em>comments</em> to be
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3531present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3532to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]3533<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3534
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3535<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3536
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3537<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3538is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3539<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3540 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
3541 xmlChar *value);</code></dt>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3542 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
3543 The value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3544 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3545</dl>
3546<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3547 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3548 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]3549 <dd><p>This function returns a pointer to new copy of the property
3550 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3551 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3552</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3553
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3554<p>Two functions are provided for reading and writing the text associated
3555with elements:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3556<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3557 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3558 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3559 <dd><p>This function takes an "external" string and converts it to one
3560 text node or possibly to a list of entity and text nodes. All
3561 non-predefined entity references like &amp;Gnome; will be stored
3562 internally as entity nodes, hence the result of the function may not be
3563 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3564 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3565</dl>
3566<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3567 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3568 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3569 <dd><p>This function is the inverse of
3570 <code>xmlStringGetNodeList()</code>. It generates a new string
3571 containing the content of the text and entity nodes. Note the extra
3572 argument inLine. If this argument is set to 1, the function will expand
3573 entity references. For example, instead of returning the &amp;Gnome;
3574 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3575 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3576 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3577</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3578
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3579<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3580
3581<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3582<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3583 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3584 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3585 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3586 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3587</dl>
3588<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3589 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3590 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3591 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3592</dl>
3593<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3594 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3595 <dd><p>Saves the document to a file. In this case, the compression
3596 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3597 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3598</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3599
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3600<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3601
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3602<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3603accesses. The level of compression on saves can be turned on either globally
3604or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3605<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3606 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3607 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3608 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3609</dl>
3610<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3611 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3612 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3613 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3614</dl>
3615<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3616 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3617 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3618 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3619</dl>
3620<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3621 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3622 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3623 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3624</dl>
3625
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3626<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3627
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3628<p>Entities in principle are similar to simple C macros. An entity defines an
3629abbreviation for a given string that you can reuse many times throughout the
3630content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3631may occur frequently within a document, or to confine the change needed to a
3632document to a restricted area in the internal subset of the document (at the
3633beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3634<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]36352 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]36363 &lt;!ENTITY xml "Extensible Markup Language"&gt;
36374 ]&gt;
36385 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]36396 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]36407 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3641
3642<p>Line 3 declares the xml entity. Line 6 uses the xml entity, by prefixing
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3643its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3644are 5 predefined entities in libxml2 allowing you to escape characters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3645predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3646<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3647for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3648<strong>&amp;quot;</strong> for the character '"', and
3649<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3650
3651<p>One of the problems related to entities is that you may want the parser to
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3652substitute an entity's content so that you can see the replacement text in
3653your application. Or you may prefer to keep entity references as such in the
3654content to be able to save the document back without losing this usually
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3655precious information (if the user went through the pain of explicitly
3656defining entities, he may have a a rather negative attitude if you blindly
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3657substitute them as saving time). The <a
Daniel Veillard5373ea12003-07-24 13:09:13 +0000[diff] [blame]3658href="html/libxml-parser.html#xmlSubstituteEntitiesDefault">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3659function allows you to check and change the behaviour, which is to not
3660substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3661
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3662<p>Here is the DOM tree built by libxml2 for the previous document in the
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3663default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3664<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3665DOCUMENT
