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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 Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]407 <p>There are however a few C++ wrappers 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
411 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
412 <p>Download: <a
413 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
414 </li>
415 <li>by Peter Jones &lt;pjones@pmade.org&gt;
416 <p>Website: <a
417 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
418 </li>
419 </ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]420 </li>
421 <li>How to validate a document a posteriori ?
422 <p>It is possible to validate documents which had not been validated at
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]423 initial parsing time or documents which have been built from scratch
424 using the API. Use the <a
Daniel Veillard5373ea12003-07-24 13:09:13 +0000[diff] [blame^]425 href="http://xmlsoft.org/html/libxml-valid.html#xmlValidateDtd">xmlValidateDtd()</a>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]426 function. It is also possible to simply add a DTD to an existing
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]427 document:</p>
428 <pre>xmlDocPtr doc; /* your existing document */
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]429xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
430
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]431 dtd-&gt;name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */
432
433 doc-&gt;intSubset = dtd;
434 if (doc-&gt;children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
435 else xmlAddPrevSibling(doc-&gt;children, (xmlNodePtr)dtd);
436 </pre>
437 </li>
Daniel Veillarddad3f682002-11-17 16:47:27 +0000[diff] [blame]438 <li>So what is this funky "xmlChar" used all the time?
439 <p>It is a null terminated sequence of utf-8 characters. And only utf-8!
440 You need to convert strings encoded in different ways to utf-8 before
441 passing them to the API. This can be accomplished with the iconv library
442 for instance.</p>
John Fleck61f6fb62002-10-31 15:23:29 +0000[diff] [blame]443 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]444 <li>etc ...</li>
445</ol>
446
447<p></p>
448
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]449<h2><a name="Documentat">Developer Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]450
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]451<p>There are several on-line resources related to using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]452<ol>
Daniel Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame]453 <li>Use the <a href="search.php">search engine</a> to lookup
454 informations.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]455 <li>Check the <a href="FAQ.html">FAQ.</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]456 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]457 documentation</a> automatically extracted from code comments (using <a
458 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
459 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]460 <li>Look at the documentation about <a href="encoding.html">libxml
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]461 internationalization support</a>.</li>
Daniel Veillardbc66f852002-01-14 09:49:20 +0000[diff] [blame]462 <li>This page provides a global overview and <a href="example.html">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]463 examples</a> on how to use libxml.</li>
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]464 <li>John Fleck's libxml2 tutorial: <a href="tutorial/index.html">html</a>
465 or <a href="tutorial/xmltutorial.pdf">pdf</a>.</li>
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]466 <li>If you need to parse large files, check the <a
467 href="xmlreader.html">xmlReader</a> API tutorial</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]468 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]469 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
470 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]471 <li>George Lebl wrote <a
472 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]473 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]474 <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]475 file</a>.</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]476 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>
477 description. If you are starting a new project using libxml you should
478 really use the 2.x version.</li>
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]479 <li>And don't forget to look at the <a
480 href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]481</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]482
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]483<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]484
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]485<p>Well, bugs or missing features are always possible, and I will make a
486point of fixing them in a timely fashion. The best way to report a bug is to
487use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]488bug tracking database</a> (make sure to use the "libxml2" module name). I
489look at reports there regularly and it's good to have a reminder when a bug
490is 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]491
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]492<p>There is also a mailing-list <a
Daniel Veillard3197f162001-04-04 00:40:08 +0000[diff] [blame]493href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
494href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]495href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
496please visit the <a
497href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
498follow the instructions. <strong>Do not send code, I won't debug it</strong>
499(but patches are really appreciated!).</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]500
Daniel Veillard008186f2001-09-13 14:24:44 +0000[diff] [blame]501<p>Check the following <strong><span style="color: #FF0000">before
502posting</span></strong>:</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]503<ul>
Daniel Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame]504 <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]505 search engine</a> to get information related to your problem.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]506 <li>Make sure you are <a href="ftp://xmlsoft.org/">using a recent
507 version</a>, and that the problem still shows up in a recent version.</li>
508 <li>Check the <a href="http://mail.gnome.org/archives/xml/">list
509 archives</a> to see if the problem was reported already. In this case
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]510 there is probably a fix available, similarly check the <a
Daniel Veillarde7ead2d2001-08-22 23:44:09 +0000[diff] [blame]511 href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">registered
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]512 open bugs</a>.</li>
513 <li>Make sure you can reproduce the bug with xmllint or one of the test
514 programs found in source in the distribution.</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]515 <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]516 attachment)</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]517</ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]518
Daniel Veillarda37aab82003-06-09 09:10:36 +0000[diff] [blame]519<p>Then send the bug with associated information to reproduce it to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]520href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillard98d071d2003-01-10 09:22:44 +0000[diff] [blame]521related I will approve it. Please do not send mail to me directly, it makes
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]522things 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]523answer a given question, ask on the list.</p>
524
525<p>To <span style="color: #E50000">be really clear about support</span>:</p>
526<ul>
Daniel Veillarda37aab82003-06-09 09:10:36 +0000[diff] [blame]527 <li>Support or help <span style="color: #E50000">requests MUST be sent to
Daniel Veillard98d071d2003-01-10 09:22:44 +0000[diff] [blame]528 the list or on bugzilla</span> in case of problems, so that the Question
529 and Answers can be shared publicly. Failing to do so carries the implicit
530 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]531 others" and is not welcome. I will automatically Carbon-Copy the
532 xml@gnome.org mailing list for any technical reply made about libxml2 or
533 libxslt.</li>
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]534 <li>There is <span style="color: #E50000">no garantee of support</span>, if
535 your question remains unanswered after a week, repost it, making sure you
536 gave all the detail needed and the information requested.</li>
Daniel Veillarda37aab82003-06-09 09:10:36 +0000[diff] [blame]537 <li>Failing to provide information as requested or double checking first
Daniel Veillard98d071d2003-01-10 09:22:44 +0000[diff] [blame]538 for prior feedback also carries the implicit message "the time of the
539 library maintainers is less valuable than my time" and might not be
540 welcome.</li>
541</ul>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]542
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]543<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]544probably be processed faster than those without.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]545
546<p>If you're looking for help, a quick look at <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]547href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]548provide the answer. I usually send source samples when answering libxml2
549usage questions. The <a
550href="http://xmlsoft.org/html/book1.html">auto-generated documentation</a> is
551not as polished as I would like (i need to learn more about DocBook), but
552it's a good starting point.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]553
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]554<h2><a name="help">How to help</a></h2>
555
556<p>You can help the project in various ways, the best thing to do first is to
557subscribe to the mailing-list as explained before, check the <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]558href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
559href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]560database</a>:</p>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]561<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]562 <li>Provide patches when you find problems.</li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]563 <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]564 be integrated in all cases but help pinpointing portability problems
565 and</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]566 <li>Provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]567 as HTML diffs).</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]568 <li>Provide new documentations pieces (translations, examples, etc
569 ...).</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]570 <li>Check the TODO file and try to close one of the items.</li>
571 <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]572 provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me
573 </a>before to avoid synchronization problems and check that the suggested
574 fix will fit in nicely :-)</li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]575</ol>
576
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]577<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]578
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]579<p>The latest versions of libxml2 can be found on <a
Daniel Veillard20c8cf22001-06-26 22:47:36 +0000[diff] [blame]580href="ftp://xmlsoft.org/">xmlsoft.org</a> (<a
581href="ftp://speakeasy.rpmfind.net/pub/libxml/">Seattle</a>, <a
582href="ftp://fr.rpmfind.net/pub/libxml/">France</a>) or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]583href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard6581e1b2003-02-09 22:21:43 +0000[diff] [blame]584as 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]585archive</a><!-- commenting this out because they seem to have disappeared or <a
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]586href="ftp://ftp.gnome.org/pub/GNOME/stable/redhat/i386/libxml/">RPM
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]587packages</a> -->
Daniel Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame]588 , Antonin Sprinzl also provide <a href="ftp://gd.tuwien.ac.at/pub/libxml/">a
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]589mirror in Austria</a>. (NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]590href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
591href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillardb46a5732003-04-08 13:35:48 +0000[diff] [blame]592packages installed to compile applications using libxml.)</p>
593
594<p>Binary ports:</p>
595<ul>
596 <li>Red Hat RPMs for i386 are available directly on <a
597 href="ftp://xmlsoft.org/">xmlsoft.org</a>, the source RPM will compile on
598 any architecture supported by Red Hat.</li>
Daniel Veillardf83a2c72003-04-08 13:48:40 +0000[diff] [blame]599 <li><p><a href="mailto:igor@zlatkovic.com">Igor Zlatkovic</a></p>
Daniel Veillardce192eb2003-04-16 15:58:05 +0000[diff] [blame]600 is now the maintainer of the Windows port, <a
Daniel Veillardb46a5732003-04-08 13:35:48 +0000[diff] [blame]601 href="http://www.zlatkovic.com/projects/libxml/index.html">he provides
602 binaries</a>.</li>
603 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
604 <a href="http://garypennington.net/libxml2/">Solaris binaries</a>.</li>
605 <li><a href="mailto:Steve.Ball@zveno.com">Steve Ball</a> provides <a
606 href="http://www.zveno.com/open_source/libxml2xslt.html">Mac Os X
607 binaries</a>.</li>
608 <li>The HP-UX porting center provides <a
609 href="http://hpux.connect.org.uk/hppd/hpux/Gnome/">HP-UX binaries</a></li>
610</ul>
611
612<p>If you know other supported binary ports, please <a
613href="http://veillard.com/">contact me</a>.</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]614
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]615<p><a name="Snapshot">Snapshot:</a></p>
616<ul>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]617 <li>Code from the W3C cvs base gnome-xml <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]618 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]619 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]620 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]621</ul>
622
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]623<p><a name="Contribs">Contributions:</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]624
625<p>I do accept external contributions, especially if compiling on another
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]626platform, get in touch with me to upload the package, wrappers for various
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]627languages have been provided, and can be found in the <a
628href="contribs.html">contrib section</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]629
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]630<p>Libxml2 is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]631<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]632 <li><p>The <a
633 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]634 CVS base</a>. Check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]635 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a>
636 page; the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]637 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]638 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]639</ul>
640
641<h2><a name="News">News</a></h2>
642
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]643<h3>CVS only : check the <a
644href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]645for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]646
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]647<p>Items not finished and worked on, get in touch with the list if you want
648to test those</p>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]649<ul>
Daniel Veillard72fef162003-02-05 14:31:19 +0000[diff] [blame]650 <li>More testing on RelaxNG</li>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]651 <li>Finishing up <a href="http://www.w3.org/TR/xmlschema-1/">XML
Daniel Veillard72fef162003-02-05 14:31:19 +0000[diff] [blame]652 Schemas</a></li>
653</ul>
654
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]655<h3>2.5.8: Jul 6 2003</h3>
656<ul>
657 <li>bugfixes: XPath, XInclude, file/URI mapping, UTF-16 save (Mark
658 Itzcovitz), UTF-8 checking, URI saving, error printing (William Brack),
659 PI related memleak, compilation without schemas or without xpath (Joerg
660 Schmitz-Linneweber/Garry Pennington), xmlUnlinkNode problem with DTDs,
661 rpm problem on , i86_64, removed a few compilation problems from 2.5.7,
662 xmlIOParseDTD, and xmlSAXParseDTD (Malcolm Tredinnick)</li>
663 <li>portability: DJGPP (MsDos) , OpenVMS (Craig A. Berry)</li>
664 <li>William Brack fixed multithreading lock problems</li>
665 <li>IPv6 patch for FTP and HTTP accesses (Archana Shah/Wipro)</li>
666 <li>Windows fixes (Igor Zlatkovic, Eric Zurcher), threading (Stéphane
667 Bidoul)</li>
668 <li>A few W3C Schemas Structure improvements</li>
669 <li>W3C Schemas Datatype improvements (Charlie Bozeman)</li>
670 <li>Python bindings for thread globals (Stéphane Bidoul), and method/class
671 generator </li>
672 <li>added --nonet option to xmllint </li>
673 <li>documentation improvements (John Fleck)</li>
674</ul>
675
Daniel Veillard92fc02c2003-04-24 23:12:35 +0000[diff] [blame]676<h3>2.5.7: Apr 25 2003</h3>
677<ul>
678 <li>Relax-NG: Compiling to regexp and streaming validation on top of the
679 xmlReader interface, added to xmllint --stream</li>
680 <li>xmlReader: Expand(), Next() and DOM access glue, bug fixes</li>
681 <li>Support for large files: RGN validated a 4.5GB instance</li>
682 <li>Thread support is now configured in by default</li>
683 <li>Fixes: update of the Trio code (Bjorn), WXS Date and Duration fixes
684 (Charles Bozeman), DTD and namespaces (Brent Hendricks), HTML push parser
685 and zero bytes handling, some missing Windows file path conversions,
686 behaviour of the parser and validator in the presence of "out of memory"
Daniel Veillard93d95252003-04-29 20:25:40 +0000[diff] [blame]687 error conditions</li>
Daniel Veillard92fc02c2003-04-24 23:12:35 +0000[diff] [blame]688 <li>extended the API to be able to plug a garbage collecting memory
689 allocator, added xmlMallocAtomic() and modified the allocations
690 accordingly.</li>
691 <li>Performances: removed excessive malloc() calls, speedup of the push and
692 xmlReader interfaces, removed excessive thread locking</li>
693 <li>Documentation: man page (John Fleck), xmlReader documentation</li>
694 <li>Python: adding binding for xmlCatalogAddLocal (Brent M Hendricks)</li>
695</ul>
696
Daniel Veillardc2d4a932003-04-01 11:13:05 +0000[diff] [blame]697<h3>2.5.6: Apr 1 2003</h3>
698<ul>
699 <li>Fixed W3C XML Schemas datatype, should be compliant now except for
700 binHex and base64 which are not supported yet.</li>
701 <li>bug fixes: non-ASCII IDs, HTML output, XInclude on large docs and
702 XInclude entities handling, encoding detection on external subsets, XML
703 Schemas bugs and memory leaks, HTML parser (James Bursa)</li>
704 <li>portability: python/trio (Albert Chin), Sun compiler warnings</li>
705 <li>documentation: added --relaxng option to xmllint man page (John)</li>
706 <li>improved error reporting: xml:space, start/end tag mismatches, Relax NG
707 errors</li>
708</ul>
709
710<h3>2.5.5: Mar 24 2003</h3>
Daniel Veillardd8da01c2003-03-24 15:58:23 +0000[diff] [blame]711<ul>
712 <li>Lot of fixes on the Relax NG implementation. More testing including
713 DocBook and TEI examples.</li>
714 <li>Increased the support for W3C XML Schemas datatype</li>
715 <li>Several bug fixes in the URI handling layer</li>
716 <li>Bug fixes: HTML parser, xmlReader, DTD validation, XPath, encoding
717 conversion, line counting in the parser.</li>
718 <li>Added support for $XMLLINT_INDENT environment variable, FTP delete</li>
719 <li>Fixed the RPM spec file name</li>
720</ul>
721
Daniel Veillard17bed982003-02-24 20:11:43 +0000[diff] [blame]722<h3>2.5.4: Feb 20 2003</h3>
723<ul>
724 <li>Conformance testing and lot of fixes on Relax NG and XInclude
725 implementation</li>
726 <li>Implementation of XPointer element() scheme</li>
727 <li>Bug fixes: XML parser, XInclude entities merge, validity checking on
728 namespaces,
729 <p>2 serialization bugs, node info generation problems, a DTD regexp
730 generation problem.</p>
731 </li>
732 <li>Portability: windows updates and path canonicalization (Igor)</li>
733 <li>A few typo fixes (Kjartan Maraas)</li>
734 <li>Python bindings generator fixes (Stephane Bidoul)</li>
735</ul>
736
Daniel Veillard1d788d22003-02-10 16:21:58 +0000[diff] [blame]737<h3>2.5.3: Feb 10 2003</h3>
738<ul>
739 <li>RelaxNG and XML Schemas datatypes improvements, and added a first
740 version of RelaxNG Python bindings</li>
741 <li>Fixes: XLink (Sean Chittenden), XInclude (Sean Chittenden), API fix for
742 serializing namespace nodes, encoding conversion bug, XHTML1
743 serialization</li>
744 <li>Portability fixes: Windows (Igor), AMD 64bits RPM spec file</li>
745</ul>
746
Daniel Veillard72fef162003-02-05 14:31:19 +0000[diff] [blame]747<h3>2.5.2: Feb 5 2003</h3>
748<ul>
749 <li>First implementation of RelaxNG, added --relaxng flag to xmllint</li>
750 <li>Schemas support now compiled in by default.</li>
751 <li>Bug fixes: DTD validation, namespace checking, XInclude and entities,
752 delegateURI in XML Catalogs, HTML parser, XML reader (Stéphane Bidoul),
753 XPath parser and evaluation, UTF8ToUTF8 serialization, XML reader memory
754 consumption, HTML parser, HTML serialization in the presence of
755 namespaces</li>
756 <li>added an HTML API to check elements and attributes.</li>
757 <li>Documentation improvement, PDF for the tutorial (John Fleck), doc
758 patches (Stefan Kost)</li>
759 <li>Portability fixes: NetBSD (Julio Merino), Windows (Igor Zlatkovic)</li>
760 <li>Added python bindings for XPointer, contextual error reporting
761 (Stéphane Bidoul)</li>
762 <li>URI/file escaping problems (Stefano Zacchiroli)</li>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]763</ul>
764
Daniel Veillarde2830f12003-01-08 17:47:49 +0000[diff] [blame]765<h3>2.5.1: Jan 8 2003</h3>
766<ul>
767 <li>Fixes a memory leak and configuration/compilation problems in 2.5.0</li>
768 <li>documentation updates (John)</li>
769 <li>a couple of XmlTextReader fixes</li>
770</ul>
771
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000[diff] [blame]772<h3>2.5.0: Jan 6 2003</h3>
773<ul>
774 <li>New <a href="xmlreader.html">XmltextReader interface</a> based on C#
775 API (with help of Stéphane Bidoul)</li>
776 <li>Windows: more exports, including the new API (Igor)</li>
777 <li>XInclude fallback fix</li>
778 <li>Python: bindings for the new API, packaging (Stéphane Bidoul),
779 drv_libxml2.py Python xml.sax driver (Stéphane Bidoul), fixes, speedup
780 and iterators for Python-2.2 (Hannu Krosing)</li>
781 <li>Tutorial fixes (john Fleck and Niraj Tolia) xmllint man update
782 (John)</li>
783 <li>Fix an XML parser bug raised by Vyacheslav Pindyura</li>
784 <li>Fix for VMS serialization (Nigel Hall) and config (Craig A. Berry)</li>
785 <li>Entities handling fixes</li>
786 <li>new API to optionally track node creation and deletion (Lukas
787 Schroeder)</li>
788 <li>Added documentation for the XmltextReader interface and some <a
789 href="guidelines.html">XML guidelines</a></li>
790</ul>
791
Daniel Veillardc1eed322002-12-12 11:01:32 +0000[diff] [blame]792<h3>2.4.30: Dec 12 2002</h3>
793<ul>
794 <li>2.4.29 broke the python bindings, rereleasing</li>
795 <li>Improvement/fixes of the XML API generator, and couple of minor code
796 fixes.</li>
797</ul>
798
Daniel Veillard9b4bb4d2002-12-11 19:28:47 +0000[diff] [blame]799<h3>2.4.29: Dec 11 2002</h3>
800<ul>
801 <li>Windows fixes (Igor): Windows CE port, pthread linking, python bindings
802 (Stéphane Bidoul), Mingw (Magnus Henoch), and export list updates</li>
803 <li>Fix for prev in python bindings (ERDI Gergo)</li>
