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Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
2 "http://www.w3.org/TR/html4/loose.dtd">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3<html>
4<head>
Daniel 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 Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame^]419 <li>Use the <a href="search.php">search engine</a> to lookup
420 informations.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]421 <li>Check the <a href="FAQ.html">FAQ.</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]422 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]423 documentation</a> automatically extracted from code comments (using <a
424 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
425 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]426 <li>Look at the documentation about <a href="encoding.html">libxml
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]427 internationalization support</a>.</li>
Daniel Veillardbc66f852002-01-14 09:49:20 +0000[diff] [blame]428 <li>This page provides a global overview and <a href="example.html">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]429 examples</a> on how to use libxml.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]430 <li>John Fleck's <a href="tutorial/index.html">libxml tutorial</a>.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]431 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]432 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
433 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]434 <li>George Lebl wrote <a
435 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]436 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]437 <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]438 file</a>.</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]439 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>
440 description. If you are starting a new project using libxml you should
441 really use the 2.x version.</li>
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]442 <li>And don't forget to look at the <a
443 href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]444</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]445
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]446<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]447
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]448<p>Well, bugs or missing features are always possible, and I will make a
449point of fixing them in a timely fashion. The best way to report a bug is to
450use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]451bug tracking database</a> (make sure to use the "libxml2" module name). I
452look at reports there regularly and it's good to have a reminder when a bug
453is 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]454
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]455<p>There is also a mailing-list <a
Daniel Veillard3197f162001-04-04 00:40:08 +0000[diff] [blame]456href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
457href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]458href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
459please visit the <a
460href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
461follow the instructions. <strong>Do not send code, I won't debug it</strong>
462(but patches are really appreciated!).</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]463
Daniel Veillard008186f2001-09-13 14:24:44 +0000[diff] [blame]464<p>Check the following <strong><span style="color: #FF0000">before
465posting</span></strong>:</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]466<ul>
Daniel Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame^]467 <li>Read the <a href="FAQ.html">FAQ</a> and <a href="search.php">use the
468 search engine</a> to get informations related to your problem.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]469 <li>Make sure you are <a href="ftp://xmlsoft.org/">using a recent
470 version</a>, and that the problem still shows up in a recent version.</li>
471 <li>Check the <a href="http://mail.gnome.org/archives/xml/">list
472 archives</a> to see if the problem was reported already. In this case
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]473 there is probably a fix available, similarly check the <a
Daniel Veillarde7ead2d2001-08-22 23:44:09 +0000[diff] [blame]474 href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">registered
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]475 open bugs</a>.</li>
476 <li>Make sure you can reproduce the bug with xmllint or one of the test
477 programs found in source in the distribution.</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]478 <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]479 attachment)</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]480</ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]481
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]482<p>Then send the bug with associated informations to reproduce it to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]483href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]484related I will approve it.. Please do not send mail to me directly, it makes
485things really hard to track and in some cases I am not the best person to
486answer a given question. Ask the list instead.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]487
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]488<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]489probably be processed faster than those without.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]490
491<p>If you're looking for help, a quick look at <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]492href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]493provide the answer. I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]494questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]495documentation</a> is not as polished as I would like (i need to learn more
496about DocBook), but it's a good starting point.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]497
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]498<h2><a name="help">How to help</a></h2>
499
500<p>You can help the project in various ways, the best thing to do first is to
501subscribe to the mailing-list as explained before, check the <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]502href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
503href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]504database</a>:</p>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]505<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]506 <li>Provide patches when you find problems.</li>
507 <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]508 be integrated in all cases but help pinpointing portability problems
509 and</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]510 <li>Provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]511 as HTML diffs).</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]512 <li>Provide new documentations pieces (translations, examples, etc
513 ...).</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]514 <li>Check the TODO file and try to close one of the items.</li>
515 <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]516 provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me
517 </a>before to avoid synchronization problems and check that the suggested
518 fix will fit in nicely :-)</li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]519</ol>
520
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]521<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]522
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]523<p>The latest versions of libxml can be found on <a
Daniel Veillard20c8cf22001-06-26 22:47:36 +0000[diff] [blame]524href="ftp://xmlsoft.org/">xmlsoft.org</a> (<a
525href="ftp://speakeasy.rpmfind.net/pub/libxml/">Seattle</a>, <a
526href="ftp://fr.rpmfind.net/pub/libxml/">France</a>) or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]527href="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]528as a <a href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.4/">source
529archive</a><!-- commenting this out because they seem to have disappeared or <a
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]530href="ftp://ftp.gnome.org/pub/GNOME/stable/redhat/i386/libxml/">RPM
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]531packages</a> -->
Daniel Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame^]532 , Antonin Sprinzl also provide <a href="ftp://gd.tuwien.ac.at/pub/libxml/">a
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]533mirror in Austria</a>. (NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]534href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
535href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]536packages installed to compile applications using libxml.) <a
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]537href="mailto:igor@stud.fh-frankfurt.de">Igor Zlatkovic</a> is now the
538maintainer of the Windows port, <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]539href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]540provides binaries</a>. <a href="mailto:Gary.Pennington@sun.com">Gary
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]541Pennington</a> provides <a href="http://garypennington.net/libxml2/">Solaris
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]542binaries</a>. <a href="mailto:Steve.Ball@zveno.com">Steve Ball</a> provides
543<a href="http://www.zveno.com/open_source/libxml2xslt.html">Mac Os X
544binaries</a>.</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]545
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]546<p><a name="Snapshot">Snapshot:</a></p>
547<ul>
548 <li>Code from the W3C cvs base libxml <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]549 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]550 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]551 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]552</ul>
553
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]554<p><a name="Contribs">Contributions:</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]555
556<p>I do accept external contributions, especially if compiling on another
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]557platform, get in touch with me to upload the package, wrappers for various
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]558languages have been provided, and can be found in the <a
559href="contribs.html">contrib section</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]560
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]561<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]562<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]563 <li><p>The <a
564 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]565 CVS base</a>. Check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]566 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a>
567 page; the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]568 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]569 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]570</ul>
571
572<h2><a name="News">News</a></h2>
573
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]574<h3>CVS only : check the <a
575href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]576for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]577
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]578<p>Items not finished and worked on, get in touch with the list if you want
579to test those</p>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]580<ul>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]581 <li>Finishing up <a href="http://www.w3.org/TR/xmlschema-1/">XML
582 Schemas</a> and <a href="http://www.w3.org/TR/xinclude">XInclude</a></li>
583</ul>
584
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]585<h3>2.4.25: Sep 26 2002</h3>
586<ul>
587 <li>A number of bug fixes: XPath, validation, Python bindings, DOM and
588 tree, xmlI/O, Html</li>
589 <li>Serious rewrite of XInclude</li>
590 <li>Made XML Schemas regexp part of the default build and APIs, small fix
591 and improvement of the regexp core</li>
592 <li>Changed the validation code to reuse XML Schemas regexp APIs</li>
593 <li>Better handling of Windows file paths, improvement of Makefiles (Igor,
594 Daniel Gehriger, Mark Vakoc)</li>
595 <li>Improved the python I/O bindings, the tests, added resolver and regexp
Daniel Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame^]596 APIs</li>
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]597 <li>New logos from Marc Liyanage</li>
598 <li>Tutorial improvements: John Fleck, Christopher Harris</li>
599 <li>Makefile: Fixes for AMD x86_64 (Mandrake), DESTDIR (Christophe
600 Merlet)</li>
601 <li>removal of all stderr/perror use for error reporting</li>
602 <li>Better error reporting: XPath and DTD validation</li>
603 <li>update of the trio portability layer (Bjorn Reese)</li>
604</ul>
605
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]606<p><strong>2.4.24: Aug 22 2002</strong></p>
607<ul>
608 <li>XPath fixes (William), xf:escape-uri() (Wesley Terpstra)</li>
609 <li>Python binding fixes: makefiles (William), generator, rpm build, x86-64
610 (fcrozat)</li>
611 <li>HTML &lt;style&gt; and boolean attributes serializer fixes</li>
612 <li>C14N improvements by Aleksey</li>
Daniel Veillarde1662542002-08-28 11:50:59 +0000[diff] [blame]613 <li>doc cleanups: Rick Jones</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]614 <li>Windows compiler makefile updates: Igor and Elizabeth Barham</li>