3666version=1.0
3667 ELEMENT EXAMPLE
3668 TEXT
3669 content=
3670 ENTITY_REF
3671 INTERNAL_GENERAL_ENTITY xml
3672 content=Extensible Markup Language
3673 TEXT
3674 content=</pre>
3675
3676<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3677<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3678DOCUMENT
3679version=1.0
3680 ELEMENT EXAMPLE
3681 TEXT
3682 content= Extensible Markup Language</pre>
3683
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3684<p>So, entities or no entities? Basically, it depends on your use case. I
3685suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3686entities in your XML document or data if you are not willing to handle the
3687entity references elements in the DOM tree.</p>
3688
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3689<p>Note that at save time libxml2 enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3690entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3691transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3692reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3693finding them in the input).</p>
3694
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3695<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3696on top of the libxml2 SAX interface is difficult!!! If you plan to use
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3697non-predefined entities in your documents, then the learning curve to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3698then using the SAX API may be long. If you plan to use complex documents, I
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3699strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]3700deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3701
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3702<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3703
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3704<p>The libxml2 library implements <a
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3705href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3706recognizing namespace constructs in the input, and does namespace lookup
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3707automatically when building the DOM tree. A namespace declaration is
3708associated with an in-memory structure and all elements or attributes within
3709that namespace point to it. Hence testing the namespace is a simple and fast
3710equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3711
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3712<p>I suggest that people using libxml2 use a namespace, and declare it in the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3713root element of their document as the default namespace. Then they don't need
3714to use the prefix in the content but we will have a basis for future semantic
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3715refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3716the size of the XML output significantly, but significantly increases its
3717value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3718<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
3719 &lt;elem1&gt;...&lt;/elem1&gt;
3720 &lt;elem2&gt;...&lt;/elem2&gt;
3721&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3722
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3723<p>The namespace value has to be an absolute URL, but the URL doesn't have to
3724point to any existing resource on the Web. It will bind all the element and
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3725attributes with that URL. I suggest to use an URL within a domain you
3726control, and that the URL should contain some kind of version information if
3727possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a
3728good namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3729
3730<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3731version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3732and if the version information don't match something you know, warn the user
3733and be liberal in what you accept as the input. Also do *not* try to base
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3734namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3735same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3736associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3737just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3738<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3739prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3740
3741<p>@@Interfaces@@</p>
3742
3743<p>@@Examples@@</p>
3744
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3745<p>Usually people object to using namespaces together with validity checking.
3746I will try to make sure that using namespaces won't break validity checking,
3747so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3748suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3749<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3750flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3751from multiple DTDs will certainly break current validation schemes. I will
3752try to provide ways to do this, but this may not be portable or
3753standardized.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3754
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3755<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3756
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3757<p>Incompatible changes:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3758
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3759<p>Version 2 of libxml2 is the first version introducing serious backward
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3760incompatible changes. The main goals were:</p>
3761<ul>
3762 <li>a general cleanup. A number of mistakes inherited from the very early
3763 versions couldn't be changed due to compatibility constraints. Example
3764 the "childs" element in the nodes.</li>
3765 <li>Uniformization of the various nodes, at least for their header and link
3766 parts (doc, parent, children, prev, next), the goal is a simpler
3767 programming model and simplifying the task of the DOM implementors.</li>
3768 <li>better conformances to the XML specification, for example version 1.x
3769 had an heuristic to try to detect ignorable white spaces. As a result the
3770 SAX event generated were ignorableWhitespace() while the spec requires
3771 character() in that case. This also mean that a number of DOM node
3772 containing blank text may populate the DOM tree which were not present
3773 before.</li>
3774</ul>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3775
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3776<h3>How to fix libxml-1.x code:</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3777
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3778<p>So client code of libxml designed to run with version 1.x may have to be
3779changed to compile against version 2.x of libxml. Here is a list of changes
3780that I have collected, they may not be sufficient, so in case you find other
3781change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
3782mail</a>:</p>
3783<ol>
3784 <li>The package name have changed from libxml to libxml2, the library name
3785 is now -lxml2 . There is a new xml2-config script which should be used to
3786 select the right parameters libxml2</li>
3787 <li>Node <strong>childs</strong> field has been renamed
3788 <strong>children</strong> so s/childs/children/g should be applied
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3789 (probability of having "childs" anywhere else is close to 0+</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3790 <li>The document don't have anymore a <strong>root</strong> element it has
3791 been replaced by <strong>children</strong> and usually you will get a
3792 list of element here. For example a Dtd element for the internal subset
3793 and it's declaration may be found in that list, as well as processing
3794 instructions or comments found before or after the document root element.