804 <li>Fix for entities handling (Marcus Clarke)</li>
805 <li>Refactored the XML and HTML dumps to a single code path, fixed XHTML1
806 dump</li>
807 <li>Fix for URI parsing when handling URNs with fragment identifiers</li>
808 <li>Fix for HTTP URL escaping problem</li>
809 <li>added an TextXmlReader (C#) like API (work in progress)</li>
810 <li>Rewrote the API in XML generation script, includes a C parser and saves
811 more informations needed for C# bindings</li>
812</ul>
813
Daniel Veillardf9c4cad2002-11-22 15:57:07 +0000[diff] [blame]814<h3>2.4.28: Nov 22 2002</h3>
815<ul>
816 <li>a couple of python binding fixes</li>
817 <li>2 bug fixes in the XML push parser</li>
818 <li>potential memory leak removed (Martin Stoilov)</li>
819 <li>fix to the configure script for Unix (Dimitri Papadopoulos)</li>
820 <li>added encoding support for XInclude parse="text"</li>
821 <li>autodetection of XHTML1 and specific serialization rules added</li>
Daniel Veillard9b4bb4d2002-12-11 19:28:47 +0000[diff] [blame]822 <li>nasty threading bug fixed (William Brack)</li>
Daniel Veillardf9c4cad2002-11-22 15:57:07 +0000[diff] [blame]823</ul>
824
Daniel Veillarddad3f682002-11-17 16:47:27 +0000[diff] [blame]825<h3>2.4.27: Nov 17 2002</h3>
826<ul>
827 <li>fixes for the Python bindings</li>
828 <li>a number of bug fixes: SGML catalogs, xmlParseBalancedChunkMemory(),
829 HTML parser, Schemas (Charles Bozeman), document fragment support
830 (Christian Glahn), xmlReconciliateNs (Brian Stafford), XPointer,
831 xmlFreeNode(), xmlSAXParseMemory (Peter Jones), xmlGetNodePath (Petr
832 Pajas), entities processing</li>
833 <li>added grep to xmllint --shell</li>
834 <li>VMS update patch from Craig A. Berry</li>
835 <li>cleanup of the Windows build with support for more compilers (Igor),
836 better thread support on Windows</li>
837 <li>cleanup of Unix Makefiles and spec file</li>
838 <li>Improvements to the documentation (John Fleck)</li>
839</ul>
840
Daniel Veillard48267432002-10-18 11:21:38 +0000[diff] [blame]841<h3>2.4.26: Oct 18 2002</h3>
842<ul>
843 <li>Patches for Windows CE port, improvements on Windows paths handling</li>
844 <li>Fixes to the validation code (DTD and Schemas), xmlNodeGetPath() ,
845 HTML serialization, Namespace compliance, and a number of small
846 problems</li>
847</ul>
848
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]849<h3>2.4.25: Sep 26 2002</h3>
850<ul>
851 <li>A number of bug fixes: XPath, validation, Python bindings, DOM and
852 tree, xmlI/O, Html</li>
853 <li>Serious rewrite of XInclude</li>
854 <li>Made XML Schemas regexp part of the default build and APIs, small fix
855 and improvement of the regexp core</li>
856 <li>Changed the validation code to reuse XML Schemas regexp APIs</li>
857 <li>Better handling of Windows file paths, improvement of Makefiles (Igor,
858 Daniel Gehriger, Mark Vakoc)</li>
859 <li>Improved the python I/O bindings, the tests, added resolver and regexp
Daniel Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame]860 APIs</li>
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]861 <li>New logos from Marc Liyanage</li>
862 <li>Tutorial improvements: John Fleck, Christopher Harris</li>
863 <li>Makefile: Fixes for AMD x86_64 (Mandrake), DESTDIR (Christophe
864 Merlet)</li>
865 <li>removal of all stderr/perror use for error reporting</li>
866 <li>Better error reporting: XPath and DTD validation</li>
867 <li>update of the trio portability layer (Bjorn Reese)</li>
868</ul>
869
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]870<p><strong>2.4.24: Aug 22 2002</strong></p>
871<ul>
872 <li>XPath fixes (William), xf:escape-uri() (Wesley Terpstra)</li>
873 <li>Python binding fixes: makefiles (William), generator, rpm build, x86-64
874 (fcrozat)</li>
875 <li>HTML &lt;style&gt; and boolean attributes serializer fixes</li>
876 <li>C14N improvements by Aleksey</li>
Daniel Veillarde1662542002-08-28 11:50:59 +0000[diff] [blame]877 <li>doc cleanups: Rick Jones</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]878 <li>Windows compiler makefile updates: Igor and Elizabeth Barham</li>
879 <li>XInclude: implementation of fallback and xml:base fixup added</li>
880</ul>
881
Daniel Veillard782afda2002-07-08 15:12:49 +0000[diff] [blame]882<h3>2.4.23: July 6 2002</h3>
883<ul>
884 <li>performances patches: Peter Jacobi</li>
885 <li>c14n fixes, testsuite and performances: Aleksey Sanin</li>
886 <li>added xmlDocFormatDump: Chema Celorio</li>
887 <li>new tutorial: John Fleck</li>
888 <li>new hash functions and performances: Sander Vesik, portability fix from
889 Peter Jacobi</li>
890 <li>a number of bug fixes: XPath (William Brack, Richard Jinks), XML and
891 HTML parsers, ID lookup function</li>
892 <li>removal of all remaining sprintf: Aleksey Sanin</li>
893</ul>
894
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]895<h3>2.4.22: May 27 2002</h3>
896<ul>
897 <li>a number of bug fixes: configure scripts, base handling, parser, memory
898 usage, HTML parser, XPath, documentation (Christian Cornelssen),
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]899 indentation, URI parsing</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]900 <li>Optimizations for XMLSec, fixing and making public some of the network
901 protocol handlers (Aleksey)</li>
902 <li>performance patch from Gary Pennington</li>
903 <li>Charles Bozeman provided date and time support for XML Schemas
904 datatypes</li>
905</ul>
906
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]907<h3>2.4.21: Apr 29 2002</h3>
908
909<p>This release is both a bug fix release and also contains the early XML
910Schemas <a href="http://www.w3.org/TR/xmlschema-1/">structures</a> and <a
911href="http://www.w3.org/TR/xmlschema-2/">datatypes</a> code, beware, all
912interfaces are likely to change, there is huge holes, it is clearly a work in
913progress and don't even think of putting this code in a production system,
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]914it's actually not compiled in by default. The real fixes are:</p>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]915<ul>
916 <li>a couple of bugs or limitations introduced in 2.4.20</li>
917 <li>patches for Borland C++ and MSC by Igor</li>
918 <li>some fixes on XPath strings and conformance patches by Richard
919 Jinks</li>
920 <li>patch from Aleksey for the ExcC14N specification</li>
921 <li>OSF/1 bug fix by Bjorn</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]922</ul>
923
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]924<h3>2.4.20: Apr 15 2002</h3>
925<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]926 <li>bug fixes: file descriptor leak, XPath, HTML output, DTD validation</li>
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]927 <li>XPath conformance testing by Richard Jinks</li>
928 <li>Portability fixes: Solaris, MPE/iX, Windows, OSF/1, python bindings,
929 libxml.m4</li>
930</ul>
931
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]932<h3>2.4.19: Mar 25 2002</h3>
933<ul>
934 <li>bug fixes: half a dozen XPath bugs, Validation, ISO-Latin to UTF8
935 encoder</li>
936 <li>portability fixes in the HTTP code</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]937 <li>memory allocation checks using valgrind, and profiling tests</li>
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]938 <li>revamp of the Windows build and Makefiles</li>
939</ul>
940
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]941<h3>2.4.18: Mar 18 2002</h3>
942<ul>
943 <li>bug fixes: tree, SAX, canonicalization, validation, portability,
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]944 XPath</li>
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]945 <li>removed the --with-buffer option it was becoming unmaintainable</li>
946 <li>serious cleanup of the Python makefiles</li>
947 <li>speedup patch to XPath very effective for DocBook stylesheets</li>
948 <li>Fixes for Windows build, cleanup of the documentation</li>
949</ul>
950
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]951<h3>2.4.17: Mar 8 2002</h3>
952<ul>
953 <li>a lot of bug fixes, including "namespace nodes have no parents in
954 XPath"</li>
955 <li>fixed/improved the Python wrappers, added more examples and more
956 regression tests, XPath extension functions can now return node-sets</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]957 <li>added the XML Canonicalization support from Aleksey Sanin</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]958</ul>
959
Daniel Veillard5f4b5992002-02-20 10:22:49 +0000[diff] [blame]960<h3>2.4.16: Feb 20 2002</h3>
961<ul>
962 <li>a lot of bug fixes, most of them were triggered by the XML Testsuite
963 from OASIS and W3C. Compliance has been significantly improved.</li>
964 <li>a couple of portability fixes too.</li>
965</ul>
966
Daniel Veillard397ff112002-02-11 18:27:20 +0000[diff] [blame]967<h3>2.4.15: Feb 11 2002</h3>
968<ul>
969 <li>Fixed the Makefiles, especially the python module ones</li>
970 <li>A few bug fixes and cleanup</li>
971 <li>Includes cleanup</li>
972</ul>
973
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]974<h3>2.4.14: Feb 8 2002</h3>
975<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]976 <li>Change of License to the <a
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]977 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]978 License</a> basically for integration in XFree86 codebase, and removing
979 confusion around the previous dual-licensing</li>
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]980 <li>added Python bindings, beta software but should already be quite
981 complete</li>
982 <li>a large number of fixes and cleanups, especially for all tree
983 manipulations</li>
984 <li>cleanup of the headers, generation of a reference API definition in
985 XML</li>
986</ul>
987
988<h3>2.4.13: Jan 14 2002</h3>
Daniel Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame]989<ul>
990 <li>update of the documentation: John Fleck and Charlie Bozeman</li>
991 <li>cleanup of timing code from Justin Fletcher</li>
992 <li>fixes for Windows and initial thread support on Win32: Igor and Serguei
993 Narojnyi</li>
994 <li>Cygwin patch from Robert Collins</li>
995 <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
996</ul>
997
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]998<h3>2.4.12: Dec 7 2001</h3>
999<ul>
1000 <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
1001 XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
1002 (robert)</li>
1003 <li>Eric Lavigne contributed project files for MacOS</li>
1004 <li>some makefiles cleanups</li>
1005</ul>
1006
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]1007<h3>2.4.11: Nov 26 2001</h3>
1008<ul>
1009 <li>fixed a couple of errors in the includes, fixed a few bugs, some code
1010 cleanups</li>
1011 <li>xmllint man pages improvement by Heiko Rupp</li>
1012 <li>updated VMS build instructions from John A Fotheringham</li>
1013 <li>Windows Makefiles updates from Igor</li>
1014</ul>
1015
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]1016<h3>2.4.10: Nov 10 2001</h3>
1017<ul>
1018 <li>URI escaping fix (Joel Young)</li>
1019 <li>added xmlGetNodePath() (for paths or XPointers generation)</li>
1020 <li>Fixes namespace handling problems when using DTD and validation</li>
1021 <li>improvements on xmllint: Morus Walter patches for --format and
1022 --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
1023 <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
1024 <li>fixes to the HTML parser</li>
1025</ul>
1026
1027<h3>2.4.9: Nov 6 2001</h3>
1028<ul>
1029 <li>fixes more catalog bugs</li>
1030 <li>avoid a compilation problem, improve xmlGetLineNo()</li>
1031</ul>
1032
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]1033<h3>2.4.8: Nov 4 2001</h3>
1034<ul>
1035 <li>fixed SGML catalogs broken in previous release, updated xmlcatalog
1036 tool</li>
1037 <li>fixed a compile errors and some includes troubles.</li>
1038</ul>
1039
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]1040<h3>2.4.7: Oct 30 2001</h3>
1041<ul>
1042 <li>exported some debugging interfaces</li>
1043 <li>serious rewrite of the catalog code</li>
1044 <li>integrated Gary Pennington thread safety patch, added configure option
1045 and regression tests</li>
1046 <li>removed an HTML parser bug</li>
1047 <li>fixed a couple of potentially serious validation bugs</li>
1048 <li>integrated the SGML DocBook support in xmllint</li>
1049 <li>changed the nanoftp anonymous login passwd</li>
1050 <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
1051 <li>general bug fixes</li>
1052 <li>updated xmllint man page by John Fleck</li>
1053 <li>some VMS and Windows updates</li>
1054</ul>
1055
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]1056<h3>2.4.6: Oct 10 2001</h3>
1057<ul>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]1058 <li>added an updated man pages by John Fleck</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]1059 <li>portability and configure fixes</li>
1060 <li>an infinite loop on the HTML parser was removed (William)</li>
1061 <li>Windows makefile patches from Igor</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1062 <li>fixed half a dozen bugs reported for libxml or libxslt</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]1063 <li>updated xmlcatalog to be able to modify SGML super catalogs</li>
1064</ul>
1065
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]1066<h3>2.4.5: Sep 14 2001</h3>
1067<ul>
1068 <li>Remove a few annoying bugs in 2.4.4</li>
1069 <li>forces the HTML serializer to output decimal charrefs since some
1070 version of Netscape can't handle hexadecimal ones</li>
1071</ul>
1072
1073<h3>1.8.16: Sep 14 2001</h3>
1074<ul>
1075 <li>maintenance release of the old libxml1 branch, couple of bug and
1076 portability fixes</li>
1077</ul>
1078
Daniel Veillard04382ae2001-09-12 18:51:30 +0000[diff] [blame]1079<h3>2.4.4: Sep 12 2001</h3>
1080<ul>
1081 <li>added --convert to xmlcatalog, bug fixes and cleanups of XML
1082 Catalog</li>
1083 <li>a few bug fixes and some portability changes</li>
1084 <li>some documentation cleanups</li>
1085</ul>
1086
Daniel Veillard39936902001-08-24 00:49:01 +0000[diff] [blame]1087<h3>2.4.3: Aug 23 2001</h3>
1088<ul>
1089 <li>XML Catalog support see the doc</li>
1090 <li>New NaN/Infinity floating point code</li>
1091 <li>A few bug fixes</li>
1092</ul>
1093
1094<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1095<ul>
1096 <li>adds xmlLineNumbersDefault() to control line number generation</li>
1097 <li>lot of bug fixes</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1098 <li>the Microsoft MSC projects files should now be up to date</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1099 <li>inheritance of namespaces from DTD defaulted attributes</li>
1100 <li>fixes a serious potential security bug</li>
1101 <li>added a --format option to xmllint</li>
1102</ul>
1103
1104<h3>2.4.1: July 24 2001</h3>
1105<ul>
1106 <li>possibility to keep line numbers in the tree</li>
1107 <li>some computation NaN fixes</li>
1108 <li>extension of the XPath API</li>
1109 <li>cleanup for alpha and ia64 targets</li>
1110 <li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]1111</ul>
1112
1113<h3>2.4.0: July 10 2001</h3>
1114<ul>
1115 <li>Fixed a few bugs in XPath, validation, and tree handling.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1116 <li>Fixed XML Base implementation, added a couple of examples to the
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]1117 regression tests</li>
1118 <li>A bit of cleanup</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1119</ul>
1120
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]1121<h3>2.3.14: July 5 2001</h3>
1122<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1123 <li>fixed some entities problems and reduce memory requirement when
1124 substituting them</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]1125 <li>lots of improvements in the XPath queries interpreter can be
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1126 substantially faster</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]1127 <li>Makefiles and configure cleanups</li>
1128 <li>Fixes to XPath variable eval, and compare on empty node set</li>
1129 <li>HTML tag closing bug fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1130 <li>Fixed an URI reference computation problem when validating</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]1131</ul>
1132
Daniel Veillard2adbb512001-06-28 16:20:36 +0000[diff] [blame]1133<h3>2.3.13: June 28 2001</h3>
1134<ul>
1135 <li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
1136 <li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
1137</ul>
1138
1139<h3>1.8.14: June 28 2001</h3>
1140<ul>
1141 <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
1142 <li>Small Makefile fix</li>
1143</ul>
1144
Daniel Veillard11648102001-06-26 16:08:24 +0000[diff] [blame]1145<h3>2.3.12: June 26 2001</h3>
1146<ul>
1147 <li>lots of cleanup</li>
1148 <li>a couple of validation fix</li>
1149 <li>fixed line number counting</li>
1150 <li>fixed serious problems in the XInclude processing</li>
1151 <li>added support for UTF8 BOM at beginning of entities</li>
1152 <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
1153 miscompile uri.c (William), Thomas Leitner provided a fix for the
1154 optimizer on Tru64</li>
1155 <li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
1156 compilation on Windows MSC</li>
1157 <li>update of libxml-doc.el (Felix Natter)</li>
1158 <li>fixed 2 bugs in URI normalization code</li>
1159</ul>
1160
Daniel Veillarde3c81b52001-06-17 14:50:34 +0000[diff] [blame]1161<h3>2.3.11: June 17 2001</h3>
1162<ul>
1163 <li>updates to trio, Makefiles and configure should fix some portability
1164 problems (alpha)</li>
1165 <li>fixed some HTML serialization problems (pre, script, and block/inline
1166 handling), added encoding aware APIs, cleanup of this code</li>
1167 <li>added xmlHasNsProp()</li>
1168 <li>implemented a specific PI for encoding support in the DocBook SGML
1169 parser</li>
1170 <li>some XPath fixes (-Infinity, / as a function parameter and namespaces
1171 node selection)</li>
1172 <li>fixed a performance problem and an error in the validation code</li>
1173 <li>fixed XInclude routine to implement the recursive behaviour</li>
1174 <li>fixed xmlFreeNode problem when libxml is included statically twice</li>
1175 <li>added --version to xmllint for bug reports</li>
1176</ul>
1177
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]1178<h3>2.3.10: June 1 2001</h3>
1179<ul>
1180 <li>fixed the SGML catalog support</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1181 <li>a number of reported bugs got fixed, in XPath, iconv detection,
1182 XInclude processing</li>
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]1183 <li>XPath string function should now handle unicode correctly</li>
1184</ul>
1185
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]1186<h3>2.3.9: May 19 2001</h3>
1187
1188<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
1189<ul>
1190 <li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1191 <li>some serious speed optimization again</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]1192 <li>some documentation cleanups</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1193 <li>trying to get better linking on Solaris (-R)</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]1194 <li>XPath API cleanup from Thomas Broyer</li>
1195 <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
1196 xmlValidGetValidElements()</li>
1197 <li>Added an INSTALL file</li>
1198 <li>Attribute removal added to API: #54433</li>
1199 <li>added a basic support for SGML catalogs</li>
1200 <li>fixed xmlKeepBlanksDefault(0) API</li>
1201 <li>bugfix in xmlNodeGetLang()</li>
1202 <li>fixed a small configure portability problem</li>
1203 <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
1204</ul>
1205
Daniel Veillarda265af72001-05-14 11:13:58 +0000[diff] [blame]1206<h3>1.8.13: May 14 2001</h3>
1207<ul>
1208 <li>bugfixes release of the old libxml1 branch used by Gnome</li>
1209</ul>
1210
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]1211<h3>2.3.8: May 3 2001</h3>
1212<ul>
1213 <li>Integrated an SGML DocBook parser for the Gnome project</li>
1214 <li>Fixed a few things in the HTML parser</li>
1215 <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
1216 point portability issue</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1217 <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
1218 DOM+validation using the XML REC as input and a 700MHz celeron).</li>
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]1219 <li>incorporated more Windows cleanup</li>
1220 <li>added xmlSaveFormatFile()</li>
1221 <li>fixed problems in copying nodes with entities references (gdome)</li>
1222 <li>removed some troubles surrounding the new validation module</li>
1223</ul>
1224
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]1225<h3>2.3.7: April 22 2001</h3>
1226<ul>
1227 <li>lots of small bug fixes, corrected XPointer</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1228 <li>Non deterministic content model validation support</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]1229 <li>added xmlDocCopyNode for gdome2</li>
1230 <li>revamped the way the HTML parser handles end of tags</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1231 <li>XPath: corrections of namespaces support and number formatting</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]1232 <li>Windows: Igor Zlatkovic patches for MSC compilation</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1233 <li>HTML output fixes from P C Chow and William M. Brack</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]1234 <li>Improved validation speed sensible for DocBook</li>
1235 <li>fixed a big bug with ID declared in external parsed entities</li>
1236 <li>portability fixes, update of Trio from Bjorn Reese</li>
1237</ul>
1238
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]1239<h3>2.3.6: April 8 2001</h3>
1240<ul>
1241 <li>Code cleanup using extreme gcc compiler warning options, found and
1242 cleared half a dozen potential problem</li>
1243 <li>the Eazel team found an XML parser bug</li>
1244 <li>cleaned up the user of some of the string formatting function. used the
1245 trio library code to provide the one needed when the platform is missing
1246 them</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1247 <li>xpath: removed a memory leak and fixed the predicate evaluation
1248 problem, extended the testsuite and cleaned up the result. XPointer seems
1249 broken ...</li>
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]1250</ul>
1251
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame]1252<h3>2.3.5: Mar 23 2001</h3>
1253<ul>
1254 <li>Biggest change is separate parsing and evaluation of XPath expressions,
1255 there is some new APIs for this too</li>
1256 <li>included a number of bug fixes(XML push parser, 51876, notations,
1257 52299)</li>
1258 <li>Fixed some portability issues</li>
1259</ul>
1260
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1261<h3>2.3.4: Mar 10 2001</h3>
1262<ul>
1263 <li>Fixed bugs #51860 and #51861</li>
1264 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
1265 size to be application tunable.</li>
1266 <li>Some cleanup in the validation code, still a bug left and this part
1267 should probably be rewritten to support ambiguous content model :-\</li>
1268 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
1269 parser</li>
1270 <li>Fixed another bug in xmlNodeGetContent()</li>
1271 <li>Bjorn fixed XPath node collection and Number formatting</li>
1272 <li>Fixed a loop reported in the HTML parsing</li>
1273 <li>blank space are reported even if the Dtd content model proves that they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1274 are formatting spaces, this is for XML conformance</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1275</ul>
1276
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]1277<h3>2.3.3: Mar 1 2001</h3>
1278<ul>
1279 <li>small change in XPath for XSLT</li>
1280 <li>documentation cleanups</li>
1281 <li>fix in validation by Gary Pennington</li>
1282 <li>serious parsing performances improvements</li>
1283</ul>
1284
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1285<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]1286<ul>
1287 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
