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blob: 97e62930723205283fe7aa7052bf246d18704696 [file] [log] [blame]
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 Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]5 <title>The XML C library for 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 Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]11<h1 align="center">The XML C library for 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 Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]20<p>Libxml is the XML C library developed for the Gnome project. XML itself
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]21is a metalanguage to design markup languages, i.e. text language where
22semantic and structure are added to the content using extra "markup"
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]23information enclosed between angle brackets. HTML is the most well-known
Daniel Veillard1eb24242002-03-18 11:33:03 +0000[diff] [blame]24markup language. Though the library is written in C <a href="python.html">a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]25variety of language bindings</a> make it available in other environments.</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]26
27<p>Libxml2 implements a number of existing standards related to markup
28languages:</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]29<ul>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]30 <li>the XML standard: <a
31 href="http://www.w3.org/TR/REC-xml">http://www.w3.org/TR/REC-xml</a></li>
32 <li>Namespaces in XML: <a
33 href="http://www.w3.org/TR/REC-xml-names/">http://www.w3.org/TR/REC-xml-names/</a></li>
34 <li>XML Base: <a
35 href="http://www.w3.org/TR/xmlbase/">http://www.w3.org/TR/xmlbase/</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]36 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc2396.txt">RFC 2396</a> :
37 Uniform Resource Identifiers <a
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]38 href="http://www.ietf.org/rfc/rfc2396.txt">http://www.ietf.org/rfc/rfc2396.txt</a></li>
39 <li>XML Path Language (XPath) 1.0: <a
40 href="http://www.w3.org/TR/xpath">http://www.w3.org/TR/xpath</a></li>
41 <li>HTML4 parser: <a
42 href="http://www.w3.org/TR/html401/">http://www.w3.org/TR/html401/</a></li>
43 <li>most of XML Pointer Language (XPointer) Version 1.0: <a
44 href="http://www.w3.org/TR/xptr">http://www.w3.org/TR/xptr</a></li>
45 <li>XML Inclusions (XInclude) Version 1.0: <a
46 href="http://www.w3.org/TR/xinclude/">http://www.w3.org/TR/xinclude/</a></li>
47 <li>[ISO-8859-1], <a
48 href="http://www.cis.ohio-state.edu/rfc/rfc2044.txt">rfc2044</a> [UTF-8]
49 and <a href="http://www.cis.ohio-state.edu/rfc/rfc2781.txt">rfc2781</a>
50 [UTF-16] core encodings</li>
51 <li>part of SGML Open Technical Resolution TR9401:1997</li>
52 <li>XML Catalogs Working Draft 06 August 2001: <a
53 href="http://www.oasis-open.org/committees/entity/spec-2001-08-06.html">http://www.oasis-open.org/committees/entity/spec-2001-08-06.html</a></li>
Daniel Veillard5c396542002-03-15 07:57:50 +0000[diff] [blame]54 <li>Canonical XML Version 1.0: <a
55 href="http://www.w3.org/TR/xml-c14n">http://www.w3.org/TR/xml-c14n</a>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]56 and the Exclusive XML Canonicalization CR draft <a
57 href="http://www.w3.org/TR/xml-exc-c14n">http://www.w3.org/TR/xml-exc-c14n</a></li>
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]58</ul>
59
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]60<p>In most cases libxml tries to implement the specifications in a relatively
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]61strictly compliant way. As of release 2.4.16, libxml2 passes all 1800+ tests
62from the <a
Daniel Veillarda5393562002-02-20 11:40:49 +0000[diff] [blame]63href="http://www.oasis-open.org/committees/xml-conformance/">OASIS XML Tests
64Suite</a>.</p>
Daniel Veillard5b16f582002-02-20 11:38:46 +0000[diff] [blame]65
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]66<p>To some extent libxml2 provides support for the following additional
67specifications but doesn't claim to implement them completely:</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]68<ul>
69 <li>Document Object Model (DOM) <a
70 href="http://www.w3.org/TR/DOM-Level-2-Core/">http://www.w3.org/TR/DOM-Level-2-Core/</a>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]71 it doesn't implement the API itself, gdome2 does this on top of
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]72 libxml2</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]73 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc959.txt">RFC 959</a> :
74 libxml implements a basic FTP client code</li>
75 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc1945.txt">RFC 1945</a> :
76 HTTP/1.0, again a basic HTTP client code</li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]77 <li>SAX: a minimal SAX implementation compatible with early expat
78 versions</li>
79 <li>DocBook SGML v4: libxml2 includes a hackish parser to transition to
80 XML</li>
81</ul>
82
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]83<p>XML Schemas is being worked on but it would be far too early to make any
84conformance statement about it at the moment.</p>
85
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]86<p>Libxml2 is known to be very portable, the library should build and work
87without serious troubles on a variety of systems (Linux, Unix, Windows,
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]88CygWin, MacOS, MacOS X, RISC Os, OS/2, VMS, QNX, MVS, ...)</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]89
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]90<p>Separate documents:</p>
91<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]92 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a> providing an
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]93 implementation of XSLT 1.0 and common extensions like EXSLT for
94 libxml2</li>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]95 <li><a href="http://www.cs.unibo.it/~casarini/gdome2/">the gdome2 page</a>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]96 : a standard DOM2 implementation for libxml2</li>
97 <li><a href="http://www.aleksey.com/xmlsec/">the XMLSec page</a>: an
98 implementation of <a href="http://www.w3.org/TR/xmldsig-core/">W3C XML
99 Digital Signature</a> for libxml2</li>
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]100 <li>also check the related links section below for more related and active
101 projects.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]102</ul>
103
Daniel Veillarde1662542002-08-28 11:50:59 +0000[diff] [blame]104<p>Logo designed by <a href="mailto:liyanage@access.ch">Marc Liyanage</a>.</p>
105
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]106<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]107
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]108<p>This document describes libxml, the <a
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]109href="http://www.w3.org/XML/">XML</a> C library developed for the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]110href="http://www.gnome.org/">Gnome</a> project. <a
111href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
112structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]113
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]114<p>Here are some key points about libxml:</p>
115<ul>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]116 <li>Libxml exports Push (progressive) and Pull (blocking) type parser
117 interfaces for both XML and HTML.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]118 <li>Libxml can do DTD validation at parse time, using a parsed document
119 instance, or with an arbitrary DTD.</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]120 <li>Libxml includes complete <a
Daniel Veillard8c2ecaf2001-07-10 17:53:07 +0000[diff] [blame]121 href="http://www.w3.org/TR/xpath">XPath</a>, <a
122 href="http://www.w3.org/TR/xptr">XPointer</a> and <a
123 href="http://www.w3.org/TR/xinclude">XInclude</a> implementations.</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]124 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]125 sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]126 Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]127 <li>Basic support for HTTP and FTP client allowing applications to fetch
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]128 remote resources.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]129 <li>The design is modular, most of the extensions can be compiled out.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]130 <li>The internal document representation is as close as possible to the <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]131 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
132 <li>Libxml also has a <a href="http://www.megginson.com/SAX/index.html">SAX
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]133 like interface</a>; the interface is designed to be compatible with <a
134 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]135 <li>This library is released under the <a
136 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]137 License</a>. See the Copyright file in the distribution for the precise
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]138 wording.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]139</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]140
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]141<p>Warning: unless you are forced to because your application links with a
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]142Gnome-1.X library requiring it, <strong><span
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]143style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
144libxml2</p>
145
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]146<h2><a name="FAQ">FAQ</a></h2>
147
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]148<p>Table of Contents:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]149<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]150 <li><a href="FAQ.html#License">License(s)</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]151 <li><a href="FAQ.html#Installati">Installation</a></li>
152 <li><a href="FAQ.html#Compilatio">Compilation</a></li>
153 <li><a href="FAQ.html#Developer">Developer corner</a></li>
154</ul>
155
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]156<h3><a name="License">License</a>(s)</h3>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]157<ol>
158 <li><em>Licensing Terms for libxml</em>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]159 <p>libxml is released under the <a
160 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]161 License</a>; see the file Copyright in the distribution for the precise
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]162 wording</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]163 </li>
164 <li><em>Can I embed libxml in a proprietary application ?</em>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]165 <p>Yes. The MIT License allows you to keep proprietary the changes you
166 made to libxml, but it would be graceful to send-back bug fixes and
167 improvements as patches for possible incorporation in the main
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]168 development tree.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]169 </li>
170</ol>
171
172<h3><a name="Installati">Installation</a></h3>
173<ol>
174 <li>Unless you are forced to because your application links with a Gnome
175 library requiring it, <strong><span style="background-color: #FF0000">Do
176 Not Use libxml1</span></strong>, use libxml2</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]177 <li><em>Where can I get libxml</em> ?
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]178 <p>The original distribution comes from <a
179 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a
MDT 2002 John Fleck30c70542002-09-24 14:24:54 +0000[diff] [blame]180 href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.4/">gnome.org</a></p>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]181 <p>Most Linux and BSD distributions include libxml, this is probably the
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]182 safer way for end-users to use libxml.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]183 <p>David Doolin provides precompiled Windows versions at <a
184 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
185 </li>
186 <li><em>I see libxml and libxml2 releases, which one should I install ?</em>
187 <ul>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]188 <li>If you are not constrained by backward compatibility issues with
189 existing applications, install libxml2 only</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]190 <li>If you are not doing development, you can safely install both.
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]191 Usually the packages <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]192 href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a
193 href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]194 compatible (this is not the case for development packages).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]195 <li>If you are a developer and your system provides separate packaging
196 for shared libraries and the development components, it is possible
197 to install libxml and libxml2, and also <a
198 href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
199 and <a
200 href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
201 too for libxml2 &gt;= 2.3.0</li>
202 <li>If you are developing a new application, please develop against
203 libxml2(-devel)</li>
204 </ul>
205 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]206 <li><em>I can't install the libxml package, it conflicts with libxml0</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]207 <p>You probably have an old libxml0 package used to provide the shared
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]208 library for libxml.so.0, you can probably safely remove it. The libxml
209 packages provided on <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]210 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provide
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]211 libxml.so.0</p>
212 </li>
213 <li><em>I can't install the libxml(2) RPM package due to failed
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]214 dependencies</em>
215 <p>The most generic solution is to re-fetch the latest src.rpm , and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]216 rebuild it locally with</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]217 <p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code>.</p>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]218 <p>If everything goes well it will generate two binary rpm packages (one
219 providing the shared libs and xmllint, and the other one, the -devel
220 package, providing includes, static libraries and scripts needed to build
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]221 applications with libxml(2)) that you can install locally.</p>
222 </li>
223</ol>
224
225<h3><a name="Compilatio">Compilation</a></h3>
226<ol>
227 <li><em>What is the process to compile libxml ?</em>
228 <p>As most UNIX libraries libxml follows the "standard":</p>
229 <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p>
230 <p><code>cd libxml-xxxx</code></p>
231 <p><code>./configure --help</code></p>
232 <p>to see the options, then the compilation/installation proper</p>
233 <p><code>./configure [possible options]</code></p>
234 <p><code>make</code></p>
235 <p><code>make install</code></p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]236 <p>At that point you may have to rerun ldconfig or a similar utility to
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]237 update your list of installed shared libs.</p>
238 </li>
239 <li><em>What other libraries are needed to compile/install libxml ?</em>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]240 <p>Libxml does not require any other library, the normal C ANSI API
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]241 should be sufficient (please report any violation to this rule you may
242 find).</p>
243 <p>However if found at configuration time libxml will detect and use the
244 following libs:</p>
245 <ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]246 <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a> : a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]247 highly portable and available widely compression library.</li>
248 <li>iconv: a powerful character encoding conversion library. It is
249 included by default in recent glibc libraries, so it doesn't need to
250 be installed specifically on Linux. It now seems a <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]251 href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
252 of the official UNIX</a> specification. Here is one <a
253 href="http://clisp.cons.org/~haible/packages-libiconv.html">implementation
254 of the library</a> which source can be found <a
255 href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
256 </ul>
257 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]258 <li><em>Make check fails on some platforms</em>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]259 <p>Sometimes the regression tests' results don't completely match the
260 value produced by the parser, and the makefile uses diff to print the
261 delta. On some platforms the diff return breaks the compilation process;
262 if the diff is small this is probably not a serious problem.</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]263 <p>Sometimes (especially on Solaris) make checks fail due to limitations
Daniel Veillarde46182c2002-02-12 14:29:11 +0000[diff] [blame]264 in make. Try using GNU-make instead.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]265 </li>
266 <li><em>I use the CVS version and there is no configure script</em>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]267 <p>The configure script (and other Makefiles) are generated. Use the
268 autogen.sh script to regenerate the configure script and Makefiles,
269 like:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]270 <p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
271 </li>
272 <li><em>I have troubles when running make tests with gcc-3.0</em>
273 <p>It seems the initial release of gcc-3.0 has a problem with the
274 optimizer which miscompiles the URI module. Please use another
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]275 compiler.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]276 </li>
277</ol>
278
279<h3><a name="Developer">Developer</a> corner</h3>
280<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]281 <li><em>xmlDocDump() generates output on one line.</em>
282 <p>Libxml will not <strong>invent</strong> spaces in the content of a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]283 document since <strong>all spaces in the content of a document are
284 significant</strong>. If you build a tree from the API and want
285 indentation:</p>
286 <ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]287 <li>the correct way is to generate those yourself too.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]288 <li>the dangerous way is to ask libxml to add those blanks to your
289 content <strong>modifying the content of your document in the
290 process</strong>. The result may not be what you expect. There is
291 <strong>NO</strong> way to guarantee that such a modification won't
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]292 affect other parts of the content of your document. See <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]293 href="http://xmlsoft.org/html/libxml-parser.html#XMLKEEPBLANKSDEFAULT">xmlKeepBlanksDefault
294 ()</a> and <a
295 href="http://xmlsoft.org/html/libxml-tree.html#XMLSAVEFORMATFILE">xmlSaveFormatFile
296 ()</a></li>
297 </ol>
298 </li>
299 <li>Extra nodes in the document:
300 <p><em>For a XML file as below:</em></p>
301 <pre>&lt;?xml version="1.0"?&gt;
302&lt;PLAN xmlns="http://www.argus.ca/autotest/1.0/"&gt;
303&lt;NODE CommFlag="0"/&gt;
304&lt;NODE CommFlag="1"/&gt;
305&lt;/PLAN&gt;</pre>
306 <p><em>after parsing it with the function
307 pxmlDoc=xmlParseFile(...);</em></p>
308 <p><em>I want to the get the content of the first node (node with the
309 CommFlag="0")</em></p>
310 <p><em>so I did it as following;</em></p>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]311 <pre>xmlNodePtr pnode;
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]312pnode=pxmlDoc-&gt;children-&gt;children;</pre>
313 <p><em>but it does not work. If I change it to</em></p>
314 <pre>pnode=pxmlDoc-&gt;children-&gt;children-&gt;next;</pre>
315 <p><em>then it works. Can someone explain it to me.</em></p>
316 <p></p>
317 <p>In XML all characters in the content of the document are significant
318 <strong>including blanks and formatting line breaks</strong>.</p>
319 <p>The extra nodes you are wondering about are just that, text nodes with
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]320 the formatting spaces which are part of the document but that people tend
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]321 to forget. There is a function <a
322 href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
323 ()</a> to remove those at parse time, but that's an heuristic, and its
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]324 use should be limited to cases where you are certain there is no
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]325 mixed-content in the document.</p>
326 </li>
327 <li><em>I get compilation errors of existing code like when accessing
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]328 <strong>root</strong> or <strong>child fields</strong> of nodes.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]329 <p>You are compiling code developed for libxml version 1 and using a
330 libxml2 development environment. Either switch back to libxml v1 devel or
331 even better fix the code to compile with libxml2 (or both) by <a
332 href="upgrade.html">following the instructions</a>.</p>
333 </li>
334 <li><em>I get compilation errors about non existing
335 <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]336 fields.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]337 <p>The source code you are using has been <a
338 href="upgrade.html">upgraded</a> to be able to compile with both libxml
339 and libxml2, but you need to install a more recent version:
340 libxml(-devel) &gt;= 1.8.8 or libxml2(-devel) &gt;= 2.1.0</p>
341 </li>
342 <li><em>XPath implementation looks seriously broken</em>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]343 <p>XPath implementation prior to 2.3.0 was really incomplete. Upgrade to
344 a recent version, there are no known bugs in the current version.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]345 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]346 <li><em>The example provided in the web page does not compile.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]347 <p>It's hard to maintain the documentation in sync with the code
348 &lt;grin/&gt; ...</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]349 <p>Check the previous points 1/ and 2/ raised before, and please send
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]350 patches.</p>
351 </li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]352 <li><em>Where can I get more examples and information than privoded on the
353 web page?</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]354 <p>Ideally a libxml book would be nice. I have no such plan ... But you
355 can:</p>
356 <ul>
357 <li>check more deeply the <a href="html/libxml-lib.html">existing
358 generated doc</a></li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]359 <li>look for examples of use for libxml function using the Gnome code.
360 For example the following will query the full Gnome CVS base for the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]361 use of the <strong>xmlAddChild()</strong> function:
362 <p><a
363 href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p>
364 <p>This may be slow, a large hardware donation to the gnome project
365 could cure this :-)</p>
366 </li>
367 <li><a
368 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gnome-xml">Browse
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]369 the libxml source</a> , I try to write code as clean and documented
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]370 as possible, so looking at it may be helpful. In particular the code
371 of xmllint.c and of the various testXXX.c test programs should
372 provide good examples of how to do things with the library.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]373 </ul>
374 </li>
375 <li>What about C++ ?
376 <p>libxml is written in pure C in order to allow easy reuse on a number
377 of platforms, including embedded systems. I don't intend to convert to
378 C++.</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]379 <p>There are however a few C++ wrappers which may fulfill your needs:</p>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]380 <ul>
381 <li>by Ari Johnson &lt;ari@btigate.com&gt;:
382 <p>Website: <a
383 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
384 <p>Download: <a
385 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
386 </li>
387 <li>by Peter Jones &lt;pjones@pmade.org&gt;
388 <p>Website: <a
389 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
390 </li>
391 </ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]392 </li>
393 <li>How to validate a document a posteriori ?