3795 Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3796 a document. Alternatively if you are sure to not reference DTDs nor have
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3797 PIs or comments before or after the root element
3798 s/-&gt;root/-&gt;children/g will probably do it.</li>
3799 <li>The white space issue, this one is more complex, unless special case of
3800 validating parsing, the line breaks and spaces usually used for indenting
3801 and formatting the document content becomes significant. So they are
3802 reported by SAX and if your using the DOM tree, corresponding nodes are
3803 generated. Too approach can be taken:
3804 <ol>
3805 <li>lazy one, use the compatibility call
3806 <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
3807 relying on a special (and possibly broken) set of heuristics of
3808 libxml to detect ignorable blanks. Don't complain if it breaks or
3809 make your application not 100% clean w.r.t. to it's input.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3810 <li>the Right Way: change you code to accept possibly insignificant
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3811 blanks characters, or have your tree populated with weird blank text
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3812 nodes. You can spot them using the commodity function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3813 <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
3814 nodes.</li>
3815 </ol>
3816 <p>Note also that with the new default the output functions don't add any
3817 extra indentation when saving a tree in order to be able to round trip
3818 (read and save) without inflating the document with extra formatting
3819 chars.</p>
3820 </li>
3821 <li>The include path has changed to $prefix/libxml/ and the includes
3822 themselves uses this new prefix in includes instructions... If you are
3823 using (as expected) the
3824 <pre>xml2-config --cflags</pre>
3825 <p>output to generate you compile commands this will probably work out of
3826 the box</p>
3827 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3828 <li>xmlDetectCharEncoding takes an extra argument indicating the length in
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3829 byte of the head of the document available for character detection.</li>
3830</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3831
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3832<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3833
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3834<p>Two new version of libxml (1.8.11) and libxml2 (2.3.4) have been released
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3835to allow smooth upgrade of existing libxml v1code while retaining
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3836compatibility. They offers the following:</p>
3837<ol>
3838 <li>similar include naming, one should use
3839 <strong>#include&lt;libxml/...&gt;</strong> in both cases.</li>
3840 <li>similar identifiers defined via macros for the child and root fields:
3841 respectively <strong>xmlChildrenNode</strong> and
3842 <strong>xmlRootNode</strong></li>
3843 <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
3844 inserted once in the client code</li>
3845</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3846
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3847<p>So the roadmap to upgrade your existing libxml applications is the
3848following:</p>
3849<ol>
3850 <li>install the libxml-1.8.8 (and libxml-devel-1.8.8) packages</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3851 <li>find all occurrences where the xmlDoc <strong>root</strong> field is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3852 used and change it to <strong>xmlRootNode</strong></li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3853 <li>similarly find all occurrences where the xmlNode
3854 <strong>childs</strong> field is used and change it to
3855 <strong>xmlChildrenNode</strong></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3856 <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
3857 <strong>main()</strong> or in the library init entry point</li>
3858 <li>Recompile, check compatibility, it should still work</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3859 <li>Change your configure script to look first for xml2-config and fall
3860 back using xml-config . Use the --cflags and --libs output of the command
3861 as the Include and Linking parameters needed to use libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3862 <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
3863 libxml-devel-1.8.y can be kept simultaneously)</li>
3864 <li>remove your config.cache, relaunch your configuration mechanism, and
3865 recompile, if steps 2 and 3 were done right it should compile as-is</li>
3866 <li>Test that your application is still running correctly, if not this may
3867 be due to extra empty nodes due to formating spaces being kept in libxml2
3868 contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
3869 code before calling the parser (next to
3870 <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
3871</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3872
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3873<p>Following those steps should work. It worked for some of my own code.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3874
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3875<p>Let me put some emphasis on the fact that there is far more changes from
3876libxml 1.x to 2.x than the ones you may have to patch for. The overall code
3877has been considerably cleaned up and the conformance to the XML specification
3878has been drastically improved too. Don't take those changes as an excuse to
3879not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3880
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3881<h2><a name="Thread">Thread safety</a></h2>
3882
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3883<p>Starting with 2.4.7, libxml2 makes provisions to ensure that concurrent
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3884threads can safely work in parallel parsing different documents. There is
3885however a couple of things to do to ensure it:</p>
3886<ul>
3887 <li>configure the library accordingly using the --with-threads options</li>
3888 <li>call xmlInitParser() in the "main" thread before using any of the
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3889 libxml2 API (except possibly selecting a different memory allocator)</li>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3890</ul>
3891
3892<p>Note that the thread safety cannot be ensured for multiple threads sharing
3893the same document, the locking must be done at the application level, libxml
3894exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
3895The parts of the library checked for thread safety are:</p>
3896<ul>