1288 <li>fixed a Dtd parsing bug</li>
1289 <li>fixed a bug in xmlNodeGetContent</li>
1290 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
1291</ul>
1292
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1293<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1294<ul>
1295 <li>some XPath and HTML bug fixes for XSLT</li>
1296 <li>small extension of the hash table interfaces for DOM gdome2
1297 implementation</li>
1298 <li>A few bug fixes</li>
1299</ul>
1300
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1301<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]1302<ul>
1303 <li>Lots of XPath bug fixes</li>
1304 <li>Add a mode with Dtd lookup but without validation error reporting for
1305 XSLT</li>
1306 <li>Add support for text node without escaping (XSLT)</li>
1307 <li>bug fixes for xmlCheckFilename</li>
1308 <li>validation code bug fixes from Gary Pennington</li>
1309 <li>Patch from Paul D. Smith correcting URI path normalization</li>
1310 <li>Patch to allow simultaneous install of libxml-devel and
1311 libxml2-devel</li>
1312 <li>the example Makefile is now fixed</li>
1313 <li>added HTML to the RPM packages</li>
1314 <li>tree copying bugfixes</li>
1315 <li>updates to Windows makefiles</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1316 <li>optimization patch from Bjorn Reese</li>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1317</ul>
1318
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1319<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]1320<ul>
1321 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
1322 <li>added htmlHandleOmittedElem()</li>
1323 <li>Applied Bjorn Reese's IPV6 first patch</li>
1324 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1325 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]1326</ul>
1327
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]1328<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]1329<ul>
1330 <li>Fix the Windows problems of 2.2.8</li>
1331 <li>integrate OpenVMS patches</li>
1332 <li>better handling of some nasty HTML input</li>
1333 <li>Improved the XPointer implementation</li>
1334 <li>integrate a number of provided patches</li>
1335</ul>
1336
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]1337<h3>2.2.9: Nov 25 2000</h3>
1338<ul>
1339 <li>erroneous release :-(</li>
1340</ul>
1341
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]1342<h3>2.2.8: Nov 13 2000</h3>
1343<ul>
1344 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
1345 support</li>
1346 <li>Patch in conditional section handling</li>
1347 <li>updated MS compiler project</li>
1348 <li>fixed some XPath problems</li>
1349 <li>added an URI escaping function</li>
1350 <li>some other bug fixes</li>
1351</ul>
1352
1353<h3>2.2.7: Oct 31 2000</h3>
1354<ul>
1355 <li>added message redirection</li>
1356 <li>XPath improvements (thanks TOM !)</li>
1357 <li>xmlIOParseDTD() added</li>
1358 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
1359 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
1360</ul>
1361
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]1362<h3>2.2.6: Oct 25 2000:</h3>
1363<ul>
1364 <li>Added an hash table module, migrated a number of internal structure to
1365 those</li>
1366 <li>Fixed a posteriori validation problems</li>
1367 <li>HTTP module cleanups</li>
1368 <li>HTML parser improvements (tag errors, script/style handling, attribute
1369 normalization)</li>
1370 <li>coalescing of adjacent text nodes</li>
1371 <li>couple of XPath bug fixes, exported the internal API</li>
1372</ul>
1373
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1374<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1375<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1376 <li>XPointer implementation and testsuite</li>
1377 <li>Lot of XPath fixes, added variable and functions registration, more
1378 tests</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1379 <li>Portability fixes, lots of enhancements toward an easy Windows build
1380 and release</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1381 <li>Late validation fixes</li>
1382 <li>Integrated a lot of contributed patches</li>
1383 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1384 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1385</ul>
1386
1387<h3>2.2.4: Oct 1 2000:</h3>
1388<ul>
1389 <li>main XPath problem fixed</li>
1390 <li>Integrated portability patches for Windows</li>
1391 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1392</ul>
1393
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1394<h3>2.2.3: Sep 17 2000</h3>
1395<ul>
1396 <li>bug fixes</li>
1397 <li>cleanup of entity handling code</li>
1398 <li>overall review of all loops in the parsers, all sprintf usage has been
1399 checked too</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1400 <li>Far better handling of larges Dtd. Validating against DocBook XML Dtd
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1401 works smoothly now.</li>
1402</ul>
1403
1404<h3>1.8.10: Sep 6 2000</h3>
1405<ul>
1406 <li>bug fix release for some Gnome projects</li>
1407</ul>
1408
1409<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1410<ul>
1411 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]1412 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1413</ul>
1414
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1415<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1416<ul>
1417 <li>a purely bug fixes release</li>
1418 <li>fixed an encoding support problem when parsing from a memory block</li>
1419 <li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1420 <li>removed a bug in the function allowing to override the memory
1421 allocation routines</li>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1422</ul>
1423
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1424<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]1425<ul>
1426 <li>applied a lot of portability fixes</li>
1427 <li>better encoding support/cleanup and saving (content is now always
1428 encoded in UTF-8)</li>
1429 <li>the HTML parser now correctly handles encodings</li>
1430 <li>added xmlHasProp()</li>
1431 <li>fixed a serious problem with &amp;#38;</li>
1432 <li>propagated the fix to FTP client</li>
1433 <li>cleanup, bugfixes, etc ...</li>
1434 <li>Added a page about <a href="encoding.html">libxml Internationalization
1435 support</a></li>
1436</ul>
1437
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1438<h3>1.8.9: July 9 2000</h3>
1439<ul>
1440 <li>fixed the spec the RPMs should be better</li>
1441 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
1442 rpmfind users problem</li>
1443</ul>
1444
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]1445<h3>2.1.1: July 1 2000</h3>
1446<ul>
1447 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
1448 <li>improvements on the HTML parser</li>
1449</ul>
1450
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1451<h3>2.1.0 and 1.8.8: June 29 2000</h3>
1452<ul>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1453 <li>1.8.8 is mostly a commodity package for upgrading to libxml2 according
1454 to <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1455 about &amp;#38; charref parsing</li>
1456 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
1457 also contains numerous fixes and enhancements:
1458 <ul>
1459 <li>added xmlStopParser() to stop parsing</li>
1460 <li>improved a lot parsing speed when there is large CDATA blocs</li>
1461 <li>includes XPath patches provided by Picdar Technology</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1462 <li>tried to fix as much as possible DTD validation and namespace
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1463 related problems</li>
1464 <li>output to a given encoding has been added/tested</li>
1465 <li>lot of various fixes</li>
1466 </ul>
1467 </li>
1468</ul>
1469
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1470<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1471<ul>
1472 <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]1473 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initially
1474 scheduled for Apr 3 the release occurred only on Apr 12 due to massive
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1475 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1476 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1477 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1478 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1479 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1480 <pre>#include "xxx.h"</pre>
1481 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]1482 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
1483 <li>the memory allocation routines used by libxml can now be overloaded
1484 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1485 <li>The previously CVS only tool tester has been renamed
1486 <strong>xmllint</strong> and is now installed as part of the libxml2
1487 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1488 <li>The I/O interface has been revamped. There is now ways to plug in
1489 specific I/O modules, either at the URI scheme detection level using
1490 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
1491 parser context using xmlCreateIOParserCtxt()</li>
1492 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
1493 number of the libxml module in use</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1494 <li>a number of optional features of libxml can now be excluded at
1495 configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1496</ul>
1497
1498<h3>2.0.0beta: Mar 14 2000</h3>
1499<ul>
1500 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1501 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
1502 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
1503 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1504 <li>This version is now the head in the Gnome CVS base, the old one is
1505 available under the tag LIB_XML_1_X</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1506 <li>This includes a very large set of changes. From a programmatic point
1507 of view applications should not have to be modified too much, check the
1508 <a href="upgrade.html">upgrade page</a></li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1509 <li>Some interfaces may changes (especially a bit about encoding).</li>
1510 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1511 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1512 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
1513 handled now</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1514 <li>Better handling of entities, especially well-formedness checking
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1515 and proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1516 <li>DTD conditional sections</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1517 <li>Validation now correctly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1518 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1519 structures to accommodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1520 </ul>
1521 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1522 <li>Serious progress were made toward compliance, <a
1523 href="conf/result.html">here are the result of the test</a> against the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1524 OASIS testsuite (except the Japanese tests since I don't support that
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1525 encoding yet). This URL is rebuilt every couple of hours using the CVS
1526 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1527</ul>
1528
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1529<h3>1.8.7: Mar 6 2000</h3>
1530<ul>
1531 <li>This is a bug fix release:</li>
1532 <li>It is possible to disable the ignorable blanks heuristic used by
1533 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1534 that for adherence to XML spec, this behaviour will be disabled by
1535 default in 2.x . The same function will allow to keep compatibility for
1536 old code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1537 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
1538 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1539 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
1540 compilation on some platforms has been fixed</li>
1541 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
1542 URIs</li>
1543</ul>
1544
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1545<h3>1.8.6: Jan 31 2000</h3>
1546<ul>
1547 <li>added a nanoFTP transport module, debugged until the new version of <a
1548 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
1549 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]1550</ul>
1551
1552<h3>1.8.5: Jan 21 2000</h3>
1553<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1554 <li>adding APIs to parse a well balanced chunk of XML (production <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1555 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
1556 XML spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1557 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1558 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
1559 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1560 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
1561 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1562</ul>
1563
1564<h3>1.8.4: Jan 13 2000</h3>
1565<ul>
1566 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
1567 <li>all exit() call should have been removed from libxml</li>
1568 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
1569 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1570</ul>
1571
1572<h3>1.8.3: Jan 5 2000</h3>
1573<ul>
1574 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1575 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1576 <li>lots of bug fixes and improvement added over XMas holidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1577 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1578 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
1579 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1580 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1581 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1582 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1583</ul>
1584
1585<h3>1.8.2: Dec 21 1999</h3>
1586<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1587 <li>I got another problem with includes and C++, I hope this issue is fixed
1588 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1589 <li>Added a few tree modification functions: xmlReplaceNode,
1590 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
1591 xmlDocSetRootElement</li>
1592 <li>Tried to improve the HTML output with help from <a
1593 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1594</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1595
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1596<h3>1.8.1: Dec 18 1999</h3>
1597<ul>
1598 <li>various patches to avoid troubles when using libxml with C++ compilers
1599 the "namespace" keyword and C escaping in include files</li>
1600 <li>a problem in one of the core macros IS_CHAR was corrected</li>
1601 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
1602 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]1603 <li>fixed a posteriori validation (validation after parsing, or by using a
1604 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1605 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]1606</ul>
1607
1608<h3>1.8.0: Dec 12 1999</h3>
1609<ul>
1610 <li>cleanup, especially memory wise</li>
1611 <li>the parser should be more reliable, especially the HTML one, it should
1612 not crash, whatever the input !</li>
1613 <li>Integrated various patches, especially a speedup improvement for large
1614 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
1615 configure with --with-buffers to enable them.</li>
1616 <li>attribute normalization, oops should have been added long ago !</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1617 <li>attributes defaulted from DTDs should be available, xmlSetProp() now
1618 does entities escaping by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1619</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1620
1621<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1622<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1623 <li>Lots of HTML improvement</li>
1624 <li>Fixed some errors when saving both XML and HTML</li>
1625 <li>More examples, the regression tests should now look clean</li>
1626 <li>Fixed a bug with contiguous charref</li>
1627</ul>
1628
1629<h3>1.7.3: Sep 29 1999</h3>
1630<ul>
1631 <li>portability problems fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1632 <li>snprintf was used unconditionally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1633 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1634</ul>
1635
1636<h3>1.7.1: Sep 24 1999</h3>
1637<ul>
1638 <li>The basic type for strings manipulated by libxml has been renamed in
1639 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1640 is that CHAR was conflicting with a predefined type on Windows. However
1641 on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1642 <strong>#define </strong>.</li>
1643 <li>Changed another error : the use of a structure field called errno, and
1644 leading to troubles on platforms where it's a macro</li>
1645</ul>
1646
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1647<h3>1.7.0: Sep 23 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1648<ul>
1649 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1650 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1651 <li>Added an errno to report errors by another mean than a simple printf
1652 like callback</li>
1653 <li>Finished ID/IDREF support and checking when validation</li>
1654 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1655 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1656 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
1657 implementation</li>
1658 <li>Added an HTML parser front-end</li>
1659</ul>
1660
1661<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1662
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1663<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]1664markup-based structured documents. Here is <a name="example">an example XML
1665document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1666<pre>&lt;?xml version="1.0"?&gt;
1667&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
1668 &lt;head&gt;
1669 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
1670 &lt;/head&gt;
1671 &lt;chapter&gt;
1672 &lt;title&gt;The Linux adventure&lt;/title&gt;
1673 &lt;p&gt;bla bla bla ...&lt;/p&gt;
1674 &lt;image href="linus.gif"/&gt;
1675 &lt;p&gt;...&lt;/p&gt;
1676 &lt;/chapter&gt;
1677&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1678
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1679<p>The first line specifies that it is an XML document and gives useful
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1680information about its encoding. Then the rest of the document is a text
1681format whose structure is specified by tags between brackets. <strong>Each
1682tag opened has to be closed</strong>. XML is pedantic about this. However, if
1683a tag is empty (no content), a single tag can serve as both the opening and
1684closing tag if it ends with <code>/&gt;</code> rather than with
1685<code>&gt;</code>. Note that, for example, the image tag has no content (just
1686an attribute) and is closed by ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1687
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1688<p>XML can be applied successfully to a wide range of tasks, ranging from
1689long term structured document maintenance (where it follows the steps of
1690SGML) to simple data encoding mechanisms like configuration file formatting
1691(glade), spreadsheets (gnumeric), or even shorter lived documents such as
1692WebDAV where it is used to encode remote calls between a client and a
1693server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1694
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1695<h2><a name="XSLT">XSLT</a></h2>
1696
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1697<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
1698
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1699<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
1700language for transforming XML documents into other XML documents (or
1701HTML/textual output).</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1702
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]1703<p>A separate library called libxslt is available implementing XSLT-1.0 for
1704libxml2. This module "libxslt" too can be found in the Gnome CVS base.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1705
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]1706<p>You can check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1707href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
1708supported and the progresses on the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1709href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog"
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1710name="Changelog">Changelog</a>.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1711
1712<h2><a name="Python">Python and bindings</a></h2>
1713
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1714<p>There are a number of language bindings and wrappers available for
1715libxml2, the list below is not exhaustive. Please contact the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1716href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a>
1717(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in
1718order to get updates to this list or to discuss the specific topic of libxml2
1719or libxslt wrappers or bindings:</p>
1720<ul>
Daniel Veillardc14401e2002-11-20 14:28:17 +0000[diff] [blame]1721 <li><a href="http://libxmlplusplus.sourceforge.net/">Libxml++</a> seems the
1722 most up-to-date C++ bindings for libxml2, check the <a
1723 href="http://libxmlplusplus.sourceforge.net/reference/html/hierarchy.html">documentation</a>
1724 and the <a
1725 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]1726 <li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1727 based on the gdome2 bindings</a> maintained by Tobias Peters.</li>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]1728 <li>and a third C++ wrapper by Peter Jones &lt;pjones@pmade.org&gt;
1729 <p>Website: <a
1730 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
1731 </li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1732 <li><a
1733 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1734 Sergeant</a> developed <a
1735 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1736 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1737 application server</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]1738 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides an
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1739 earlier version of the libxml/libxslt <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1740 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]1741 <li>Gopal.V and Peter Minten develop <a
1742 href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1743 C# libxml2 bindings.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1744 <li>Petr Kozelka provides <a
1745 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1746 libxml2</a> with Kylix, Delphi and other Pascal compilers.</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]1747 <li>Uwe Fechner also provides <a
1748 href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1749 implementation for Kylix2/D5/D6 from Borland.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1750 <li>Wai-Sun "Squidster" Chia provides <a
1751 href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and
1752 libxml2 bindings are also available in Ruby through the <a
1753 href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module
1754 maintained by Tobias Peters.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1755 <li>Steve Ball and contributors maintains <a
1756 href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1757 Tcl</a>.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1758 <li>There is support for libxml2 in the DOM module of PHP.</li>