394 <p>It is possible to validate documents which had not been validated at
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]395 initial parsing time or documents which have been built from scratch
396 using the API. Use the <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]397 href="http://xmlsoft.org/html/libxml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]398 function. It is also possible to simply add a DTD to an existing
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]399 document:</p>
400 <pre>xmlDocPtr doc; /* your existing document */
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]401xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
402
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]403 dtd-&gt;name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */
404
405 doc-&gt;intSubset = dtd;
406 if (doc-&gt;children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
407 else xmlAddPrevSibling(doc-&gt;children, (xmlNodePtr)dtd);
408 </pre>
409 </li>
410 <li>etc ...</li>
411</ol>
412
413<p></p>
414
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]415<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]416
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]417<p>There are several on-line resources related to using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]418<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]419 <li>Check the <a href="FAQ.html">FAQ.</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]420 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]421 documentation</a> automatically extracted from code comments (using <a
422 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
423 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]424 <li>Look at the documentation about <a href="encoding.html">libxml
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]425 internationalization support</a>.</li>
Daniel Veillardbc66f852002-01-14 09:49:20 +0000[diff] [blame]426 <li>This page provides a global overview and <a href="example.html">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]427 examples</a> on how to use libxml.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]428 <li>John Fleck's <a href="tutorial/index.html">libxml tutorial</a>.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]429 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]430 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
431 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]432 <li>George Lebl wrote <a
433 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]434 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]435 <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]436 file</a>.</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]437 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>
438 description. If you are starting a new project using libxml you should
439 really use the 2.x version.</li>
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]440 <li>And don't forget to look at the <a
441 href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]442</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]443
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]444<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]445
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]446<p>Well, bugs or missing features are always possible, and I will make a
447point of fixing them in a timely fashion. The best way to report a bug is to
448use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]449bug tracking database</a> (make sure to use the "libxml2" module name). I
450look at reports there regularly and it's good to have a reminder when a bug
451is 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]452
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]453<p>There is also a mailing-list <a
Daniel Veillard3197f162001-04-04 00:40:08 +0000[diff] [blame]454href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
455href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]456href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
457please visit the <a
458href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
459follow the instructions. <strong>Do not send code, I won't debug it</strong>
460(but patches are really appreciated!).</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]461
Daniel Veillard008186f2001-09-13 14:24:44 +0000[diff] [blame]462<p>Check the following <strong><span style="color: #FF0000">before
463posting</span></strong>:</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]464<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]465 <li>Read the <a href="FAQ.html">FAQ</a>.</li>
466 <li>Make sure you are <a href="ftp://xmlsoft.org/">using a recent
467 version</a>, and that the problem still shows up in a recent version.</li>
468 <li>Check the <a href="http://mail.gnome.org/archives/xml/">list
469 archives</a> to see if the problem was reported already. In this case
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]470 there is probably a fix available, similarly check the <a
Daniel Veillarde7ead2d2001-08-22 23:44:09 +0000[diff] [blame]471 href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">registered
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]472 open bugs</a>.</li>
473 <li>Make sure you can reproduce the bug with xmllint or one of the test
474 programs found in source in the distribution.</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]475 <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]476 attachment)</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]477</ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]478
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]479<p>Then send the bug with associated informations to reproduce it to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]480href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]481related I will approve it.. Please do not send mail to me directly, it makes
482things really hard to track and in some cases I am not the best person to
483answer a given question. Ask the list instead.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]484
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]485<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]486probably be processed faster than those without.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]487
488<p>If you're looking for help, a quick look at <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]489href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]490provide the answer. I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]491questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]492documentation</a> is not as polished as I would like (i need to learn more
493about DocBook), but it's a good starting point.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]494
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]495<h2><a name="help">How to help</a></h2>
496
497<p>You can help the project in various ways, the best thing to do first is to
498subscribe to the mailing-list as explained before, check the <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]499href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
500href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]501database</a>:</p>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]502<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]503 <li>Provide patches when you find problems.</li>
504 <li>Provide the diffs when you port libxml to a new platform. They may not
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]505 be integrated in all cases but help pinpointing portability problems
506 and</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]507 <li>Provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]508 as HTML diffs).</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]509 <li>Provide new documentations pieces (translations, examples, etc
510 ...).</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]511 <li>Check the TODO file and try to close one of the items.</li>
512 <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]513 provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me
514 </a>before to avoid synchronization problems and check that the suggested
515 fix will fit in nicely :-)</li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]516</ol>
517
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]518<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]519
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]520<p>The latest versions of libxml can be found on <a
Daniel Veillard20c8cf22001-06-26 22:47:36 +0000[diff] [blame]521href="ftp://xmlsoft.org/">xmlsoft.org</a> (<a
522href="ftp://speakeasy.rpmfind.net/pub/libxml/">Seattle</a>, <a
523href="ftp://fr.rpmfind.net/pub/libxml/">France</a>) or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]524href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
MDT 2002 John Fleck30c70542002-09-24 14:24:54 +0000[diff] [blame]525as a <a href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.4/">source
526archive</a><!-- commenting this out because they seem to have disappeared or <a
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]527href="ftp://ftp.gnome.org/pub/GNOME/stable/redhat/i386/libxml/">RPM
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame^]528packages</a> -->
529, Antonin Sprinzl also provide <a href="ftp://gd.tuwien.ac.at/pub/libxml/">a
530mirror in Austria</a>. (NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]531href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
532href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]533packages installed to compile applications using libxml.) <a
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]534href="mailto:igor@stud.fh-frankfurt.de">Igor Zlatkovic</a> is now the
535maintainer of the Windows port, <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]536href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]537provides binaries</a>. <a href="mailto:Gary.Pennington@sun.com">Gary
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]538Pennington</a> provides <a href="http://garypennington.net/libxml2/">Solaris
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]539binaries</a>. <a href="mailto:Steve.Ball@zveno.com">Steve Ball</a> provides
540<a href="http://www.zveno.com/open_source/libxml2xslt.html">Mac Os X
541binaries</a>.</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]542
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]543<p><a name="Snapshot">Snapshot:</a></p>
544<ul>
545 <li>Code from the W3C cvs base libxml <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]546 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]547 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]548 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]549</ul>
550
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]551<p><a name="Contribs">Contributions:</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]552
553<p>I do accept external contributions, especially if compiling on another
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]554platform, get in touch with me to upload the package, wrappers for various
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]555languages have been provided, and can be found in the <a
556href="contribs.html">contrib section</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]557
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]558<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]559<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]560 <li><p>The <a
561 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]562 CVS base</a>. Check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]563 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a>
564 page; the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]565 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]566 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]567</ul>
568
569<h2><a name="News">News</a></h2>
570
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]571<h3>CVS only : check the <a
572href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]573for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]574
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]575<p>Items not finished and worked on, get in touch with the list if you want
576to test those</p>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]577<ul>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]578 <li>Finishing up <a href="http://www.w3.org/TR/xmlschema-1/">XML
579 Schemas</a> and <a href="http://www.w3.org/TR/xinclude">XInclude</a></li>
580</ul>
581
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame^]582<h3>2.4.25: Sep 26 2002</h3>
583<ul>
584 <li>A number of bug fixes: XPath, validation, Python bindings, DOM and
585 tree, xmlI/O, Html</li>
586 <li>Serious rewrite of XInclude</li>
587 <li>Made XML Schemas regexp part of the default build and APIs, small fix
588 and improvement of the regexp core</li>
589 <li>Changed the validation code to reuse XML Schemas regexp APIs</li>
590 <li>Better handling of Windows file paths, improvement of Makefiles (Igor,
591 Daniel Gehriger, Mark Vakoc)</li>
592 <li>Improved the python I/O bindings, the tests, added resolver and regexp
593 APIs </li>
594 <li>New logos from Marc Liyanage</li>
595 <li>Tutorial improvements: John Fleck, Christopher Harris</li>
596 <li>Makefile: Fixes for AMD x86_64 (Mandrake), DESTDIR (Christophe
597 Merlet)</li>
598 <li>removal of all stderr/perror use for error reporting</li>
599 <li>Better error reporting: XPath and DTD validation</li>
600 <li>update of the trio portability layer (Bjorn Reese)</li>
601</ul>
602
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]603<p><strong>2.4.24: Aug 22 2002</strong></p>
604<ul>
605 <li>XPath fixes (William), xf:escape-uri() (Wesley Terpstra)</li>
606 <li>Python binding fixes: makefiles (William), generator, rpm build, x86-64
607 (fcrozat)</li>
608 <li>HTML &lt;style&gt; and boolean attributes serializer fixes</li>
609 <li>C14N improvements by Aleksey</li>
Daniel Veillarde1662542002-08-28 11:50:59 +0000[diff] [blame]610 <li>doc cleanups: Rick Jones</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]611 <li>Windows compiler makefile updates: Igor and Elizabeth Barham</li>
612 <li>XInclude: implementation of fallback and xml:base fixup added</li>
613</ul>
614
Daniel Veillard782afda2002-07-08 15:12:49 +0000[diff] [blame]615<h3>2.4.23: July 6 2002</h3>
616<ul>
617 <li>performances patches: Peter Jacobi</li>
618 <li>c14n fixes, testsuite and performances: Aleksey Sanin</li>
619 <li>added xmlDocFormatDump: Chema Celorio</li>
620 <li>new tutorial: John Fleck</li>
621 <li>new hash functions and performances: Sander Vesik, portability fix from
622 Peter Jacobi</li>
623 <li>a number of bug fixes: XPath (William Brack, Richard Jinks), XML and
624 HTML parsers, ID lookup function</li>
625 <li>removal of all remaining sprintf: Aleksey Sanin</li>
626</ul>
627
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]628<h3>2.4.22: May 27 2002</h3>
629<ul>
630 <li>a number of bug fixes: configure scripts, base handling, parser, memory
631 usage, HTML parser, XPath, documentation (Christian Cornelssen),
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]632 indentation, URI parsing</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]633 <li>Optimizations for XMLSec, fixing and making public some of the network
634 protocol handlers (Aleksey)</li>
635 <li>performance patch from Gary Pennington</li>
636 <li>Charles Bozeman provided date and time support for XML Schemas
637 datatypes</li>
638</ul>
639
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]640<h3>2.4.21: Apr 29 2002</h3>
641
642<p>This release is both a bug fix release and also contains the early XML
643Schemas <a href="http://www.w3.org/TR/xmlschema-1/">structures</a> and <a
644href="http://www.w3.org/TR/xmlschema-2/">datatypes</a> code, beware, all
645interfaces are likely to change, there is huge holes, it is clearly a work in
646progress and don't even think of putting this code in a production system,
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]647it's actually not compiled in by default. The real fixes are:</p>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]648<ul>
649 <li>a couple of bugs or limitations introduced in 2.4.20</li>
650 <li>patches for Borland C++ and MSC by Igor</li>
651 <li>some fixes on XPath strings and conformance patches by Richard
652 Jinks</li>
653 <li>patch from Aleksey for the ExcC14N specification</li>
654 <li>OSF/1 bug fix by Bjorn</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]655</ul>
656
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]657<h3>2.4.20: Apr 15 2002</h3>
658<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]659 <li>bug fixes: file descriptor leak, XPath, HTML output, DTD validation</li>
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]660 <li>XPath conformance testing by Richard Jinks</li>
661 <li>Portability fixes: Solaris, MPE/iX, Windows, OSF/1, python bindings,
662 libxml.m4</li>
663</ul>
664
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]665<h3>2.4.19: Mar 25 2002</h3>
666<ul>
667 <li>bug fixes: half a dozen XPath bugs, Validation, ISO-Latin to UTF8
668 encoder</li>
669 <li>portability fixes in the HTTP code</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]670 <li>memory allocation checks using valgrind, and profiling tests</li>
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]671 <li>revamp of the Windows build and Makefiles</li>
672</ul>
673
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]674<h3>2.4.18: Mar 18 2002</h3>
675<ul>
676 <li>bug fixes: tree, SAX, canonicalization, validation, portability,
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]677 XPath</li>
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]678 <li>removed the --with-buffer option it was becoming unmaintainable</li>
679 <li>serious cleanup of the Python makefiles</li>
680 <li>speedup patch to XPath very effective for DocBook stylesheets</li>
681 <li>Fixes for Windows build, cleanup of the documentation</li>
682</ul>
683
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]684<h3>2.4.17: Mar 8 2002</h3>
685<ul>
686 <li>a lot of bug fixes, including "namespace nodes have no parents in
687 XPath"</li>
688 <li>fixed/improved the Python wrappers, added more examples and more
689 regression tests, XPath extension functions can now return node-sets</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]690 <li>added the XML Canonicalization support from Aleksey Sanin</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]691</ul>
692
Daniel Veillard5f4b5992002-02-20 10:22:49 +0000[diff] [blame]693<h3>2.4.16: Feb 20 2002</h3>
694<ul>
695 <li>a lot of bug fixes, most of them were triggered by the XML Testsuite
696 from OASIS and W3C. Compliance has been significantly improved.</li>
697 <li>a couple of portability fixes too.</li>
698</ul>
699
Daniel Veillard397ff112002-02-11 18:27:20 +0000[diff] [blame]700<h3>2.4.15: Feb 11 2002</h3>
701<ul>
702 <li>Fixed the Makefiles, especially the python module ones</li>
703 <li>A few bug fixes and cleanup</li>
704 <li>Includes cleanup</li>
705</ul>
706
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]707<h3>2.4.14: Feb 8 2002</h3>
708<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]709 <li>Change of License to the <a
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]710 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]711 License</a> basically for integration in XFree86 codebase, and removing
712 confusion around the previous dual-licensing</li>
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]713 <li>added Python bindings, beta software but should already be quite
714 complete</li>
715 <li>a large number of fixes and cleanups, especially for all tree
716 manipulations</li>
717 <li>cleanup of the headers, generation of a reference API definition in
718 XML</li>
719</ul>
720
721<h3>2.4.13: Jan 14 2002</h3>
Daniel Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame]722<ul>
723 <li>update of the documentation: John Fleck and Charlie Bozeman</li>
724 <li>cleanup of timing code from Justin Fletcher</li>
725 <li>fixes for Windows and initial thread support on Win32: Igor and Serguei
726 Narojnyi</li>
727 <li>Cygwin patch from Robert Collins</li>
728 <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
729</ul>
730
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]731<h3>2.4.12: Dec 7 2001</h3>
732<ul>
733 <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
734 XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
735 (robert)</li>
736 <li>Eric Lavigne contributed project files for MacOS</li>
737 <li>some makefiles cleanups</li>
738</ul>
739
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]740<h3>2.4.11: Nov 26 2001</h3>
741<ul>
742 <li>fixed a couple of errors in the includes, fixed a few bugs, some code
743 cleanups</li>
744 <li>xmllint man pages improvement by Heiko Rupp</li>
745 <li>updated VMS build instructions from John A Fotheringham</li>
746 <li>Windows Makefiles updates from Igor</li>
747</ul>
748
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]749<h3>2.4.10: Nov 10 2001</h3>
750<ul>
751 <li>URI escaping fix (Joel Young)</li>
752 <li>added xmlGetNodePath() (for paths or XPointers generation)</li>
753 <li>Fixes namespace handling problems when using DTD and validation</li>
754 <li>improvements on xmllint: Morus Walter patches for --format and
755 --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
756 <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
757 <li>fixes to the HTML parser</li>
758</ul>
759
760<h3>2.4.9: Nov 6 2001</h3>
761<ul>
762 <li>fixes more catalog bugs</li>
763 <li>avoid a compilation problem, improve xmlGetLineNo()</li>
764</ul>
765
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]766<h3>2.4.8: Nov 4 2001</h3>
767<ul>
768 <li>fixed SGML catalogs broken in previous release, updated xmlcatalog
769 tool</li>
770 <li>fixed a compile errors and some includes troubles.</li>
771</ul>
772
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]773<h3>2.4.7: Oct 30 2001</h3>
774<ul>
775 <li>exported some debugging interfaces</li>
776 <li>serious rewrite of the catalog code</li>
777 <li>integrated Gary Pennington thread safety patch, added configure option
778 and regression tests</li>
779 <li>removed an HTML parser bug</li>
780 <li>fixed a couple of potentially serious validation bugs</li>
781 <li>integrated the SGML DocBook support in xmllint</li>
782 <li>changed the nanoftp anonymous login passwd</li>
783 <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
784 <li>general bug fixes</li>
785 <li>updated xmllint man page by John Fleck</li>
786 <li>some VMS and Windows updates</li>
787</ul>
788
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]789<h3>2.4.6: Oct 10 2001</h3>
790<ul>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]791 <li>added an updated man pages by John Fleck</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]792 <li>portability and configure fixes</li>
793 <li>an infinite loop on the HTML parser was removed (William)</li>
794 <li>Windows makefile patches from Igor</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]795 <li>fixed half a dozen bugs reported for libxml or libxslt</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]796 <li>updated xmlcatalog to be able to modify SGML super catalogs</li>
797</ul>
798
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]799<h3>2.4.5: Sep 14 2001</h3>
800<ul>
801 <li>Remove a few annoying bugs in 2.4.4</li>
802 <li>forces the HTML serializer to output decimal charrefs since some
803 version of Netscape can't handle hexadecimal ones</li>
804</ul>
805
806<h3>1.8.16: Sep 14 2001</h3>
807<ul>
808 <li>maintenance release of the old libxml1 branch, couple of bug and
809 portability fixes</li>
810</ul>
811
Daniel Veillard04382ae2001-09-12 18:51:30 +0000[diff] [blame]812<h3>2.4.4: Sep 12 2001</h3>
813<ul>
814 <li>added --convert to xmlcatalog, bug fixes and cleanups of XML
815 Catalog</li>
816 <li>a few bug fixes and some portability changes</li>
817 <li>some documentation cleanups</li>
818</ul>
819
Daniel Veillard39936902001-08-24 00:49:01 +0000[diff] [blame]820<h3>2.4.3: Aug 23 2001</h3>
821<ul>
822 <li>XML Catalog support see the doc</li>
823 <li>New NaN/Infinity floating point code</li>
824 <li>A few bug fixes</li>
825</ul>
826
827<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]828<ul>
829 <li>adds xmlLineNumbersDefault() to control line number generation</li>
830 <li>lot of bug fixes</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]831 <li>the Microsoft MSC projects files should now be up to date</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]832 <li>inheritance of namespaces from DTD defaulted attributes</li>
833 <li>fixes a serious potential security bug</li>
834 <li>added a --format option to xmllint</li>
835</ul>
836
837<h3>2.4.1: July 24 2001</h3>
838<ul>
839 <li>possibility to keep line numbers in the tree</li>
840 <li>some computation NaN fixes</li>
841 <li>extension of the XPath API</li>
842 <li>cleanup for alpha and ia64 targets</li>
843 <li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]844</ul>
845
846<h3>2.4.0: July 10 2001</h3>
847<ul>
848 <li>Fixed a few bugs in XPath, validation, and tree handling.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]849 <li>Fixed XML Base implementation, added a couple of examples to the
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]850 regression tests</li>
851 <li>A bit of cleanup</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]852</ul>
853
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]854<h3>2.3.14: July 5 2001</h3>
855<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]856 <li>fixed some entities problems and reduce memory requirement when
857 substituting them</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]858 <li>lots of improvements in the XPath queries interpreter can be
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]859 substantially faster</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]860 <li>Makefiles and configure cleanups</li>
861 <li>Fixes to XPath variable eval, and compare on empty node set</li>
862 <li>HTML tag closing bug fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]863 <li>Fixed an URI reference computation problem when validating</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]864</ul>
865
Daniel Veillard2adbb512001-06-28 16:20:36 +0000[diff] [blame]866<h3>2.3.13: June 28 2001</h3>
867<ul>
868 <li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
869 <li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
870</ul>
871
872<h3>1.8.14: June 28 2001</h3>
873<ul>
874 <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
875 <li>Small Makefile fix</li>
876</ul>
877
Daniel Veillard11648102001-06-26 16:08:24 +0000[diff] [blame]878<h3>2.3.12: June 26 2001</h3>
879<ul>
880 <li>lots of cleanup</li>
881 <li>a couple of validation fix</li>
882 <li>fixed line number counting</li>
883 <li>fixed serious problems in the XInclude processing</li>
884 <li>added support for UTF8 BOM at beginning of entities</li>
885 <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
886 miscompile uri.c (William), Thomas Leitner provided a fix for the
887 optimizer on Tru64</li>
888 <li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
889 compilation on Windows MSC</li>