615 <li>XInclude: implementation of fallback and xml:base fixup added</li>
616</ul>
617
Daniel Veillard782afda2002-07-08 15:12:49 +0000[diff] [blame]618<h3>2.4.23: July 6 2002</h3>
619<ul>
620 <li>performances patches: Peter Jacobi</li>
621 <li>c14n fixes, testsuite and performances: Aleksey Sanin</li>
622 <li>added xmlDocFormatDump: Chema Celorio</li>
623 <li>new tutorial: John Fleck</li>
624 <li>new hash functions and performances: Sander Vesik, portability fix from
625 Peter Jacobi</li>
626 <li>a number of bug fixes: XPath (William Brack, Richard Jinks), XML and
627 HTML parsers, ID lookup function</li>
628 <li>removal of all remaining sprintf: Aleksey Sanin</li>
629</ul>
630
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]631<h3>2.4.22: May 27 2002</h3>
632<ul>
633 <li>a number of bug fixes: configure scripts, base handling, parser, memory
634 usage, HTML parser, XPath, documentation (Christian Cornelssen),
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]635 indentation, URI parsing</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]636 <li>Optimizations for XMLSec, fixing and making public some of the network
637 protocol handlers (Aleksey)</li>
638 <li>performance patch from Gary Pennington</li>
639 <li>Charles Bozeman provided date and time support for XML Schemas
640 datatypes</li>
641</ul>
642
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]643<h3>2.4.21: Apr 29 2002</h3>
644
645<p>This release is both a bug fix release and also contains the early XML
646Schemas <a href="http://www.w3.org/TR/xmlschema-1/">structures</a> and <a
647href="http://www.w3.org/TR/xmlschema-2/">datatypes</a> code, beware, all
648interfaces are likely to change, there is huge holes, it is clearly a work in
649progress and don't even think of putting this code in a production system,
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]650it's actually not compiled in by default. The real fixes are:</p>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]651<ul>
652 <li>a couple of bugs or limitations introduced in 2.4.20</li>
653 <li>patches for Borland C++ and MSC by Igor</li>
654 <li>some fixes on XPath strings and conformance patches by Richard
655 Jinks</li>
656 <li>patch from Aleksey for the ExcC14N specification</li>
657 <li>OSF/1 bug fix by Bjorn</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]658</ul>
659
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]660<h3>2.4.20: Apr 15 2002</h3>
661<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]662 <li>bug fixes: file descriptor leak, XPath, HTML output, DTD validation</li>
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]663 <li>XPath conformance testing by Richard Jinks</li>
664 <li>Portability fixes: Solaris, MPE/iX, Windows, OSF/1, python bindings,
665 libxml.m4</li>
666</ul>
667
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]668<h3>2.4.19: Mar 25 2002</h3>
669<ul>
670 <li>bug fixes: half a dozen XPath bugs, Validation, ISO-Latin to UTF8
671 encoder</li>
672 <li>portability fixes in the HTTP code</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]673 <li>memory allocation checks using valgrind, and profiling tests</li>
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]674 <li>revamp of the Windows build and Makefiles</li>
675</ul>
676
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]677<h3>2.4.18: Mar 18 2002</h3>
678<ul>
679 <li>bug fixes: tree, SAX, canonicalization, validation, portability,
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]680 XPath</li>
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]681 <li>removed the --with-buffer option it was becoming unmaintainable</li>
682 <li>serious cleanup of the Python makefiles</li>
683 <li>speedup patch to XPath very effective for DocBook stylesheets</li>
684 <li>Fixes for Windows build, cleanup of the documentation</li>
685</ul>
686
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]687<h3>2.4.17: Mar 8 2002</h3>
688<ul>
689 <li>a lot of bug fixes, including "namespace nodes have no parents in
690 XPath"</li>
691 <li>fixed/improved the Python wrappers, added more examples and more
692 regression tests, XPath extension functions can now return node-sets</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]693 <li>added the XML Canonicalization support from Aleksey Sanin</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]694</ul>
695
Daniel Veillard5f4b5992002-02-20 10:22:49 +0000[diff] [blame]696<h3>2.4.16: Feb 20 2002</h3>
697<ul>
698 <li>a lot of bug fixes, most of them were triggered by the XML Testsuite
699 from OASIS and W3C. Compliance has been significantly improved.</li>
700 <li>a couple of portability fixes too.</li>
701</ul>
702
Daniel Veillard397ff112002-02-11 18:27:20 +0000[diff] [blame]703<h3>2.4.15: Feb 11 2002</h3>
704<ul>
705 <li>Fixed the Makefiles, especially the python module ones</li>
706 <li>A few bug fixes and cleanup</li>
707 <li>Includes cleanup</li>
708</ul>
709
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]710<h3>2.4.14: Feb 8 2002</h3>
711<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]712 <li>Change of License to the <a
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]713 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]714 License</a> basically for integration in XFree86 codebase, and removing
715 confusion around the previous dual-licensing</li>
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]716 <li>added Python bindings, beta software but should already be quite
717 complete</li>
718 <li>a large number of fixes and cleanups, especially for all tree
719 manipulations</li>
720 <li>cleanup of the headers, generation of a reference API definition in
721 XML</li>
722</ul>
723
724<h3>2.4.13: Jan 14 2002</h3>
Daniel Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame]725<ul>
726 <li>update of the documentation: John Fleck and Charlie Bozeman</li>
727 <li>cleanup of timing code from Justin Fletcher</li>
728 <li>fixes for Windows and initial thread support on Win32: Igor and Serguei
729 Narojnyi</li>
730 <li>Cygwin patch from Robert Collins</li>
731 <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
732</ul>
733
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]734<h3>2.4.12: Dec 7 2001</h3>
735<ul>
736 <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
737 XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
738 (robert)</li>
739 <li>Eric Lavigne contributed project files for MacOS</li>
740 <li>some makefiles cleanups</li>
741</ul>
742
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]743<h3>2.4.11: Nov 26 2001</h3>
744<ul>
745 <li>fixed a couple of errors in the includes, fixed a few bugs, some code
746 cleanups</li>
747 <li>xmllint man pages improvement by Heiko Rupp</li>
748 <li>updated VMS build instructions from John A Fotheringham</li>
749 <li>Windows Makefiles updates from Igor</li>
750</ul>
751
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]752<h3>2.4.10: Nov 10 2001</h3>
753<ul>
754 <li>URI escaping fix (Joel Young)</li>
755 <li>added xmlGetNodePath() (for paths or XPointers generation)</li>
756 <li>Fixes namespace handling problems when using DTD and validation</li>
757 <li>improvements on xmllint: Morus Walter patches for --format and
758 --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
759 <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
760 <li>fixes to the HTML parser</li>
761</ul>
762
763<h3>2.4.9: Nov 6 2001</h3>
764<ul>
765 <li>fixes more catalog bugs</li>
766 <li>avoid a compilation problem, improve xmlGetLineNo()</li>
767</ul>
768
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]769<h3>2.4.8: Nov 4 2001</h3>
770<ul>
771 <li>fixed SGML catalogs broken in previous release, updated xmlcatalog
772 tool</li>
773 <li>fixed a compile errors and some includes troubles.</li>
774</ul>
775
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]776<h3>2.4.7: Oct 30 2001</h3>
777<ul>
778 <li>exported some debugging interfaces</li>
779 <li>serious rewrite of the catalog code</li>
780 <li>integrated Gary Pennington thread safety patch, added configure option
781 and regression tests</li>
782 <li>removed an HTML parser bug</li>
783 <li>fixed a couple of potentially serious validation bugs</li>
784 <li>integrated the SGML DocBook support in xmllint</li>
785 <li>changed the nanoftp anonymous login passwd</li>
786 <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
787 <li>general bug fixes</li>
788 <li>updated xmllint man page by John Fleck</li>
789 <li>some VMS and Windows updates</li>
790</ul>
791
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]792<h3>2.4.6: Oct 10 2001</h3>
793<ul>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]794 <li>added an updated man pages by John Fleck</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]795 <li>portability and configure fixes</li>
796 <li>an infinite loop on the HTML parser was removed (William)</li>
797 <li>Windows makefile patches from Igor</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]798 <li>fixed half a dozen bugs reported for libxml or libxslt</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]799 <li>updated xmlcatalog to be able to modify SGML super catalogs</li>
800</ul>
801
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]802<h3>2.4.5: Sep 14 2001</h3>
803<ul>
804 <li>Remove a few annoying bugs in 2.4.4</li>
805 <li>forces the HTML serializer to output decimal charrefs since some
806 version of Netscape can't handle hexadecimal ones</li>
807</ul>
808
809<h3>1.8.16: Sep 14 2001</h3>
810<ul>
811 <li>maintenance release of the old libxml1 branch, couple of bug and
812 portability fixes</li>
813</ul>
814
Daniel Veillard04382ae2001-09-12 18:51:30 +0000[diff] [blame]815<h3>2.4.4: Sep 12 2001</h3>
816<ul>
817 <li>added --convert to xmlcatalog, bug fixes and cleanups of XML
818 Catalog</li>
819 <li>a few bug fixes and some portability changes</li>
820 <li>some documentation cleanups</li>
821</ul>
822
Daniel Veillard39936902001-08-24 00:49:01 +0000[diff] [blame]823<h3>2.4.3: Aug 23 2001</h3>
824<ul>
825 <li>XML Catalog support see the doc</li>
826 <li>New NaN/Infinity floating point code</li>
827 <li>A few bug fixes</li>
828</ul>
829
830<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]831<ul>
832 <li>adds xmlLineNumbersDefault() to control line number generation</li>
833 <li>lot of bug fixes</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]834 <li>the Microsoft MSC projects files should now be up to date</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]835 <li>inheritance of namespaces from DTD defaulted attributes</li>
836 <li>fixes a serious potential security bug</li>
837 <li>added a --format option to xmllint</li>
838</ul>
839
840<h3>2.4.1: July 24 2001</h3>
841<ul>
842 <li>possibility to keep line numbers in the tree</li>
843 <li>some computation NaN fixes</li>
844 <li>extension of the XPath API</li>
845 <li>cleanup for alpha and ia64 targets</li>
846 <li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]847</ul>
848
849<h3>2.4.0: July 10 2001</h3>
850<ul>
851 <li>Fixed a few bugs in XPath, validation, and tree handling.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]852 <li>Fixed XML Base implementation, added a couple of examples to the
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]853 regression tests</li>
854 <li>A bit of cleanup</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]855</ul>
856
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]857<h3>2.3.14: July 5 2001</h3>
858<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]859 <li>fixed some entities problems and reduce memory requirement when
860 substituting them</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]861 <li>lots of improvements in the XPath queries interpreter can be
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]862 substantially faster</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]863 <li>Makefiles and configure cleanups</li>
864 <li>Fixes to XPath variable eval, and compare on empty node set</li>
865 <li>HTML tag closing bug fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]866 <li>Fixed an URI reference computation problem when validating</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]867</ul>
868
Daniel Veillard2adbb512001-06-28 16:20:36 +0000[diff] [blame]869<h3>2.3.13: June 28 2001</h3>
870<ul>
871 <li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
872 <li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
873</ul>
874
875<h3>1.8.14: June 28 2001</h3>
876<ul>
877 <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
878 <li>Small Makefile fix</li>
879</ul>
880
Daniel Veillard11648102001-06-26 16:08:24 +0000[diff] [blame]881<h3>2.3.12: June 26 2001</h3>
882<ul>
883 <li>lots of cleanup</li>
884 <li>a couple of validation fix</li>
885 <li>fixed line number counting</li>
886 <li>fixed serious problems in the XInclude processing</li>
887 <li>added support for UTF8 BOM at beginning of entities</li>
888 <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
889 miscompile uri.c (William), Thomas Leitner provided a fix for the
890 optimizer on Tru64</li>
891 <li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
892 compilation on Windows MSC</li>
893 <li>update of libxml-doc.el (Felix Natter)</li>
894 <li>fixed 2 bugs in URI normalization code</li>
895</ul>
896
Daniel Veillarde3c81b52001-06-17 14:50:34 +0000[diff] [blame]897<h3>2.3.11: June 17 2001</h3>
898<ul>
899 <li>updates to trio, Makefiles and configure should fix some portability
900 problems (alpha)</li>
901 <li>fixed some HTML serialization problems (pre, script, and block/inline