Daniel Veillard41b01a82003-02-27 11:09:06 +0000[diff] [blame]1759 <li><a href="http://savannah.gnu.org/projects/classpathx/">LibxmlJ</a> is
Daniel Veillard806cada2003-03-19 21:58:59 +0000[diff] [blame]1760 an effort to create a 100% JAXP-compatible Java wrapper for libxml2 and
1761 libxslt as part of GNU ClasspathX project.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1762</ul>
1763
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1764<p>The distribution includes a set of Python bindings, which are guaranteed
1765to be maintained as part of the library in the future, though the Python
Daniel Veillard41b01a82003-02-27 11:09:06 +0000[diff] [blame]1766interface have not yet reached the completeness of the C API.</p>
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000[diff] [blame]1767
Daniel Veillard27907c72002-12-16 16:05:58 +0000[diff] [blame]1768<p><a href="mailto:stephane.bidoul@softwareag.com">Stéphane Bidoul</a>
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000[diff] [blame]1769maintains <a href="http://users.skynet.be/sbi/libxml-python/">a Windows port
1770of the Python bindings</a>.</p>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1771
Daniel Veillard7ef0fcb2002-12-14 10:38:55 +0000[diff] [blame]1772<p>Note to people interested in building bindings, the API is formalized as
1773<a href="libxml2-api.xml">an XML API description file</a> which allows to
1774automate a large part of the Python bindings, this includes function
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000[diff] [blame]1775descriptions, enums, structures, typedefs, etc... The Python script used to
1776build the bindings is python/generator.py in the source distribution.</p>
Daniel Veillard7ef0fcb2002-12-14 10:38:55 +0000[diff] [blame]1777
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1778<p>To install the Python bindings there are 2 options:</p>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1779<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1780 <li>If you use an RPM based distribution, simply install the <a
1781 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python
1782 RPM</a> (and if needed the <a
1783 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python
1784 RPM</a>).</li>
1785 <li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python
1786 module distribution</a> corresponding to your installed version of
1787 libxml2 and libxslt. Note that to install it you will need both libxml2
1788 and libxslt installed and run "python setup.py build install" in the
1789 module tree.</li>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1790</ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1791
1792<p>The distribution includes a set of examples and regression tests for the
1793python bindings in the <code>python/tests</code> directory. Here are some
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1794excerpts from those tests:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1795
1796<h3>tst.py:</h3>
1797
1798<p>This is a basic test of the file interface and DOM navigation:</p>
1799<pre>import libxml2
1800
1801doc = libxml2.parseFile("tst.xml")
1802if doc.name != "tst.xml":
1803 print "doc.name failed"
1804 sys.exit(1)
1805root = doc.children
1806if root.name != "doc":
1807 print "root.name failed"
1808 sys.exit(1)
1809child = root.children
1810if child.name != "foo":
1811 print "child.name failed"
1812 sys.exit(1)
1813doc.freeDoc()</pre>
1814
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1815<p>The Python module is called libxml2; parseFile is the equivalent of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1816xmlParseFile (most of the bindings are automatically generated, and the xml
1817prefix is removed and the casing convention are kept). All node seen at the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1818binding level share the same subset of accessors:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1819<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1820 <li><code>name</code> : returns the node name</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1821 <li><code>type</code> : returns a string indicating the node type</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1822 <li><code>content</code> : returns the content of the node, it is based on
1823 xmlNodeGetContent() and hence is recursive.</li>
1824 <li><code>parent</code> , <code>children</code>, <code>last</code>,
1825 <code>next</code>, <code>prev</code>, <code>doc</code>,
1826 <code>properties</code>: pointing to the associated element in the tree,
1827 those may return None in case no such link exists.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1828</ul>
1829
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1830<p>Also note the need to explicitly deallocate documents with freeDoc() .
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1831Reference counting for libxml2 trees would need quite a lot of work to
1832function properly, and rather than risk memory leaks if not implemented
1833correctly it sounds safer to have an explicit function to free a tree. The
1834wrapper python objects like doc, root or child are them automatically garbage
1835collected.</p>
1836
1837<h3>validate.py:</h3>
1838
1839<p>This test check the validation interfaces and redirection of error
1840messages:</p>
1841<pre>import libxml2
1842
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1843#deactivate error messages from the validation
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1844def noerr(ctx, str):
1845 pass
1846
1847libxml2.registerErrorHandler(noerr, None)
1848
1849ctxt = libxml2.createFileParserCtxt("invalid.xml")
1850ctxt.validate(1)
1851ctxt.parseDocument()
1852doc = ctxt.doc()
1853valid = ctxt.isValid()
1854doc.freeDoc()
1855if valid != 0:
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1856 print "validity check failed"</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1857
1858<p>The first thing to notice is the call to registerErrorHandler(), it
1859defines a new error handler global to the library. It is used to avoid seeing
1860the error messages when trying to validate the invalid document.</p>
1861
1862<p>The main interest of that test is the creation of a parser context with
1863createFileParserCtxt() and how the behaviour can be changed before calling
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1864parseDocument() . Similarly the informations resulting from the parsing phase
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1865are also available using context methods.</p>
1866
1867<p>Contexts like nodes are defined as class and the libxml2 wrappers maps the
1868C function interfaces in terms of objects method as much as possible. The
1869best to get a complete view of what methods are supported is to look at the
1870libxml2.py module containing all the wrappers.</p>
1871
1872<h3>push.py:</h3>
1873
1874<p>This test show how to activate the push parser interface:</p>
1875<pre>import libxml2
1876
1877ctxt = libxml2.createPushParser(None, "&lt;foo", 4, "test.xml")
1878ctxt.parseChunk("/&gt;", 2, 1)
1879doc = ctxt.doc()
1880
1881doc.freeDoc()</pre>
1882
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1883<p>The context is created with a special call based on the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1884xmlCreatePushParser() from the C library. The first argument is an optional
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1885SAX callback object, then the initial set of data, the length and the name of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1886the resource in case URI-References need to be computed by the parser.</p>
1887
1888<p>Then the data are pushed using the parseChunk() method, the last call
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1889setting the third argument terminate to 1.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1890
1891<h3>pushSAX.py:</h3>
1892
1893<p>this test show the use of the event based parsing interfaces. In this case
1894the parser does not build a document, but provides callback information as
1895the parser makes progresses analyzing the data being provided:</p>
1896<pre>import libxml2
1897log = ""
1898
1899class callback:
1900 def startDocument(self):
1901 global log
1902 log = log + "startDocument:"
1903
1904 def endDocument(self):
1905 global log
1906 log = log + "endDocument:"
1907
1908 def startElement(self, tag, attrs):
1909 global log
1910 log = log + "startElement %s %s:" % (tag, attrs)
1911
1912 def endElement(self, tag):
1913 global log
1914 log = log + "endElement %s:" % (tag)
1915
1916 def characters(self, data):
1917 global log
1918 log = log + "characters: %s:" % (data)
1919
1920 def warning(self, msg):
1921 global log
1922 log = log + "warning: %s:" % (msg)
1923
1924 def error(self, msg):
1925 global log
1926 log = log + "error: %s:" % (msg)
1927
1928 def fatalError(self, msg):
1929 global log
1930 log = log + "fatalError: %s:" % (msg)
1931
1932handler = callback()
1933
1934ctxt = libxml2.createPushParser(handler, "&lt;foo", 4, "test.xml")
1935chunk = " url='tst'&gt;b"
1936ctxt.parseChunk(chunk, len(chunk), 0)
1937chunk = "ar&lt;/foo&gt;"
1938ctxt.parseChunk(chunk, len(chunk), 1)
1939
Daniel Veillardfcbfa2d2002-02-21 17:54:27 +0000[diff] [blame]1940reference = "startDocument:startElement foo {'url': 'tst'}:" + \
1941 "characters: bar:endElement foo:endDocument:"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1942if log != reference:
1943 print "Error got: %s" % log
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1944 print "Expected: %s" % reference</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1945
1946<p>The key object in that test is the handler, it provides a number of entry
1947points which can be called by the parser as it makes progresses to indicate
1948the information set obtained. The full set of callback is larger than what
1949the callback class in that specific example implements (see the SAX
1950definition for a complete list). The wrapper will only call those supplied by
1951the object when activated. The startElement receives the names of the element
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1952and a dictionary containing the attributes carried by this element.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1953
1954<p>Also note that the reference string generated from the callback shows a
1955single character call even though the string "bar" is passed to the parser
1956from 2 different call to parseChunk()</p>
1957
1958<h3>xpath.py:</h3>
1959
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1960<p>This is a basic test of XPath wrappers support</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1961<pre>import libxml2
1962
1963doc = libxml2.parseFile("tst.xml")
1964ctxt = doc.xpathNewContext()
1965res = ctxt.xpathEval("//*")
1966if len(res) != 2:
1967 print "xpath query: wrong node set size"
1968 sys.exit(1)
1969if res[0].name != "doc" or res[1].name != "foo":
1970 print "xpath query: wrong node set value"
1971 sys.exit(1)
1972doc.freeDoc()
1973ctxt.xpathFreeContext()</pre>
1974
1975<p>This test parses a file, then create an XPath context to evaluate XPath
1976expression on it. The xpathEval() method execute an XPath query and returns
1977the result mapped in a Python way. String and numbers are natively converted,
1978and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1979the document, the XPath context need to be freed explicitly, also not that
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1980the result of the XPath query may point back to the document tree and hence
1981the document must be freed after the result of the query is used.</p>
1982
1983<h3>xpathext.py:</h3>
1984
1985<p>This test shows how to extend the XPath engine with functions written in
1986python:</p>
1987<pre>import libxml2
1988
1989def foo(ctx, x):
1990 return x + 1
1991
1992doc = libxml2.parseFile("tst.xml")
1993ctxt = doc.xpathNewContext()
1994libxml2.registerXPathFunction(ctxt._o, "foo", None, foo)
1995res = ctxt.xpathEval("foo(1)")
1996if res != 2:
1997 print "xpath extension failure"
1998doc.freeDoc()
1999ctxt.xpathFreeContext()</pre>
2000
2001<p>Note how the extension function is registered with the context (but that
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2002part is not yet finalized, this may change slightly in the future).</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]2003
2004<h3>tstxpath.py:</h3>
2005
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2006<p>This test is similar to the previous one but shows how the extension
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]2007function can access the XPath evaluation context:</p>
2008<pre>def foo(ctx, x):
2009 global called
2010
2011 #
2012 # test that access to the XPath evaluation contexts
2013 #
2014 pctxt = libxml2.xpathParserContext(_obj=ctx)
2015 ctxt = pctxt.context()
2016 called = ctxt.function()
2017 return x + 1</pre>
2018
2019<p>All the interfaces around the XPath parser(or rather evaluation) context
2020are not finalized, but it should be sufficient to do contextual work at the
2021evaluation point.</p>
2022
2023<h3>Memory debugging:</h3>
2024
2025<p>last but not least, all tests starts with the following prologue:</p>
2026<pre>#memory debug specific
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2027libxml2.debugMemory(1)</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]2028
2029<p>and ends with the following epilogue:</p>
2030<pre>#memory debug specific
2031libxml2.cleanupParser()
2032if libxml2.debugMemory(1) == 0:
2033 print "OK"
2034else:
2035 print "Memory leak %d bytes" % (libxml2.debugMemory(1))
2036 libxml2.dumpMemory()</pre>
2037
2038<p>Those activate the memory debugging interface of libxml2 where all
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2039allocated block in the library are tracked. The prologue then cleans up the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]2040library state and checks that all allocated memory has been freed. If not it
2041calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]2042
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2043<h2><a name="architecture">libxml2 architecture</a></h2>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2044
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]2045<p>Libxml2 is made of multiple components; some of them are optional, and
2046most of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2047<ul>
2048 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2049 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2050 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2051 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2052 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2053 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2054 <li>a SAX tree module to build an in-memory DOM representation</li>
2055 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2056 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2057 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2058 (optional)</li>
2059 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]2060</ul>
2061
2062<p>Graphically this gives the following:</p>
2063
2064<p><img src="libxml.gif" alt="a graphical view of the various"></p>
2065
2066<p></p>
2067
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2068<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2069
2070<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]2071returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2072<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]2073as the file name, the document type, and a <strong>children</strong> pointer
2074which is the root of the document (or more exactly the first child under the
2075root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2076chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]2077relationship. An xmlNode can also carry properties (a chain of xmlAttr
2078structures). An attribute may have a value which is a list of TEXT or
2079ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2080
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2081<p>Here is an example (erroneous with respect to the XML spec since there
2082should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2083
2084<p><img src="structure.gif" alt=" structure.gif "></p>
2085
2086<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]2087called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2088prints them back as parsed. This is useful for detecting errors both in XML
2089code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2090which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2091result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2092<pre>DOCUMENT
2093version=1.0
2094standalone=true
2095 ELEMENT EXAMPLE
2096 ATTRIBUTE prop1
2097 TEXT
2098 content=gnome is great
2099 ATTRIBUTE prop2
2100 ENTITY_REF
2101 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2102 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]2103 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2104 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2105 TEXT
2106 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2107 ELEMENT chapter
2108 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2109 TEXT
2110 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2111 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2112 TEXT
2113 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2114 ELEMENT image
2115 ATTRIBUTE href
2116 TEXT
2117 content=linus.gif
2118 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2119 TEXT
2120 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2121
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2122<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]2123
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2124<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2125
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]2126<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2127memory. 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]2128loaded using libxml), it's better to use the SAX interface of libxml. SAX is
2129a <strong>callback-based interface</strong> to the parser. Before parsing,
2130the application layer registers a customized set of callbacks which are
2131called by the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2132
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2133<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]2134libxml, see the <a
2135href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
2136documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2137Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2138
2139<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
2140program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2141binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]2142distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2143testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2144<pre>SAX.setDocumentLocator()
2145SAX.startDocument()
2146SAX.getEntity(amp)
2147SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
2148SAX.characters( , 3)
2149SAX.startElement(head)
2150SAX.characters( , 4)
2151SAX.startElement(title)
2152SAX.characters(Welcome to Gnome, 16)
2153SAX.endElement(title)
2154SAX.characters( , 3)
2155SAX.endElement(head)
2156SAX.characters( , 3)
2157SAX.startElement(chapter)
2158SAX.characters( , 4)
2159SAX.startElement(title)
2160SAX.characters(The Linux adventure, 19)
2161SAX.endElement(title)
2162SAX.characters( , 4)
2163SAX.startElement(p)
2164SAX.characters(bla bla bla ..., 15)
2165SAX.endElement(p)
2166SAX.characters( , 4)
2167SAX.startElement(image, href='linus.gif')
2168SAX.endElement(image)
2169SAX.characters( , 4)
2170SAX.startElement(p)
2171SAX.characters(..., 3)
2172SAX.endElement(p)
2173SAX.characters( , 3)
2174SAX.endElement(chapter)
2175SAX.characters( , 1)
2176SAX.endElement(EXAMPLE)
2177SAX.endDocument()</pre>
2178
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2179<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]2180facility, so nearly everything up to the end of this document presupposes the
2181use of the standard DOM tree build. Note that the DOM tree itself is built by
2182a set of registered default callbacks, without internal specific
2183interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2184
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2185<h2><a name="Validation">Validation &amp; DTDs</a></h2>
2186
2187<p>Table of Content:</p>
2188<ol>
2189 <li><a href="#General5">General overview</a></li>
2190 <li><a href="#definition">The definition</a></li>
2191 <li><a href="#Simple">Simple rules</a>
2192 <ol>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2193 <li><a href="#reference">How to reference a DTD from a document</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2194 <li><a href="#Declaring">Declaring elements</a></li>
2195 <li><a href="#Declaring1">Declaring attributes</a></li>
2196 </ol>
2197 </li>
2198 <li><a href="#Some">Some examples</a></li>
2199 <li><a href="#validate">How to validate</a></li>
2200 <li><a href="#Other">Other resources</a></li>
2201</ol>
2202
2203<h3><a name="General5">General overview</a></h3>
2204
2205<p>Well what is validation and what is a DTD ?</p>
2206
2207<p>DTD is the acronym for Document Type Definition. This is a description of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2208the 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]2209specification, and allows one to describe and verify that a given document
2210instance conforms to the set of rules detailing its structure and content.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2211
2212<p>Validation is the process of checking a document against a DTD (more
2213generally against a set of construction rules).</p>
2214
2215<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2216of the XML life cycle. Briefly a DTD defines all the possible elements to be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2217found within your document, what is the formal shape of your document tree
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2218(by defining the allowed content of an element; either text, a regular
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2219expression for the allowed list of children, or mixed content i.e. both text
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2220and children). The DTD also defines the valid attributes for all elements and
2221the types of those attributes.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2222
2223<h3><a name="definition1">The definition</a></h3>
2224
2225<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
2226href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
2227Rev1</a>):</p>
2228<ul>
2229 <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
2230 elements</a></li>
2231 <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
2232 attributes</a></li>
2233</ul>
2234
2235<p>(unfortunately) all this is inherited from the SGML world, the syntax is
2236ancient...</p>
2237
2238<h3><a name="Simple1">Simple rules</a></h3>
2239
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2240<p>Writing DTDs can be done in many ways. The rules to build them if you need
2241something permanent or something which can evolve over time can be radically
2242different. Really complex DTDs like DocBook ones are flexible but quite
2243harder 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]2244structure. It is just a set of basic rules, and definitely not exhaustive nor
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2245usable for complex DTD design.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2246
2247<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
2248
2249<p>Assuming the top element of the document is <code>spec</code> and the dtd
2250is placed in the file <code>mydtd</code> in the subdirectory
2251<code>dtds</code> of the directory from where the document were loaded:</p>
2252
2253<p><code>&lt;!DOCTYPE spec SYSTEM "dtds/mydtd"&gt;</code></p>
2254
2255<p>Notes:</p>
2256<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2257 <li>The system string is actually an URI-Reference (as defined in <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2258 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]2259 full URL string indicating the location of your DTD on the Web. This is a