890 <li>update of libxml-doc.el (Felix Natter)</li>
891 <li>fixed 2 bugs in URI normalization code</li>
892</ul>
893
Daniel Veillarde3c81b52001-06-17 14:50:34 +0000[diff] [blame]894<h3>2.3.11: June 17 2001</h3>
895<ul>
896 <li>updates to trio, Makefiles and configure should fix some portability
897 problems (alpha)</li>
898 <li>fixed some HTML serialization problems (pre, script, and block/inline
899 handling), added encoding aware APIs, cleanup of this code</li>
900 <li>added xmlHasNsProp()</li>
901 <li>implemented a specific PI for encoding support in the DocBook SGML
902 parser</li>
903 <li>some XPath fixes (-Infinity, / as a function parameter and namespaces
904 node selection)</li>
905 <li>fixed a performance problem and an error in the validation code</li>
906 <li>fixed XInclude routine to implement the recursive behaviour</li>
907 <li>fixed xmlFreeNode problem when libxml is included statically twice</li>
908 <li>added --version to xmllint for bug reports</li>
909</ul>
910
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]911<h3>2.3.10: June 1 2001</h3>
912<ul>
913 <li>fixed the SGML catalog support</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]914 <li>a number of reported bugs got fixed, in XPath, iconv detection,
915 XInclude processing</li>
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]916 <li>XPath string function should now handle unicode correctly</li>
917</ul>
918
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]919<h3>2.3.9: May 19 2001</h3>
920
921<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
922<ul>
923 <li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]924 <li>some serious speed optimization again</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]925 <li>some documentation cleanups</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]926 <li>trying to get better linking on Solaris (-R)</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]927 <li>XPath API cleanup from Thomas Broyer</li>
928 <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
929 xmlValidGetValidElements()</li>
930 <li>Added an INSTALL file</li>
931 <li>Attribute removal added to API: #54433</li>
932 <li>added a basic support for SGML catalogs</li>
933 <li>fixed xmlKeepBlanksDefault(0) API</li>
934 <li>bugfix in xmlNodeGetLang()</li>
935 <li>fixed a small configure portability problem</li>
936 <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
937</ul>
938
Daniel Veillarda265af72001-05-14 11:13:58 +0000[diff] [blame]939<h3>1.8.13: May 14 2001</h3>
940<ul>
941 <li>bugfixes release of the old libxml1 branch used by Gnome</li>
942</ul>
943
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]944<h3>2.3.8: May 3 2001</h3>
945<ul>
946 <li>Integrated an SGML DocBook parser for the Gnome project</li>
947 <li>Fixed a few things in the HTML parser</li>
948 <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
949 point portability issue</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]950 <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
951 DOM+validation using the XML REC as input and a 700MHz celeron).</li>
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]952 <li>incorporated more Windows cleanup</li>
953 <li>added xmlSaveFormatFile()</li>
954 <li>fixed problems in copying nodes with entities references (gdome)</li>
955 <li>removed some troubles surrounding the new validation module</li>
956</ul>
957
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]958<h3>2.3.7: April 22 2001</h3>
959<ul>
960 <li>lots of small bug fixes, corrected XPointer</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]961 <li>Non deterministic content model validation support</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]962 <li>added xmlDocCopyNode for gdome2</li>
963 <li>revamped the way the HTML parser handles end of tags</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]964 <li>XPath: corrections of namespaces support and number formatting</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]965 <li>Windows: Igor Zlatkovic patches for MSC compilation</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]966 <li>HTML output fixes from P C Chow and William M. Brack</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]967 <li>Improved validation speed sensible for DocBook</li>
968 <li>fixed a big bug with ID declared in external parsed entities</li>
969 <li>portability fixes, update of Trio from Bjorn Reese</li>
970</ul>
971
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]972<h3>2.3.6: April 8 2001</h3>
973<ul>
974 <li>Code cleanup using extreme gcc compiler warning options, found and
975 cleared half a dozen potential problem</li>
976 <li>the Eazel team found an XML parser bug</li>
977 <li>cleaned up the user of some of the string formatting function. used the
978 trio library code to provide the one needed when the platform is missing
979 them</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]980 <li>xpath: removed a memory leak and fixed the predicate evaluation
981 problem, extended the testsuite and cleaned up the result. XPointer seems
982 broken ...</li>
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]983</ul>
984
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame]985<h3>2.3.5: Mar 23 2001</h3>
986<ul>
987 <li>Biggest change is separate parsing and evaluation of XPath expressions,
988 there is some new APIs for this too</li>
989 <li>included a number of bug fixes(XML push parser, 51876, notations,
990 52299)</li>
991 <li>Fixed some portability issues</li>
992</ul>
993
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]994<h3>2.3.4: Mar 10 2001</h3>
995<ul>
996 <li>Fixed bugs #51860 and #51861</li>
997 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
998 size to be application tunable.</li>
999 <li>Some cleanup in the validation code, still a bug left and this part
1000 should probably be rewritten to support ambiguous content model :-\</li>
1001 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
1002 parser</li>
1003 <li>Fixed another bug in xmlNodeGetContent()</li>
1004 <li>Bjorn fixed XPath node collection and Number formatting</li>
1005 <li>Fixed a loop reported in the HTML parsing</li>
1006 <li>blank space are reported even if the Dtd content model proves that they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1007 are formatting spaces, this is for XML conformance</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1008</ul>
1009
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]1010<h3>2.3.3: Mar 1 2001</h3>
1011<ul>
1012 <li>small change in XPath for XSLT</li>
1013 <li>documentation cleanups</li>
1014 <li>fix in validation by Gary Pennington</li>
1015 <li>serious parsing performances improvements</li>
1016</ul>
1017
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1018<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]1019<ul>
1020 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
1021 <li>fixed a Dtd parsing bug</li>
1022 <li>fixed a bug in xmlNodeGetContent</li>
1023 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
1024</ul>
1025
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1026<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1027<ul>
1028 <li>some XPath and HTML bug fixes for XSLT</li>
1029 <li>small extension of the hash table interfaces for DOM gdome2
1030 implementation</li>
1031 <li>A few bug fixes</li>
1032</ul>
1033
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1034<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]1035<ul>
1036 <li>Lots of XPath bug fixes</li>
1037 <li>Add a mode with Dtd lookup but without validation error reporting for
1038 XSLT</li>
1039 <li>Add support for text node without escaping (XSLT)</li>
1040 <li>bug fixes for xmlCheckFilename</li>
1041 <li>validation code bug fixes from Gary Pennington</li>
1042 <li>Patch from Paul D. Smith correcting URI path normalization</li>
1043 <li>Patch to allow simultaneous install of libxml-devel and
1044 libxml2-devel</li>
1045 <li>the example Makefile is now fixed</li>
1046 <li>added HTML to the RPM packages</li>
1047 <li>tree copying bugfixes</li>
1048 <li>updates to Windows makefiles</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1049 <li>optimization patch from Bjorn Reese</li>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1050</ul>
1051
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1052<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]1053<ul>
1054 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
1055 <li>added htmlHandleOmittedElem()</li>
1056 <li>Applied Bjorn Reese's IPV6 first patch</li>
1057 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1058 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]1059</ul>
1060
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]1061<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]1062<ul>
1063 <li>Fix the Windows problems of 2.2.8</li>
1064 <li>integrate OpenVMS patches</li>
1065 <li>better handling of some nasty HTML input</li>
1066 <li>Improved the XPointer implementation</li>
1067 <li>integrate a number of provided patches</li>
1068</ul>
1069
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]1070<h3>2.2.9: Nov 25 2000</h3>
1071<ul>
1072 <li>erroneous release :-(</li>
1073</ul>
1074
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]1075<h3>2.2.8: Nov 13 2000</h3>
1076<ul>
1077 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
1078 support</li>
1079 <li>Patch in conditional section handling</li>
1080 <li>updated MS compiler project</li>
1081 <li>fixed some XPath problems</li>
1082 <li>added an URI escaping function</li>
1083 <li>some other bug fixes</li>
1084</ul>
1085
1086<h3>2.2.7: Oct 31 2000</h3>
1087<ul>
1088 <li>added message redirection</li>
1089 <li>XPath improvements (thanks TOM !)</li>
1090 <li>xmlIOParseDTD() added</li>
1091 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
1092 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
1093</ul>
1094
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]1095<h3>2.2.6: Oct 25 2000:</h3>
1096<ul>
1097 <li>Added an hash table module, migrated a number of internal structure to
1098 those</li>
1099 <li>Fixed a posteriori validation problems</li>
1100 <li>HTTP module cleanups</li>
1101 <li>HTML parser improvements (tag errors, script/style handling, attribute
1102 normalization)</li>
1103 <li>coalescing of adjacent text nodes</li>
1104 <li>couple of XPath bug fixes, exported the internal API</li>
1105</ul>
1106
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1107<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1108<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1109 <li>XPointer implementation and testsuite</li>
1110 <li>Lot of XPath fixes, added variable and functions registration, more
1111 tests</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1112 <li>Portability fixes, lots of enhancements toward an easy Windows build
1113 and release</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1114 <li>Late validation fixes</li>
1115 <li>Integrated a lot of contributed patches</li>
1116 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1117 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1118</ul>
1119
1120<h3>2.2.4: Oct 1 2000:</h3>
1121<ul>
1122 <li>main XPath problem fixed</li>
1123 <li>Integrated portability patches for Windows</li>
1124 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1125</ul>
1126
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1127<h3>2.2.3: Sep 17 2000</h3>
1128<ul>
1129 <li>bug fixes</li>
1130 <li>cleanup of entity handling code</li>
1131 <li>overall review of all loops in the parsers, all sprintf usage has been
1132 checked too</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1133 <li>Far better handling of larges Dtd. Validating against DocBook XML Dtd
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1134 works smoothly now.</li>
1135</ul>
1136
1137<h3>1.8.10: Sep 6 2000</h3>
1138<ul>
1139 <li>bug fix release for some Gnome projects</li>
1140</ul>
1141
1142<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1143<ul>
1144 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]1145 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1146</ul>
1147
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1148<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1149<ul>
1150 <li>a purely bug fixes release</li>
1151 <li>fixed an encoding support problem when parsing from a memory block</li>
1152 <li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1153 <li>removed a bug in the function allowing to override the memory
1154 allocation routines</li>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1155</ul>
1156
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1157<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]1158<ul>
1159 <li>applied a lot of portability fixes</li>
1160 <li>better encoding support/cleanup and saving (content is now always
1161 encoded in UTF-8)</li>
1162 <li>the HTML parser now correctly handles encodings</li>
1163 <li>added xmlHasProp()</li>
1164 <li>fixed a serious problem with &amp;#38;</li>
1165 <li>propagated the fix to FTP client</li>
1166 <li>cleanup, bugfixes, etc ...</li>
1167 <li>Added a page about <a href="encoding.html">libxml Internationalization
1168 support</a></li>
1169</ul>
1170
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1171<h3>1.8.9: July 9 2000</h3>
1172<ul>
1173 <li>fixed the spec the RPMs should be better</li>
1174 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
1175 rpmfind users problem</li>
1176</ul>
1177
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]1178<h3>2.1.1: July 1 2000</h3>
1179<ul>
1180 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
1181 <li>improvements on the HTML parser</li>
1182</ul>
1183
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1184<h3>2.1.0 and 1.8.8: June 29 2000</h3>
1185<ul>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1186 <li>1.8.8 is mostly a commodity package for upgrading to libxml2 according
1187 to <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1188 about &amp;#38; charref parsing</li>
1189 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
1190 also contains numerous fixes and enhancements:
1191 <ul>
1192 <li>added xmlStopParser() to stop parsing</li>
1193 <li>improved a lot parsing speed when there is large CDATA blocs</li>
1194 <li>includes XPath patches provided by Picdar Technology</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1195 <li>tried to fix as much as possible DTD validation and namespace
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1196 related problems</li>
1197 <li>output to a given encoding has been added/tested</li>
1198 <li>lot of various fixes</li>
1199 </ul>
1200 </li>
1201</ul>
1202
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1203<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1204<ul>
1205 <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]1206 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initially
1207 scheduled for Apr 3 the release occurred only on Apr 12 due to massive
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1208 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1209 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1210 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1211 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1212 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1213 <pre>#include "xxx.h"</pre>
1214 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]1215 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
1216 <li>the memory allocation routines used by libxml can now be overloaded
1217 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1218 <li>The previously CVS only tool tester has been renamed
1219 <strong>xmllint</strong> and is now installed as part of the libxml2
1220 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1221 <li>The I/O interface has been revamped. There is now ways to plug in
1222 specific I/O modules, either at the URI scheme detection level using
1223 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
1224 parser context using xmlCreateIOParserCtxt()</li>
1225 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
1226 number of the libxml module in use</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1227 <li>a number of optional features of libxml can now be excluded at
1228 configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1229</ul>
1230
1231<h3>2.0.0beta: Mar 14 2000</h3>
1232<ul>
1233 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1234 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
1235 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
1236 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1237 <li>This version is now the head in the Gnome CVS base, the old one is
1238 available under the tag LIB_XML_1_X</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1239 <li>This includes a very large set of changes. From a programmatic point
1240 of view applications should not have to be modified too much, check the
1241 <a href="upgrade.html">upgrade page</a></li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1242 <li>Some interfaces may changes (especially a bit about encoding).</li>
1243 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1244 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1245 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
1246 handled now</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1247 <li>Better handling of entities, especially well-formedness checking
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1248 and proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1249 <li>DTD conditional sections</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1250 <li>Validation now correctly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1251 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1252 structures to accommodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1253 </ul>
1254 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1255 <li>Serious progress were made toward compliance, <a
1256 href="conf/result.html">here are the result of the test</a> against the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1257 OASIS testsuite (except the Japanese tests since I don't support that
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1258 encoding yet). This URL is rebuilt every couple of hours using the CVS
1259 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1260</ul>
1261
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1262<h3>1.8.7: Mar 6 2000</h3>
1263<ul>
1264 <li>This is a bug fix release:</li>
1265 <li>It is possible to disable the ignorable blanks heuristic used by
1266 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1267 that for adherence to XML spec, this behaviour will be disabled by
1268 default in 2.x . The same function will allow to keep compatibility for
1269 old code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1270 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
1271 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1272 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
1273 compilation on some platforms has been fixed</li>
1274 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
1275 URIs</li>
1276</ul>
1277
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1278<h3>1.8.6: Jan 31 2000</h3>
1279<ul>
1280 <li>added a nanoFTP transport module, debugged until the new version of <a
1281 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
1282 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]1283</ul>
1284
1285<h3>1.8.5: Jan 21 2000</h3>
1286<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1287 <li>adding APIs to parse a well balanced chunk of XML (production <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1288 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
1289 XML spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1290 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1291 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
1292 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1293 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
1294 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1295</ul>
1296
1297<h3>1.8.4: Jan 13 2000</h3>
1298<ul>
1299 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
1300 <li>all exit() call should have been removed from libxml</li>
1301 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
1302 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1303</ul>
1304
1305<h3>1.8.3: Jan 5 2000</h3>
1306<ul>
1307 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1308 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1309 <li>lots of bug fixes and improvement added over XMas holidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1310 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1311 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
1312 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1313 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1314 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1315 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1316</ul>
1317
1318<h3>1.8.2: Dec 21 1999</h3>
1319<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1320 <li>I got another problem with includes and C++, I hope this issue is fixed
1321 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1322 <li>Added a few tree modification functions: xmlReplaceNode,
1323 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
1324 xmlDocSetRootElement</li>
1325 <li>Tried to improve the HTML output with help from <a
1326 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1327</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1328
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1329<h3>1.8.1: Dec 18 1999</h3>
1330<ul>
1331 <li>various patches to avoid troubles when using libxml with C++ compilers
1332 the "namespace" keyword and C escaping in include files</li>
1333 <li>a problem in one of the core macros IS_CHAR was corrected</li>
1334 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
1335 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]1336 <li>fixed a posteriori validation (validation after parsing, or by using a
1337 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1338 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]1339</ul>
1340
1341<h3>1.8.0: Dec 12 1999</h3>
1342<ul>
1343 <li>cleanup, especially memory wise</li>
1344 <li>the parser should be more reliable, especially the HTML one, it should
1345 not crash, whatever the input !</li>
1346 <li>Integrated various patches, especially a speedup improvement for large
1347 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
1348 configure with --with-buffers to enable them.</li>
1349 <li>attribute normalization, oops should have been added long ago !</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1350 <li>attributes defaulted from DTDs should be available, xmlSetProp() now
1351 does entities escaping by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1352</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1353
1354<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1355<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1356 <li>Lots of HTML improvement</li>
1357 <li>Fixed some errors when saving both XML and HTML</li>
1358 <li>More examples, the regression tests should now look clean</li>
1359 <li>Fixed a bug with contiguous charref</li>
1360</ul>
1361
1362<h3>1.7.3: Sep 29 1999</h3>
1363<ul>
1364 <li>portability problems fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1365 <li>snprintf was used unconditionally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1366 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1367</ul>
1368
1369<h3>1.7.1: Sep 24 1999</h3>
1370<ul>
1371 <li>The basic type for strings manipulated by libxml has been renamed in
1372 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1373 is that CHAR was conflicting with a predefined type on Windows. However
1374 on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1375 <strong>#define </strong>.</li>
1376 <li>Changed another error : the use of a structure field called errno, and
1377 leading to troubles on platforms where it's a macro</li>
1378</ul>
1379
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1380<h3>1.7.0: Sep 23 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1381<ul>
1382 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1383 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1384 <li>Added an errno to report errors by another mean than a simple printf
1385 like callback</li>
1386 <li>Finished ID/IDREF support and checking when validation</li>
1387 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1388 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1389 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
1390 implementation</li>
1391 <li>Added an HTML parser front-end</li>
1392</ul>
1393
1394<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1395
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1396<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]1397markup-based structured documents. Here is <a name="example">an example XML
1398document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1399<pre>&lt;?xml version="1.0"?&gt;
1400&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
1401 &lt;head&gt;
1402 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
1403 &lt;/head&gt;
1404 &lt;chapter&gt;
1405 &lt;title&gt;The Linux adventure&lt;/title&gt;
1406 &lt;p&gt;bla bla bla ...&lt;/p&gt;
1407 &lt;image href="linus.gif"/&gt;
1408 &lt;p&gt;...&lt;/p&gt;
1409 &lt;/chapter&gt;
1410&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1411
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1412<p>The first line specifies that it is an XML document and gives useful
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1413information about its encoding. Then the rest of the document is a text
1414format whose structure is specified by tags between brackets. <strong>Each
1415tag opened has to be closed</strong>. XML is pedantic about this. However, if
1416a tag is empty (no content), a single tag can serve as both the opening and
1417closing tag if it ends with <code>/&gt;</code> rather than with
1418<code>&gt;</code>. Note that, for example, the image tag has no content (just
1419an attribute) and is closed by ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1420
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1421<p>XML can be applied successfully to a wide range of tasks, ranging from
1422long term structured document maintenance (where it follows the steps of
1423SGML) to simple data encoding mechanisms like configuration file formatting
1424(glade), spreadsheets (gnumeric), or even shorter lived documents such as
1425WebDAV where it is used to encode remote calls between a client and a
1426server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1427
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1428<h2><a name="XSLT">XSLT</a></h2>
1429
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1430<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
1431
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1432<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
1433language for transforming XML documents into other XML documents (or
1434HTML/textual output).</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1435
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1436<p>A separate library called libxslt is being developed on top of libxml2.