902 handling), added encoding aware APIs, cleanup of this code</li>
903 <li>added xmlHasNsProp()</li>
904 <li>implemented a specific PI for encoding support in the DocBook SGML
905 parser</li>
906 <li>some XPath fixes (-Infinity, / as a function parameter and namespaces
907 node selection)</li>
908 <li>fixed a performance problem and an error in the validation code</li>
909 <li>fixed XInclude routine to implement the recursive behaviour</li>
910 <li>fixed xmlFreeNode problem when libxml is included statically twice</li>
911 <li>added --version to xmllint for bug reports</li>
912</ul>
913
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]914<h3>2.3.10: June 1 2001</h3>
915<ul>
916 <li>fixed the SGML catalog support</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]917 <li>a number of reported bugs got fixed, in XPath, iconv detection,
918 XInclude processing</li>
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]919 <li>XPath string function should now handle unicode correctly</li>
920</ul>
921
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]922<h3>2.3.9: May 19 2001</h3>
923
924<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
925<ul>
926 <li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]927 <li>some serious speed optimization again</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]928 <li>some documentation cleanups</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]929 <li>trying to get better linking on Solaris (-R)</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]930 <li>XPath API cleanup from Thomas Broyer</li>
931 <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
932 xmlValidGetValidElements()</li>
933 <li>Added an INSTALL file</li>
934 <li>Attribute removal added to API: #54433</li>
935 <li>added a basic support for SGML catalogs</li>
936 <li>fixed xmlKeepBlanksDefault(0) API</li>
937 <li>bugfix in xmlNodeGetLang()</li>
938 <li>fixed a small configure portability problem</li>
939 <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
940</ul>
941
Daniel Veillarda265af72001-05-14 11:13:58 +0000[diff] [blame]942<h3>1.8.13: May 14 2001</h3>
943<ul>
944 <li>bugfixes release of the old libxml1 branch used by Gnome</li>
945</ul>
946
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]947<h3>2.3.8: May 3 2001</h3>
948<ul>
949 <li>Integrated an SGML DocBook parser for the Gnome project</li>
950 <li>Fixed a few things in the HTML parser</li>
951 <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
952 point portability issue</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]953 <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
954 DOM+validation using the XML REC as input and a 700MHz celeron).</li>
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]955 <li>incorporated more Windows cleanup</li>
956 <li>added xmlSaveFormatFile()</li>
957 <li>fixed problems in copying nodes with entities references (gdome)</li>
958 <li>removed some troubles surrounding the new validation module</li>
959</ul>
960
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]961<h3>2.3.7: April 22 2001</h3>
962<ul>
963 <li>lots of small bug fixes, corrected XPointer</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]964 <li>Non deterministic content model validation support</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]965 <li>added xmlDocCopyNode for gdome2</li>
966 <li>revamped the way the HTML parser handles end of tags</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]967 <li>XPath: corrections of namespaces support and number formatting</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]968 <li>Windows: Igor Zlatkovic patches for MSC compilation</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]969 <li>HTML output fixes from P C Chow and William M. Brack</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]970 <li>Improved validation speed sensible for DocBook</li>
971 <li>fixed a big bug with ID declared in external parsed entities</li>
972 <li>portability fixes, update of Trio from Bjorn Reese</li>
973</ul>
974
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]975<h3>2.3.6: April 8 2001</h3>
976<ul>
977 <li>Code cleanup using extreme gcc compiler warning options, found and
978 cleared half a dozen potential problem</li>
979 <li>the Eazel team found an XML parser bug</li>
980 <li>cleaned up the user of some of the string formatting function. used the
981 trio library code to provide the one needed when the platform is missing
982 them</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]983 <li>xpath: removed a memory leak and fixed the predicate evaluation
984 problem, extended the testsuite and cleaned up the result. XPointer seems
985 broken ...</li>
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]986</ul>
987
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame]988<h3>2.3.5: Mar 23 2001</h3>
989<ul>
990 <li>Biggest change is separate parsing and evaluation of XPath expressions,
991 there is some new APIs for this too</li>
992 <li>included a number of bug fixes(XML push parser, 51876, notations,
993 52299)</li>
994 <li>Fixed some portability issues</li>
995</ul>
996
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]997<h3>2.3.4: Mar 10 2001</h3>
998<ul>
999 <li>Fixed bugs #51860 and #51861</li>
1000 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
1001 size to be application tunable.</li>
1002 <li>Some cleanup in the validation code, still a bug left and this part
1003 should probably be rewritten to support ambiguous content model :-\</li>
1004 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
1005 parser</li>
1006 <li>Fixed another bug in xmlNodeGetContent()</li>
1007 <li>Bjorn fixed XPath node collection and Number formatting</li>
1008 <li>Fixed a loop reported in the HTML parsing</li>
1009 <li>blank space are reported even if the Dtd content model proves that they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1010 are formatting spaces, this is for XML conformance</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1011</ul>
1012
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]1013<h3>2.3.3: Mar 1 2001</h3>
1014<ul>
1015 <li>small change in XPath for XSLT</li>
1016 <li>documentation cleanups</li>
1017 <li>fix in validation by Gary Pennington</li>
1018 <li>serious parsing performances improvements</li>
1019</ul>
1020
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1021<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]1022<ul>
1023 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
1024 <li>fixed a Dtd parsing bug</li>
1025 <li>fixed a bug in xmlNodeGetContent</li>
1026 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
1027</ul>
1028
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1029<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1030<ul>
1031 <li>some XPath and HTML bug fixes for XSLT</li>
1032 <li>small extension of the hash table interfaces for DOM gdome2
1033 implementation</li>
1034 <li>A few bug fixes</li>
1035</ul>
1036
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1037<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]1038<ul>
1039 <li>Lots of XPath bug fixes</li>
1040 <li>Add a mode with Dtd lookup but without validation error reporting for
1041 XSLT</li>
1042 <li>Add support for text node without escaping (XSLT)</li>
1043 <li>bug fixes for xmlCheckFilename</li>
1044 <li>validation code bug fixes from Gary Pennington</li>
1045 <li>Patch from Paul D. Smith correcting URI path normalization</li>
1046 <li>Patch to allow simultaneous install of libxml-devel and
1047 libxml2-devel</li>
1048 <li>the example Makefile is now fixed</li>
1049 <li>added HTML to the RPM packages</li>
1050 <li>tree copying bugfixes</li>
1051 <li>updates to Windows makefiles</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1052 <li>optimization patch from Bjorn Reese</li>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1053</ul>
1054
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1055<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]1056<ul>
1057 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
1058 <li>added htmlHandleOmittedElem()</li>
1059 <li>Applied Bjorn Reese's IPV6 first patch</li>
1060 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1061 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]1062</ul>
1063
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]1064<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]1065<ul>
1066 <li>Fix the Windows problems of 2.2.8</li>
1067 <li>integrate OpenVMS patches</li>
1068 <li>better handling of some nasty HTML input</li>
1069 <li>Improved the XPointer implementation</li>
1070 <li>integrate a number of provided patches</li>
1071</ul>
1072
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]1073<h3>2.2.9: Nov 25 2000</h3>
1074<ul>
1075 <li>erroneous release :-(</li>
1076</ul>
1077
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]1078<h3>2.2.8: Nov 13 2000</h3>
1079<ul>
1080 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
1081 support</li>
1082 <li>Patch in conditional section handling</li>
1083 <li>updated MS compiler project</li>
1084 <li>fixed some XPath problems</li>
1085 <li>added an URI escaping function</li>
1086 <li>some other bug fixes</li>
1087</ul>
1088
1089<h3>2.2.7: Oct 31 2000</h3>
1090<ul>
1091 <li>added message redirection</li>
1092 <li>XPath improvements (thanks TOM !)</li>
1093 <li>xmlIOParseDTD() added</li>
1094 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
1095 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
1096</ul>
1097
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]1098<h3>2.2.6: Oct 25 2000:</h3>
1099<ul>
1100 <li>Added an hash table module, migrated a number of internal structure to
1101 those</li>
1102 <li>Fixed a posteriori validation problems</li>
1103 <li>HTTP module cleanups</li>
1104 <li>HTML parser improvements (tag errors, script/style handling, attribute
1105 normalization)</li>
1106 <li>coalescing of adjacent text nodes</li>
1107 <li>couple of XPath bug fixes, exported the internal API</li>
1108</ul>
1109
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1110<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1111<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1112 <li>XPointer implementation and testsuite</li>
1113 <li>Lot of XPath fixes, added variable and functions registration, more
1114 tests</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1115 <li>Portability fixes, lots of enhancements toward an easy Windows build
1116 and release</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1117 <li>Late validation fixes</li>
1118 <li>Integrated a lot of contributed patches</li>
1119 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1120 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1121</ul>
1122
1123<h3>2.2.4: Oct 1 2000:</h3>
1124<ul>
1125 <li>main XPath problem fixed</li>
1126 <li>Integrated portability patches for Windows</li>
1127 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1128</ul>
1129
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1130<h3>2.2.3: Sep 17 2000</h3>
1131<ul>
1132 <li>bug fixes</li>
1133 <li>cleanup of entity handling code</li>
1134 <li>overall review of all loops in the parsers, all sprintf usage has been
1135 checked too</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1136 <li>Far better handling of larges Dtd. Validating against DocBook XML Dtd
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1137 works smoothly now.</li>
1138</ul>
1139
1140<h3>1.8.10: Sep 6 2000</h3>
1141<ul>
1142 <li>bug fix release for some Gnome projects</li>
1143</ul>
1144
1145<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1146<ul>
1147 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]1148 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1149</ul>
1150
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1151<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1152<ul>
1153 <li>a purely bug fixes release</li>
1154 <li>fixed an encoding support problem when parsing from a memory block</li>
1155 <li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1156 <li>removed a bug in the function allowing to override the memory
1157 allocation routines</li>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1158</ul>
1159
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1160<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]1161<ul>
1162 <li>applied a lot of portability fixes</li>
1163 <li>better encoding support/cleanup and saving (content is now always
1164 encoded in UTF-8)</li>
1165 <li>the HTML parser now correctly handles encodings</li>
1166 <li>added xmlHasProp()</li>
1167 <li>fixed a serious problem with &amp;#38;</li>
1168 <li>propagated the fix to FTP client</li>
1169 <li>cleanup, bugfixes, etc ...</li>
1170 <li>Added a page about <a href="encoding.html">libxml Internationalization
1171 support</a></li>
1172</ul>
1173
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1174<h3>1.8.9: July 9 2000</h3>
1175<ul>
1176 <li>fixed the spec the RPMs should be better</li>
1177 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
1178 rpmfind users problem</li>
1179</ul>
1180
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]1181<h3>2.1.1: July 1 2000</h3>
1182<ul>
1183 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
1184 <li>improvements on the HTML parser</li>
1185</ul>
1186
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1187<h3>2.1.0 and 1.8.8: June 29 2000</h3>
1188<ul>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1189 <li>1.8.8 is mostly a commodity package for upgrading to libxml2 according