2260 really good thing to do if you want others to validate your document.</li>
2261 <li>It is also possible to associate a <code>PUBLIC</code> identifier (a
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2262 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]2263 without having to locate it on the web.</li>
2264 <li>A DTD contains a set of element and attribute declarations, but they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2265 don't define what the root of the document should be. This is explicitly
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2266 told to the parser/validator as the first element of the
2267 <code>DOCTYPE</code> declaration.</li>
2268</ul>
2269
2270<h4><a name="Declaring2">Declaring elements</a>:</h4>
2271
2272<p>The following declares an element <code>spec</code>:</p>
2273
2274<p><code>&lt;!ELEMENT spec (front, body, back?)&gt;</code></p>
2275
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2276<p>It also expresses that the spec element contains one <code>front</code>,
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2277one <code>body</code> and one optional <code>back</code> children elements in
2278this order. The declaration of one element of the structure and its content
2279are done in a single declaration. Similarly the following declares
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2280<code>div1</code> elements:</p>
2281
Daniel Veillard51737272002-01-23 23:10:38 +0000[diff] [blame]2282<p><code>&lt;!ELEMENT div1 (head, (p | list | note)*, div2?)&gt;</code></p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2283
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2284<p>which means div1 contains one <code>head</code> then a series of optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2285<code>p</code>, <code>list</code>s and <code>note</code>s and then an
2286optional <code>div2</code>. And last but not least an element can contain
2287text:</p>
2288
2289<p><code>&lt;!ELEMENT b (#PCDATA)&gt;</code></p>
2290
2291<p><code>b</code> contains text or being of mixed content (text and elements
2292in no particular order):</p>
2293
2294<p><code>&lt;!ELEMENT p (#PCDATA|a|ul|b|i|em)*&gt;</code></p>
2295
2296<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
2297<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
2298order.</p>
2299
2300<h4><a name="Declaring1">Declaring attributes</a>:</h4>
2301
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2302<p>Again the attributes declaration includes their content definition:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2303
2304<p><code>&lt;!ATTLIST termdef name CDATA #IMPLIED&gt;</code></p>
2305
2306<p>means that the element <code>termdef</code> can have a <code>name</code>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2307attribute containing text (<code>CDATA</code>) and which is optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2308(<code>#IMPLIED</code>). The attribute value can also be defined within a
2309set:</p>
2310
2311<p><code>&lt;!ATTLIST list type (bullets|ordered|glossary)
2312"ordered"&gt;</code></p>
2313
2314<p>means <code>list</code> element have a <code>type</code> attribute with 3
2315allowed values "bullets", "ordered" or "glossary" and which default to
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2316"ordered" if the attribute is not explicitly specified.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2317
2318<p>The content type of an attribute can be text (<code>CDATA</code>),
2319anchor/reference/references
2320(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
2321(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
2322(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
2323<code>chapter</code> element can have an optional <code>id</code> attribute
2324of type <code>ID</code>, usable for reference from attribute of type
2325IDREF:</p>
2326
2327<p><code>&lt;!ATTLIST chapter id ID #IMPLIED&gt;</code></p>
2328
2329<p>The last value of an attribute definition can be <code>#REQUIRED
2330</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
2331meaning that it is optional, or the default value (possibly prefixed by
2332<code>#FIXED</code> if it is the only allowed).</p>
2333
2334<p>Notes:</p>
2335<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2336 <li>Usually the attributes pertaining to a given element are declared in a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2337 single expression, but it is just a convention adopted by a lot of DTD
2338 writers:
2339 <pre>&lt;!ATTLIST termdef
2340 id ID #REQUIRED
2341 name CDATA #IMPLIED&gt;</pre>
2342 <p>The previous construct defines both <code>id</code> and
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2343 <code>name</code> attributes for the element <code>termdef</code>.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2344 </li>
2345</ul>
2346
2347<h3><a name="Some1">Some examples</a></h3>
2348
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2349<p>The directory <code>test/valid/dtds/</code> in the libxml2 distribution
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2350contains some complex DTD examples. The example in the file
2351<code>test/valid/dia.xml</code> shows an XML file where the simple DTD is
2352directly included within the document.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2353
2354<h3><a name="validate1">How to validate</a></h3>
2355
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2356<p>The simplest way is to use the xmllint program included with libxml. The
2357<code>--valid</code> option turns-on validation of the files given as input.
2358For example the following validates a copy of the first revision of the XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]23591.0 specification:</p>
2360
2361<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
2362
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2363<p>the -- noout is used to disable output of the resulting tree.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2364
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2365<p>The <code>--dtdvalid dtd</code> allows validation of the document(s)
2366against a given DTD.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2367
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2368<p>Libxml2 exports an API to handle DTDs and validation, check the <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2369href="http://xmlsoft.org/html/libxml-valid.html">associated
2370description</a>.</p>
2371
2372<h3><a name="Other1">Other resources</a></h3>
2373
2374<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
2375will just list one for now, others pointers welcome:</p>
2376<ul>
2377 <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
2378</ul>
2379
2380<p>I suggest looking at the examples found under test/valid/dtd and any of
2381the large number of books available on XML. The dia example in test/valid
2382should be both simple and complete enough to allow you to build your own.</p>
2383
2384<p></p>
2385
2386<h2><a name="Memory">Memory Management</a></h2>
2387
2388<p>Table of Content:</p>
2389<ol>
2390 <li><a href="#General3">General overview</a></li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2391 <li><a href="#setting">Setting libxml2 set of memory routines</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2392 <li><a href="#cleanup">Cleaning up after parsing</a></li>
2393 <li><a href="#Debugging">Debugging routines</a></li>
2394 <li><a href="#General4">General memory requirements</a></li>
2395</ol>
2396
2397<h3><a name="General3">General overview</a></h3>
2398
2399<p>The module <code><a
2400href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2401provides the interfaces to the libxml2 memory system:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2402<ul>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2403 <li>libxml2 does not use the libc memory allocator directly but xmlFree(),
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2404 xmlMalloc() and xmlRealloc()</li>
2405 <li>those routines can be reallocated to a specific set of routine, by
2406 default the libc ones i.e. free(), malloc() and realloc()</li>
2407 <li>the xmlmemory.c module includes a set of debugging routine</li>
2408</ul>
2409
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2410<h3><a name="setting">Setting libxml2 set of memory routines</a></h3>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2411
2412<p>It is sometimes useful to not use the default memory allocator, either for
2413debugging, analysis or to implement a specific behaviour on memory management
2414(like on embedded systems). Two function calls are available to do so:</p>
2415<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2416 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet
2417 ()</a> which return the current set of functions in use by the parser</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2418 <li><a
2419 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2420 which allow to set up a new set of memory allocation functions</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2421</ul>
2422
2423<p>Of course a call to xmlMemSetup() should probably be done before calling
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2424any other libxml2 routines (unless you are sure your allocations routines are
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2425compatibles).</p>
2426
2427<h3><a name="cleanup">Cleaning up after parsing</a></h3>
2428
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2429<p>Libxml2 is not stateless, there is a few set of memory structures needing
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2430allocation before the parser is fully functional (some encoding structures
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2431for example). This also mean that once parsing is finished there is a tiny
2432amount of memory (a few hundred bytes) which can be recollected if you don't
2433reuse the parser immediately:</p>
2434<ul>
2435 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2436 ()</a> is a centralized routine to free the parsing states. Note that it
2437 won't deallocate any produced tree if any (use the xmlFreeDoc() and
2438 related routines for this).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2439 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2440 ()</a> is the dual routine allowing to preallocate the parsing state
2441 which can be useful for example to avoid initialization reentrancy
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2442 problems when using libxml2 in multithreaded applications</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2443</ul>
2444
2445<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
2446at the next invocation of parser routines, but be careful of the consequences
2447in multithreaded applications.</p>
2448
2449<h3><a name="Debugging">Debugging routines</a></h3>
2450
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2451<p>When configured using --with-mem-debug flag (off by default), libxml2 uses
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2452a set of memory allocation debugging routines keeping track of all allocated
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2453blocks and the location in the code where the routine was called. A couple of
2454other debugging routines allow to dump the memory allocated infos to a file
2455or call a specific routine when a given block number is allocated:</p>
2456<ul>
2457 <li><a
2458 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2459 <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2460 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
2461 and <a
2462 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
2463 are the memory debugging replacement allocation routines</li>
2464 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2465 ()</a> dumps all the informations about the allocated memory block lefts
2466 in the <code>.memdump</code> file</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2467</ul>
2468
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2469<p>When developing libxml2 memory debug is enabled, the tests programs call
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2470xmlMemoryDump () and the "make test" regression tests will check for any
2471memory leak during the full regression test sequence, this helps a lot
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2472ensuring that libxml2 does not leak memory and bullet proof memory
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2473allocations use (some libc implementations are known to be far too permissive
2474resulting in major portability problems!).</p>
2475
2476<p>If the .memdump reports a leak, it displays the allocation function and
2477also tries to give some informations about the content and structure of the
2478allocated blocks left. This is sufficient in most cases to find the culprit,
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2479but not always. Assuming the allocation problem is reproducible, it is
2480possible to find more easily:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2481<ol>
2482 <li>write down the block number xxxx not allocated</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2483 <li>export the environment variable XML_MEM_BREAKPOINT=xxxx , the easiest
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2484 when using GDB is to simply give the command
2485 <p><code>set environment XML_MEM_BREAKPOINT xxxx</code></p>
2486 <p>before running the program.</p>
2487 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2488 <li>run the program under a debugger and set a breakpoint on
2489 xmlMallocBreakpoint() a specific function called when this precise block
2490 is allocated</li>
2491 <li>when the breakpoint is reached you can then do a fine analysis of the
2492 allocation an step to see the condition resulting in the missing
2493 deallocation.</li>
2494</ol>
2495
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2496<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]2497noticing that it was not detecting memory leaks that simple mechanism was
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2498used and proved extremely efficient until now. Lately I have also used <a
2499href="http://developer.kde.org/~sewardj/">valgrind</a> with quite some
2500success, it is tied to the i386 architecture since it works by emulating the
2501processor and instruction set, it is slow but extremely efficient, i.e. it
2502spot memory usage errors in a very precise way.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2503
2504<h3><a name="General4">General memory requirements</a></h3>
2505
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2506<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]2507of a number of things:</p>
2508<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2509 <li>the parser itself should work in a fixed amount of memory, except for
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2510 information maintained about the stacks of names and entities locations.
2511 The I/O and encoding handlers will probably account for a few KBytes.
2512 This is true for both the XML and HTML parser (though the HTML parser
2513 need more state).</li>
2514 <li>If you are generating the DOM tree then memory requirements will grow
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2515 nearly linear with the size of the data. In general for a balanced
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2516 textual document the internal memory requirement is about 4 times the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2517 size of the UTF8 serialization of this document (example the XML-1.0
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2518 recommendation is a bit more of 150KBytes and takes 650KBytes of main
2519 memory when parsed). Validation will add a amount of memory required for
2520 maintaining the external Dtd state which should be linear with the
2521 complexity of the content model defined by the Dtd</li>
Daniel Veillardce192eb2003-04-16 15:58:05 +0000[diff] [blame]2522 <li>If you need to work with fixed memory requirements or don't need the
2523 full DOM tree then using the <a href="xmlreader.html">xmlReader
2524 interface</a> is probably the best way to proceed, it still allows to
2525 validate or operate on subset of the tree if needed.</li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2526 <li>If you don't care about the advanced features of libxml2 like
Daniel Veillardce192eb2003-04-16 15:58:05 +0000[diff] [blame]2527 validation, DOM, XPath or XPointer, don't use entities, need to work with
2528 fixed memory requirements, and try to get the fastest parsing possible
2529 then the SAX interface should be used, but it has known restrictions.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2530</ul>
2531
2532<p></p>
2533
2534<h2><a name="Encodings">Encodings support</a></h2>
2535
2536<p>Table of Content:</p>
2537<ol>
2538 <li><a href="encoding.html#What">What does internationalization support
2539 mean ?</a></li>
2540 <li><a href="encoding.html#internal">The internal encoding, how and
2541 why</a></li>
2542 <li><a href="encoding.html#implemente">How is it implemented ?</a></li>
2543 <li><a href="encoding.html#Default">Default supported encodings</a></li>
2544 <li><a href="encoding.html#extend">How to extend the existing
2545 support</a></li>
2546</ol>
2547
2548<h3><a name="What">What does internationalization support mean ?</a></h3>
2549
Daniel Veillard238836e2003-04-07 22:57:29 +0000[diff] [blame]2550<p>If you are not really familiar with Internationalization (usual shorcut is
2551I18N) , Unicode, characters and glyphs, I suggest you read a <a
2552href="http://www.tbray.org/ongoing/When/200x/2003/04/06/Unicode">presentation</a>
2553by Tim Bray on Unicode and why you should care about it.</p>
2554
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2555<p>XML was designed from the start to allow the support of any character set
2556by using Unicode. Any conformant XML parser has to support the UTF-8 and
2557UTF-16 default encodings which can both express the full unicode ranges. UTF8
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2558is a variable length encoding whose greatest points are to reuse the same
2559encoding for ASCII and to save space for Western encodings, but it is a bit
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2560more complex to handle in practice. UTF-16 use 2 bytes per characters (and
2561sometimes combines two pairs), it makes implementation easier, but looks a
2562bit overkill for Western languages encoding. Moreover the XML specification
2563allows document to be encoded in other encodings at the condition that they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2564are clearly labeled as such. For example the following is a wellformed XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2565document encoded in ISO-8859 1 and using accentuated letter that we French
2566likes for both markup and content:</p>
2567<pre>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2568&lt;très&gt;là&lt;/très&gt;</pre>
2569
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2570<p>Having internationalization support in libxml2 means the following:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2571<ul>
2572 <li>the document is properly parsed</li>
2573 <li>informations about it's encoding are saved</li>
2574 <li>it can be modified</li>
2575 <li>it can be saved in its original encoding</li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2576 <li>it can also be saved in another encoding supported by libxml2 (for
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2577 example straight UTF8 or even an ASCII form)</li>
2578</ul>
2579
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2580<p>Another very important point is that the whole libxml2 API, with the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2581exception of a few routines to read with a specific encoding or save to a
2582specific encoding, is completely agnostic about the original encoding of the
2583document.</p>
2584
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2585<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]2586the 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]2587an internationalized fashion by libxml2 too:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2588<pre>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
2589 "http://www.w3.org/TR/REC-html40/loose.dtd"&gt;
2590&lt;html lang="fr"&gt;
2591&lt;head&gt;
2592 &lt;META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&gt;
2593&lt;/head&gt;
2594&lt;body&gt;
2595&lt;p&gt;W3C crée des standards pour le Web.&lt;/body&gt;
2596&lt;/html&gt;</pre>
2597
2598<h3><a name="internal">The internal encoding, how and why</a></h3>
2599
2600<p>One of the core decision was to force all documents to be converted to a
2601default internal encoding, and that encoding to be UTF-8, here are the
2602rationale for those choices:</p>
2603<ul>
2604 <li>keeping the native encoding in the internal form would force the libxml
2605 users (or the code associated) to be fully aware of the encoding of the
2606 original document, for examples when adding a text node to a document,
2607 the content would have to be provided in the document encoding, i.e. the
2608 client code would have to check it before hand, make sure it's conformant
2609 to the encoding, etc ... Very hard in practice, though in some specific
2610 cases this may make sense.</li>
2611 <li>the second decision was which encoding. From the XML spec only UTF8 and
2612 UTF16 really makes sense as being the two only encodings for which there
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2613 is mandatory support. UCS-4 (32 bits fixed size encoding) could be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2614 considered an intelligent choice too since it's a direct Unicode mapping
2615 support. I selected UTF-8 on the basis of efficiency and compatibility
2616 with surrounding software:
2617 <ul>
2618 <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
2619 more costly to import and export CPU wise) is also far more compact
2620 than UTF-16 (and UCS-4) for a majority of the documents I see it used
2621 for right now (RPM RDF catalogs, advogato data, various configuration
2622 file formats, etc.) and the key point for today's computer
2623 architecture is efficient uses of caches. If one nearly double the
2624 memory requirement to store the same amount of data, this will trash
2625 caches (main memory/external caches/internal caches) and my take is
2626 that this harms the system far more than the CPU requirements needed
2627 for the conversion to UTF-8</li>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2628 <li>Most of libxml2 version 1 users were using it with straight ASCII
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2629 most of the time, doing the conversion with an internal encoding
2630 requiring all their code to be rewritten was a serious show-stopper
2631 for using UTF-16 or UCS-4.</li>
2632 <li>UTF-8 is being used as the de-facto internal encoding standard for
2633 related code like the <a href="http://www.pango.org/">pango</a>
2634 upcoming Gnome text widget, and a lot of Unix code (yep another place
2635 where Unix programmer base takes a different approach from Microsoft
2636 - they are using UTF-16)</li>
2637 </ul>
2638 </li>
2639</ul>
2640
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2641<p>What does this mean in practice for the libxml2 user:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2642<ul>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2643 <li>xmlChar, the libxml2 data type is a byte, those bytes must be assembled
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2644 as UTF-8 valid strings. The proper way to terminate an xmlChar * string
2645 is simply to append 0 byte, as usual.</li>
2646 <li>One just need to make sure that when using chars outside the ASCII set,
2647 the values has been properly converted to UTF-8</li>
2648</ul>
2649
2650<h3><a name="implemente">How is it implemented ?</a></h3>
2651
2652<p>Let's describe how all this works within libxml, basically the I18N
2653(internationalization) support get triggered only during I/O operation, i.e.