1437This module "libxslt" too can be found in the Gnome CVS base.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1438
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]1439<p>You can check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1440href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
1441supported and the progresses on the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1442href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog"
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1443name="Changelog">Changelog</a>.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1444
1445<h2><a name="Python">Python and bindings</a></h2>
1446
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1447<p>There are a number of language bindings and wrappers available for
1448libxml2, the list below is not exhaustive. Please contact the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1449href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a>
1450(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in
1451order to get updates to this list or to discuss the specific topic of libxml2
1452or libxslt wrappers or bindings:</p>
1453<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1454 <li><a href="mailto:ari@lusis.org">Ari Johnson</a> provides a C++ wrapper
1455 for libxml:<br>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1456 Website: <a
1457 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a><br>
1458 Download: <a
1459 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></li>
1460 <li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1461 based on the gdome2 bindings</a> maintained by Tobias Peters.</li>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]1462 <li>and a third C++ wrapper by Peter Jones &lt;pjones@pmade.org&gt;
1463 <p>Website: <a
1464 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
1465 </li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1466 <li><a
1467 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1468 Sergeant</a> developed <a
1469 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1470 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1471 application server</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]1472 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides an
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1473 earlier version of the libxml/libxslt <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1474 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]1475 <li>Gopal.V and Peter Minten develop <a
1476 href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1477 C# libxml2 bindings.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1478 <li>Petr Kozelka provides <a
1479 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1480 libxml2</a> with Kylix, Delphi and other Pascal compilers.</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]1481 <li>Uwe Fechner also provides <a
1482 href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1483 implementation for Kylix2/D5/D6 from Borland.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1484 <li>Wai-Sun "Squidster" Chia provides <a
1485 href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and
1486 libxml2 bindings are also available in Ruby through the <a
1487 href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module
1488 maintained by Tobias Peters.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1489 <li>Steve Ball and contributors maintains <a
1490 href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1491 Tcl</a>.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1492 <li>There is support for libxml2 in the DOM module of PHP.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1493</ul>
1494
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1495<p>The distribution includes a set of Python bindings, which are guaranteed
1496to be maintained as part of the library in the future, though the Python
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1497interface have not yet reached the maturity of the C API.</p>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1498
1499<p>To install the Python bindings there are 2 options:</p>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1500<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1501 <li>If you use an RPM based distribution, simply install the <a
1502 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python
1503 RPM</a> (and if needed the <a
1504 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python
1505 RPM</a>).</li>
1506 <li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python
1507 module distribution</a> corresponding to your installed version of
1508 libxml2 and libxslt. Note that to install it you will need both libxml2
1509 and libxslt installed and run "python setup.py build install" in the
1510 module tree.</li>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1511</ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1512
1513<p>The distribution includes a set of examples and regression tests for the
1514python bindings in the <code>python/tests</code> directory. Here are some
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1515excerpts from those tests:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1516
1517<h3>tst.py:</h3>
1518
1519<p>This is a basic test of the file interface and DOM navigation:</p>
1520<pre>import libxml2
1521
1522doc = libxml2.parseFile("tst.xml")
1523if doc.name != "tst.xml":
1524 print "doc.name failed"
1525 sys.exit(1)
1526root = doc.children
1527if root.name != "doc":
1528 print "root.name failed"
1529 sys.exit(1)
1530child = root.children
1531if child.name != "foo":
1532 print "child.name failed"
1533 sys.exit(1)
1534doc.freeDoc()</pre>
1535
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1536<p>The Python module is called libxml2; parseFile is the equivalent of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1537xmlParseFile (most of the bindings are automatically generated, and the xml
1538prefix is removed and the casing convention are kept). All node seen at the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1539binding level share the same subset of accessors:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1540<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1541 <li><code>name</code> : returns the node name</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1542 <li><code>type</code> : returns a string indicating the node type</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1543 <li><code>content</code> : returns the content of the node, it is based on
1544 xmlNodeGetContent() and hence is recursive.</li>
1545 <li><code>parent</code> , <code>children</code>, <code>last</code>,
1546 <code>next</code>, <code>prev</code>, <code>doc</code>,
1547 <code>properties</code>: pointing to the associated element in the tree,
1548 those may return None in case no such link exists.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1549</ul>
1550
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1551<p>Also note the need to explicitly deallocate documents with freeDoc() .
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1552Reference counting for libxml2 trees would need quite a lot of work to
1553function properly, and rather than risk memory leaks if not implemented
1554correctly it sounds safer to have an explicit function to free a tree. The
1555wrapper python objects like doc, root or child are them automatically garbage
1556collected.</p>
1557
1558<h3>validate.py:</h3>
1559
1560<p>This test check the validation interfaces and redirection of error
1561messages:</p>
1562<pre>import libxml2
1563
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1564#deactivate error messages from the validation
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1565def noerr(ctx, str):
1566 pass
1567
1568libxml2.registerErrorHandler(noerr, None)
1569
1570ctxt = libxml2.createFileParserCtxt("invalid.xml")
1571ctxt.validate(1)
1572ctxt.parseDocument()
1573doc = ctxt.doc()
1574valid = ctxt.isValid()
1575doc.freeDoc()
1576if valid != 0:
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1577 print "validity check failed"</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1578
1579<p>The first thing to notice is the call to registerErrorHandler(), it
1580defines a new error handler global to the library. It is used to avoid seeing
1581the error messages when trying to validate the invalid document.</p>
1582
1583<p>The main interest of that test is the creation of a parser context with
1584createFileParserCtxt() and how the behaviour can be changed before calling
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1585parseDocument() . Similarly the informations resulting from the parsing phase
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1586are also available using context methods.</p>
1587
1588<p>Contexts like nodes are defined as class and the libxml2 wrappers maps the
1589C function interfaces in terms of objects method as much as possible. The
1590best to get a complete view of what methods are supported is to look at the
1591libxml2.py module containing all the wrappers.</p>
1592
1593<h3>push.py:</h3>
1594
1595<p>This test show how to activate the push parser interface:</p>
1596<pre>import libxml2
1597
1598ctxt = libxml2.createPushParser(None, "&lt;foo", 4, "test.xml")
1599ctxt.parseChunk("/&gt;", 2, 1)
1600doc = ctxt.doc()
1601
1602doc.freeDoc()</pre>
1603
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1604<p>The context is created with a special call based on the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1605xmlCreatePushParser() from the C library. The first argument is an optional
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1606SAX callback object, then the initial set of data, the length and the name of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1607the resource in case URI-References need to be computed by the parser.</p>
1608
1609<p>Then the data are pushed using the parseChunk() method, the last call
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1610setting the third argument terminate to 1.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1611
1612<h3>pushSAX.py:</h3>
1613
1614<p>this test show the use of the event based parsing interfaces. In this case
1615the parser does not build a document, but provides callback information as
1616the parser makes progresses analyzing the data being provided:</p>
1617<pre>import libxml2
1618log = ""
1619
1620class callback:
1621 def startDocument(self):
1622 global log
1623 log = log + "startDocument:"
1624
1625 def endDocument(self):
1626 global log
1627 log = log + "endDocument:"
1628
1629 def startElement(self, tag, attrs):
1630 global log
1631 log = log + "startElement %s %s:" % (tag, attrs)
1632
1633 def endElement(self, tag):
1634 global log
1635 log = log + "endElement %s:" % (tag)
1636
1637 def characters(self, data):
1638 global log
1639 log = log + "characters: %s:" % (data)
1640
1641 def warning(self, msg):
1642 global log
1643 log = log + "warning: %s:" % (msg)
1644
1645 def error(self, msg):
1646 global log
1647 log = log + "error: %s:" % (msg)
1648
1649 def fatalError(self, msg):
1650 global log
1651 log = log + "fatalError: %s:" % (msg)
1652
1653handler = callback()
1654
1655ctxt = libxml2.createPushParser(handler, "&lt;foo", 4, "test.xml")
1656chunk = " url='tst'&gt;b"
1657ctxt.parseChunk(chunk, len(chunk), 0)
1658chunk = "ar&lt;/foo&gt;"
1659ctxt.parseChunk(chunk, len(chunk), 1)
1660
Daniel Veillardfcbfa2d2002-02-21 17:54:27 +0000[diff] [blame]1661reference = "startDocument:startElement foo {'url': 'tst'}:" + \
1662 "characters: bar:endElement foo:endDocument:"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1663if log != reference:
1664 print "Error got: %s" % log
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1665 print "Expected: %s" % reference</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1666
1667<p>The key object in that test is the handler, it provides a number of entry
1668points which can be called by the parser as it makes progresses to indicate
1669the information set obtained. The full set of callback is larger than what
1670the callback class in that specific example implements (see the SAX
1671definition for a complete list). The wrapper will only call those supplied by
1672the object when activated. The startElement receives the names of the element
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1673and a dictionary containing the attributes carried by this element.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1674
1675<p>Also note that the reference string generated from the callback shows a
1676single character call even though the string "bar" is passed to the parser
1677from 2 different call to parseChunk()</p>
1678
1679<h3>xpath.py:</h3>
1680
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1681<p>This is a basic test of XPath wrappers support</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1682<pre>import libxml2
1683
1684doc = libxml2.parseFile("tst.xml")
1685ctxt = doc.xpathNewContext()
1686res = ctxt.xpathEval("//*")
1687if len(res) != 2:
1688 print "xpath query: wrong node set size"
1689 sys.exit(1)
1690if res[0].name != "doc" or res[1].name != "foo":
1691 print "xpath query: wrong node set value"
1692 sys.exit(1)
1693doc.freeDoc()
1694ctxt.xpathFreeContext()</pre>
1695
1696<p>This test parses a file, then create an XPath context to evaluate XPath
1697expression on it. The xpathEval() method execute an XPath query and returns
1698the result mapped in a Python way. String and numbers are natively converted,
1699and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1700the document, the XPath context need to be freed explicitly, also not that
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1701the result of the XPath query may point back to the document tree and hence
1702the document must be freed after the result of the query is used.</p>
1703
1704<h3>xpathext.py:</h3>
1705
1706<p>This test shows how to extend the XPath engine with functions written in
1707python:</p>
1708<pre>import libxml2
1709
1710def foo(ctx, x):
1711 return x + 1
1712
1713doc = libxml2.parseFile("tst.xml")
1714ctxt = doc.xpathNewContext()
1715libxml2.registerXPathFunction(ctxt._o, "foo", None, foo)
1716res = ctxt.xpathEval("foo(1)")
1717if res != 2:
1718 print "xpath extension failure"
1719doc.freeDoc()
1720ctxt.xpathFreeContext()</pre>
1721
1722<p>Note how the extension function is registered with the context (but that
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1723part is not yet finalized, this may change slightly in the future).</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1724
1725<h3>tstxpath.py:</h3>
1726
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1727<p>This test is similar to the previous one but shows how the extension
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1728function can access the XPath evaluation context:</p>
1729<pre>def foo(ctx, x):
1730 global called
1731
1732 #
1733 # test that access to the XPath evaluation contexts
1734 #
1735 pctxt = libxml2.xpathParserContext(_obj=ctx)
1736 ctxt = pctxt.context()
1737 called = ctxt.function()
1738 return x + 1</pre>
1739
1740<p>All the interfaces around the XPath parser(or rather evaluation) context
1741are not finalized, but it should be sufficient to do contextual work at the
1742evaluation point.</p>
1743
1744<h3>Memory debugging:</h3>
1745
1746<p>last but not least, all tests starts with the following prologue:</p>
1747<pre>#memory debug specific
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1748libxml2.debugMemory(1)</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1749
1750<p>and ends with the following epilogue:</p>
1751<pre>#memory debug specific
1752libxml2.cleanupParser()
1753if libxml2.debugMemory(1) == 0:
1754 print "OK"
1755else:
1756 print "Memory leak %d bytes" % (libxml2.debugMemory(1))
1757 libxml2.dumpMemory()</pre>
1758
1759<p>Those activate the memory debugging interface of libxml2 where all
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1760allocated block in the library are tracked. The prologue then cleans up the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1761library state and checks that all allocated memory has been freed. If not it
1762calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1763
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1764<h2><a name="architecture">libxml architecture</a></h2>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1765
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1766<p>Libxml is made of multiple components; some of them are optional, and most
1767of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1768<ul>
1769 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1770 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1771 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1772 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1773 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1774 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1775 <li>a SAX tree module to build an in-memory DOM representation</li>
1776 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1777 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1778 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1779 (optional)</li>
1780 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1781</ul>
1782
1783<p>Graphically this gives the following:</p>
1784
1785<p><img src="libxml.gif" alt="a graphical view of the various"></p>
1786
1787<p></p>
1788
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1789<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1790
1791<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1792returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1793<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1794as the file name, the document type, and a <strong>children</strong> pointer
1795which is the root of the document (or more exactly the first child under the
1796root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1797chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1798relationship. An xmlNode can also carry properties (a chain of xmlAttr
1799structures). An attribute may have a value which is a list of TEXT or
1800ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1801
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1802<p>Here is an example (erroneous with respect to the XML spec since there
1803should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1804
1805<p><img src="structure.gif" alt=" structure.gif "></p>
1806
1807<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1808called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1809prints them back as parsed. This is useful for detecting errors both in XML
1810code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1811which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1812result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1813<pre>DOCUMENT
1814version=1.0
1815standalone=true
1816 ELEMENT EXAMPLE
1817 ATTRIBUTE prop1
1818 TEXT
1819 content=gnome is great
1820 ATTRIBUTE prop2
1821 ENTITY_REF
1822 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1823 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1824 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1825 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1826 TEXT
1827 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1828 ELEMENT chapter
1829 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1830 TEXT
1831 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1832 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1833 TEXT
1834 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1835 ELEMENT image
1836 ATTRIBUTE href
1837 TEXT
1838 content=linus.gif
1839 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1840 TEXT
1841 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1842
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1843<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1844
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1845<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1846
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1847<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1848memory. 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]1849loaded using libxml), it's better to use the SAX interface of libxml. SAX is
1850a <strong>callback-based interface</strong> to the parser. Before parsing,