1190 to <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1191 about &amp;#38; charref parsing</li>
1192 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
1193 also contains numerous fixes and enhancements:
1194 <ul>
1195 <li>added xmlStopParser() to stop parsing</li>
1196 <li>improved a lot parsing speed when there is large CDATA blocs</li>
1197 <li>includes XPath patches provided by Picdar Technology</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1198 <li>tried to fix as much as possible DTD validation and namespace
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1199 related problems</li>
1200 <li>output to a given encoding has been added/tested</li>
1201 <li>lot of various fixes</li>
1202 </ul>
1203 </li>
1204</ul>
1205
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1206<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1207<ul>
1208 <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]1209 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initially
1210 scheduled for Apr 3 the release occurred only on Apr 12 due to massive
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1211 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1212 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1213 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1214 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1215 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1216 <pre>#include "xxx.h"</pre>
1217 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]1218 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
1219 <li>the memory allocation routines used by libxml can now be overloaded
1220 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1221 <li>The previously CVS only tool tester has been renamed
1222 <strong>xmllint</strong> and is now installed as part of the libxml2
1223 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1224 <li>The I/O interface has been revamped. There is now ways to plug in
1225 specific I/O modules, either at the URI scheme detection level using
1226 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
1227 parser context using xmlCreateIOParserCtxt()</li>
1228 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
1229 number of the libxml module in use</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1230 <li>a number of optional features of libxml can now be excluded at
1231 configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1232</ul>
1233
1234<h3>2.0.0beta: Mar 14 2000</h3>
1235<ul>
1236 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1237 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
1238 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
1239 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1240 <li>This version is now the head in the Gnome CVS base, the old one is
1241 available under the tag LIB_XML_1_X</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1242 <li>This includes a very large set of changes. From a programmatic point
1243 of view applications should not have to be modified too much, check the
1244 <a href="upgrade.html">upgrade page</a></li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1245 <li>Some interfaces may changes (especially a bit about encoding).</li>
1246 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1247 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1248 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
1249 handled now</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1250 <li>Better handling of entities, especially well-formedness checking
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1251 and proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1252 <li>DTD conditional sections</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1253 <li>Validation now correctly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1254 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1255 structures to accommodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1256 </ul>
1257 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1258 <li>Serious progress were made toward compliance, <a
1259 href="conf/result.html">here are the result of the test</a> against the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1260 OASIS testsuite (except the Japanese tests since I don't support that
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1261 encoding yet). This URL is rebuilt every couple of hours using the CVS
1262 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1263</ul>
1264
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1265<h3>1.8.7: Mar 6 2000</h3>
1266<ul>
1267 <li>This is a bug fix release:</li>
1268 <li>It is possible to disable the ignorable blanks heuristic used by
1269 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1270 that for adherence to XML spec, this behaviour will be disabled by
1271 default in 2.x . The same function will allow to keep compatibility for
1272 old code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1273 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
1274 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1275 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
1276 compilation on some platforms has been fixed</li>
1277 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
1278 URIs</li>
1279</ul>
1280
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1281<h3>1.8.6: Jan 31 2000</h3>
1282<ul>
1283 <li>added a nanoFTP transport module, debugged until the new version of <a
1284 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
1285 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]1286</ul>
1287
1288<h3>1.8.5: Jan 21 2000</h3>
1289<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1290 <li>adding APIs to parse a well balanced chunk of XML (production <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1291 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
1292 XML spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1293 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1294 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
1295 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1296 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
1297 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1298</ul>
1299
1300<h3>1.8.4: Jan 13 2000</h3>
1301<ul>
1302 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
1303 <li>all exit() call should have been removed from libxml</li>
1304 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
1305 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1306</ul>
1307
1308<h3>1.8.3: Jan 5 2000</h3>
1309<ul>
1310 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1311 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1312 <li>lots of bug fixes and improvement added over XMas holidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1313 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1314 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
1315 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1316 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1317 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1318 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1319</ul>
1320
1321<h3>1.8.2: Dec 21 1999</h3>
1322<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1323 <li>I got another problem with includes and C++, I hope this issue is fixed
1324 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1325 <li>Added a few tree modification functions: xmlReplaceNode,
1326 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
1327 xmlDocSetRootElement</li>
1328 <li>Tried to improve the HTML output with help from <a
1329 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1330</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1331
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1332<h3>1.8.1: Dec 18 1999</h3>
1333<ul>
1334 <li>various patches to avoid troubles when using libxml with C++ compilers
1335 the "namespace" keyword and C escaping in include files</li>
1336 <li>a problem in one of the core macros IS_CHAR was corrected</li>
1337 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
1338 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]1339 <li>fixed a posteriori validation (validation after parsing, or by using a
1340 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1341 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]1342</ul>
1343
1344<h3>1.8.0: Dec 12 1999</h3>
1345<ul>
1346 <li>cleanup, especially memory wise</li>
1347 <li>the parser should be more reliable, especially the HTML one, it should
1348 not crash, whatever the input !</li>
1349 <li>Integrated various patches, especially a speedup improvement for large
1350 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
1351 configure with --with-buffers to enable them.</li>
1352 <li>attribute normalization, oops should have been added long ago !</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1353 <li>attributes defaulted from DTDs should be available, xmlSetProp() now
1354 does entities escaping by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1355</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1356
1357<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1358<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1359 <li>Lots of HTML improvement</li>
1360 <li>Fixed some errors when saving both XML and HTML</li>
1361 <li>More examples, the regression tests should now look clean</li>
1362 <li>Fixed a bug with contiguous charref</li>
1363</ul>
1364
1365<h3>1.7.3: Sep 29 1999</h3>
1366<ul>
1367 <li>portability problems fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1368 <li>snprintf was used unconditionally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1369 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1370</ul>
1371
1372<h3>1.7.1: Sep 24 1999</h3>
1373<ul>
1374 <li>The basic type for strings manipulated by libxml has been renamed in
1375 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1376 is that CHAR was conflicting with a predefined type on Windows. However
1377 on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1378 <strong>#define </strong>.</li>
1379 <li>Changed another error : the use of a structure field called errno, and
1380 leading to troubles on platforms where it's a macro</li>
1381</ul>
1382
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1383<h3>1.7.0: Sep 23 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1384<ul>
1385 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1386 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1387 <li>Added an errno to report errors by another mean than a simple printf
1388 like callback</li>
1389 <li>Finished ID/IDREF support and checking when validation</li>
1390 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1391 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1392 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
1393 implementation</li>
1394 <li>Added an HTML parser front-end</li>
1395</ul>
1396
1397<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1398
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1399<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]1400markup-based structured documents. Here is <a name="example">an example XML
1401document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1402<pre>&lt;?xml version="1.0"?&gt;
1403&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
1404 &lt;head&gt;
1405 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
1406 &lt;/head&gt;
1407 &lt;chapter&gt;
1408 &lt;title&gt;The Linux adventure&lt;/title&gt;
1409 &lt;p&gt;bla bla bla ...&lt;/p&gt;
1410 &lt;image href="linus.gif"/&gt;
1411 &lt;p&gt;...&lt;/p&gt;
1412 &lt;/chapter&gt;
1413&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1414
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1415<p>The first line specifies that it is an XML document and gives useful
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1416information about its encoding. Then the rest of the document is a text
1417format whose structure is specified by tags between brackets. <strong>Each
1418tag opened has to be closed</strong>. XML is pedantic about this. However, if
1419a tag is empty (no content), a single tag can serve as both the opening and
1420closing tag if it ends with <code>/&gt;</code> rather than with
1421<code>&gt;</code>. Note that, for example, the image tag has no content (just
1422an attribute) and is closed by ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1423
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1424<p>XML can be applied successfully to a wide range of tasks, ranging from
1425long term structured document maintenance (where it follows the steps of
1426SGML) to simple data encoding mechanisms like configuration file formatting
1427(glade), spreadsheets (gnumeric), or even shorter lived documents such as
1428WebDAV where it is used to encode remote calls between a client and a
1429server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1430
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1431<h2><a name="XSLT">XSLT</a></h2>
1432
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1433<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
1434
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1435<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
1436language for transforming XML documents into other XML documents (or
1437HTML/textual output).</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1438
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1439<p>A separate library called libxslt is being developed on top of libxml2.