3897 <li>concurrent loading</li>
3898 <li>file access resolution</li>
3899 <li>catalog access</li>
3900 <li>catalog building</li>
3901 <li>entities lookup/accesses</li>
3902 <li>validation</li>
3903 <li>global variables per-thread override</li>
3904 <li>memory handling</li>
3905</ul>
3906
3907<p>XPath is supposed to be thread safe now, but this wasn't tested
3908seriously.</p>
3909
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3910<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3911
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3912<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
3913Object Model</em>; this is an API for accessing XML or HTML structured
3914documents. Native support for DOM in Gnome is on the way (module gnome-dom),
3915and will be based on gnome-xml. This will be a far cleaner interface to
3916manipulate XML files within Gnome since it won't expose the internal
3917structure.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3918
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3919<p>The current DOM implementation on top of libxml2 is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame]3920href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
3921is a full DOM interface, thanks to Paolo Casarini, check the <a
3922href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
3923informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3924
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3925<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3926
3927<p>Here is a real size example, where the actual content of the application
3928data is not kept in the DOM tree but uses internal structures. It is based on
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3929a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3930storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
3931base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3932<pre>&lt;?xml version="1.0"?&gt;
3933&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
3934 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3935
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3936 &lt;gjob:Job&gt;
3937 &lt;gjob:Project ID="3"/&gt;
3938 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
3939 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3940
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3941 &lt;gjob:Update&gt;
3942 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
3943 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
3944 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
3945 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3946
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3947 &lt;gjob:Developers&gt;
3948 &lt;gjob:Developer&gt;
3949 &lt;/gjob:Developer&gt;
3950 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3951
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3952 &lt;gjob:Contact&gt;
3953 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
3954 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
3955 &lt;gjob:Company&gt;
3956 &lt;/gjob:Company&gt;
3957 &lt;gjob:Organisation&gt;
3958 &lt;/gjob:Organisation&gt;
3959 &lt;gjob:Webpage&gt;
3960 &lt;/gjob:Webpage&gt;
3961 &lt;gjob:Snailmail&gt;
3962 &lt;/gjob:Snailmail&gt;
3963 &lt;gjob:Phone&gt;
3964 &lt;/gjob:Phone&gt;
3965 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3966
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3967 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3968 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3969 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3970
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3971 &lt;gjob:Skills&gt;
3972 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3973
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3974 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3975 A GNOME based system that will allow a superuser to configure
3976 compressed and uncompressed files and/or file systems to be backed
3977 up with a supported media in the system. This should be able to
3978 perform via find commands generating a list of files that are passed
3979 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
3980 or via operations performed on the filesystem itself. Email
3981 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3982 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3983
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3984 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3985
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3986 &lt;/gjob:Jobs&gt;
3987&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3988
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3989<p>While loading the XML file into an internal DOM tree is a matter of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3990calling only a couple of functions, browsing the tree to gather the data and
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3991generate the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3992
3993<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3994structure. For example, the ordering of the attributes is not significant,
3995the XML specification is clear about it. It's also usually a good idea not to
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3996depend on the order of the children of a given node, unless it really makes
3997things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3998<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3999 * A person record
4000 */
4001typedef struct person {
4002 char *name;
4003 char *email;
4004 char *company;
4005 char *organisation;
4006 char *smail;
4007 char *webPage;
4008 char *phone;
4009} person, *personPtr;
4010
4011/*
4012 * And the code needed to parse it
4013 */
4014personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
4015 personPtr ret = NULL;
4016
4017DEBUG("parsePerson\n");
4018 /*
4019 * allocate the struct
4020 */
4021 ret = (personPtr) malloc(sizeof(person));
4022 if (ret == NULL) {
4023 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4024 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4025 }
4026 memset(ret, 0, sizeof(person));
4027
4028 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]4029 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4030 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]4031 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
4032 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
4033 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
4034 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
4035 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4036 }
4037
4038 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4039}</pre>
4040
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]4041<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4042<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]4043 <li>Usually a recursive parsing style is the more convenient one: XML data