1851the application layer registers a customized set of callbacks which are
1852called by the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1853
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1854<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]1855libxml, see the <a
1856href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
1857documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1858Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1859
1860<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
1861program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1862binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1863distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1864testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1865<pre>SAX.setDocumentLocator()
1866SAX.startDocument()
1867SAX.getEntity(amp)
1868SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
1869SAX.characters( , 3)
1870SAX.startElement(head)
1871SAX.characters( , 4)
1872SAX.startElement(title)
1873SAX.characters(Welcome to Gnome, 16)
1874SAX.endElement(title)
1875SAX.characters( , 3)
1876SAX.endElement(head)
1877SAX.characters( , 3)
1878SAX.startElement(chapter)
1879SAX.characters( , 4)
1880SAX.startElement(title)
1881SAX.characters(The Linux adventure, 19)
1882SAX.endElement(title)
1883SAX.characters( , 4)
1884SAX.startElement(p)
1885SAX.characters(bla bla bla ..., 15)
1886SAX.endElement(p)
1887SAX.characters( , 4)
1888SAX.startElement(image, href='linus.gif')
1889SAX.endElement(image)
1890SAX.characters( , 4)
1891SAX.startElement(p)
1892SAX.characters(..., 3)
1893SAX.endElement(p)
1894SAX.characters( , 3)
1895SAX.endElement(chapter)
1896SAX.characters( , 1)
1897SAX.endElement(EXAMPLE)
1898SAX.endDocument()</pre>
1899
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1900<p>Most of the other interfaces of libxml are based on the DOM tree-building
1901facility, so nearly everything up to the end of this document presupposes the
1902use of the standard DOM tree build. Note that the DOM tree itself is built by
1903a set of registered default callbacks, without internal specific
1904interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1905
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1906<h2><a name="Validation">Validation &amp; DTDs</a></h2>
1907
1908<p>Table of Content:</p>
1909<ol>
1910 <li><a href="#General5">General overview</a></li>
1911 <li><a href="#definition">The definition</a></li>
1912 <li><a href="#Simple">Simple rules</a>
1913 <ol>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]1914 <li><a href="#reference">How to reference a DTD from a document</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1915 <li><a href="#Declaring">Declaring elements</a></li>
1916 <li><a href="#Declaring1">Declaring attributes</a></li>
1917 </ol>
1918 </li>
1919 <li><a href="#Some">Some examples</a></li>
1920 <li><a href="#validate">How to validate</a></li>
1921 <li><a href="#Other">Other resources</a></li>
1922</ol>
1923
1924<h3><a name="General5">General overview</a></h3>
1925
1926<p>Well what is validation and what is a DTD ?</p>
1927
1928<p>DTD is the acronym for Document Type Definition. This is a description of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1929the 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]1930specification, and allows one to describe and verify that a given document
1931instance conforms to the set of rules detailing its structure and content.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1932
1933<p>Validation is the process of checking a document against a DTD (more
1934generally against a set of construction rules).</p>
1935
1936<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1937of the XML life cycle. Briefly a DTD defines all the possible elements to be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1938found within your document, what is the formal shape of your document tree
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1939(by defining the allowed content of an element; either text, a regular
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1940expression for the allowed list of children, or mixed content i.e. both text
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1941and children). The DTD also defines the valid attributes for all elements and
1942the types of those attributes.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1943
1944<h3><a name="definition1">The definition</a></h3>
1945
1946<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
1947href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
1948Rev1</a>):</p>
1949<ul>
1950 <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
1951 elements</a></li>
1952 <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
1953 attributes</a></li>
1954</ul>
1955
1956<p>(unfortunately) all this is inherited from the SGML world, the syntax is
1957ancient...</p>
1958
1959<h3><a name="Simple1">Simple rules</a></h3>
1960
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1961<p>Writing DTDs can be done in many ways. The rules to build them if you need
1962something permanent or something which can evolve over time can be radically
1963different. Really complex DTDs like DocBook ones are flexible but quite
1964harder 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]1965structure. It is just a set of basic rules, and definitely not exhaustive nor
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1966usable for complex DTD design.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1967
1968<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
1969
1970<p>Assuming the top element of the document is <code>spec</code> and the dtd
1971is placed in the file <code>mydtd</code> in the subdirectory
1972<code>dtds</code> of the directory from where the document were loaded:</p>
1973
1974<p><code>&lt;!DOCTYPE spec SYSTEM "dtds/mydtd"&gt;</code></p>
1975
1976<p>Notes:</p>
1977<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1978 <li>The system string is actually an URI-Reference (as defined in <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1979 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]1980 full URL string indicating the location of your DTD on the Web. This is a
1981 really good thing to do if you want others to validate your document.</li>
1982 <li>It is also possible to associate a <code>PUBLIC</code> identifier (a
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1983 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]1984 without having to locate it on the web.</li>
1985 <li>A DTD contains a set of element and attribute declarations, but they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1986 don't define what the root of the document should be. This is explicitly
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1987 told to the parser/validator as the first element of the
1988 <code>DOCTYPE</code> declaration.</li>
1989</ul>
1990
1991<h4><a name="Declaring2">Declaring elements</a>:</h4>
1992
1993<p>The following declares an element <code>spec</code>:</p>
1994
1995<p><code>&lt;!ELEMENT spec (front, body, back?)&gt;</code></p>
1996
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1997<p>It also expresses that the spec element contains one <code>front</code>,
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1998one <code>body</code> and one optional <code>back</code> children elements in
1999this order. The declaration of one element of the structure and its content
2000are done in a single declaration. Similarly the following declares
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2001<code>div1</code> elements:</p>
2002
Daniel Veillard51737272002-01-23 23:10:38 +0000[diff] [blame]2003<p><code>&lt;!ELEMENT div1 (head, (p | list | note)*, div2?)&gt;</code></p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2004
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2005<p>which means div1 contains one <code>head</code> then a series of optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2006<code>p</code>, <code>list</code>s and <code>note</code>s and then an
2007optional <code>div2</code>. And last but not least an element can contain
2008text:</p>
2009
2010<p><code>&lt;!ELEMENT b (#PCDATA)&gt;</code></p>
2011
2012<p><code>b</code> contains text or being of mixed content (text and elements
2013in no particular order):</p>
2014
2015<p><code>&lt;!ELEMENT p (#PCDATA|a|ul|b|i|em)*&gt;</code></p>
2016
2017<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
2018<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
2019order.</p>
2020
2021<h4><a name="Declaring1">Declaring attributes</a>:</h4>
2022
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2023<p>Again the attributes declaration includes their content definition:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2024
2025<p><code>&lt;!ATTLIST termdef name CDATA #IMPLIED&gt;</code></p>
2026
2027<p>means that the element <code>termdef</code> can have a <code>name</code>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2028attribute containing text (<code>CDATA</code>) and which is optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2029(<code>#IMPLIED</code>). The attribute value can also be defined within a
2030set:</p>
2031
2032<p><code>&lt;!ATTLIST list type (bullets|ordered|glossary)
2033"ordered"&gt;</code></p>
2034
2035<p>means <code>list</code> element have a <code>type</code> attribute with 3
2036allowed values "bullets", "ordered" or "glossary" and which default to
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2037"ordered" if the attribute is not explicitly specified.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2038
2039<p>The content type of an attribute can be text (<code>CDATA</code>),
2040anchor/reference/references
2041(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
2042(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
2043(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
2044<code>chapter</code> element can have an optional <code>id</code> attribute
2045of type <code>ID</code>, usable for reference from attribute of type
2046IDREF:</p>
2047
2048<p><code>&lt;!ATTLIST chapter id ID #IMPLIED&gt;</code></p>
2049
2050<p>The last value of an attribute definition can be <code>#REQUIRED
2051</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
2052meaning that it is optional, or the default value (possibly prefixed by
2053<code>#FIXED</code> if it is the only allowed).</p>
2054
2055<p>Notes:</p>
2056<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2057 <li>Usually the attributes pertaining to a given element are declared in a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2058 single expression, but it is just a convention adopted by a lot of DTD
2059 writers:
2060 <pre>&lt;!ATTLIST termdef
2061 id ID #REQUIRED
2062 name CDATA #IMPLIED&gt;</pre>
2063 <p>The previous construct defines both <code>id</code> and
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2064 <code>name</code> attributes for the element <code>termdef</code>.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2065 </li>
2066</ul>
2067
2068<h3><a name="Some1">Some examples</a></h3>
2069
2070<p>The directory <code>test/valid/dtds/</code> in the libxml distribution
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2071contains some complex DTD examples. The example in the file
2072<code>test/valid/dia.xml</code> shows an XML file where the simple DTD is
2073directly included within the document.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2074
2075<h3><a name="validate1">How to validate</a></h3>
2076
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2077<p>The simplest way is to use the xmllint program included with libxml. The
2078<code>--valid</code> option turns-on validation of the files given as input.
2079For example the following validates a copy of the first revision of the XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]20801.0 specification:</p>
2081
2082<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
2083
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2084<p>the -- noout is used to disable output of the resulting tree.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2085
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2086<p>The <code>--dtdvalid dtd</code> allows validation of the document(s)
2087against a given DTD.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2088
2089<p>Libxml exports an API to handle DTDs and validation, check the <a
2090href="http://xmlsoft.org/html/libxml-valid.html">associated
2091description</a>.</p>
2092
2093<h3><a name="Other1">Other resources</a></h3>
2094
2095<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
2096will just list one for now, others pointers welcome:</p>
2097<ul>
2098 <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
2099</ul>
2100
2101<p>I suggest looking at the examples found under test/valid/dtd and any of
2102the large number of books available on XML. The dia example in test/valid
2103should be both simple and complete enough to allow you to build your own.</p>
2104
2105<p></p>
2106
2107<h2><a name="Memory">Memory Management</a></h2>
2108
2109<p>Table of Content:</p>
2110<ol>
2111 <li><a href="#General3">General overview</a></li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2112 <li><a href="#setting">Setting libxml set of memory routines</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2113 <li><a href="#cleanup">Cleaning up after parsing</a></li>
2114 <li><a href="#Debugging">Debugging routines</a></li>
2115 <li><a href="#General4">General memory requirements</a></li>
2116</ol>
2117
2118<h3><a name="General3">General overview</a></h3>
2119
2120<p>The module <code><a
2121href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
2122provides the interfaces to the libxml memory system:</p>
2123<ul>
2124 <li>libxml does not use the libc memory allocator directly but xmlFree(),
2125 xmlMalloc() and xmlRealloc()</li>
2126 <li>those routines can be reallocated to a specific set of routine, by
2127 default the libc ones i.e. free(), malloc() and realloc()</li>
2128 <li>the xmlmemory.c module includes a set of debugging routine</li>
2129</ul>
2130
2131<h3><a name="setting">Setting libxml set of memory routines</a></h3>
2132
2133<p>It is sometimes useful to not use the default memory allocator, either for
2134debugging, analysis or to implement a specific behaviour on memory management
2135(like on embedded systems). Two function calls are available to do so:</p>
2136<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2137 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet
2138 ()</a> which return the current set of functions in use by the parser</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2139 <li><a
2140 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2141 which allow to set up a new set of memory allocation functions</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2142</ul>
2143
2144<p>Of course a call to xmlMemSetup() should probably be done before calling
2145any other libxml routines (unless you are sure your allocations routines are
2146compatibles).</p>
2147
2148<h3><a name="cleanup">Cleaning up after parsing</a></h3>
2149
2150<p>Libxml is not stateless, there is a few set of memory structures needing
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2151allocation before the parser is fully functional (some encoding structures
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2152for example). This also mean that once parsing is finished there is a tiny
2153amount of memory (a few hundred bytes) which can be recollected if you don't
2154reuse the parser immediately:</p>
2155<ul>
2156 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2157 ()</a> is a centralized routine to free the parsing states. Note that it
2158 won't deallocate any produced tree if any (use the xmlFreeDoc() and
2159 related routines for this).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2160 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2161 ()</a> is the dual routine allowing to preallocate the parsing state
2162 which can be useful for example to avoid initialization reentrancy
2163 problems when using libxml in multithreaded applications</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2164</ul>
2165
2166<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
2167at the next invocation of parser routines, but be careful of the consequences
2168in multithreaded applications.</p>
2169
2170<h3><a name="Debugging">Debugging routines</a></h3>
2171
2172<p>When configured using --with-mem-debug flag (off by default), libxml uses
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2173a set of memory allocation debugging routines keeping track of all allocated
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2174blocks and the location in the code where the routine was called. A couple of
2175other debugging routines allow to dump the memory allocated infos to a file
2176or call a specific routine when a given block number is allocated:</p>
2177<ul>
2178 <li><a
2179 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2180 <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2181 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
2182 and <a
2183 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
2184 are the memory debugging replacement allocation routines</li>
2185 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2186 ()</a> dumps all the informations about the allocated memory block lefts
2187 in the <code>.memdump</code> file</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2188</ul>
2189
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2190<p>When developing libxml memory debug is enabled, the tests programs call
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2191xmlMemoryDump () and the "make test" regression tests will check for any
2192memory leak during the full regression test sequence, this helps a lot
2193ensuring that libxml does not leak memory and bullet proof memory
2194allocations use (some libc implementations are known to be far too permissive
2195resulting in major portability problems!).</p>
2196
2197<p>If the .memdump reports a leak, it displays the allocation function and
2198also tries to give some informations about the content and structure of the
2199allocated blocks left. This is sufficient in most cases to find the culprit,
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2200but not always. Assuming the allocation problem is reproducible, it is
2201possible to find more easily:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2202<ol>
2203 <li>write down the block number xxxx not allocated</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2204 <li>export the environment variable XML_MEM_BREAKPOINT=xxxx , the easiest
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2205 when using GDB is to simply give the command
2206 <p><code>set environment XML_MEM_BREAKPOINT xxxx</code></p>
2207 <p>before running the program.</p>
2208 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2209 <li>run the program under a debugger and set a breakpoint on
2210 xmlMallocBreakpoint() a specific function called when this precise block
2211 is allocated</li>
2212 <li>when the breakpoint is reached you can then do a fine analysis of the
2213 allocation an step to see the condition resulting in the missing
2214 deallocation.</li>
2215</ol>
2216
2217<p>I used to use a commercial tool to debug libxml memory problems but after
2218noticing that it was not detecting memory leaks that simple mechanism was
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2219used and proved extremely efficient until now. Lately I have also used <a
2220href="http://developer.kde.org/~sewardj/">valgrind</a> with quite some
2221success, it is tied to the i386 architecture since it works by emulating the
2222processor and instruction set, it is slow but extremely efficient, i.e. it
2223spot memory usage errors in a very precise way.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2224
2225<h3><a name="General4">General memory requirements</a></h3>
2226
2227<p>How much libxml memory require ? It's hard to tell in average it depends
2228of a number of things:</p>
2229<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2230 <li>the parser itself should work in a fixed amount of memory, except for
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2231 information maintained about the stacks of names and entities locations.