1440This module "libxslt" too can be found in the Gnome CVS base.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1441
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]1442<p>You can check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1443href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
1444supported and the progresses on the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1445href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog"
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1446name="Changelog">Changelog</a>.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1447
1448<h2><a name="Python">Python and bindings</a></h2>
1449
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1450<p>There are a number of language bindings and wrappers available for
1451libxml2, the list below is not exhaustive. Please contact the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1452href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a>
1453(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in
1454order to get updates to this list or to discuss the specific topic of libxml2
1455or libxslt wrappers or bindings:</p>
1456<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1457 <li><a href="mailto:ari@lusis.org">Ari Johnson</a> provides a C++ wrapper
1458 for libxml:<br>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1459 Website: <a
1460 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a><br>
1461 Download: <a
1462 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></li>
1463 <li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1464 based on the gdome2 bindings</a> maintained by Tobias Peters.</li>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]1465 <li>and a third C++ wrapper by Peter Jones &lt;pjones@pmade.org&gt;
1466 <p>Website: <a
1467 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
1468 </li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1469 <li><a
1470 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1471 Sergeant</a> developed <a
1472 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1473 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1474 application server</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]1475 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides an
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1476 earlier version of the libxml/libxslt <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1477 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]1478 <li>Gopal.V and Peter Minten develop <a
1479 href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1480 C# libxml2 bindings.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1481 <li>Petr Kozelka provides <a
1482 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1483 libxml2</a> with Kylix, Delphi and other Pascal compilers.</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]1484 <li>Uwe Fechner also provides <a
1485 href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1486 implementation for Kylix2/D5/D6 from Borland.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1487 <li>Wai-Sun "Squidster" Chia provides <a
1488 href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and
1489 libxml2 bindings are also available in Ruby through the <a
1490 href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module
1491 maintained by Tobias Peters.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1492 <li>Steve Ball and contributors maintains <a
1493 href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1494 Tcl</a>.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1495 <li>There is support for libxml2 in the DOM module of PHP.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1496</ul>
1497
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1498<p>The distribution includes a set of Python bindings, which are guaranteed
1499to be maintained as part of the library in the future, though the Python
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1500interface have not yet reached the maturity of the C API.</p>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1501
1502<p>To install the Python bindings there are 2 options:</p>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1503<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1504 <li>If you use an RPM based distribution, simply install the <a
1505 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python
1506 RPM</a> (and if needed the <a
1507 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python
1508 RPM</a>).</li>
1509 <li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python
1510 module distribution</a> corresponding to your installed version of
1511 libxml2 and libxslt. Note that to install it you will need both libxml2
1512 and libxslt installed and run "python setup.py build install" in the
1513 module tree.</li>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1514</ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1515
1516<p>The distribution includes a set of examples and regression tests for the
1517python bindings in the <code>python/tests</code> directory. Here are some
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1518excerpts from those tests:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1519
1520<h3>tst.py:</h3>
1521
1522<p>This is a basic test of the file interface and DOM navigation:</p>
1523<pre>import libxml2
1524
1525doc = libxml2.parseFile("tst.xml")
1526if doc.name != "tst.xml":
1527 print "doc.name failed"
1528 sys.exit(1)
1529root = doc.children
1530if root.name != "doc":
1531 print "root.name failed"
1532 sys.exit(1)
1533child = root.children
1534if child.name != "foo":
1535 print "child.name failed"
1536 sys.exit(1)
1537doc.freeDoc()</pre>
1538
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1539<p>The Python module is called libxml2; parseFile is the equivalent of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1540xmlParseFile (most of the bindings are automatically generated, and the xml
1541prefix is removed and the casing convention are kept). All node seen at the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1542binding level share the same subset of accessors:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1543<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1544 <li><code>name</code> : returns the node name</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1545 <li><code>type</code> : returns a string indicating the node type</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1546 <li><code>content</code> : returns the content of the node, it is based on
1547 xmlNodeGetContent() and hence is recursive.</li>
1548 <li><code>parent</code> , <code>children</code>, <code>last</code>,
1549 <code>next</code>, <code>prev</code>, <code>doc</code>,
1550 <code>properties</code>: pointing to the associated element in the tree,
1551 those may return None in case no such link exists.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1552</ul>
1553
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1554<p>Also note the need to explicitly deallocate documents with freeDoc() .
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1555Reference counting for libxml2 trees would need quite a lot of work to
1556function properly, and rather than risk memory leaks if not implemented
1557correctly it sounds safer to have an explicit function to free a tree. The
1558wrapper python objects like doc, root or child are them automatically garbage
1559collected.</p>
1560
1561<h3>validate.py:</h3>
1562
1563<p>This test check the validation interfaces and redirection of error
1564messages:</p>
1565<pre>import libxml2
1566
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1567#deactivate error messages from the validation
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1568def noerr(ctx, str):
1569 pass
1570
1571libxml2.registerErrorHandler(noerr, None)
1572
1573ctxt = libxml2.createFileParserCtxt("invalid.xml")
1574ctxt.validate(1)
1575ctxt.parseDocument()
1576doc = ctxt.doc()
1577valid = ctxt.isValid()
1578doc.freeDoc()
1579if valid != 0:
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1580 print "validity check failed"</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1581
1582<p>The first thing to notice is the call to registerErrorHandler(), it
1583defines a new error handler global to the library. It is used to avoid seeing
1584the error messages when trying to validate the invalid document.</p>
1585
1586<p>The main interest of that test is the creation of a parser context with
1587createFileParserCtxt() and how the behaviour can be changed before calling
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1588parseDocument() . Similarly the informations resulting from the parsing phase
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1589are also available using context methods.</p>
1590
1591<p>Contexts like nodes are defined as class and the libxml2 wrappers maps the
1592C function interfaces in terms of objects method as much as possible. The
1593best to get a complete view of what methods are supported is to look at the
1594libxml2.py module containing all the wrappers.</p>
1595
1596<h3>push.py:</h3>
1597
1598<p>This test show how to activate the push parser interface:</p>
1599<pre>import libxml2
1600
1601ctxt = libxml2.createPushParser(None, "&lt;foo", 4, "test.xml")
1602ctxt.parseChunk("/&gt;", 2, 1)
1603doc = ctxt.doc()
1604
1605doc.freeDoc()</pre>
1606
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1607<p>The context is created with a special call based on the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1608xmlCreatePushParser() from the C library. The first argument is an optional
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1609SAX callback object, then the initial set of data, the length and the name of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1610the resource in case URI-References need to be computed by the parser.</p>
1611
1612<p>Then the data are pushed using the parseChunk() method, the last call
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1613setting the third argument terminate to 1.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1614
1615<h3>pushSAX.py:</h3>
1616
1617<p>this test show the use of the event based parsing interfaces. In this case
1618the parser does not build a document, but provides callback information as
1619the parser makes progresses analyzing the data being provided:</p>
1620<pre>import libxml2
1621log = ""
1622
1623class callback:
1624 def startDocument(self):
1625 global log
1626 log = log + "startDocument:"
1627
1628 def endDocument(self):
1629 global log
1630 log = log + "endDocument:"
1631
1632 def startElement(self, tag, attrs):
1633 global log
1634 log = log + "startElement %s %s:" % (tag, attrs)
1635
1636 def endElement(self, tag):
1637 global log
1638 log = log + "endElement %s:" % (tag)
1639
1640 def characters(self, data):
1641 global log
1642 log = log + "characters: %s:" % (data)
1643
1644 def warning(self, msg):
1645 global log
1646 log = log + "warning: %s:" % (msg)
1647
1648 def error(self, msg):
1649 global log
1650 log = log + "error: %s:" % (msg)
1651
1652 def fatalError(self, msg):
1653 global log
1654 log = log + "fatalError: %s:" % (msg)
1655
1656handler = callback()
1657
1658ctxt = libxml2.createPushParser(handler, "&lt;foo", 4, "test.xml")
1659chunk = " url='tst'&gt;b"
1660ctxt.parseChunk(chunk, len(chunk), 0)
1661chunk = "ar&lt;/foo&gt;"
1662ctxt.parseChunk(chunk, len(chunk), 1)
1663
Daniel Veillardfcbfa2d2002-02-21 17:54:27 +0000[diff] [blame]1664reference = "startDocument:startElement foo {'url': 'tst'}:" + \
1665 "characters: bar:endElement foo:endDocument:"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1666if log != reference:
1667 print "Error got: %s" % log
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1668 print "Expected: %s" % reference</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1669
1670<p>The key object in that test is the handler, it provides a number of entry
1671points which can be called by the parser as it makes progresses to indicate
1672the information set obtained. The full set of callback is larger than what
1673the callback class in that specific example implements (see the SAX
1674definition for a complete list). The wrapper will only call those supplied by
1675the object when activated. The startElement receives the names of the element
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1676and a dictionary containing the attributes carried by this element.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1677
1678<p>Also note that the reference string generated from the callback shows a
1679single character call even though the string "bar" is passed to the parser
1680from 2 different call to parseChunk()</p>
1681
1682<h3>xpath.py:</h3>
1683
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1684<p>This is a basic test of XPath wrappers support</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1685<pre>import libxml2
1686
1687doc = libxml2.parseFile("tst.xml")
1688ctxt = doc.xpathNewContext()
1689res = ctxt.xpathEval("//*")
1690if len(res) != 2:
1691 print "xpath query: wrong node set size"
1692 sys.exit(1)
1693if res[0].name != "doc" or res[1].name != "foo":
1694 print "xpath query: wrong node set value"
1695 sys.exit(1)
1696doc.freeDoc()
1697ctxt.xpathFreeContext()</pre>
1698
1699<p>This test parses a file, then create an XPath context to evaluate XPath
1700expression on it. The xpathEval() method execute an XPath query and returns
1701the result mapped in a Python way. String and numbers are natively converted,
1702and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1703the document, the XPath context need to be freed explicitly, also not that
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1704the result of the XPath query may point back to the document tree and hence
1705the document must be freed after the result of the query is used.</p>
1706
1707<h3>xpathext.py:</h3>
1708
1709<p>This test shows how to extend the XPath engine with functions written in
1710python:</p>
1711<pre>import libxml2
1712
1713def foo(ctx, x):
1714 return x + 1
1715
1716doc = libxml2.parseFile("tst.xml")
1717ctxt = doc.xpathNewContext()
1718libxml2.registerXPathFunction(ctxt._o, "foo", None, foo)
1719res = ctxt.xpathEval("foo(1)")
1720if res != 2:
1721 print "xpath extension failure"
1722doc.freeDoc()
1723ctxt.xpathFreeContext()</pre>
1724
1725<p>Note how the extension function is registered with the context (but that
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1726part is not yet finalized, this may change slightly in the future).</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1727
1728<h3>tstxpath.py:</h3>
1729
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1730<p>This test is similar to the previous one but shows how the extension
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1731function can access the XPath evaluation context:</p>
1732<pre>def foo(ctx, x):
1733 global called
1734
1735 #
1736 # test that access to the XPath evaluation contexts
1737 #
1738 pctxt = libxml2.xpathParserContext(_obj=ctx)
1739 ctxt = pctxt.context()
1740 called = ctxt.function()
1741 return x + 1</pre>
1742
1743<p>All the interfaces around the XPath parser(or rather evaluation) context
1744are not finalized, but it should be sufficient to do contextual work at the
1745evaluation point.</p>
1746
1747<h3>Memory debugging:</h3>
1748
1749<p>last but not least, all tests starts with the following prologue:</p>
1750<pre>#memory debug specific
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1751libxml2.debugMemory(1)</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1752
1753<p>and ends with the following epilogue:</p>
1754<pre>#memory debug specific
1755libxml2.cleanupParser()
1756if libxml2.debugMemory(1) == 0:
1757 print "OK"
1758else:
1759 print "Memory leak %d bytes" % (libxml2.debugMemory(1))
1760 libxml2.dumpMemory()</pre>
1761
1762<p>Those activate the memory debugging interface of libxml2 where all