2654when reading a document or saving one. Let's look first at the reading
2655sequence:</p>
2656<ol>
2657 <li>when a document is processed, we usually don't know the encoding, a
2658 simple heuristic allows to detect UTF-18 and UCS-4 from whose where the
2659 ASCII range (0-0x7F) maps with ASCII</li>
2660 <li>the xml declaration if available is parsed, including the encoding
2661 declaration. At that point, if the autodetected encoding is different
2662 from the one declared a call to xmlSwitchEncoding() is issued.</li>
2663 <li>If there is no encoding declaration, then the input has to be in either
2664 UTF-8 or UTF-16, if it is not then at some point when processing the
2665 input, the converter/checker of UTF-8 form will raise an encoding error.
2666 You may end-up with a garbled document, or no document at all ! Example:
2667 <pre>~/XML -&gt; ./xmllint err.xml
2668err.xml:1: error: Input is not proper UTF-8, indicate encoding !
2669&lt;très&gt;là&lt;/très&gt;
2670 ^
2671err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
2672&lt;très&gt;là&lt;/très&gt;
2673 ^</pre>
2674 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2675 <li>xmlSwitchEncoding() does an encoding name lookup, canonicalize it, and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2676 then search the default registered encoding converters for that encoding.
2677 If it's not within the default set and iconv() support has been compiled
2678 it, it will ask iconv for such an encoder. If this fails then the parser
2679 will report an error and stops processing:
2680 <pre>~/XML -&gt; ./xmllint err2.xml
2681err2.xml:1: error: Unsupported encoding UnsupportedEnc
2682&lt;?xml version="1.0" encoding="UnsupportedEnc"?&gt;
2683 ^</pre>
2684 </li>
Daniel Veillard46c5c1d2002-05-20 07:15:54 +0000[diff] [blame]2685 <li>From that point the encoder processes progressively the input (it is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2686 plugged as a front-end to the I/O module) for that entity. It captures
2687 and convert on-the-fly the document to be parsed to UTF-8. The parser
2688 itself just does UTF-8 checking of this input and process it
2689 transparently. The only difference is that the encoding information has
2690 been added to the parsing context (more precisely to the input
2691 corresponding to this entity).</li>
2692 <li>The result (when using DOM) is an internal form completely in UTF-8
2693 with just an encoding information on the document node.</li>
2694</ol>
2695
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2696<p>Ok then what happens when saving the document (assuming you
2697collected/built an xmlDoc DOM like structure) ? It depends on the function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2698called, xmlSaveFile() will just try to save in the original encoding, while
2699xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
2700encoding:</p>
2701<ol>
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2702 <li>if no encoding is given, libxml2 will look for an encoding value
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2703 associated to the document and if it exists will try to save to that
2704 encoding,
2705 <p>otherwise everything is written in the internal form, i.e. UTF-8</p>
2706 </li>
2707 <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]2708 document, libxml2 will again canonicalize the encoding name, lookup for a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2709 converter in the registered set or through iconv. If not found the
2710 function will return an error code</li>
2711 <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]2712 buffer, then libxml2 will simply push the UTF-8 serialization to through
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2713 that buffer, which will then progressively be converted and pushed onto
2714 the I/O layer.</li>
2715 <li>It is possible that the converter code fails on some input, for example
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2716 trying to push an UTF-8 encoded Chinese character through the UTF-8 to
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2717 ISO-8859-1 converter won't work. Since the encoders are progressive they
2718 will just report the error and the number of bytes converted, at that
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2719 point libxml2 will decode the offending character, remove it from the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2720 buffer and replace it with the associated charRef encoding &amp;#123; and
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2721 resume the conversion. This guarantees that any document will be saved
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2722 without losses (except for markup names where this is not legal, this is
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2723 a problem in the current version, in practice avoid using non-ascii
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2724 characters for tags or attributes names @@). A special "ascii" encoding
2725 name is used to save documents to a pure ascii form can be used when
2726 portability is really crucial</li>
2727</ol>
2728
2729<p>Here is a few examples based on the same test document:</p>
2730<pre>~/XML -&gt; ./xmllint isolat1
2731&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2732&lt;très&gt;là&lt;/très&gt;
2733~/XML -&gt; ./xmllint --encode UTF-8 isolat1
2734&lt;?xml version="1.0" encoding="UTF-8"?&gt;
2735&lt;très&gt;là  &lt;/très&gt;
2736~/XML -&gt; </pre>
2737
2738<p>The same processing is applied (and reuse most of the code) for HTML I18N
2739processing. Looking up and modifying the content encoding is a bit more
2740difficult since it is located in a &lt;meta&gt; tag under the &lt;head&gt;,
2741so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
2742been provided. The parser also attempts to switch encoding on the fly when
2743detecting such a tag on input. Except for that the processing is the same
2744(and again reuses the same code).</p>
2745
2746<h3><a name="Default">Default supported encodings</a></h3>
2747
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2748<p>libxml2 has a set of default converters for the following encodings
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2749(located in encoding.c):</p>
2750<ol>
2751 <li>UTF-8 is supported by default (null handlers)</li>
2752 <li>UTF-16, both little and big endian</li>
2753 <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
2754 <li>ASCII, useful mostly for saving</li>
2755 <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
2756 predefined entities like &amp;copy; for the Copyright sign.</li>
2757</ol>
2758
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2759<p>More over when compiled on an Unix platform with iconv support the full
2760set of encodings supported by iconv can be instantly be used by libxml. On a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2761linux machine with glibc-2.1 the list of supported encodings and aliases fill
27623 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
2763various Japanese ones.</p>
2764
2765<h4>Encoding aliases</h4>
2766
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2767<p>From 2.2.3, libxml2 has support to register encoding names aliases. The
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2768goal is to be able to parse document whose encoding is supported but where
2769the name differs (for example from the default set of names accepted by
2770iconv). The following functions allow to register and handle new aliases for
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2771existing encodings. Once registered libxml2 will automatically lookup the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2772aliases when handling a document:</p>
2773<ul>
2774 <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li>
2775 <li>int xmlDelEncodingAlias(const char *alias);</li>
2776 <li>const char * xmlGetEncodingAlias(const char *alias);</li>
2777 <li>void xmlCleanupEncodingAliases(void);</li>
2778</ul>
2779
2780<h3><a name="extend">How to extend the existing support</a></h3>
2781
2782<p>Well adding support for new encoding, or overriding one of the encoders
2783(assuming it is buggy) should not be hard, just write an input and output
2784conversion routines to/from UTF-8, and register them using
2785xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
2786called automatically if the parser(s) encounter such an encoding name
2787(register it uppercase, this will help). The description of the encoders,
2788their arguments and expected return values are described in the encoding.h
2789header.</p>
2790
2791<p>A quick note on the topic of subverting the parser to use a different
2792internal encoding than UTF-8, in some case people will absolutely want to
2793keep the internal encoding different, I think it's still possible (but the
2794encoding must be compliant with ASCII on the same subrange) though I didn't
2795tried it. The key is to override the default conversion routines (by
2796registering null encoders/decoders for your charsets), and bypass the UTF-8
2797checking of the parser by setting the parser context charset
2798(ctxt-&gt;charset) to something different than XML_CHAR_ENCODING_UTF8, but
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2799there is no guarantee that this will work. You may also have some troubles
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2800saving back.</p>
2801
2802<p>Basically proper I18N support is important, this requires at least
2803libxml-2.0.0, but a lot of features and corrections are really available only
2804starting 2.2.</p>
2805
2806<h2><a name="IO">I/O Interfaces</a></h2>
2807
2808<p>Table of Content:</p>
2809<ol>
2810 <li><a href="#General1">General overview</a></li>
2811 <li><a href="#basic">The basic buffer type</a></li>
2812 <li><a href="#Input">Input I/O handlers</a></li>
2813 <li><a href="#Output">Output I/O handlers</a></li>
2814 <li><a href="#entities">The entities loader</a></li>
2815 <li><a href="#Example2">Example of customized I/O</a></li>
2816</ol>
2817
2818<h3><a name="General1">General overview</a></h3>
2819
2820<p>The module <code><a
2821href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2822the interfaces to the libxml2 I/O system. This consists of 4 main parts:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2823<ul>
2824 <li>Entities loader, this is a routine which tries to fetch the entities
2825 (files) based on their PUBLIC and SYSTEM identifiers. The default loader
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2826 don't look at the public identifier since libxml2 do not maintain a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2827 catalog. You can redefine you own entity loader by using
2828 <code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2829 <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
2830 example</a>.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2831 <li>Input I/O buffers which are a commodity structure used by the parser(s)
2832 input layer to handle fetching the informations to feed the parser. This
2833 provides buffering and is also a placeholder where the encoding
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2834 converters to UTF8 are piggy-backed.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2835 <li>Output I/O buffers are similar to the Input ones and fulfill similar
2836 task but when generating a serialization from a tree.</li>
2837 <li>A mechanism to register sets of I/O callbacks and associate them with
2838 specific naming schemes like the protocol part of the URIs.
2839 <p>This affect the default I/O operations and allows to use specific I/O
2840 handlers for certain names.</p>
2841 </li>
2842</ul>
2843
2844<p>The general mechanism used when loading http://rpmfind.net/xml.html for
2845example in the HTML parser is the following:</p>
2846<ol>
2847 <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
2848 the parsing context and the URI string.</li>
2849 <li>the URI string is checked against the existing registered handlers
2850 using their match() callback function, if the HTTP module was compiled
2851 in, it is registered and its match() function will succeeds</li>
2852 <li>the open() function of the handler is called and if successful will
2853 return an I/O Input buffer</li>
2854 <li>the parser will the start reading from this buffer and progressively
2855 fetch information from the resource, calling the read() function of the
2856 handler until the resource is exhausted</li>
2857 <li>if an encoding change is detected it will be installed on the input
2858 buffer, providing buffering and efficient use of the conversion
2859 routines</li>
2860 <li>once the parser has finished, the close() function of the handler is
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2861 called once and the Input buffer and associated resources are
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2862 deallocated.</li>
2863</ol>
2864
2865<p>The user defined callbacks are checked first to allow overriding of the
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]2866default libxml2 I/O routines.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2867
2868<h3><a name="basic">The basic buffer type</a></h3>
2869
2870<p>All the buffer manipulation handling is done using the
2871<code>xmlBuffer</code> type define in <code><a
2872href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
2873resizable memory buffer. The buffer allocation strategy can be selected to be
2874either best-fit or use an exponential doubling one (CPU vs. memory use
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2875trade-off). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2876<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
2877system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
2878of functions allows to manipulate buffers with names starting with the
2879<code>xmlBuffer...</code> prefix.</p>
2880
2881<h3><a name="Input">Input I/O handlers</a></h3>
2882
2883<p>An Input I/O handler is a simple structure
2884<code>xmlParserInputBuffer</code> containing a context associated to the
2885resource (file descriptor, or pointer to a protocol handler), the read() and
2886close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
2887encoding handler are also present to support charset conversion when
2888needed.</p>
2889
2890<h3><a name="Output">Output I/O handlers</a></h3>
2891
2892<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
2893Input one except the callbacks are write() and close().</p>
2894
2895<h3><a name="entities">The entities loader</a></h3>
2896
2897<p>The entity loader resolves requests for new entities and create inputs for
2898the parser. Creating an input from a filename or an URI string is done
2899through the xmlNewInputFromFile() routine. The default entity loader do not
2900handle the PUBLIC identifier associated with an entity (if any). So it just
2901calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
2902XML).</p>
2903
2904<p>If you want to hook up a catalog mechanism then you simply need to
2905override the default entity loader, here is an example:</p>
2906<pre>#include &lt;libxml/xmlIO.h&gt;
2907
2908xmlExternalEntityLoader defaultLoader = NULL;
2909
2910xmlParserInputPtr
2911xmlMyExternalEntityLoader(const char *URL, const char *ID,
2912 xmlParserCtxtPtr ctxt) {
2913 xmlParserInputPtr ret;
2914 const char *fileID = NULL;
2915 /* lookup for the fileID depending on ID */
2916
2917 ret = xmlNewInputFromFile(ctxt, fileID);
2918 if (ret != NULL)
2919 return(ret);
2920 if (defaultLoader != NULL)
2921 ret = defaultLoader(URL, ID, ctxt);
2922 return(ret);
2923}
2924
2925int main(..) {
2926 ...
2927
2928 /*
2929 * Install our own entity loader
2930 */
2931 defaultLoader = xmlGetExternalEntityLoader();
2932 xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
2933
2934 ...
2935}</pre>
2936
2937<h3><a name="Example2">Example of customized I/O</a></h3>
2938
2939<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
2940real use case</a>, xmlDocDump() closes the FILE * passed by the application
2941and this was a problem. The <a
2942href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
2943new output handler with the closing call deactivated:</p>
2944<ol>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2945 <li>First define a new I/O output allocator where the output don't close
2946 the file:
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2947 <pre>xmlOutputBufferPtr
2948xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
2949    xmlOutputBufferPtr ret;
2950    
2951    if (xmlOutputCallbackInitialized == 0)
2952        xmlRegisterDefaultOutputCallbacks();
2953
2954    if (file == NULL) return(NULL);
2955    ret = xmlAllocOutputBuffer(encoder);
2956    if (ret != NULL) {
2957        ret-&gt;context = file;
2958        ret-&gt;writecallback = xmlFileWrite;
2959        ret-&gt;closecallback = NULL; /* No close callback */
2960    }
Daniel Veillardf83a2c72003-04-08 13:48:40 +0000[diff] [blame]2961    return(ret);
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2962} </pre>
2963 </li>
2964 <li>And then use it to save the document:
2965 <pre>FILE *f;
2966xmlOutputBufferPtr output;
2967xmlDocPtr doc;
2968int res;
2969
2970f = ...
2971doc = ....