2232 The I/O and encoding handlers will probably account for a few KBytes.
2233 This is true for both the XML and HTML parser (though the HTML parser
2234 need more state).</li>
2235 <li>If you are generating the DOM tree then memory requirements will grow
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2236 nearly linear with the size of the data. In general for a balanced
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2237 textual document the internal memory requirement is about 4 times the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2238 size of the UTF8 serialization of this document (example the XML-1.0
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2239 recommendation is a bit more of 150KBytes and takes 650KBytes of main
2240 memory when parsed). Validation will add a amount of memory required for
2241 maintaining the external Dtd state which should be linear with the
2242 complexity of the content model defined by the Dtd</li>
2243 <li>If you don't care about the advanced features of libxml like
2244 validation, DOM, XPath or XPointer, but really need to work fixed memory
2245 requirements, then the SAX interface should be used.</li>
2246</ul>
2247
2248<p></p>
2249
2250<h2><a name="Encodings">Encodings support</a></h2>
2251
2252<p>Table of Content:</p>
2253<ol>
2254 <li><a href="encoding.html#What">What does internationalization support
2255 mean ?</a></li>
2256 <li><a href="encoding.html#internal">The internal encoding, how and
2257 why</a></li>
2258 <li><a href="encoding.html#implemente">How is it implemented ?</a></li>
2259 <li><a href="encoding.html#Default">Default supported encodings</a></li>
2260 <li><a href="encoding.html#extend">How to extend the existing
2261 support</a></li>
2262</ol>
2263
2264<h3><a name="What">What does internationalization support mean ?</a></h3>
2265
2266<p>XML was designed from the start to allow the support of any character set
2267by using Unicode. Any conformant XML parser has to support the UTF-8 and
2268UTF-16 default encodings which can both express the full unicode ranges. UTF8
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2269is a variable length encoding whose greatest points are to reuse the same
2270encoding for ASCII and to save space for Western encodings, but it is a bit
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2271more complex to handle in practice. UTF-16 use 2 bytes per characters (and
2272sometimes combines two pairs), it makes implementation easier, but looks a
2273bit overkill for Western languages encoding. Moreover the XML specification
2274allows document to be encoded in other encodings at the condition that they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2275are clearly labeled as such. For example the following is a wellformed XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2276document encoded in ISO-8859 1 and using accentuated letter that we French
2277likes for both markup and content:</p>
2278<pre>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2279&lt;très&gt;là&lt;/très&gt;</pre>
2280
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2281<p>Having internationalization support in libxml means the following:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2282<ul>
2283 <li>the document is properly parsed</li>
2284 <li>informations about it's encoding are saved</li>
2285 <li>it can be modified</li>
2286 <li>it can be saved in its original encoding</li>
2287 <li>it can also be saved in another encoding supported by libxml (for
2288 example straight UTF8 or even an ASCII form)</li>
2289</ul>
2290
2291<p>Another very important point is that the whole libxml API, with the
2292exception of a few routines to read with a specific encoding or save to a
2293specific encoding, is completely agnostic about the original encoding of the
2294document.</p>
2295
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2296<p>It should be noted too that the HTML parser embedded in libxml now obey
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2297the same rules too, the following document will be (as of 2.2.2) handled in
2298an internationalized fashion by libxml too:</p>
2299<pre>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
2300 "http://www.w3.org/TR/REC-html40/loose.dtd"&gt;
2301&lt;html lang="fr"&gt;
2302&lt;head&gt;
2303 &lt;META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&gt;
2304&lt;/head&gt;
2305&lt;body&gt;
2306&lt;p&gt;W3C crée des standards pour le Web.&lt;/body&gt;
2307&lt;/html&gt;</pre>
2308
2309<h3><a name="internal">The internal encoding, how and why</a></h3>
2310
2311<p>One of the core decision was to force all documents to be converted to a
2312default internal encoding, and that encoding to be UTF-8, here are the
2313rationale for those choices:</p>
2314<ul>
2315 <li>keeping the native encoding in the internal form would force the libxml
2316 users (or the code associated) to be fully aware of the encoding of the
2317 original document, for examples when adding a text node to a document,
2318 the content would have to be provided in the document encoding, i.e. the
2319 client code would have to check it before hand, make sure it's conformant
2320 to the encoding, etc ... Very hard in practice, though in some specific
2321 cases this may make sense.</li>
2322 <li>the second decision was which encoding. From the XML spec only UTF8 and
2323 UTF16 really makes sense as being the two only encodings for which there
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2324 is mandatory support. UCS-4 (32 bits fixed size encoding) could be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2325 considered an intelligent choice too since it's a direct Unicode mapping
2326 support. I selected UTF-8 on the basis of efficiency and compatibility
2327 with surrounding software:
2328 <ul>
2329 <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
2330 more costly to import and export CPU wise) is also far more compact
2331 than UTF-16 (and UCS-4) for a majority of the documents I see it used
2332 for right now (RPM RDF catalogs, advogato data, various configuration
2333 file formats, etc.) and the key point for today's computer
2334 architecture is efficient uses of caches. If one nearly double the
2335 memory requirement to store the same amount of data, this will trash
2336 caches (main memory/external caches/internal caches) and my take is
2337 that this harms the system far more than the CPU requirements needed
2338 for the conversion to UTF-8</li>
2339 <li>Most of libxml version 1 users were using it with straight ASCII
2340 most of the time, doing the conversion with an internal encoding
2341 requiring all their code to be rewritten was a serious show-stopper
2342 for using UTF-16 or UCS-4.</li>
2343 <li>UTF-8 is being used as the de-facto internal encoding standard for
2344 related code like the <a href="http://www.pango.org/">pango</a>
2345 upcoming Gnome text widget, and a lot of Unix code (yep another place
2346 where Unix programmer base takes a different approach from Microsoft
2347 - they are using UTF-16)</li>
2348 </ul>
2349 </li>
2350</ul>
2351
2352<p>What does this mean in practice for the libxml user:</p>
2353<ul>
2354 <li>xmlChar, the libxml data type is a byte, those bytes must be assembled
2355 as UTF-8 valid strings. The proper way to terminate an xmlChar * string
2356 is simply to append 0 byte, as usual.</li>
2357 <li>One just need to make sure that when using chars outside the ASCII set,
2358 the values has been properly converted to UTF-8</li>
2359</ul>
2360
2361<h3><a name="implemente">How is it implemented ?</a></h3>
2362
2363<p>Let's describe how all this works within libxml, basically the I18N
2364(internationalization) support get triggered only during I/O operation, i.e.
2365when reading a document or saving one. Let's look first at the reading
2366sequence:</p>
2367<ol>
2368 <li>when a document is processed, we usually don't know the encoding, a
2369 simple heuristic allows to detect UTF-18 and UCS-4 from whose where the
2370 ASCII range (0-0x7F) maps with ASCII</li>
2371 <li>the xml declaration if available is parsed, including the encoding
2372 declaration. At that point, if the autodetected encoding is different
2373 from the one declared a call to xmlSwitchEncoding() is issued.</li>
2374 <li>If there is no encoding declaration, then the input has to be in either
2375 UTF-8 or UTF-16, if it is not then at some point when processing the
2376 input, the converter/checker of UTF-8 form will raise an encoding error.
2377 You may end-up with a garbled document, or no document at all ! Example:
2378 <pre>~/XML -&gt; ./xmllint err.xml
2379err.xml:1: error: Input is not proper UTF-8, indicate encoding !
2380&lt;très&gt;là&lt;/très&gt;
2381 ^
2382err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
2383&lt;très&gt;là&lt;/très&gt;
2384 ^</pre>
2385 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2386 <li>xmlSwitchEncoding() does an encoding name lookup, canonicalize it, and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2387 then search the default registered encoding converters for that encoding.
2388 If it's not within the default set and iconv() support has been compiled
2389 it, it will ask iconv for such an encoder. If this fails then the parser
2390 will report an error and stops processing:
2391 <pre>~/XML -&gt; ./xmllint err2.xml
2392err2.xml:1: error: Unsupported encoding UnsupportedEnc
2393&lt;?xml version="1.0" encoding="UnsupportedEnc"?&gt;
2394 ^</pre>
2395 </li>
Daniel Veillard46c5c1d2002-05-20 07:15:54 +0000[diff] [blame]2396 <li>From that point the encoder processes progressively the input (it is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2397 plugged as a front-end to the I/O module) for that entity. It captures
2398 and convert on-the-fly the document to be parsed to UTF-8. The parser
2399 itself just does UTF-8 checking of this input and process it
2400 transparently. The only difference is that the encoding information has
2401 been added to the parsing context (more precisely to the input
2402 corresponding to this entity).</li>
2403 <li>The result (when using DOM) is an internal form completely in UTF-8
2404 with just an encoding information on the document node.</li>
2405</ol>
2406
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2407<p>Ok then what happens when saving the document (assuming you
2408collected/built an xmlDoc DOM like structure) ? It depends on the function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2409called, xmlSaveFile() will just try to save in the original encoding, while
2410xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
2411encoding:</p>
2412<ol>
2413 <li>if no encoding is given, libxml will look for an encoding value
2414 associated to the document and if it exists will try to save to that
2415 encoding,
2416 <p>otherwise everything is written in the internal form, i.e. UTF-8</p>
2417 </li>
2418 <li>so if an encoding was specified, either at the API level or on the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2419 document, libxml will again canonicalize the encoding name, lookup for a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2420 converter in the registered set or through iconv. If not found the
2421 function will return an error code</li>
2422 <li>the converter is placed before the I/O buffer layer, as another kind of
2423 buffer, then libxml will simply push the UTF-8 serialization to through
2424 that buffer, which will then progressively be converted and pushed onto
2425 the I/O layer.</li>
2426 <li>It is possible that the converter code fails on some input, for example
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2427 trying to push an UTF-8 encoded Chinese character through the UTF-8 to
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2428 ISO-8859-1 converter won't work. Since the encoders are progressive they
2429 will just report the error and the number of bytes converted, at that
2430 point libxml will decode the offending character, remove it from the
2431 buffer and replace it with the associated charRef encoding &amp;#123; and
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2432 resume the conversion. This guarantees that any document will be saved
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2433 without losses (except for markup names where this is not legal, this is
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2434 a problem in the current version, in practice avoid using non-ascii
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2435 characters for tags or attributes names @@). A special "ascii" encoding
2436 name is used to save documents to a pure ascii form can be used when
2437 portability is really crucial</li>
2438</ol>
2439
2440<p>Here is a few examples based on the same test document:</p>
2441<pre>~/XML -&gt; ./xmllint isolat1
2442&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2443&lt;très&gt;là&lt;/très&gt;
2444~/XML -&gt; ./xmllint --encode UTF-8 isolat1
2445&lt;?xml version="1.0" encoding="UTF-8"?&gt;
2446&lt;très&gt;là  &lt;/très&gt;
2447~/XML -&gt; </pre>
2448
2449<p>The same processing is applied (and reuse most of the code) for HTML I18N
2450processing. Looking up and modifying the content encoding is a bit more
2451difficult since it is located in a &lt;meta&gt; tag under the &lt;head&gt;,
2452so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
2453been provided. The parser also attempts to switch encoding on the fly when
2454detecting such a tag on input. Except for that the processing is the same
2455(and again reuses the same code).</p>
2456
2457<h3><a name="Default">Default supported encodings</a></h3>
2458
2459<p>libxml has a set of default converters for the following encodings
2460(located in encoding.c):</p>
2461<ol>
2462 <li>UTF-8 is supported by default (null handlers)</li>
2463 <li>UTF-16, both little and big endian</li>
2464 <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
2465 <li>ASCII, useful mostly for saving</li>
2466 <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
2467 predefined entities like &amp;copy; for the Copyright sign.</li>
2468</ol>
2469
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2470<p>More over when compiled on an Unix platform with iconv support the full
2471set of encodings supported by iconv can be instantly be used by libxml. On a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2472linux machine with glibc-2.1 the list of supported encodings and aliases fill
24733 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
2474various Japanese ones.</p>
2475
2476<h4>Encoding aliases</h4>
2477
2478<p>From 2.2.3, libxml has support to register encoding names aliases. The
2479goal is to be able to parse document whose encoding is supported but where
2480the name differs (for example from the default set of names accepted by
2481iconv). The following functions allow to register and handle new aliases for
2482existing encodings. Once registered libxml will automatically lookup the
2483aliases when handling a document:</p>
2484<ul>
2485 <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li>
2486 <li>int xmlDelEncodingAlias(const char *alias);</li>
2487 <li>const char * xmlGetEncodingAlias(const char *alias);</li>
2488 <li>void xmlCleanupEncodingAliases(void);</li>
2489</ul>
2490
2491<h3><a name="extend">How to extend the existing support</a></h3>
2492
2493<p>Well adding support for new encoding, or overriding one of the encoders
2494(assuming it is buggy) should not be hard, just write an input and output
2495conversion routines to/from UTF-8, and register them using
2496xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
2497called automatically if the parser(s) encounter such an encoding name
2498(register it uppercase, this will help). The description of the encoders,
2499their arguments and expected return values are described in the encoding.h
2500header.</p>
2501
2502<p>A quick note on the topic of subverting the parser to use a different
2503internal encoding than UTF-8, in some case people will absolutely want to
2504keep the internal encoding different, I think it's still possible (but the
2505encoding must be compliant with ASCII on the same subrange) though I didn't
2506tried it. The key is to override the default conversion routines (by
2507registering null encoders/decoders for your charsets), and bypass the UTF-8
2508checking of the parser by setting the parser context charset
2509(ctxt-&gt;charset) to something different than XML_CHAR_ENCODING_UTF8, but
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2510there is no guarantee that this will work. You may also have some troubles
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2511saving back.</p>
2512
2513<p>Basically proper I18N support is important, this requires at least
2514libxml-2.0.0, but a lot of features and corrections are really available only
2515starting 2.2.</p>
2516
2517<h2><a name="IO">I/O Interfaces</a></h2>
2518
2519<p>Table of Content:</p>
2520<ol>
2521 <li><a href="#General1">General overview</a></li>
2522 <li><a href="#basic">The basic buffer type</a></li>
2523 <li><a href="#Input">Input I/O handlers</a></li>
2524 <li><a href="#Output">Output I/O handlers</a></li>
2525 <li><a href="#entities">The entities loader</a></li>
2526 <li><a href="#Example2">Example of customized I/O</a></li>
2527</ol>
2528
2529<h3><a name="General1">General overview</a></h3>
2530
2531<p>The module <code><a
2532href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
2533the interfaces to the libxml I/O system. This consists of 4 main parts:</p>
2534<ul>
2535 <li>Entities loader, this is a routine which tries to fetch the entities
2536 (files) based on their PUBLIC and SYSTEM identifiers. The default loader
2537 don't look at the public identifier since libxml do not maintain a
2538 catalog. You can redefine you own entity loader by using
2539 <code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2540 <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
2541 example</a>.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2542 <li>Input I/O buffers which are a commodity structure used by the parser(s)
2543 input layer to handle fetching the informations to feed the parser. This
2544 provides buffering and is also a placeholder where the encoding
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2545 converters to UTF8 are piggy-backed.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2546 <li>Output I/O buffers are similar to the Input ones and fulfill similar
2547 task but when generating a serialization from a tree.</li>
2548 <li>A mechanism to register sets of I/O callbacks and associate them with
2549 specific naming schemes like the protocol part of the URIs.
2550 <p>This affect the default I/O operations and allows to use specific I/O
2551 handlers for certain names.</p>
2552 </li>
2553</ul>
2554
2555<p>The general mechanism used when loading http://rpmfind.net/xml.html for
2556example in the HTML parser is the following:</p>
2557<ol>
2558 <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
2559 the parsing context and the URI string.</li>
2560 <li>the URI string is checked against the existing registered handlers
2561 using their match() callback function, if the HTTP module was compiled
2562 in, it is registered and its match() function will succeeds</li>
2563 <li>the open() function of the handler is called and if successful will
2564 return an I/O Input buffer</li>
2565 <li>the parser will the start reading from this buffer and progressively
2566 fetch information from the resource, calling the read() function of the
2567 handler until the resource is exhausted</li>
2568 <li>if an encoding change is detected it will be installed on the input
2569 buffer, providing buffering and efficient use of the conversion
2570 routines</li>
2571 <li>once the parser has finished, the close() function of the handler is
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2572 called once and the Input buffer and associated resources are
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2573 deallocated.</li>
2574</ol>
2575
2576<p>The user defined callbacks are checked first to allow overriding of the
2577default libxml I/O routines.</p>
2578
2579<h3><a name="basic">The basic buffer type</a></h3>
2580
2581<p>All the buffer manipulation handling is done using the
2582<code>xmlBuffer</code> type define in <code><a
2583href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
2584resizable memory buffer. The buffer allocation strategy can be selected to be
2585either best-fit or use an exponential doubling one (CPU vs. memory use
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2586trade-off). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2587<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
2588system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
2589of functions allows to manipulate buffers with names starting with the
2590<code>xmlBuffer...</code> prefix.</p>
2591
2592<h3><a name="Input">Input I/O handlers</a></h3>
2593
2594<p>An Input I/O handler is a simple structure
2595<code>xmlParserInputBuffer</code> containing a context associated to the
2596resource (file descriptor, or pointer to a protocol handler), the read() and
2597close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
2598encoding handler are also present to support charset conversion when
2599needed.</p>
2600
2601<h3><a name="Output">Output I/O handlers</a></h3>
2602
2603<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
2604Input one except the callbacks are write() and close().</p>
2605
2606<h3><a name="entities">The entities loader</a></h3>
2607
2608<p>The entity loader resolves requests for new entities and create inputs for
2609the parser. Creating an input from a filename or an URI string is done
2610through the xmlNewInputFromFile() routine. The default entity loader do not
2611handle the PUBLIC identifier associated with an entity (if any). So it just
2612calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
2613XML).</p>
2614
2615<p>If you want to hook up a catalog mechanism then you simply need to
2616override the default entity loader, here is an example:</p>
2617<pre>#include &lt;libxml/xmlIO.h&gt;
2618
2619xmlExternalEntityLoader defaultLoader = NULL;
2620
2621xmlParserInputPtr
2622xmlMyExternalEntityLoader(const char *URL, const char *ID,
2623 xmlParserCtxtPtr ctxt) {
2624 xmlParserInputPtr ret;
2625 const char *fileID = NULL;
2626 /* lookup for the fileID depending on ID */
2627
2628 ret = xmlNewInputFromFile(ctxt, fileID);
2629 if (ret != NULL)
2630 return(ret);
2631 if (defaultLoader != NULL)
2632 ret = defaultLoader(URL, ID, ctxt);
2633 return(ret);
2634}
2635
2636int main(..) {
2637 ...
2638
2639 /*
2640 * Install our own entity loader
2641 */
2642 defaultLoader = xmlGetExternalEntityLoader();
2643 xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
2644
2645 ...
2646}</pre>
2647
2648<h3><a name="Example2">Example of customized I/O</a></h3>
2649
2650<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
2651real use case</a>, xmlDocDump() closes the FILE * passed by the application
2652and this was a problem. The <a
2653href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
2654new output handler with the closing call deactivated:</p>
2655<ol>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2656 <li>First define a new I/O output allocator where the output don't close
2657 the file:
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2658 <pre>xmlOutputBufferPtr
2659xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
2660    xmlOutputBufferPtr ret;
2661    
2662    if (xmlOutputCallbackInitialized == 0)
2663        xmlRegisterDefaultOutputCallbacks();
2664
2665    if (file == NULL) return(NULL);
2666    ret = xmlAllocOutputBuffer(encoder);
2667    if (ret != NULL) {
2668        ret-&gt;context = file;
2669        ret-&gt;writecallback = xmlFileWrite;
2670        ret-&gt;closecallback = NULL; /* No close callback */
2671    }
2672    return(ret); <br>
Daniel Veillard1eb24242002-03-18 11:33:03 +0000[diff] [blame]2673
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]2674
2675
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]2676
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]2677
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2678
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]2679
Daniel Veillard0bfbb422002-04-26 09:21:45 +0000[diff] [blame]2680
Daniel Veillard93d3a472002-04-26 14:04:55 +0000[diff] [blame]2681
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]2682
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]2683
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]2684
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2685
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]2686
Daniel Veillard782afda2002-07-08 15:12:49 +0000[diff] [blame]2687
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2688
Daniel Veillarde1662542002-08-28 11:50:59 +0000[diff] [blame]2689
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame^]2690
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2691} </pre>
2692 </li>
2693 <li>And then use it to save the document:
2694 <pre>FILE *f;
2695xmlOutputBufferPtr output;
2696xmlDocPtr doc;
2697int res;
2698
2699f = ...
2700doc = ....