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1763allocated block in the library are tracked. The prologue then cleans up the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1764library state and checks that all allocated memory has been freed. If not it
1765calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1766
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1767<h2><a name="architecture">libxml architecture</a></h2>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1768
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1769<p>Libxml is made of multiple components; some of them are optional, and most
1770of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1771<ul>
1772 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1773 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1774 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1775 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1776 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1777 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1778 <li>a SAX tree module to build an in-memory DOM representation</li>
1779 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1780 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1781 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1782 (optional)</li>
1783 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1784</ul>
1785
1786<p>Graphically this gives the following:</p>
1787
1788<p><img src="libxml.gif" alt="a graphical view of the various"></p>
1789
1790<p></p>
1791
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1792<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1793
1794<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1795returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1796<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1797as the file name, the document type, and a <strong>children</strong> pointer
1798which is the root of the document (or more exactly the first child under the
1799root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1800chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1801relationship. An xmlNode can also carry properties (a chain of xmlAttr
1802structures). An attribute may have a value which is a list of TEXT or
1803ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1804
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1805<p>Here is an example (erroneous with respect to the XML spec since there
1806should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1807
1808<p><img src="structure.gif" alt=" structure.gif "></p>
1809
1810<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1811called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1812prints them back as parsed. This is useful for detecting errors both in XML
1813code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1814which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1815result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1816<pre>DOCUMENT
1817version=1.0
1818standalone=true
1819 ELEMENT EXAMPLE
1820 ATTRIBUTE prop1
1821 TEXT
1822 content=gnome is great
1823 ATTRIBUTE prop2
1824 ENTITY_REF
1825 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1826 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1827 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1828 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1829 TEXT
1830 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1831 ELEMENT chapter
1832 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1833 TEXT
1834 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1835 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1836 TEXT
1837 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1838 ELEMENT image
1839 ATTRIBUTE href
1840 TEXT
1841 content=linus.gif
1842 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1843 TEXT
1844 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1845
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1846<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1847
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1848<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1849
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1850<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1851memory. 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]1852loaded using libxml), it's better to use the SAX interface of libxml. SAX is
1853a <strong>callback-based interface</strong> to the parser. Before parsing,
1854the application layer registers a customized set of callbacks which are
1855called by the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1856
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1857<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]1858libxml, see the <a
1859href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
1860documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1861Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1862
1863<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
1864program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1865binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1866distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1867testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1868<pre>SAX.setDocumentLocator()
1869SAX.startDocument()
1870SAX.getEntity(amp)
1871SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
1872SAX.characters( , 3)
1873SAX.startElement(head)
1874SAX.characters( , 4)
1875SAX.startElement(title)
1876SAX.characters(Welcome to Gnome, 16)
1877SAX.endElement(title)
1878SAX.characters( , 3)
1879SAX.endElement(head)
1880SAX.characters( , 3)
1881SAX.startElement(chapter)
1882SAX.characters( , 4)
1883SAX.startElement(title)
1884SAX.characters(The Linux adventure, 19)
1885SAX.endElement(title)
1886SAX.characters( , 4)
1887SAX.startElement(p)
1888SAX.characters(bla bla bla ..., 15)
1889SAX.endElement(p)
1890SAX.characters( , 4)
1891SAX.startElement(image, href='linus.gif')
1892SAX.endElement(image)
1893SAX.characters( , 4)
1894SAX.startElement(p)
1895SAX.characters(..., 3)
1896SAX.endElement(p)
1897SAX.characters( , 3)
1898SAX.endElement(chapter)
1899SAX.characters( , 1)
1900SAX.endElement(EXAMPLE)
1901SAX.endDocument()</pre>
1902
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1903<p>Most of the other interfaces of libxml are based on the DOM tree-building
1904facility, so nearly everything up to the end of this document presupposes the
1905use of the standard DOM tree build. Note that the DOM tree itself is built by
1906a set of registered default callbacks, without internal specific
1907interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1908
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1909<h2><a name="Validation">Validation &amp; DTDs</a></h2>
1910
1911<p>Table of Content:</p>
1912<ol>
1913 <li><a href="#General5">General overview</a></li>
1914 <li><a href="#definition">The definition</a></li>
1915 <li><a href="#Simple">Simple rules</a>
1916 <ol>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]1917 <li><a href="#reference">How to reference a DTD from a document</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1918 <li><a href="#Declaring">Declaring elements</a></li>
1919 <li><a href="#Declaring1">Declaring attributes</a></li>
1920 </ol>
1921 </li>
1922 <li><a href="#Some">Some examples</a></li>
1923 <li><a href="#validate">How to validate</a></li>
1924 <li><a href="#Other">Other resources</a></li>
1925</ol>
1926
1927<h3><a name="General5">General overview</a></h3>
1928
1929<p>Well what is validation and what is a DTD ?</p>
1930
1931<p>DTD is the acronym for Document Type Definition. This is a description of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1932the 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]1933specification, and allows one to describe and verify that a given document
1934instance conforms to the set of rules detailing its structure and content.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1935
1936<p>Validation is the process of checking a document against a DTD (more
1937generally against a set of construction rules).</p>
1938
1939<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1940of the XML life cycle. Briefly a DTD defines all the possible elements to be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1941found within your document, what is the formal shape of your document tree
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1942(by defining the allowed content of an element; either text, a regular
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1943expression for the allowed list of children, or mixed content i.e. both text
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1944and children). The DTD also defines the valid attributes for all elements and
1945the types of those attributes.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1946
1947<h3><a name="definition1">The definition</a></h3>
1948
1949<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
1950href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
1951Rev1</a>):</p>
1952<ul>
1953 <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
1954 elements</a></li>
1955 <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
1956 attributes</a></li>
1957</ul>
1958
1959<p>(unfortunately) all this is inherited from the SGML world, the syntax is
1960ancient...</p>
1961
1962<h3><a name="Simple1">Simple rules</a></h3>
1963
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]1964<p>Writing DTDs can be done in many ways. The rules to build them if you need
1965something permanent or something which can evolve over time can be radically
1966different. Really complex DTDs like DocBook ones are flexible but quite
1967harder 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]1968structure. It is just a set of basic rules, and definitely not exhaustive nor
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1969usable for complex DTD design.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1970
1971<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
1972
1973<p>Assuming the top element of the document is <code>spec</code> and the dtd
1974is placed in the file <code>mydtd</code> in the subdirectory
1975<code>dtds</code> of the directory from where the document were loaded:</p>
1976
1977<p><code>&lt;!DOCTYPE spec SYSTEM "dtds/mydtd"&gt;</code></p>
1978
1979<p>Notes:</p>
1980<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1981 <li>The system string is actually an URI-Reference (as defined in <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1982 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]1983 full URL string indicating the location of your DTD on the Web. This is a
1984 really good thing to do if you want others to validate your document.</li>
1985 <li>It is also possible to associate a <code>PUBLIC</code> identifier (a
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1986 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]1987 without having to locate it on the web.</li>
1988 <li>A DTD contains a set of element and attribute declarations, but they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1989 don't define what the root of the document should be. This is explicitly
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1990 told to the parser/validator as the first element of the
1991 <code>DOCTYPE</code> declaration.</li>
1992</ul>
1993
1994<h4><a name="Declaring2">Declaring elements</a>:</h4>
1995
1996<p>The following declares an element <code>spec</code>:</p>
1997
1998<p><code>&lt;!ELEMENT spec (front, body, back?)&gt;</code></p>
1999
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2000<p>It also expresses that the spec element contains one <code>front</code>,
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2001one <code>body</code> and one optional <code>back</code> children elements in
2002this order. The declaration of one element of the structure and its content
2003are done in a single declaration. Similarly the following declares
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2004<code>div1</code> elements:</p>
2005
Daniel Veillard51737272002-01-23 23:10:38 +0000[diff] [blame]2006<p><code>&lt;!ELEMENT div1 (head, (p | list | note)*, div2?)&gt;</code></p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2007
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2008<p>which means div1 contains one <code>head</code> then a series of optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2009<code>p</code>, <code>list</code>s and <code>note</code>s and then an
2010optional <code>div2</code>. And last but not least an element can contain
2011text:</p>
2012
2013<p><code>&lt;!ELEMENT b (#PCDATA)&gt;</code></p>
2014
2015<p><code>b</code> contains text or being of mixed content (text and elements
2016in no particular order):</p>
2017
2018<p><code>&lt;!ELEMENT p (#PCDATA|a|ul|b|i|em)*&gt;</code></p>
2019
2020<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
2021<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
2022order.</p>
2023
2024<h4><a name="Declaring1">Declaring attributes</a>:</h4>
2025
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2026<p>Again the attributes declaration includes their content definition:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2027
2028<p><code>&lt;!ATTLIST termdef name CDATA #IMPLIED&gt;</code></p>
2029
2030<p>means that the element <code>termdef</code> can have a <code>name</code>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2031attribute containing text (<code>CDATA</code>) and which is optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2032(<code>#IMPLIED</code>). The attribute value can also be defined within a
2033set:</p>
2034
2035<p><code>&lt;!ATTLIST list type (bullets|ordered|glossary)
2036"ordered"&gt;</code></p>
2037
2038<p>means <code>list</code> element have a <code>type</code> attribute with 3
2039allowed values "bullets", "ordered" or "glossary" and which default to
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2040"ordered" if the attribute is not explicitly specified.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2041
2042<p>The content type of an attribute can be text (<code>CDATA</code>),
2043anchor/reference/references
2044(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
2045(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
2046(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
2047<code>chapter</code> element can have an optional <code>id</code> attribute
2048of type <code>ID</code>, usable for reference from attribute of type
2049IDREF:</p>
2050
2051<p><code>&lt;!ATTLIST chapter id ID #IMPLIED&gt;</code></p>
2052
2053<p>The last value of an attribute definition can be <code>#REQUIRED
2054</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
2055meaning that it is optional, or the default value (possibly prefixed by
2056<code>#FIXED</code> if it is the only allowed).</p>
2057
2058<p>Notes:</p>
2059<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2060 <li>Usually the attributes pertaining to a given element are declared in a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2061 single expression, but it is just a convention adopted by a lot of DTD
2062 writers:
2063 <pre>&lt;!ATTLIST termdef
2064 id ID #REQUIRED
2065 name CDATA #IMPLIED&gt;</pre>
2066 <p>The previous construct defines both <code>id</code> and
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2067 <code>name</code> attributes for the element <code>termdef</code>.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2068 </li>
2069</ul>
2070
2071<h3><a name="Some1">Some examples</a></h3>
2072
2073<p>The directory <code>test/valid/dtds/</code> in the libxml distribution
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2074contains some complex DTD examples. The example in the file
2075<code>test/valid/dia.xml</code> shows an XML file where the simple DTD is
2076directly included within the document.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2077
2078<h3><a name="validate1">How to validate</a></h3>
2079
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2080<p>The simplest way is to use the xmllint program included with libxml. The
2081<code>--valid</code> option turns-on validation of the files given as input.