2972
2973output = xmlOutputBufferCreateOwn(f, NULL);
2974res = xmlSaveFileTo(output, doc, NULL);
2975 </pre>
2976 </li>
2977</ol>
2978
2979<h2><a name="Catalog">Catalog support</a></h2>
2980
2981<p>Table of Content:</p>
2982<ol>
2983 <li><a href="General2">General overview</a></li>
2984 <li><a href="#definition">The definition</a></li>
2985 <li><a href="#Simple">Using catalogs</a></li>
2986 <li><a href="#Some">Some examples</a></li>
2987 <li><a href="#reference">How to tune catalog usage</a></li>
2988 <li><a href="#validate">How to debug catalog processing</a></li>
2989 <li><a href="#Declaring">How to create and maintain catalogs</a></li>
2990 <li><a href="#implemento">The implementor corner quick review of the
2991 API</a></li>
2992 <li><a href="#Other">Other resources</a></li>
2993</ol>
2994
2995<h3><a name="General2">General overview</a></h3>
2996
2997<p>What is a catalog? Basically it's a lookup mechanism used when an entity
2998(a file or a remote resource) references another entity. The catalog lookup
2999is inserted between the moment the reference is recognized by the software
3000(XML parser, stylesheet processing, or even images referenced for inclusion
3001in a rendering) and the time where loading that resource is actually
3002started.</p>
3003
3004<p>It is basically used for 3 things:</p>
3005<ul>
3006 <li>mapping from "logical" names, the public identifiers and a more
3007 concrete name usable for download (and URI). For example it can associate
3008 the logical name
3009 <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
3010 <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
3011 downloaded</p>
3012 <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
3013 </li>
3014 <li>remapping from a given URL to another one, like an HTTP indirection
3015 saying that
3016 <p>"http://www.oasis-open.org/committes/tr.xsl"</p>
3017 <p>should really be looked at</p>
3018 <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
3019 </li>
3020 <li>providing a local cache mechanism allowing to load the entities
3021 associated to public identifiers or remote resources, this is a really
3022 important feature for any significant deployment of XML or SGML since it
3023 allows to avoid the aleas and delays associated to fetching remote
3024 resources.</li>
3025</ul>
3026
3027<h3><a name="definition">The definitions</a></h3>
3028
3029<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
3030<ul>
3031 <li>the older SGML catalogs, the official spec is SGML Open Technical
3032 Resolution TR9401:1997, but is better understood by reading <a
3033 href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
3034 James Clark. This is relatively old and not the preferred mode of
3035 operation of libxml.</li>
3036 <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3037 Catalogs</a> is far more flexible, more recent, uses an XML syntax and
3038 should scale quite better. This is the default option of libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3039</ul>
3040
3041<p></p>
3042
3043<h3><a name="Simple">Using catalog</a></h3>
3044
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3045<p>In a normal environment libxml2 will by default check the presence of a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3046catalog in /etc/xml/catalog, and assuming it has been correctly populated,
3047the processing is completely transparent to the document user. To take a
3048concrete example, suppose you are authoring a DocBook document, this one
3049starts with the following DOCTYPE definition:</p>
3050<pre>&lt;?xml version='1.0'?&gt;
3051&lt;!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
3052 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"&gt;</pre>
3053
3054<p>When validating the document with libxml, the catalog will be
3055automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
3056DocBk XML V3.1.4//EN" and the system identifier
3057"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
3058been installed on your system and the catalogs actually point to them, libxml
3059will fetch them from the local disk.</p>
3060
3061<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
3062DOCTYPE example it's a really old version, but is fine as an example.</p>
3063
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3064<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]3065entity, this includes DTD, external parsed entities, stylesheets, etc ... If
3066your system is correctly configured all the authoring phase and processing
3067should use only local files, even if your document stays portable because it
3068uses the canonical public and system ID, referencing the remote document.</p>
3069
3070<h3><a name="Some">Some examples:</a></h3>
3071
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3072<p>Here is a couple of fragments from XML Catalogs used in libxml2 early
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3073regression tests in <code>test/catalogs</code> :</p>
3074<pre>&lt;?xml version="1.0"?&gt;
3075&lt;!DOCTYPE catalog PUBLIC
3076 "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
3077 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
3078&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
3079 &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
3080 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
3081...</pre>
3082
3083<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
3084written in XML, there is a specific namespace for catalog elements
3085"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
3086catalog is a <code>public</code> mapping it allows to associate a Public
3087Identifier with an URI.</p>
3088<pre>...
3089 &lt;rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
3090 rewritePrefix="file:///usr/share/xml/docbook/"/&gt;
3091...</pre>
3092
3093<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
3094any URI starting with a given prefix should be looked at another URI
3095constructed by replacing the prefix with an new one. In effect this acts like
3096a cache system for a full area of the Web. In practice it is extremely useful
3097with a file prefix if you have installed a copy of those resources on your
3098local system.</p>
3099<pre>...
3100&lt;delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
3101 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3102&lt;delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
3103 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3104&lt;delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
3105 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3106&lt;delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
3107 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3108&lt;delegateURI uriStartString="http://www.oasis-open.org/docbook/"
3109 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3110...</pre>
3111
3112<p>Delegation is the core features which allows to build a tree of catalogs,
3113easier to maintain than a single catalog, based on Public Identifier, System
3114Identifier or URI prefixes it instructs the catalog software to look up
3115entries in another resource. This feature allow to build hierarchies of
3116catalogs, the set of entries presented should be sufficient to redirect the
3117resolution of all DocBook references to the specific catalog in
3118<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
3119references for DocBook 4.2.1 to a specific catalog installed at the same time
3120as the DocBook resources on the local machine.</p>
3121
3122<h3><a name="reference">How to tune catalog usage:</a></h3>
3123
3124<p>The user can change the default catalog behaviour by redirecting queries
3125to its own set of catalogs, this can be done by setting the
3126<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
3127empty one should deactivate loading the default <code>/etc/xml/catalog</code>
3128default catalog</p>
3129
3130<h3><a name="validate">How to debug catalog processing:</a></h3>
3131
3132<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3133make libxml2 output debugging informations for each catalog operations, for
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3134example:</p>
3135<pre>orchis:~/XML -&gt; xmllint --memory --noout test/ent2
3136warning: failed to load external entity "title.xml"
3137orchis:~/XML -&gt; export XML_DEBUG_CATALOG=
3138orchis:~/XML -&gt; xmllint --memory --noout test/ent2
3139Failed to parse catalog /etc/xml/catalog
3140Failed to parse catalog /etc/xml/catalog
3141warning: failed to load external entity "title.xml"
3142Catalogs cleanup
3143orchis:~/XML -&gt; </pre>
3144
3145<p>The test/ent2 references an entity, running the parser from memory makes
3146the base URI unavailable and the the "title.xml" entity cannot be loaded.
3147Setting up the debug environment variable allows to detect that an attempt is
3148made to load the <code>/etc/xml/catalog</code> but since it's not present the
3149resolution fails.</p>
3150
3151<p>But the most advanced way to debug XML catalog processing is to use the
3152<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
3153catalogs and make resolution queries to see what is going on. This is also
3154used for the regression tests:</p>
3155<pre>orchis:~/XML -&gt; ./xmlcatalog test/catalogs/docbook.xml \
3156 "-//OASIS//DTD DocBook XML V4.1.2//EN"
3157http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
3158orchis:~/XML -&gt; </pre>
3159
3160<p>For debugging what is going on, adding one -v flags increase the verbosity
3161level to indicate the processing done (adding a second flag also indicate
3162what elements are recognized at parsing):</p>
3163<pre>orchis:~/XML -&gt; ./xmlcatalog -v test/catalogs/docbook.xml \
3164 "-//OASIS//DTD DocBook XML V4.1.2//EN"
3165Parsing catalog test/catalogs/docbook.xml's content
3166Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
3167http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
3168Catalogs cleanup
3169orchis:~/XML -&gt; </pre>
3170
3171<p>A shell interface is also available to debug and process multiple queries
3172(and for regression tests):</p>
3173<pre>orchis:~/XML -&gt; ./xmlcatalog -shell test/catalogs/docbook.xml \
3174 "-//OASIS//DTD DocBook XML V4.1.2//EN"
3175&gt; help
3176Commands available:
3177public PublicID: make a PUBLIC identifier lookup
3178system SystemID: make a SYSTEM identifier lookup
3179resolve PublicID SystemID: do a full resolver lookup
3180add 'type' 'orig' 'replace' : add an entry
3181del 'values' : remove values
3182dump: print the current catalog state
3183debug: increase the verbosity level
3184quiet: decrease the verbosity level
3185exit: quit the shell
3186&gt; public "-//OASIS//DTD DocBook XML V4.1.2//EN"
3187http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
3188&gt; quit
3189orchis:~/XML -&gt; </pre>
3190
3191<p>This should be sufficient for most debugging purpose, this was actually
3192used heavily to debug the XML Catalog implementation itself.</p>
3193
3194<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
3195
3196<p>Basically XML Catalogs are XML files, you can either use XML tools to
3197manage them or use <strong>xmlcatalog</strong> for this. The basic step is
3198to create a catalog the -create option provide this facility:</p>
3199<pre>orchis:~/XML -&gt; ./xmlcatalog --create tst.xml
3200&lt;?xml version="1.0"?&gt;
3201&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
3202 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
3203&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
3204orchis:~/XML -&gt; </pre>
3205
3206<p>By default xmlcatalog does not overwrite the original catalog and save the
3207result on the standard output, this can be overridden using the -noout
3208option. The <code>-add</code> command allows to add entries in the
3209catalog:</p>
3210<pre>orchis:~/XML -&gt; ./xmlcatalog --noout --create --add "public" \
3211 "-//OASIS//DTD DocBook XML V4.1.2//EN" \
3212 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
3213orchis:~/XML -&gt; cat tst.xml
3214&lt;?xml version="1.0"?&gt;
3215&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
3216 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
3217&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
3218&lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
3219 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
3220&lt;/catalog&gt;
3221orchis:~/XML -&gt; </pre>
3222
3223<p>The <code>-add</code> option will always take 3 parameters even if some of
3224the XML Catalog constructs (like nextCatalog) will have only a single
3225argument, just pass a third empty string, it will be ignored.</p>
3226
3227<p>Similarly the <code>-del</code> option remove matching entries from the
3228catalog:</p>
3229<pre>orchis:~/XML -&gt; ./xmlcatalog --del \
3230 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
3231&lt;?xml version="1.0"?&gt;
3232&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
3233 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
3234&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
3235orchis:~/XML -&gt; </pre>
3236
3237<p>The catalog is now empty. Note that the matching of <code>-del</code> is
3238exact and would have worked in a similar fashion with the Public ID
3239string.</p>
3240
3241<p>This is rudimentary but should be sufficient to manage a not too complex
3242catalog tree of resources.</p>
3243
3244<h3><a name="implemento">The implementor corner quick review of the
3245API:</a></h3>
3246
3247<p>First, and like for every other module of libxml, there is an
3248automatically generated <a href="html/libxml-catalog.html">API page for
3249catalog support</a>.</p>
3250
3251<p>The header for the catalog interfaces should be included as:</p>
3252<pre>#include &lt;libxml/catalog.h&gt;</pre>
3253
3254<p>The API is voluntarily kept very simple. First it is not obvious that
3255applications really need access to it since it is the default behaviour of
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]3256libxml2 (Note: it is possible to completely override libxml2 default catalog
3257by using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3258plug an application specific resolver).</p>
3259
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3260<p>Basically libxml2 support 2 catalog lists:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3261<ul>
3262 <li>the default one, global shared by all the application</li>
3263 <li>a per-document catalog, this one is built if the document uses the
3264 <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
3265 associated to the parser context and destroyed when the parsing context
3266 is destroyed.</li>
3267</ul>
3268
3269<p>the document one will be used first if it exists.</p>
3270
3271<h4>Initialization routines:</h4>
3272
3273<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
3274used at startup to initialize the catalog, if the catalog should be
3275initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
3276should be called before xmlInitializeCatalog() which would otherwise do a
3277default initialization first.</p>
3278
3279<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
3280own catalog list if needed.</p>
3281
3282<h4>Preferences setup:</h4>
3283
3284<p>The XML Catalog spec requires the possibility to select default
3285preferences between public and system delegation,
3286xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
3287xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
3288be forbidden, allowed for global catalog, for document catalog or both, the
3289default is to allow both.</p>
3290
3291<p>And of course xmlCatalogSetDebug() allows to generate debug messages
3292(through the xmlGenericError() mechanism).</p>
3293
3294<h4>Querying routines:</h4>
3295
3296<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
3297and xmlCatalogResolveURI() are relatively explicit if you read the XML
3298Catalog specification they correspond to section 7 algorithms, they should
3299also work if you have loaded an SGML catalog with a simplified semantic.</p>
3300
3301<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
3302operate on the document catalog list</p>
3303
3304<h4>Cleanup and Miscellaneous:</h4>
3305
3306<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
3307the per-document equivalent.</p>
3308
3309<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
3310first catalog in the global list, and xmlCatalogDump() allows to dump a
3311catalog state, those routines are primarily designed for xmlcatalog, I'm not
3312sure that exposing more complex interfaces (like navigation ones) would be
3313really useful.</p>
3314
3315<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
3316it's similar as xmlParseFile() except it bypass all catalog lookups, it's
3317provided because this functionality may be useful for client tools.</p>
3318
3319<h4>threaded environments:</h4>
3320
3321<p>Since the catalog tree is built progressively, some care has been taken to
3322try to avoid troubles in multithreaded environments. The code is now thread
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3323safe assuming that the libxml2 library has been compiled with threads
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3324support.</p>
3325
3326<p></p>
3327
3328<h3><a name="Other">Other resources</a></h3>
3329
3330<p>The XML Catalog specification is relatively recent so there isn't much
3331literature to point at:</p>
3332<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3333 <li>You can find a good rant from Norm Walsh about <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3334 href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
3335 need for catalogs</a>, it provides a lot of context informations even if
Daniel Veillard93d3a472002-04-26 14:04:55 +0000[diff] [blame]3336 I don't agree with everything presented. Norm also wrote a more recent
3337 article <a
3338 href="http://wwws.sun.com/software/xml/developers/resolver/article/">XML
3339 entities and URI resolvers</a> describing them.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3340 <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
3341 catalog proposal</a> from John Cowan</li>
3342 <li>The <a href="http://www.rddl.org/">Resource Directory Description
3343 Language</a> (RDDL) another catalog system but more oriented toward
3344 providing metadata for XML namespaces.</li>
3345 <li>the page from the OASIS Technical <a
3346 href="http://www.oasis-open.org/committees/entity/">Committee on Entity
3347 Resolution</a> who maintains XML Catalog, you will find pointers to the
3348 specification update, some background and pointers to others tools
3349 providing XML Catalog support</li>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3350 <li>Here is a <a href="buildDocBookCatalog">shell script</a> to generate
3351 XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
3352 directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
3353 the resources found on the system. Otherwise it will just create
3354 ~/xmlcatalog and ~/dbkxmlcatalog and doing:
Daniel Veillard8594de92003-04-25 10:08:44 +0000[diff] [blame]3355 <p><code>export XML_CATALOG_FILES=$HOME/xmlcatalog</code></p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3356 <p>should allow to process DocBook documentations without requiring
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3357 network accesses for the DTD or stylesheets</p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3358 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3359 <li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3360 small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
3361 to work fine for me too</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3362 <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
3363 manual page</a></li>
3364</ul>
3365
3366<p>If you have suggestions for corrections or additions, simply contact
3367me:</p>
3368
3369<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3370
3371<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3372using the XML tollkit from the C language. It is not intended to be
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3373extensive. I hope the automatically generated documents will provide the
3374completeness required, but as a separate set of documents. The interfaces of
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]3375the XML parser are by principle low level, Those interested in a higher level
3376API should <a href="#DOM">look at DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3377
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3378<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
3379separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3380interfaces</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]3381
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3382<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3383
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3384<p>Usually, the first thing to do is to read an XML input. The parser accepts
3385documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3386defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3387<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3388 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3389 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3390 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3391</dl>
3392<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3393 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3394 <dd><p>Parse an XML document contained in a (possibly compressed)
3395 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3396 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3397</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3398
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3399<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]3400failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3401
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3402<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3403
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3404<p>In order for the application to keep the control when the document is
Daniel Veillard560c2a42003-07-06 21:13:49 +0000[diff] [blame]3405being fetched (which is common for GUI based programs) libxml2 provides a
3406push interface, too, as of version 1.8.3. Here are the interface
3407functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3408<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
3409 void *user_data,
3410 const char *chunk,
3411 int size,
3412 const char *filename);
3413int xmlParseChunk (xmlParserCtxtPtr ctxt,
3414 const char *chunk,
3415 int size,
3416 int terminate);</pre>
3417
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3418<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3419<pre> FILE *f;
3420
3421 f = fopen(filename, "r");
3422 if (f != NULL) {
3423 int res, size = 1024;
3424 char chars[1024];
3425 xmlParserCtxtPtr ctxt;
3426
3427 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3428 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3429 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
3430 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3431 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3432 xmlParseChunk(ctxt, chars, res, 0);
3433 }
3434 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3435 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3436 xmlFreeParserCtxt(ctxt);
3437 }
3438 }</pre>
3439
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3440<p>The HTML parser embedded into libxml2 also has a push interface; the
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3441functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3442
3443<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
3444
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3445<p>The tree-building interface makes the parser memory-hungry, first loading
3446the document in memory and then building the tree itself. Reading a document
3447without building the tree is possible using the SAX interfaces (see SAX.h and
3448<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]3449Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3450limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3451<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3452
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3453<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3454
3455<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]3456there is a set of functions dedicated to building new elements. (These are
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3457also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of
3458code that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3459<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3460 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3461 xmlNodePtr tree, subtree;
3462
3463 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3464 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
3465 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
3466 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
3467 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3468 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3469 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3470 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
3471 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
3472 subtree = xmlNewChild(tree, NULL, "image", NULL);
3473 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3474
3475<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3476
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3477<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3478
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3479<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3480code has access to the internal structure of all the elements of the tree.