2701
2702output = xmlOutputBufferCreateOwn(f, NULL);
2703res = xmlSaveFileTo(output, doc, NULL);
2704 </pre>
2705 </li>
2706</ol>
2707
2708<h2><a name="Catalog">Catalog support</a></h2>
2709
2710<p>Table of Content:</p>
2711<ol>
2712 <li><a href="General2">General overview</a></li>
2713 <li><a href="#definition">The definition</a></li>
2714 <li><a href="#Simple">Using catalogs</a></li>
2715 <li><a href="#Some">Some examples</a></li>
2716 <li><a href="#reference">How to tune catalog usage</a></li>
2717 <li><a href="#validate">How to debug catalog processing</a></li>
2718 <li><a href="#Declaring">How to create and maintain catalogs</a></li>
2719 <li><a href="#implemento">The implementor corner quick review of the
2720 API</a></li>
2721 <li><a href="#Other">Other resources</a></li>
2722</ol>
2723
2724<h3><a name="General2">General overview</a></h3>
2725
2726<p>What is a catalog? Basically it's a lookup mechanism used when an entity
2727(a file or a remote resource) references another entity. The catalog lookup
2728is inserted between the moment the reference is recognized by the software
2729(XML parser, stylesheet processing, or even images referenced for inclusion
2730in a rendering) and the time where loading that resource is actually
2731started.</p>
2732
2733<p>It is basically used for 3 things:</p>
2734<ul>
2735 <li>mapping from "logical" names, the public identifiers and a more
2736 concrete name usable for download (and URI). For example it can associate
2737 the logical name
2738 <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
2739 <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
2740 downloaded</p>
2741 <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
2742 </li>
2743 <li>remapping from a given URL to another one, like an HTTP indirection
2744 saying that
2745 <p>"http://www.oasis-open.org/committes/tr.xsl"</p>
2746 <p>should really be looked at</p>
2747 <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
2748 </li>
2749 <li>providing a local cache mechanism allowing to load the entities
2750 associated to public identifiers or remote resources, this is a really
2751 important feature for any significant deployment of XML or SGML since it
2752 allows to avoid the aleas and delays associated to fetching remote
2753 resources.</li>
2754</ul>
2755
2756<h3><a name="definition">The definitions</a></h3>
2757
2758<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
2759<ul>
2760 <li>the older SGML catalogs, the official spec is SGML Open Technical
2761 Resolution TR9401:1997, but is better understood by reading <a
2762 href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
2763 James Clark. This is relatively old and not the preferred mode of
2764 operation of libxml.</li>
2765 <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2766 Catalogs</a> is far more flexible, more recent, uses an XML syntax and
2767 should scale quite better. This is the default option of libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2768</ul>
2769
2770<p></p>
2771
2772<h3><a name="Simple">Using catalog</a></h3>
2773
2774<p>In a normal environment libxml will by default check the presence of a
2775catalog in /etc/xml/catalog, and assuming it has been correctly populated,
2776the processing is completely transparent to the document user. To take a
2777concrete example, suppose you are authoring a DocBook document, this one
2778starts with the following DOCTYPE definition:</p>
2779<pre>&lt;?xml version='1.0'?&gt;
2780&lt;!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
2781 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"&gt;</pre>
2782
2783<p>When validating the document with libxml, the catalog will be
2784automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
2785DocBk XML V3.1.4//EN" and the system identifier
2786"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
2787been installed on your system and the catalogs actually point to them, libxml
2788will fetch them from the local disk.</p>
2789
2790<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
2791DOCTYPE example it's a really old version, but is fine as an example.</p>
2792
2793<p>Libxml will check the catalog each time that it is requested to load an
2794entity, this includes DTD, external parsed entities, stylesheets, etc ... If
2795your system is correctly configured all the authoring phase and processing
2796should use only local files, even if your document stays portable because it
2797uses the canonical public and system ID, referencing the remote document.</p>
2798
2799<h3><a name="Some">Some examples:</a></h3>
2800
2801<p>Here is a couple of fragments from XML Catalogs used in libxml early
2802regression tests in <code>test/catalogs</code> :</p>
2803<pre>&lt;?xml version="1.0"?&gt;
2804&lt;!DOCTYPE catalog PUBLIC
2805 "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2806 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2807&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2808 &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2809 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2810...</pre>
2811
2812<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
2813written in XML, there is a specific namespace for catalog elements
2814"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
2815catalog is a <code>public</code> mapping it allows to associate a Public
2816Identifier with an URI.</p>
2817<pre>...
2818 &lt;rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2819 rewritePrefix="file:///usr/share/xml/docbook/"/&gt;
2820...</pre>
2821
2822<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
2823any URI starting with a given prefix should be looked at another URI
2824constructed by replacing the prefix with an new one. In effect this acts like
2825a cache system for a full area of the Web. In practice it is extremely useful
2826with a file prefix if you have installed a copy of those resources on your
2827local system.</p>
2828<pre>...
2829&lt;delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
2830 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2831&lt;delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
2832 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2833&lt;delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
2834 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2835&lt;delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2836 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2837&lt;delegateURI uriStartString="http://www.oasis-open.org/docbook/"
2838 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2839...</pre>
2840
2841<p>Delegation is the core features which allows to build a tree of catalogs,
2842easier to maintain than a single catalog, based on Public Identifier, System
2843Identifier or URI prefixes it instructs the catalog software to look up
2844entries in another resource. This feature allow to build hierarchies of
2845catalogs, the set of entries presented should be sufficient to redirect the
2846resolution of all DocBook references to the specific catalog in
2847<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
2848references for DocBook 4.2.1 to a specific catalog installed at the same time
2849as the DocBook resources on the local machine.</p>
2850
2851<h3><a name="reference">How to tune catalog usage:</a></h3>
2852
2853<p>The user can change the default catalog behaviour by redirecting queries
2854to its own set of catalogs, this can be done by setting the
2855<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
2856empty one should deactivate loading the default <code>/etc/xml/catalog</code>
2857default catalog</p>
2858
2859<h3><a name="validate">How to debug catalog processing:</a></h3>
2860
2861<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
2862make libxml output debugging informations for each catalog operations, for
2863example:</p>
2864<pre>orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2865warning: failed to load external entity "title.xml"
2866orchis:~/XML -&gt; export XML_DEBUG_CATALOG=
2867orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2868Failed to parse catalog /etc/xml/catalog
2869Failed to parse catalog /etc/xml/catalog
2870warning: failed to load external entity "title.xml"
2871Catalogs cleanup
2872orchis:~/XML -&gt; </pre>
2873
2874<p>The test/ent2 references an entity, running the parser from memory makes
2875the base URI unavailable and the the "title.xml" entity cannot be loaded.
2876Setting up the debug environment variable allows to detect that an attempt is
2877made to load the <code>/etc/xml/catalog</code> but since it's not present the
2878resolution fails.</p>
2879
2880<p>But the most advanced way to debug XML catalog processing is to use the
2881<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
2882catalogs and make resolution queries to see what is going on. This is also
2883used for the regression tests:</p>
2884<pre>orchis:~/XML -&gt; ./xmlcatalog test/catalogs/docbook.xml \
2885 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2886http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2887orchis:~/XML -&gt; </pre>
2888
2889<p>For debugging what is going on, adding one -v flags increase the verbosity
2890level to indicate the processing done (adding a second flag also indicate
2891what elements are recognized at parsing):</p>
2892<pre>orchis:~/XML -&gt; ./xmlcatalog -v test/catalogs/docbook.xml \
2893 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2894Parsing catalog test/catalogs/docbook.xml's content
2895Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
2896http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2897Catalogs cleanup
2898orchis:~/XML -&gt; </pre>
2899
2900<p>A shell interface is also available to debug and process multiple queries
2901(and for regression tests):</p>
2902<pre>orchis:~/XML -&gt; ./xmlcatalog -shell test/catalogs/docbook.xml \
2903 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2904&gt; help
2905Commands available:
2906public PublicID: make a PUBLIC identifier lookup
2907system SystemID: make a SYSTEM identifier lookup
2908resolve PublicID SystemID: do a full resolver lookup
2909add 'type' 'orig' 'replace' : add an entry
2910del 'values' : remove values
2911dump: print the current catalog state
2912debug: increase the verbosity level
2913quiet: decrease the verbosity level
2914exit: quit the shell
2915&gt; public "-//OASIS//DTD DocBook XML V4.1.2//EN"
2916http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2917&gt; quit
2918orchis:~/XML -&gt; </pre>
2919
2920<p>This should be sufficient for most debugging purpose, this was actually
2921used heavily to debug the XML Catalog implementation itself.</p>
2922
2923<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
2924
2925<p>Basically XML Catalogs are XML files, you can either use XML tools to
2926manage them or use <strong>xmlcatalog</strong> for this. The basic step is
2927to create a catalog the -create option provide this facility:</p>
2928<pre>orchis:~/XML -&gt; ./xmlcatalog --create tst.xml
2929&lt;?xml version="1.0"?&gt;
2930&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2931 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2932&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2933orchis:~/XML -&gt; </pre>
2934
2935<p>By default xmlcatalog does not overwrite the original catalog and save the
2936result on the standard output, this can be overridden using the -noout
2937option. The <code>-add</code> command allows to add entries in the
2938catalog:</p>
2939<pre>orchis:~/XML -&gt; ./xmlcatalog --noout --create --add "public" \
2940 "-//OASIS//DTD DocBook XML V4.1.2//EN" \
2941 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
2942orchis:~/XML -&gt; cat tst.xml
2943&lt;?xml version="1.0"?&gt;
2944&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
2945 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2946&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2947&lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2948 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2949&lt;/catalog&gt;
2950orchis:~/XML -&gt; </pre>
2951
2952<p>The <code>-add</code> option will always take 3 parameters even if some of
2953the XML Catalog constructs (like nextCatalog) will have only a single
2954argument, just pass a third empty string, it will be ignored.</p>
2955
2956<p>Similarly the <code>-del</code> option remove matching entries from the
2957catalog:</p>
2958<pre>orchis:~/XML -&gt; ./xmlcatalog --del \
2959 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
2960&lt;?xml version="1.0"?&gt;
2961&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2962 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2963&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2964orchis:~/XML -&gt; </pre>
2965
2966<p>The catalog is now empty. Note that the matching of <code>-del</code> is
2967exact and would have worked in a similar fashion with the Public ID
2968string.</p>
2969
2970<p>This is rudimentary but should be sufficient to manage a not too complex
2971catalog tree of resources.</p>
2972
2973<h3><a name="implemento">The implementor corner quick review of the
2974API:</a></h3>
2975
2976<p>First, and like for every other module of libxml, there is an
2977automatically generated <a href="html/libxml-catalog.html">API page for
2978catalog support</a>.</p>
2979
2980<p>The header for the catalog interfaces should be included as:</p>
2981<pre>#include &lt;libxml/catalog.h&gt;</pre>
2982
2983<p>The API is voluntarily kept very simple. First it is not obvious that
2984applications really need access to it since it is the default behaviour of
2985libxml (Note: it is possible to completely override libxml default catalog by
2986using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
2987plug an application specific resolver).</p>
2988
2989<p>Basically libxml support 2 catalog lists:</p>
2990<ul>
2991 <li>the default one, global shared by all the application</li>
2992 <li>a per-document catalog, this one is built if the document uses the
2993 <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
2994 associated to the parser context and destroyed when the parsing context
2995 is destroyed.</li>
2996</ul>
2997
2998<p>the document one will be used first if it exists.</p>
2999
3000<h4>Initialization routines:</h4>
3001
3002<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
3003used at startup to initialize the catalog, if the catalog should be
3004initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
3005should be called before xmlInitializeCatalog() which would otherwise do a
3006default initialization first.</p>
3007
3008<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
3009own catalog list if needed.</p>
3010
3011<h4>Preferences setup:</h4>
3012
3013<p>The XML Catalog spec requires the possibility to select default
3014preferences between public and system delegation,
3015xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
3016xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
3017be forbidden, allowed for global catalog, for document catalog or both, the
3018default is to allow both.</p>
3019
3020<p>And of course xmlCatalogSetDebug() allows to generate debug messages
3021(through the xmlGenericError() mechanism).</p>
3022
3023<h4>Querying routines:</h4>
3024
3025<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
3026and xmlCatalogResolveURI() are relatively explicit if you read the XML
3027Catalog specification they correspond to section 7 algorithms, they should
3028also work if you have loaded an SGML catalog with a simplified semantic.</p>
3029
3030<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
3031operate on the document catalog list</p>
3032
3033<h4>Cleanup and Miscellaneous:</h4>
3034
3035<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
3036the per-document equivalent.</p>
3037
3038<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
3039first catalog in the global list, and xmlCatalogDump() allows to dump a
3040catalog state, those routines are primarily designed for xmlcatalog, I'm not
3041sure that exposing more complex interfaces (like navigation ones) would be
3042really useful.</p>
3043
3044<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
3045it's similar as xmlParseFile() except it bypass all catalog lookups, it's
3046provided because this functionality may be useful for client tools.</p>
3047
3048<h4>threaded environments:</h4>
3049
3050<p>Since the catalog tree is built progressively, some care has been taken to
3051try to avoid troubles in multithreaded environments. The code is now thread
3052safe assuming that the libxml library has been compiled with threads
3053support.</p>
3054
3055<p></p>
3056
3057<h3><a name="Other">Other resources</a></h3>
3058
3059<p>The XML Catalog specification is relatively recent so there isn't much
3060literature to point at:</p>
3061<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3062 <li>You can find a good rant from Norm Walsh about <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3063 href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
3064 need for catalogs</a>, it provides a lot of context informations even if
Daniel Veillard93d3a472002-04-26 14:04:55 +0000[diff] [blame]3065 I don't agree with everything presented. Norm also wrote a more recent
3066 article <a
3067 href="http://wwws.sun.com/software/xml/developers/resolver/article/">XML
3068 entities and URI resolvers</a> describing them.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3069 <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
3070 catalog proposal</a> from John Cowan</li>
3071 <li>The <a href="http://www.rddl.org/">Resource Directory Description
3072 Language</a> (RDDL) another catalog system but more oriented toward
3073 providing metadata for XML namespaces.</li>
3074 <li>the page from the OASIS Technical <a
3075 href="http://www.oasis-open.org/committees/entity/">Committee on Entity
3076 Resolution</a> who maintains XML Catalog, you will find pointers to the
3077 specification update, some background and pointers to others tools
3078 providing XML Catalog support</li>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3079 <li>Here is a <a href="buildDocBookCatalog">shell script</a> to generate
3080 XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
3081 directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
3082 the resources found on the system. Otherwise it will just create
3083 ~/xmlcatalog and ~/dbkxmlcatalog and doing:
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]3084 <p><code>export XMLCATALOG=$HOME/xmlcatalog</code></p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3085 <p>should allow to process DocBook documentations without requiring
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3086 network accesses for the DTD or stylesheets</p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3087 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3088 <li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3089 small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
3090 to work fine for me too</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3091 <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
3092 manual page</a></li>
3093</ul>
3094
3095<p>If you have suggestions for corrections or additions, simply contact
3096me:</p>
3097
3098<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3099
3100<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3101using the XML library from the C language. It is not intended to be
3102extensive. I hope the automatically generated documents will provide the
3103completeness required, but as a separate set of documents. The interfaces of
3104the XML library are by principle low level, there is nearly zero abstraction.
3105Those interested in a higher level API should <a href="#DOM">look at
3106DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3107
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3108<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
3109separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3110interfaces</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]3111
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3112<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3113
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3114<p>Usually, the first thing to do is to read an XML input. The parser accepts
3115documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3116defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3117<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3118 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3119 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3120 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3121</dl>
3122<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3123 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3124 <dd><p>Parse an XML document contained in a (possibly compressed)
3125 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3126 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3127</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3128
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3129<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]3130failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3131
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3132<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3133
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3134<p>In order for the application to keep the control when the document is
3135being fetched (which is common for GUI based programs) libxml provides a push
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3136interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3137<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
3138 void *user_data,
3139 const char *chunk,
3140 int size,
3141 const char *filename);
3142int xmlParseChunk (xmlParserCtxtPtr ctxt,
3143 const char *chunk,
3144 int size,
3145 int terminate);</pre>
3146
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3147<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3148<pre> FILE *f;
3149
3150 f = fopen(filename, "r");
3151 if (f != NULL) {
3152 int res, size = 1024;
3153 char chars[1024];
3154 xmlParserCtxtPtr ctxt;
3155
3156 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3157 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3158 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
3159 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3160 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3161 xmlParseChunk(ctxt, chars, res, 0);
3162 }
3163 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3164 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3165 xmlFreeParserCtxt(ctxt);
3166 }
3167 }</pre>
3168
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3169<p>The HTML parser embedded into libxml also has a push interface; the
3170functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3171
3172<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
3173
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3174<p>The tree-building interface makes the parser memory-hungry, first loading
3175the document in memory and then building the tree itself. Reading a document
3176without building the tree is possible using the SAX interfaces (see SAX.h and
3177<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]3178Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3179limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3180<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3181
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3182<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3183
3184<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]3185there is a set of functions dedicated to building new elements. (These are
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3186also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of
3187code that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3188<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3189 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3190 xmlNodePtr tree, subtree;
3191
3192 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3193 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
3194 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
3195 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
3196 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3197 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3198 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3199 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
3200 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
3201 subtree = xmlNewChild(tree, NULL, "image", NULL);
3202 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3203
3204<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3205
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3206<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3207
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3208<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3209code has access to the internal structure of all the elements of the tree.