2082For example the following validates a copy of the first revision of the XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]20831.0 specification:</p>
2084
2085<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
2086
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2087<p>the -- noout is used to disable output of the resulting tree.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2088
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2089<p>The <code>--dtdvalid dtd</code> allows validation of the document(s)
2090against a given DTD.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2091
2092<p>Libxml exports an API to handle DTDs and validation, check the <a
2093href="http://xmlsoft.org/html/libxml-valid.html">associated
2094description</a>.</p>
2095
2096<h3><a name="Other1">Other resources</a></h3>
2097
2098<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
2099will just list one for now, others pointers welcome:</p>
2100<ul>
2101 <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
2102</ul>
2103
2104<p>I suggest looking at the examples found under test/valid/dtd and any of
2105the large number of books available on XML. The dia example in test/valid
2106should be both simple and complete enough to allow you to build your own.</p>
2107
2108<p></p>
2109
2110<h2><a name="Memory">Memory Management</a></h2>
2111
2112<p>Table of Content:</p>
2113<ol>
2114 <li><a href="#General3">General overview</a></li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2115 <li><a href="#setting">Setting libxml set of memory routines</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2116 <li><a href="#cleanup">Cleaning up after parsing</a></li>
2117 <li><a href="#Debugging">Debugging routines</a></li>
2118 <li><a href="#General4">General memory requirements</a></li>
2119</ol>
2120
2121<h3><a name="General3">General overview</a></h3>
2122
2123<p>The module <code><a
2124href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
2125provides the interfaces to the libxml memory system:</p>
2126<ul>
2127 <li>libxml does not use the libc memory allocator directly but xmlFree(),
2128 xmlMalloc() and xmlRealloc()</li>
2129 <li>those routines can be reallocated to a specific set of routine, by
2130 default the libc ones i.e. free(), malloc() and realloc()</li>
2131 <li>the xmlmemory.c module includes a set of debugging routine</li>
2132</ul>
2133
2134<h3><a name="setting">Setting libxml set of memory routines</a></h3>
2135
2136<p>It is sometimes useful to not use the default memory allocator, either for
2137debugging, analysis or to implement a specific behaviour on memory management
2138(like on embedded systems). Two function calls are available to do so:</p>
2139<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2140 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet
2141 ()</a> which return the current set of functions in use by the parser</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2142 <li><a
2143 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2144 which allow to set up a new set of memory allocation functions</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2145</ul>
2146
2147<p>Of course a call to xmlMemSetup() should probably be done before calling
2148any other libxml routines (unless you are sure your allocations routines are
2149compatibles).</p>
2150
2151<h3><a name="cleanup">Cleaning up after parsing</a></h3>
2152
2153<p>Libxml is not stateless, there is a few set of memory structures needing
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2154allocation before the parser is fully functional (some encoding structures
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2155for example). This also mean that once parsing is finished there is a tiny
2156amount of memory (a few hundred bytes) which can be recollected if you don't
2157reuse the parser immediately:</p>
2158<ul>
2159 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2160 ()</a> is a centralized routine to free the parsing states. Note that it
2161 won't deallocate any produced tree if any (use the xmlFreeDoc() and
2162 related routines for this).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2163 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2164 ()</a> is the dual routine allowing to preallocate the parsing state
2165 which can be useful for example to avoid initialization reentrancy
2166 problems when using libxml in multithreaded applications</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2167</ul>
2168
2169<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
2170at the next invocation of parser routines, but be careful of the consequences
2171in multithreaded applications.</p>
2172
2173<h3><a name="Debugging">Debugging routines</a></h3>
2174
2175<p>When configured using --with-mem-debug flag (off by default), libxml uses
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2176a set of memory allocation debugging routines keeping track of all allocated
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2177blocks and the location in the code where the routine was called. A couple of
2178other debugging routines allow to dump the memory allocated infos to a file
2179or call a specific routine when a given block number is allocated:</p>
2180<ul>
2181 <li><a
2182 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2183 <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2184 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
2185 and <a
2186 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
2187 are the memory debugging replacement allocation routines</li>
2188 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2189 ()</a> dumps all the informations about the allocated memory block lefts
2190 in the <code>.memdump</code> file</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2191</ul>
2192
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2193<p>When developing libxml memory debug is enabled, the tests programs call
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2194xmlMemoryDump () and the "make test" regression tests will check for any
2195memory leak during the full regression test sequence, this helps a lot
2196ensuring that libxml does not leak memory and bullet proof memory
2197allocations use (some libc implementations are known to be far too permissive
2198resulting in major portability problems!).</p>
2199
2200<p>If the .memdump reports a leak, it displays the allocation function and
2201also tries to give some informations about the content and structure of the
2202allocated blocks left. This is sufficient in most cases to find the culprit,
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2203but not always. Assuming the allocation problem is reproducible, it is
2204possible to find more easily:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2205<ol>
2206 <li>write down the block number xxxx not allocated</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2207 <li>export the environment variable XML_MEM_BREAKPOINT=xxxx , the easiest
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2208 when using GDB is to simply give the command
2209 <p><code>set environment XML_MEM_BREAKPOINT xxxx</code></p>
2210 <p>before running the program.</p>
2211 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2212 <li>run the program under a debugger and set a breakpoint on
2213 xmlMallocBreakpoint() a specific function called when this precise block
2214 is allocated</li>
2215 <li>when the breakpoint is reached you can then do a fine analysis of the
2216 allocation an step to see the condition resulting in the missing
2217 deallocation.</li>
2218</ol>
2219
2220<p>I used to use a commercial tool to debug libxml memory problems but after
2221noticing that it was not detecting memory leaks that simple mechanism was
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2222used and proved extremely efficient until now. Lately I have also used <a
2223href="http://developer.kde.org/~sewardj/">valgrind</a> with quite some
2224success, it is tied to the i386 architecture since it works by emulating the
2225processor and instruction set, it is slow but extremely efficient, i.e. it
2226spot memory usage errors in a very precise way.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2227
2228<h3><a name="General4">General memory requirements</a></h3>
2229
2230<p>How much libxml memory require ? It's hard to tell in average it depends
2231of a number of things:</p>
2232<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2233 <li>the parser itself should work in a fixed amount of memory, except for
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2234 information maintained about the stacks of names and entities locations.
2235 The I/O and encoding handlers will probably account for a few KBytes.
2236 This is true for both the XML and HTML parser (though the HTML parser
2237 need more state).</li>
2238 <li>If you are generating the DOM tree then memory requirements will grow
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2239 nearly linear with the size of the data. In general for a balanced
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2240 textual document the internal memory requirement is about 4 times the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2241 size of the UTF8 serialization of this document (example the XML-1.0
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2242 recommendation is a bit more of 150KBytes and takes 650KBytes of main
2243 memory when parsed). Validation will add a amount of memory required for
2244 maintaining the external Dtd state which should be linear with the
2245 complexity of the content model defined by the Dtd</li>
2246 <li>If you don't care about the advanced features of libxml like
2247 validation, DOM, XPath or XPointer, but really need to work fixed memory
2248 requirements, then the SAX interface should be used.</li>
2249</ul>
2250
2251<p></p>
2252
2253<h2><a name="Encodings">Encodings support</a></h2>
2254
2255<p>Table of Content:</p>
2256<ol>
2257 <li><a href="encoding.html#What">What does internationalization support
2258 mean ?</a></li>
2259 <li><a href="encoding.html#internal">The internal encoding, how and
2260 why</a></li>
2261 <li><a href="encoding.html#implemente">How is it implemented ?</a></li>
2262 <li><a href="encoding.html#Default">Default supported encodings</a></li>
2263 <li><a href="encoding.html#extend">How to extend the existing
2264 support</a></li>
2265</ol>
2266
2267<h3><a name="What">What does internationalization support mean ?</a></h3>
2268
2269<p>XML was designed from the start to allow the support of any character set
2270by using Unicode. Any conformant XML parser has to support the UTF-8 and
2271UTF-16 default encodings which can both express the full unicode ranges. UTF8
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2272is a variable length encoding whose greatest points are to reuse the same
2273encoding for ASCII and to save space for Western encodings, but it is a bit
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2274more complex to handle in practice. UTF-16 use 2 bytes per characters (and
2275sometimes combines two pairs), it makes implementation easier, but looks a
2276bit overkill for Western languages encoding. Moreover the XML specification
2277allows document to be encoded in other encodings at the condition that they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2278are clearly labeled as such. For example the following is a wellformed XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2279document encoded in ISO-8859 1 and using accentuated letter that we French
2280likes for both markup and content:</p>
2281<pre>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2282&lt;très&gt;là&lt;/très&gt;</pre>
2283
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2284<p>Having internationalization support in libxml means the following:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2285<ul>
2286 <li>the document is properly parsed</li>
2287 <li>informations about it's encoding are saved</li>
2288 <li>it can be modified</li>
2289 <li>it can be saved in its original encoding</li>
2290 <li>it can also be saved in another encoding supported by libxml (for
2291 example straight UTF8 or even an ASCII form)</li>
2292</ul>
2293
2294<p>Another very important point is that the whole libxml API, with the
2295exception of a few routines to read with a specific encoding or save to a
2296specific encoding, is completely agnostic about the original encoding of the
2297document.</p>
2298
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2299<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]2300the same rules too, the following document will be (as of 2.2.2) handled in
2301an internationalized fashion by libxml too:</p>
2302<pre>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
2303 "http://www.w3.org/TR/REC-html40/loose.dtd"&gt;
2304&lt;html lang="fr"&gt;
2305&lt;head&gt;
2306 &lt;META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&gt;
2307&lt;/head&gt;
2308&lt;body&gt;
2309&lt;p&gt;W3C crée des standards pour le Web.&lt;/body&gt;
2310&lt;/html&gt;</pre>
2311
2312<h3><a name="internal">The internal encoding, how and why</a></h3>
2313
2314<p>One of the core decision was to force all documents to be converted to a
2315default internal encoding, and that encoding to be UTF-8, here are the
2316rationale for those choices:</p>
2317<ul>
2318 <li>keeping the native encoding in the internal form would force the libxml
2319 users (or the code associated) to be fully aware of the encoding of the
2320 original document, for examples when adding a text node to a document,
2321 the content would have to be provided in the document encoding, i.e. the
2322 client code would have to check it before hand, make sure it's conformant
2323 to the encoding, etc ... Very hard in practice, though in some specific
2324 cases this may make sense.</li>
2325 <li>the second decision was which encoding. From the XML spec only UTF8 and
2326 UTF16 really makes sense as being the two only encodings for which there
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2327 is mandatory support. UCS-4 (32 bits fixed size encoding) could be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2328 considered an intelligent choice too since it's a direct Unicode mapping
2329 support. I selected UTF-8 on the basis of efficiency and compatibility
2330 with surrounding software:
2331 <ul>
2332 <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
2333 more costly to import and export CPU wise) is also far more compact
2334 than UTF-16 (and UCS-4) for a majority of the documents I see it used
2335 for right now (RPM RDF catalogs, advogato data, various configuration
2336 file formats, etc.) and the key point for today's computer
2337 architecture is efficient uses of caches. If one nearly double the
2338 memory requirement to store the same amount of data, this will trash
2339 caches (main memory/external caches/internal caches) and my take is
2340 that this harms the system far more than the CPU requirements needed
2341 for the conversion to UTF-8</li>
2342 <li>Most of libxml version 1 users were using it with straight ASCII
2343 most of the time, doing the conversion with an internal encoding
2344 requiring all their code to be rewritten was a serious show-stopper
2345 for using UTF-16 or UCS-4.</li>
2346 <li>UTF-8 is being used as the de-facto internal encoding standard for
2347 related code like the <a href="http://www.pango.org/">pango</a>
2348 upcoming Gnome text widget, and a lot of Unix code (yep another place
2349 where Unix programmer base takes a different approach from Microsoft
2350 - they are using UTF-16)</li>
2351 </ul>
2352 </li>
2353</ul>
2354
2355<p>What does this mean in practice for the libxml user:</p>
2356<ul>
2357 <li>xmlChar, the libxml data type is a byte, those bytes must be assembled
2358 as UTF-8 valid strings. The proper way to terminate an xmlChar * string
2359 is simply to append 0 byte, as usual.</li>
2360 <li>One just need to make sure that when using chars outside the ASCII set,
2361 the values has been properly converted to UTF-8</li>
2362</ul>
2363
2364<h3><a name="implemente">How is it implemented ?</a></h3>
2365
2366<p>Let's describe how all this works within libxml, basically the I18N
2367(internationalization) support get triggered only during I/O operation, i.e.