3481The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]3482<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3483<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3484example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3485<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3486
3487<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3488<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3489
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3490<p>points to the text node containing the chapter title "The Linux
3491adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3492
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3493<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]3494present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3495to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]3496<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3497
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3498<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3499
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3500<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3501is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3502<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3503 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
3504 xmlChar *value);</code></dt>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3505 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
3506 The value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3507 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3508</dl>
3509<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3510 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3511 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]3512 <dd><p>This function returns a pointer to new copy of the property
3513 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3514 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3515</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3516
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3517<p>Two functions are provided for reading and writing the text associated
3518with elements:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3519<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3520 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3521 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3522 <dd><p>This function takes an "external" string and converts it to one
3523 text node or possibly to a list of entity and text nodes. All
3524 non-predefined entity references like &amp;Gnome; will be stored
3525 internally as entity nodes, hence the result of the function may not be
3526 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3527 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3528</dl>
3529<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3530 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3531 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3532 <dd><p>This function is the inverse of
3533 <code>xmlStringGetNodeList()</code>. It generates a new string
3534 containing the content of the text and entity nodes. Note the extra
3535 argument inLine. If this argument is set to 1, the function will expand
3536 entity references. For example, instead of returning the &amp;Gnome;
3537 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3538 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3539 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3540</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3541
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3542<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3543
3544<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3545<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3546 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3547 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3548 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3549 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3550</dl>
3551<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3552 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3553 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3554 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3555</dl>
3556<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3557 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3558 <dd><p>Saves the document to a file. In this case, the compression
3559 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3560 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3561</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3562
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3563<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3564
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3565<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3566accesses. The level of compression on saves can be turned on either globally
3567or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3568<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3569 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3570 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3571 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3572</dl>
3573<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3574 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3575 <dd><p>Sets the document compression ratio.</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>
3578<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3579 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3580 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3581 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3582</dl>
3583<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3584 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3585 <dd><p>Sets the default compression ratio.</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
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3589<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3590
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3591<p>Entities in principle are similar to simple C macros. An entity defines an
3592abbreviation for a given string that you can reuse many times throughout the
3593content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3594may occur frequently within a document, or to confine the change needed to a
3595document to a restricted area in the internal subset of the document (at the
3596beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3597<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]35982 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]35993 &lt;!ENTITY xml "Extensible Markup Language"&gt;
36004 ]&gt;
36015 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]36026 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]36037 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3604
3605<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]3606its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3607are 5 predefined entities in libxml2 allowing you to escape characters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3608predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3609<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3610for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3611<strong>&amp;quot;</strong> for the character '"', and
3612<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3613
3614<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]3615substitute an entity's content so that you can see the replacement text in
3616your application. Or you may prefer to keep entity references as such in the
3617content to be able to save the document back without losing this usually
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3618precious information (if the user went through the pain of explicitly
3619defining entities, he may have a a rather negative attitude if you blindly
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3620substitute them as saving time). The <a
Daniel Veillard5373ea12003-07-24 13:09:13 +0000[diff] [blame^]3621href="html/libxml-parser.html#xmlSubstituteEntitiesDefault">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3622function allows you to check and change the behaviour, which is to not
3623substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3624
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3625<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]3626default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3627<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3628DOCUMENT
3629version=1.0
3630 ELEMENT EXAMPLE
3631 TEXT
3632 content=
3633 ENTITY_REF
3634 INTERNAL_GENERAL_ENTITY xml
3635 content=Extensible Markup Language
3636 TEXT
3637 content=</pre>
3638
3639<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3640<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3641DOCUMENT
3642version=1.0
3643 ELEMENT EXAMPLE
3644 TEXT
3645 content= Extensible Markup Language</pre>
3646
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3647<p>So, entities or no entities? Basically, it depends on your use case. I
3648suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3649entities in your XML document or data if you are not willing to handle the
3650entity references elements in the DOM tree.</p>
3651
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3652<p>Note that at save time libxml2 enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3653entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3654transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3655reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3656finding them in the input).</p>
3657
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3658<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3659on top of the libxml2 SAX interface is difficult!!! If you plan to use
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3660non-predefined entities in your documents, then the learning curve to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3661then 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]3662strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]3663deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3664
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3665<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3666
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3667<p>The libxml2 library implements <a
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3668href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3669recognizing namespace constructs in the input, and does namespace lookup
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3670automatically when building the DOM tree. A namespace declaration is
3671associated with an in-memory structure and all elements or attributes within
3672that namespace point to it. Hence testing the namespace is a simple and fast
3673equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3674
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3675<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]3676root element of their document as the default namespace. Then they don't need
3677to 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]3678refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3679the size of the XML output significantly, but significantly increases its
3680value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3681<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
3682 &lt;elem1&gt;...&lt;/elem1&gt;
3683 &lt;elem2&gt;...&lt;/elem2&gt;
3684&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3685
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3686<p>The namespace value has to be an absolute URL, but the URL doesn't have to
3687point to any existing resource on the Web. It will bind all the element and
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3688attributes with that URL. I suggest to use an URL within a domain you
3689control, and that the URL should contain some kind of version information if
3690possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a
3691good namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3692
3693<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3694version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3695and if the version information don't match something you know, warn the user
3696and 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]3697namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3698same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3699associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3700just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3701<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3702prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3703
3704<p>@@Interfaces@@</p>
3705
3706<p>@@Examples@@</p>
3707
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3708<p>Usually people object to using namespaces together with validity checking.
3709I will try to make sure that using namespaces won't break validity checking,
3710so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3711suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3712<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3713flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3714from multiple DTDs will certainly break current validation schemes. I will
3715try to provide ways to do this, but this may not be portable or
3716standardized.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3717
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3718<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3719
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3720<p>Incompatible changes:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3721
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3722<p>Version 2 of libxml2 is the first version introducing serious backward
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3723incompatible changes. The main goals were:</p>
3724<ul>
3725 <li>a general cleanup. A number of mistakes inherited from the very early
3726 versions couldn't be changed due to compatibility constraints. Example
3727 the "childs" element in the nodes.</li>
3728 <li>Uniformization of the various nodes, at least for their header and link
3729 parts (doc, parent, children, prev, next), the goal is a simpler
3730 programming model and simplifying the task of the DOM implementors.</li>
3731 <li>better conformances to the XML specification, for example version 1.x
3732 had an heuristic to try to detect ignorable white spaces. As a result the
3733 SAX event generated were ignorableWhitespace() while the spec requires
3734 character() in that case. This also mean that a number of DOM node
3735 containing blank text may populate the DOM tree which were not present
3736 before.</li>
3737</ul>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3738
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3739<h3>How to fix libxml-1.x code:</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3740
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3741<p>So client code of libxml designed to run with version 1.x may have to be
3742changed to compile against version 2.x of libxml. Here is a list of changes
3743that I have collected, they may not be sufficient, so in case you find other
3744change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
3745mail</a>:</p>
3746<ol>
3747 <li>The package name have changed from libxml to libxml2, the library name
3748 is now -lxml2 . There is a new xml2-config script which should be used to
3749 select the right parameters libxml2</li>
3750 <li>Node <strong>childs</strong> field has been renamed
3751 <strong>children</strong> so s/childs/children/g should be applied
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3752 (probability of having "childs" anywhere else is close to 0+</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3753 <li>The document don't have anymore a <strong>root</strong> element it has
3754 been replaced by <strong>children</strong> and usually you will get a
3755 list of element here. For example a Dtd element for the internal subset
3756 and it's declaration may be found in that list, as well as processing
3757 instructions or comments found before or after the document root element.
3758 Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3759 a document. Alternatively if you are sure to not reference DTDs nor have
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3760 PIs or comments before or after the root element
3761 s/-&gt;root/-&gt;children/g will probably do it.</li>
3762 <li>The white space issue, this one is more complex, unless special case of
3763 validating parsing, the line breaks and spaces usually used for indenting
3764 and formatting the document content becomes significant. So they are
3765 reported by SAX and if your using the DOM tree, corresponding nodes are
3766 generated. Too approach can be taken:
3767 <ol>
3768 <li>lazy one, use the compatibility call
3769 <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
3770 relying on a special (and possibly broken) set of heuristics of
3771 libxml to detect ignorable blanks. Don't complain if it breaks or
3772 make your application not 100% clean w.r.t. to it's input.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3773 <li>the Right Way: change you code to accept possibly insignificant
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3774 blanks characters, or have your tree populated with weird blank text
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3775 nodes. You can spot them using the commodity function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3776 <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
3777 nodes.</li>
3778 </ol>
3779 <p>Note also that with the new default the output functions don't add any
3780 extra indentation when saving a tree in order to be able to round trip
3781 (read and save) without inflating the document with extra formatting
3782 chars.</p>
3783 </li>
3784 <li>The include path has changed to $prefix/libxml/ and the includes
3785 themselves uses this new prefix in includes instructions... If you are
3786 using (as expected) the
3787 <pre>xml2-config --cflags</pre>
3788 <p>output to generate you compile commands this will probably work out of
3789 the box</p>
3790 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3791 <li>xmlDetectCharEncoding takes an extra argument indicating the length in
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3792 byte of the head of the document available for character detection.</li>
3793</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3794
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3795<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3796
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3797<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]3798to allow smooth upgrade of existing libxml v1code while retaining
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3799compatibility. They offers the following:</p>
3800<ol>
3801 <li>similar include naming, one should use
3802 <strong>#include&lt;libxml/...&gt;</strong> in both cases.</li>
3803 <li>similar identifiers defined via macros for the child and root fields:
3804 respectively <strong>xmlChildrenNode</strong> and
3805 <strong>xmlRootNode</strong></li>
3806 <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
3807 inserted once in the client code</li>
3808</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3809
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3810<p>So the roadmap to upgrade your existing libxml applications is the
3811following:</p>
3812<ol>
3813 <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]3814 <li>find all occurrences where the xmlDoc <strong>root</strong> field is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3815 used and change it to <strong>xmlRootNode</strong></li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3816 <li>similarly find all occurrences where the xmlNode
3817 <strong>childs</strong> field is used and change it to
3818 <strong>xmlChildrenNode</strong></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3819 <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
3820 <strong>main()</strong> or in the library init entry point</li>
3821 <li>Recompile, check compatibility, it should still work</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3822 <li>Change your configure script to look first for xml2-config and fall
3823 back using xml-config . Use the --cflags and --libs output of the command
3824 as the Include and Linking parameters needed to use libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3825 <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
3826 libxml-devel-1.8.y can be kept simultaneously)</li>
3827 <li>remove your config.cache, relaunch your configuration mechanism, and
3828 recompile, if steps 2 and 3 were done right it should compile as-is</li>
3829 <li>Test that your application is still running correctly, if not this may
3830 be due to extra empty nodes due to formating spaces being kept in libxml2
3831 contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
3832 code before calling the parser (next to
3833 <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
3834</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3835
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3836<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]3837
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3838<p>Let me put some emphasis on the fact that there is far more changes from
3839libxml 1.x to 2.x than the ones you may have to patch for. The overall code
3840has been considerably cleaned up and the conformance to the XML specification
3841has been drastically improved too. Don't take those changes as an excuse to
3842not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3843
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3844<h2><a name="Thread">Thread safety</a></h2>
3845
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3846<p>Starting with 2.4.7, libxml2 makes provisions to ensure that concurrent
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3847threads can safely work in parallel parsing different documents. There is
3848however a couple of things to do to ensure it:</p>
3849<ul>
3850 <li>configure the library accordingly using the --with-threads options</li>
3851 <li>call xmlInitParser() in the "main" thread before using any of the
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3852 libxml2 API (except possibly selecting a different memory allocator)</li>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3853</ul>
3854
3855<p>Note that the thread safety cannot be ensured for multiple threads sharing
3856the same document, the locking must be done at the application level, libxml
3857exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
3858The parts of the library checked for thread safety are:</p>
3859<ul>
3860 <li>concurrent loading</li>
3861 <li>file access resolution</li>
3862 <li>catalog access</li>
3863 <li>catalog building</li>
3864 <li>entities lookup/accesses</li>
3865 <li>validation</li>
3866 <li>global variables per-thread override</li>
3867 <li>memory handling</li>
3868</ul>
3869
3870<p>XPath is supposed to be thread safe now, but this wasn't tested
3871seriously.</p>
3872
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3873<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3874
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3875<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
3876Object Model</em>; this is an API for accessing XML or HTML structured
3877documents. Native support for DOM in Gnome is on the way (module gnome-dom),
3878and will be based on gnome-xml. This will be a far cleaner interface to
3879manipulate XML files within Gnome since it won't expose the internal
3880structure.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3881
Daniel Veillard8a469172003-06-12 16:05:07 +0000[diff] [blame]3882<p>The current DOM implementation on top of libxml2 is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame]3883href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
3884is a full DOM interface, thanks to Paolo Casarini, check the <a
3885href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
3886informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3887
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3888<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3889
3890<p>Here is a real size example, where the actual content of the application
3891data 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]3892a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3893storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
3894base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3895<pre>&lt;?xml version="1.0"?&gt;
3896&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
3897 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3898
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3899 &lt;gjob:Job&gt;
3900 &lt;gjob:Project ID="3"/&gt;
3901 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
3902 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3903
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3904 &lt;gjob:Update&gt;
3905 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
3906 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
3907 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
3908 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3909
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3910 &lt;gjob:Developers&gt;
3911 &lt;gjob:Developer&gt;
3912 &lt;/gjob:Developer&gt;
3913 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3914
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3915 &lt;gjob:Contact&gt;
3916 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
3917 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
3918 &lt;gjob:Company&gt;
3919 &lt;/gjob:Company&gt;
3920 &lt;gjob:Organisation&gt;
3921 &lt;/gjob:Organisation&gt;
3922 &lt;gjob:Webpage&gt;
3923 &lt;/gjob:Webpage&gt;
3924 &lt;gjob:Snailmail&gt;
3925 &lt;/gjob:Snailmail&gt;
3926 &lt;gjob:Phone&gt;
3927 &lt;/gjob:Phone&gt;
3928 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3929
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3930 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3931 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3932 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3933
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3934 &lt;gjob:Skills&gt;
3935 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3936
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3937 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3938 A GNOME based system that will allow a superuser to configure
3939 compressed and uncompressed files and/or file systems to be backed
3940 up with a supported media in the system. This should be able to
3941 perform via find commands generating a list of files that are passed
3942 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
3943 or via operations performed on the filesystem itself. Email
3944 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3945 &lt;/gjob:Details&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:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3948
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3949 &lt;/gjob:Jobs&gt;
3950&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3951
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3952<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]3953calling only a couple of functions, browsing the tree to gather the data and
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3954generate the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3955
3956<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3957structure. For example, the ordering of the attributes is not significant,
3958the 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]3959depend on the order of the children of a given node, unless it really makes
3960things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3961<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3962 * A person record
3963 */
3964typedef struct person {
3965 char *name;
3966 char *email;
3967 char *company;
3968 char *organisation;
3969 char *smail;
3970 char *webPage;
3971 char *phone;
3972} person, *personPtr;
3973
3974/*
3975 * And the code needed to parse it
3976 */
3977personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3978 personPtr ret = NULL;
3979
3980DEBUG("parsePerson\n");
3981 /*
3982 * allocate the struct
3983 */
3984 ret = (personPtr) malloc(sizeof(person));
3985 if (ret == NULL) {
3986 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3987 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3988 }
3989 memset(ret, 0, sizeof(person));
3990
3991 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3992 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3993 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3994 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
3995 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3996 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
3997 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3998 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3999 }
4000
4001 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4002}</pre>
4003
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]4004<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4005<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]4006 <li>Usually a recursive parsing style is the more convenient one: XML data
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]4007 is by nature subject to repetitive constructs and usually exhibits highly
4008 structured patterns.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]4009 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
4010 i.e. the pointer to the global XML document and the namespace reserved to
4011 the application. Document wide information are needed for example to
4012 decode entities and it's a good coding practice to define a namespace for
4013 your application set of data and test that the element and attributes
4014 you're analyzing actually pertains to your application space. This is
4015 done by a simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]4016 <li>To retrieve text and attributes value, you can use the function
4017 <em>xmlNodeListGetString</em> to gather all the text and entity reference
4018 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4019</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4020
4021<p>Here is another piece of code used to parse another level of the
4022structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]4023<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]4024/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4025 * a Description for a Job
4026 */
4027typedef struct job {
4028 char *projectID;
4029 char *application;
4030 char *category;
4031 personPtr contact;
4032 int nbDevelopers;
4033 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
4034} job, *jobPtr;
4035
4036/*
4037 * And the code needed to parse it
4038 */
4039jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
4040 jobPtr ret = NULL;
4041
4042DEBUG("parseJob\n");
4043 /*
4044 * allocate the struct
4045 */
4046 ret = (jobPtr) malloc(sizeof(job));
4047 if (ret == NULL) {
4048 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4049 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4050 }
4051 memset(ret, 0, sizeof(job));
4052
4053 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]4054 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4055 while (cur != NULL) {
4056
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]4057 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
4058 ret-&gt;projectID = xmlGetProp(cur, "ID");
4059 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4060 fprintf(stderr, "Project has no ID\n");
4061 }
4062 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]4063 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
4064 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
4065 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
4066 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
4067 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
4068 ret-&gt;contact = parsePerson(doc, ns, cur);
4069 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4070 }
4071
4072 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4073}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]4074
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]4075<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]4076boring. Ultimately, it could be possible to write stubbers taking either C
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]4077data structure definitions, a set of XML examples or an XML DTD and produce
4078the code needed to import and export the content between C data and XML
4079storage. This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4080
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]4081<p>Feel free to use <a href="example/gjobread.c">the code for the full C
4082parsing example</a> as a template, it is also available with Makefile in the
4083Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]4084
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]4085<h2><a name="Contributi">Contributions</a></h2>
4086<ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]4087 <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
4088 patches, Gary Pennington worked on the validation API, threading support
4089 and Solaris port.</li>
4090 <li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000[diff] [blame]4091 <li><a href="mailto:igor@zlatkovic.com">Igor Zlatkovic</a> is now the
4092 maintainer of the Windows port, <a
4093 href="http://www.zlatkovic.com/projects/libxml/index.html">he provides
4094 binaries</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]4095 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
4096 <a href="http://garypennington.net/libxml2/">Solaris binaries</a></li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]4097 <li><a
4098 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]4099 Sergeant</a> developed <a
4100 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]4101 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
4102 application server</a></li>
4103 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> and <a
4104 href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillardca989762001-06-23 17:39:29 +0000[diff] [blame]4105 href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]4106 documentation</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]4107 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
4108 href="http://xmlsoft.org/messages/0488.html">man pages</a></li>
Daniel Veillard5168dbf2001-07-07 00:18:23 +0000[diff] [blame]4109 <li>there is a module for <a
4110 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
4111 in OpenNSD/AOLServer</a></li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]4112 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provided the
4113 first version of libxml/libxslt <a
4114 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li>
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]4115 <li>Petr Kozelka provides <a
4116 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
4117 libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]4118 <li><a href="mailto:aleksey@aleksey.com">Aleksey Sanin</a> implemented the
4119 <a href="http://www.w3.org/Signature/">XML Canonicalization and XML
4120 Digital Signature</a> <a
4121 href="http://www.aleksey.com/xmlsec/">implementations for libxml2</a></li>
Daniel Veillard17bed982003-02-24 20:11:43 +0000[diff] [blame]4122 <li><a href="mailto:Steve.Ball@zveno.com">Steve Ball</a>, <a
4123 href="http://www.zveno.com/">Zveno</a> and contributors maintain <a
4124 href="http://tclxml.sourceforge.net/">tcl bindings for libxml2 and
4125 libxslt</a>, as well as <a
4126 href="http://tclxml.sf.net/tkxmllint.html">tkxmllint</a> a GUI for
4127 xmllint and <a href="http://tclxml.sf.net/tkxsltproc.html">tkxsltproc</a>
4128 a GUI for xsltproc.</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]4129</ul>
4130
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]4131<p></p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]4132</body>
4133</html>