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]4044 is by nature subject to repetitive constructs and usually exhibits highly
4045 structured patterns.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]4046 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
4047 i.e. the pointer to the global XML document and the namespace reserved to
4048 the application. Document wide information are needed for example to
4049 decode entities and it's a good coding practice to define a namespace for
4050 your application set of data and test that the element and attributes
4051 you're analyzing actually pertains to your application space. This is
4052 done by a simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]4053 <li>To retrieve text and attributes value, you can use the function
4054 <em>xmlNodeListGetString</em> to gather all the text and entity reference
4055 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4056</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4057
4058<p>Here is another piece of code used to parse another level of the
4059structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]4060<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]4061/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4062 * a Description for a Job
4063 */
4064typedef struct job {
4065 char *projectID;
4066 char *application;
4067 char *category;
4068 personPtr contact;
4069 int nbDevelopers;
4070 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
4071} job, *jobPtr;
4072
4073/*
4074 * And the code needed to parse it
4075 */
4076jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
4077 jobPtr ret = NULL;
4078
4079DEBUG("parseJob\n");
4080 /*
4081 * allocate the struct
4082 */
4083 ret = (jobPtr) malloc(sizeof(job));
4084 if (ret == NULL) {
4085 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4086 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4087 }
4088 memset(ret, 0, sizeof(job));
4089
4090 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]4091 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4092 while (cur != NULL) {
4093
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]4094 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
4095 ret-&gt;projectID = xmlGetProp(cur, "ID");
4096 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4097 fprintf(stderr, "Project has no ID\n");
4098 }
4099 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]4100 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
4101 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
4102 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
4103 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
4104 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
4105 ret-&gt;contact = parsePerson(doc, ns, cur);
4106 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4107 }
4108
4109 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4110}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4111
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]4112<p>Once you are used to it, writing this kind of code is quite simple, but
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]4113boring. Ultimately, it could be possible to write stubbers taking either C
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]4114data structure definitions, a set of XML examples or an XML DTD and produce
4115the code needed to import and export the content between C data and XML
4116storage. This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4117
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]4118<p>Feel free to use <a href="example/gjobread.c">the code for the full C
4119parsing example</a> as a template, it is also available with Makefile in the
4120Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4121
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]4122<h2><a name="Contributi">Contributions</a></h2>
4123<ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]4124 <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
4125 patches, Gary Pennington worked on the validation API, threading support
4126 and Solaris port.</li>
4127 <li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000[diff] [blame]4128 <li><a href="mailto:igor@zlatkovic.com">Igor Zlatkovic</a> is now the
4129 maintainer of the Windows port, <a
4130 href="http://www.zlatkovic.com/projects/libxml/index.html">he provides
4131 binaries</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]4132 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
4133 <a href="http://garypennington.net/libxml2/">Solaris binaries</a></li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]4134 <li><a
4135 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]4136 Sergeant</a> developed <a
4137 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]4138 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
4139 application server</a></li>
4140 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> and <a
4141 href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillardca989762001-06-23 17:39:29 +0000[diff] [blame]4142 href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]4143 documentation</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]4144 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
4145 href="http://xmlsoft.org/messages/0488.html">man pages</a></li>
Daniel Veillard5168dbf2001-07-07 00:18:23 +0000[diff] [blame]4146 <li>there is a module for <a
4147 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
4148 in OpenNSD/AOLServer</a></li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]4149 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provided the
4150 first version of libxml/libxslt <a
4151 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li>
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]4152 <li>Petr Kozelka provides <a
4153 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
4154 libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]4155 <li><a href="mailto:aleksey@aleksey.com">Aleksey Sanin</a> implemented the
4156 <a href="http://www.w3.org/Signature/">XML Canonicalization and XML
4157 Digital Signature</a> <a
4158 href="http://www.aleksey.com/xmlsec/">implementations for libxml2</a></li>
Daniel Veillard17bed982003-02-24 20:11:43 +0000[diff] [blame]4159 <li><a href="mailto:Steve.Ball@zveno.com">Steve Ball</a>, <a
4160 href="http://www.zveno.com/">Zveno</a> and contributors maintain <a
4161 href="http://tclxml.sourceforge.net/">tcl bindings for libxml2 and
4162 libxslt</a>, as well as <a
4163 href="http://tclxml.sf.net/tkxmllint.html">tkxmllint</a> a GUI for
4164 xmllint and <a href="http://tclxml.sf.net/tkxsltproc.html">tkxsltproc</a>
4165 a GUI for xsltproc.</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]4166</ul>
4167
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]4168<p></p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]4169</body>
4170</html>