3210The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]3211<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3212<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3213example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3214<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3215
3216<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3217<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3218
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3219<p>points to the text node containing the chapter title "The Linux
3220adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3221
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3222<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]3223present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3224to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]3225<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3226
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3227<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3228
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3229<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3230is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3231<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3232 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
3233 xmlChar *value);</code></dt>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3234 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
3235 The value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3236 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3237</dl>
3238<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3239 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3240 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]3241 <dd><p>This function returns a pointer to new copy of the property
3242 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3243 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3244</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3245
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3246<p>Two functions are provided for reading and writing the text associated
3247with elements:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3248<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3249 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3250 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3251 <dd><p>This function takes an "external" string and converts it to one
3252 text node or possibly to a list of entity and text nodes. All
3253 non-predefined entity references like &amp;Gnome; will be stored
3254 internally as entity nodes, hence the result of the function may not be
3255 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3256 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3257</dl>
3258<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3259 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3260 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3261 <dd><p>This function is the inverse of
3262 <code>xmlStringGetNodeList()</code>. It generates a new string
3263 containing the content of the text and entity nodes. Note the extra
3264 argument inLine. If this argument is set to 1, the function will expand
3265 entity references. For example, instead of returning the &amp;Gnome;
3266 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3267 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3268 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3269</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3270
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3271<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3272
3273<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3274<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3275 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3276 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3277 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3278 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3279</dl>
3280<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3281 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3282 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3283 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3284</dl>
3285<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3286 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3287 <dd><p>Saves the document to a file. In this case, the compression
3288 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3289 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3290</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3291
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3292<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3293
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3294<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3295accesses. The level of compression on saves can be turned on either globally
3296or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3297<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3298 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3299 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3300 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3301</dl>
3302<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3303 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3304 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3305 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3306</dl>
3307<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3308 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3309 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3310 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3311</dl>
3312<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3313 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3314 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3315 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3316</dl>
3317
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3318<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3319
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3320<p>Entities in principle are similar to simple C macros. An entity defines an
3321abbreviation for a given string that you can reuse many times throughout the
3322content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3323may occur frequently within a document, or to confine the change needed to a
3324document to a restricted area in the internal subset of the document (at the
3325beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3326<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]33272 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]33283 &lt;!ENTITY xml "Extensible Markup Language"&gt;
33294 ]&gt;
33305 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]33316 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]33327 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3333
3334<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]3335its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3336are 5 predefined entities in libxml allowing you to escape characters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3337predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3338<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3339for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3340<strong>&amp;quot;</strong> for the character '"', and
3341<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3342
3343<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]3344substitute an entity's content so that you can see the replacement text in
3345your application. Or you may prefer to keep entity references as such in the
3346content to be able to save the document back without losing this usually
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3347precious information (if the user went through the pain of explicitly
3348defining entities, he may have a a rather negative attitude if you blindly
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3349substitute them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3350href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3351function allows you to check and change the behaviour, which is to not
3352substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3353
3354<p>Here is the DOM tree built by libxml for the previous document in the
3355default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3356<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3357DOCUMENT
3358version=1.0
3359 ELEMENT EXAMPLE
3360 TEXT
3361 content=
3362 ENTITY_REF
3363 INTERNAL_GENERAL_ENTITY xml
3364 content=Extensible Markup Language
3365 TEXT
3366 content=</pre>
3367
3368<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3369<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3370DOCUMENT
3371version=1.0
3372 ELEMENT EXAMPLE
3373 TEXT
3374 content= Extensible Markup Language</pre>
3375
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3376<p>So, entities or no entities? Basically, it depends on your use case. I
3377suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3378entities in your XML document or data if you are not willing to handle the
3379entity references elements in the DOM tree.</p>
3380
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3381<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3382entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3383transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3384reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3385finding them in the input).</p>
3386
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3387<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3388on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3389non-predefined entities in your documents, then the learning curve to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3390then 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]3391strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]3392deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3393
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3394<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3395
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3396<p>The libxml library implements <a
3397href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3398recognizing namespace constructs in the input, and does namespace lookup
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3399automatically when building the DOM tree. A namespace declaration is
3400associated with an in-memory structure and all elements or attributes within
3401that namespace point to it. Hence testing the namespace is a simple and fast
3402equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3403
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3404<p>I suggest that people using libxml use a namespace, and declare it in the
3405root element of their document as the default namespace. Then they don't need
3406to 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]3407refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3408the size of the XML output significantly, but significantly increases its
3409value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3410<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
3411 &lt;elem1&gt;...&lt;/elem1&gt;
3412 &lt;elem2&gt;...&lt;/elem2&gt;
3413&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3414
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3415<p>The namespace value has to be an absolute URL, but the URL doesn't have to
3416point to any existing resource on the Web. It will bind all the element and
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3417attributes with that URL. I suggest to use an URL within a domain you
3418control, and that the URL should contain some kind of version information if
3419possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a
3420good namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3421
3422<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3423version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3424and if the version information don't match something you know, warn the user
3425and 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]3426namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3427same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3428associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3429just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3430<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3431prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3432
3433<p>@@Interfaces@@</p>
3434
3435<p>@@Examples@@</p>
3436
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3437<p>Usually people object to using namespaces together with validity checking.
3438I will try to make sure that using namespaces won't break validity checking,
3439so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3440suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3441<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3442flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3443from multiple DTDs will certainly break current validation schemes. I will
3444try to provide ways to do this, but this may not be portable or
3445standardized.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3446
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3447<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3448
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3449<p>Incompatible changes:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3450
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3451<p>Version 2 of libxml is the first version introducing serious backward
3452incompatible changes. The main goals were:</p>
3453<ul>
3454 <li>a general cleanup. A number of mistakes inherited from the very early
3455 versions couldn't be changed due to compatibility constraints. Example
3456 the "childs" element in the nodes.</li>
3457 <li>Uniformization of the various nodes, at least for their header and link
3458 parts (doc, parent, children, prev, next), the goal is a simpler
3459 programming model and simplifying the task of the DOM implementors.</li>
3460 <li>better conformances to the XML specification, for example version 1.x
3461 had an heuristic to try to detect ignorable white spaces. As a result the
3462 SAX event generated were ignorableWhitespace() while the spec requires
3463 character() in that case. This also mean that a number of DOM node
3464 containing blank text may populate the DOM tree which were not present
3465 before.</li>
3466</ul>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3467
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3468<h3>How to fix libxml-1.x code:</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3469
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3470<p>So client code of libxml designed to run with version 1.x may have to be
3471changed to compile against version 2.x of libxml. Here is a list of changes
3472that I have collected, they may not be sufficient, so in case you find other
3473change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
3474mail</a>:</p>
3475<ol>
3476 <li>The package name have changed from libxml to libxml2, the library name
3477 is now -lxml2 . There is a new xml2-config script which should be used to
3478 select the right parameters libxml2</li>
3479 <li>Node <strong>childs</strong> field has been renamed
3480 <strong>children</strong> so s/childs/children/g should be applied
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3481 (probability of having "childs" anywhere else is close to 0+</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3482 <li>The document don't have anymore a <strong>root</strong> element it has
3483 been replaced by <strong>children</strong> and usually you will get a
3484 list of element here. For example a Dtd element for the internal subset
3485 and it's declaration may be found in that list, as well as processing
3486 instructions or comments found before or after the document root element.
3487 Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3488 a document. Alternatively if you are sure to not reference DTDs nor have
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3489 PIs or comments before or after the root element
3490 s/-&gt;root/-&gt;children/g will probably do it.</li>
3491 <li>The white space issue, this one is more complex, unless special case of
3492 validating parsing, the line breaks and spaces usually used for indenting
3493 and formatting the document content becomes significant. So they are
3494 reported by SAX and if your using the DOM tree, corresponding nodes are
3495 generated. Too approach can be taken:
3496 <ol>
3497 <li>lazy one, use the compatibility call
3498 <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
3499 relying on a special (and possibly broken) set of heuristics of
3500 libxml to detect ignorable blanks. Don't complain if it breaks or
3501 make your application not 100% clean w.r.t. to it's input.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3502 <li>the Right Way: change you code to accept possibly insignificant
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3503 blanks characters, or have your tree populated with weird blank text
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3504 nodes. You can spot them using the commodity function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3505 <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
3506 nodes.</li>
3507 </ol>
3508 <p>Note also that with the new default the output functions don't add any
3509 extra indentation when saving a tree in order to be able to round trip
3510 (read and save) without inflating the document with extra formatting
3511 chars.</p>
3512 </li>
3513 <li>The include path has changed to $prefix/libxml/ and the includes
3514 themselves uses this new prefix in includes instructions... If you are
3515 using (as expected) the
3516 <pre>xml2-config --cflags</pre>
3517 <p>output to generate you compile commands this will probably work out of
3518 the box</p>
3519 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3520 <li>xmlDetectCharEncoding takes an extra argument indicating the length in
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3521 byte of the head of the document available for character detection.</li>
3522</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3523
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3524<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3525
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3526<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]3527to allow smooth upgrade of existing libxml v1code while retaining
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3528compatibility. They offers the following:</p>
3529<ol>
3530 <li>similar include naming, one should use
3531 <strong>#include&lt;libxml/...&gt;</strong> in both cases.</li>
3532 <li>similar identifiers defined via macros for the child and root fields:
3533 respectively <strong>xmlChildrenNode</strong> and
3534 <strong>xmlRootNode</strong></li>
3535 <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
3536 inserted once in the client code</li>
3537</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3538
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3539<p>So the roadmap to upgrade your existing libxml applications is the
3540following:</p>
3541<ol>
3542 <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]3543 <li>find all occurrences where the xmlDoc <strong>root</strong> field is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3544 used and change it to <strong>xmlRootNode</strong></li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3545 <li>similarly find all occurrences where the xmlNode
3546 <strong>childs</strong> field is used and change it to
3547 <strong>xmlChildrenNode</strong></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3548 <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
3549 <strong>main()</strong> or in the library init entry point</li>
3550 <li>Recompile, check compatibility, it should still work</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3551 <li>Change your configure script to look first for xml2-config and fall
3552 back using xml-config . Use the --cflags and --libs output of the command
3553 as the Include and Linking parameters needed to use libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3554 <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
3555 libxml-devel-1.8.y can be kept simultaneously)</li>
3556 <li>remove your config.cache, relaunch your configuration mechanism, and
3557 recompile, if steps 2 and 3 were done right it should compile as-is</li>
3558 <li>Test that your application is still running correctly, if not this may
3559 be due to extra empty nodes due to formating spaces being kept in libxml2
3560 contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
3561 code before calling the parser (next to
3562 <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
3563</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3564
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3565<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]3566
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3567<p>Let me put some emphasis on the fact that there is far more changes from
3568libxml 1.x to 2.x than the ones you may have to patch for. The overall code
3569has been considerably cleaned up and the conformance to the XML specification
3570has been drastically improved too. Don't take those changes as an excuse to
3571not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3572
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3573<h2><a name="Thread">Thread safety</a></h2>
3574
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3575<p>Starting with 2.4.7, libxml makes provisions to ensure that concurrent
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3576threads can safely work in parallel parsing different documents. There is
3577however a couple of things to do to ensure it:</p>
3578<ul>
3579 <li>configure the library accordingly using the --with-threads options</li>
3580 <li>call xmlInitParser() in the "main" thread before using any of the
3581 libxml API (except possibly selecting a different memory allocator)</li>
3582</ul>
3583
3584<p>Note that the thread safety cannot be ensured for multiple threads sharing
3585the same document, the locking must be done at the application level, libxml
3586exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
3587The parts of the library checked for thread safety are:</p>
3588<ul>
3589 <li>concurrent loading</li>
3590 <li>file access resolution</li>
3591 <li>catalog access</li>
3592 <li>catalog building</li>
3593 <li>entities lookup/accesses</li>
3594 <li>validation</li>
3595 <li>global variables per-thread override</li>
3596 <li>memory handling</li>
3597</ul>
3598
3599<p>XPath is supposed to be thread safe now, but this wasn't tested
3600seriously.</p>
3601
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3602<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3603
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3604<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
3605Object Model</em>; this is an API for accessing XML or HTML structured
3606documents. Native support for DOM in Gnome is on the way (module gnome-dom),
3607and will be based on gnome-xml. This will be a far cleaner interface to
3608manipulate XML files within Gnome since it won't expose the internal
3609structure.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3610
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3611<p>The current DOM implementation on top of libxml is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame]3612href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
3613is a full DOM interface, thanks to Paolo Casarini, check the <a
3614href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
3615informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3616
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3617<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3618
3619<p>Here is a real size example, where the actual content of the application
3620data 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]3621a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3622storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
3623base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3624<pre>&lt;?xml version="1.0"?&gt;
3625&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
3626 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3627
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3628 &lt;gjob:Job&gt;
3629 &lt;gjob:Project ID="3"/&gt;
3630 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
3631 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3632
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3633 &lt;gjob:Update&gt;
3634 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
3635 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
3636 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
3637 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3638
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3639 &lt;gjob:Developers&gt;
3640 &lt;gjob:Developer&gt;
3641 &lt;/gjob:Developer&gt;
3642 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3643
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3644 &lt;gjob:Contact&gt;
3645 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
3646 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
3647 &lt;gjob:Company&gt;
3648 &lt;/gjob:Company&gt;
3649 &lt;gjob:Organisation&gt;
3650 &lt;/gjob:Organisation&gt;
3651 &lt;gjob:Webpage&gt;
3652 &lt;/gjob:Webpage&gt;
3653 &lt;gjob:Snailmail&gt;
3654 &lt;/gjob:Snailmail&gt;
3655 &lt;gjob:Phone&gt;
3656 &lt;/gjob:Phone&gt;
3657 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3658
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3659 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3660 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3661 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3662
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3663 &lt;gjob:Skills&gt;
3664 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3665
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3666 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3667 A GNOME based system that will allow a superuser to configure
3668 compressed and uncompressed files and/or file systems to be backed
3669 up with a supported media in the system. This should be able to
3670 perform via find commands generating a list of files that are passed
3671 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
3672 or via operations performed on the filesystem itself. Email
3673 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3674 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3675
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3676 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3677
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3678 &lt;/gjob:Jobs&gt;
3679&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3680
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3681<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]3682calling only a couple of functions, browsing the tree to gather the data and
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3683generate the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3684
3685<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3686structure. For example, the ordering of the attributes is not significant,
3687the 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]3688depend on the order of the children of a given node, unless it really makes
3689things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3690<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3691 * A person record
3692 */
3693typedef struct person {
3694 char *name;
3695 char *email;
3696 char *company;
3697 char *organisation;
3698 char *smail;
3699 char *webPage;
3700 char *phone;
3701} person, *personPtr;
3702
3703/*
3704 * And the code needed to parse it
3705 */
3706personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3707 personPtr ret = NULL;
3708
3709DEBUG("parsePerson\n");
3710 /*
3711 * allocate the struct
3712 */
3713 ret = (personPtr) malloc(sizeof(person));
3714 if (ret == NULL) {
3715 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3716 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3717 }
3718 memset(ret, 0, sizeof(person));
3719
3720 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3721 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3722 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3723 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
3724 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3725 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
3726 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3727 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3728 }
3729
3730 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3731}</pre>
3732
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3733<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3734<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3735 <li>Usually a recursive parsing style is the more convenient one: XML data
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3736 is by nature subject to repetitive constructs and usually exhibits highly
3737 structured patterns.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3738 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
3739 i.e. the pointer to the global XML document and the namespace reserved to
3740 the application. Document wide information are needed for example to
3741 decode entities and it's a good coding practice to define a namespace for
3742 your application set of data and test that the element and attributes
3743 you're analyzing actually pertains to your application space. This is
3744 done by a simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3745 <li>To retrieve text and attributes value, you can use the function
3746 <em>xmlNodeListGetString</em> to gather all the text and entity reference
3747 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3748</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3749
3750<p>Here is another piece of code used to parse another level of the
3751structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3752<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3753/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3754 * a Description for a Job
3755 */
3756typedef struct job {
3757 char *projectID;
3758 char *application;
3759 char *category;
3760 personPtr contact;
3761 int nbDevelopers;
3762 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
3763} job, *jobPtr;
3764
3765/*
3766 * And the code needed to parse it
3767 */
3768jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3769 jobPtr ret = NULL;
3770
3771DEBUG("parseJob\n");
3772 /*
3773 * allocate the struct
3774 */
3775 ret = (jobPtr) malloc(sizeof(job));
3776 if (ret == NULL) {
3777 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3778 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3779 }
3780 memset(ret, 0, sizeof(job));
3781
3782 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3783 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3784 while (cur != NULL) {
3785
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3786 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
3787 ret-&gt;projectID = xmlGetProp(cur, "ID");
3788 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3789 fprintf(stderr, "Project has no ID\n");
3790 }
3791 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3792 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
3793 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3794 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
3795 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3796 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
3797 ret-&gt;contact = parsePerson(doc, ns, cur);
3798 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3799 }
3800
3801 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3802}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3803
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3804<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]3805boring. Ultimately, it could be possible to write stubbers taking either C
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3806data structure definitions, a set of XML examples or an XML DTD and produce
3807the code needed to import and export the content between C data and XML
3808storage. This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3809
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]3810<p>Feel free to use <a href="example/gjobread.c">the code for the full C
3811parsing example</a> as a template, it is also available with Makefile in the
3812Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3813
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3814<h2><a name="Contributi">Contributions</a></h2>
3815<ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3816 <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
3817 patches, Gary Pennington worked on the validation API, threading support
3818 and Solaris port.</li>
3819 <li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]3820 <li><a href="mailto:igor@stud.fh-frankfurt.de">Igor Zlatkovic</a> is now
3821 the maintainer of the Windows port, <a
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]3822 href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
3823 provides binaries</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3824 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
3825 <a href="http://garypennington.net/libxml2/">Solaris binaries</a></li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]3826 <li><a
3827 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3828 Sergeant</a> developed <a
3829 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3830 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
3831 application server</a></li>
3832 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> and <a
3833 href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillardca989762001-06-23 17:39:29 +0000[diff] [blame]3834 href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]3835 documentation</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3836 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
3837 href="http://xmlsoft.org/messages/0488.html">man pages</a></li>
Daniel Veillard5168dbf2001-07-07 00:18:23 +0000[diff] [blame]3838 <li>there is a module for <a
3839 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
3840 in OpenNSD/AOLServer</a></li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]3841 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provided the
3842 first version of libxml/libxslt <a
3843 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li>
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]3844 <li>Petr Kozelka provides <a
3845 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
3846 libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]3847 <li><a href="mailto:aleksey@aleksey.com">Aleksey Sanin</a> implemented the
3848 <a href="http://www.w3.org/Signature/">XML Canonicalization and XML
3849 Digital Signature</a> <a
3850 href="http://www.aleksey.com/xmlsec/">implementations for libxml2</a></li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3851</ul>
3852
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3853<p></p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3854</body>
3855</html>