2368when reading a document or saving one. Let's look first at the reading
2369sequence:</p>
2370<ol>
2371 <li>when a document is processed, we usually don't know the encoding, a
2372 simple heuristic allows to detect UTF-18 and UCS-4 from whose where the
2373 ASCII range (0-0x7F) maps with ASCII</li>
2374 <li>the xml declaration if available is parsed, including the encoding
2375 declaration. At that point, if the autodetected encoding is different
2376 from the one declared a call to xmlSwitchEncoding() is issued.</li>
2377 <li>If there is no encoding declaration, then the input has to be in either
2378 UTF-8 or UTF-16, if it is not then at some point when processing the
2379 input, the converter/checker of UTF-8 form will raise an encoding error.
2380 You may end-up with a garbled document, or no document at all ! Example:
2381 <pre>~/XML -&gt; ./xmllint err.xml
2382err.xml:1: error: Input is not proper UTF-8, indicate encoding !
2383&lt;très&gt;là&lt;/très&gt;
2384 ^
2385err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
2386&lt;très&gt;là&lt;/très&gt;
2387 ^</pre>
2388 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2389 <li>xmlSwitchEncoding() does an encoding name lookup, canonicalize it, and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2390 then search the default registered encoding converters for that encoding.
2391 If it's not within the default set and iconv() support has been compiled
2392 it, it will ask iconv for such an encoder. If this fails then the parser
2393 will report an error and stops processing:
2394 <pre>~/XML -&gt; ./xmllint err2.xml
2395err2.xml:1: error: Unsupported encoding UnsupportedEnc
2396&lt;?xml version="1.0" encoding="UnsupportedEnc"?&gt;
2397 ^</pre>
2398 </li>
Daniel Veillard46c5c1d2002-05-20 07:15:54 +0000[diff] [blame]2399 <li>From that point the encoder processes progressively the input (it is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2400 plugged as a front-end to the I/O module) for that entity. It captures
2401 and convert on-the-fly the document to be parsed to UTF-8. The parser
2402 itself just does UTF-8 checking of this input and process it
2403 transparently. The only difference is that the encoding information has
2404 been added to the parsing context (more precisely to the input
2405 corresponding to this entity).</li>
2406 <li>The result (when using DOM) is an internal form completely in UTF-8
2407 with just an encoding information on the document node.</li>
2408</ol>
2409
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2410<p>Ok then what happens when saving the document (assuming you
2411collected/built an xmlDoc DOM like structure) ? It depends on the function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2412called, xmlSaveFile() will just try to save in the original encoding, while
2413xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
2414encoding:</p>
2415<ol>
2416 <li>if no encoding is given, libxml will look for an encoding value
2417 associated to the document and if it exists will try to save to that
2418 encoding,
2419 <p>otherwise everything is written in the internal form, i.e. UTF-8</p>
2420 </li>
2421 <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]2422 document, libxml will again canonicalize the encoding name, lookup for a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2423 converter in the registered set or through iconv. If not found the
2424 function will return an error code</li>
2425 <li>the converter is placed before the I/O buffer layer, as another kind of
2426 buffer, then libxml will simply push the UTF-8 serialization to through
2427 that buffer, which will then progressively be converted and pushed onto
2428 the I/O layer.</li>
2429 <li>It is possible that the converter code fails on some input, for example
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2430 trying to push an UTF-8 encoded Chinese character through the UTF-8 to
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2431 ISO-8859-1 converter won't work. Since the encoders are progressive they
2432 will just report the error and the number of bytes converted, at that
2433 point libxml will decode the offending character, remove it from the
2434 buffer and replace it with the associated charRef encoding &amp;#123; and
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2435 resume the conversion. This guarantees that any document will be saved
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2436 without losses (except for markup names where this is not legal, this is
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2437 a problem in the current version, in practice avoid using non-ascii
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2438 characters for tags or attributes names @@). A special "ascii" encoding
2439 name is used to save documents to a pure ascii form can be used when
2440 portability is really crucial</li>
2441</ol>
2442
2443<p>Here is a few examples based on the same test document:</p>
2444<pre>~/XML -&gt; ./xmllint isolat1
2445&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2446&lt;très&gt;là&lt;/très&gt;
2447~/XML -&gt; ./xmllint --encode UTF-8 isolat1
2448&lt;?xml version="1.0" encoding="UTF-8"?&gt;
2449&lt;très&gt;là  &lt;/très&gt;
2450~/XML -&gt; </pre>
2451
2452<p>The same processing is applied (and reuse most of the code) for HTML I18N
2453processing. Looking up and modifying the content encoding is a bit more
2454difficult since it is located in a &lt;meta&gt; tag under the &lt;head&gt;,
2455so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
2456been provided. The parser also attempts to switch encoding on the fly when
2457detecting such a tag on input. Except for that the processing is the same
2458(and again reuses the same code).</p>
2459
2460<h3><a name="Default">Default supported encodings</a></h3>
2461
2462<p>libxml has a set of default converters for the following encodings
2463(located in encoding.c):</p>
2464<ol>
2465 <li>UTF-8 is supported by default (null handlers)</li>
2466 <li>UTF-16, both little and big endian</li>
2467 <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
2468 <li>ASCII, useful mostly for saving</li>
2469 <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
2470 predefined entities like &amp;copy; for the Copyright sign.</li>
2471</ol>
2472
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2473<p>More over when compiled on an Unix platform with iconv support the full
2474set of encodings supported by iconv can be instantly be used by libxml. On a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2475linux machine with glibc-2.1 the list of supported encodings and aliases fill
24763 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
2477various Japanese ones.</p>
2478
2479<h4>Encoding aliases</h4>
2480
2481<p>From 2.2.3, libxml has support to register encoding names aliases. The
2482goal is to be able to parse document whose encoding is supported but where
2483the name differs (for example from the default set of names accepted by
2484iconv). The following functions allow to register and handle new aliases for
2485existing encodings. Once registered libxml will automatically lookup the
2486aliases when handling a document:</p>
2487<ul>
2488 <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li>
2489 <li>int xmlDelEncodingAlias(const char *alias);</li>
2490 <li>const char * xmlGetEncodingAlias(const char *alias);</li>
2491 <li>void xmlCleanupEncodingAliases(void);</li>
2492</ul>
2493
2494<h3><a name="extend">How to extend the existing support</a></h3>
2495
2496<p>Well adding support for new encoding, or overriding one of the encoders
2497(assuming it is buggy) should not be hard, just write an input and output
2498conversion routines to/from UTF-8, and register them using
2499xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
2500called automatically if the parser(s) encounter such an encoding name
2501(register it uppercase, this will help). The description of the encoders,
2502their arguments and expected return values are described in the encoding.h
2503header.</p>
2504
2505<p>A quick note on the topic of subverting the parser to use a different
2506internal encoding than UTF-8, in some case people will absolutely want to
2507keep the internal encoding different, I think it's still possible (but the
2508encoding must be compliant with ASCII on the same subrange) though I didn't
2509tried it. The key is to override the default conversion routines (by
2510registering null encoders/decoders for your charsets), and bypass the UTF-8
2511checking of the parser by setting the parser context charset
2512(ctxt-&gt;charset) to something different than XML_CHAR_ENCODING_UTF8, but
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2513there is no guarantee that this will work. You may also have some troubles
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2514saving back.</p>
2515
2516<p>Basically proper I18N support is important, this requires at least
2517libxml-2.0.0, but a lot of features and corrections are really available only
2518starting 2.2.</p>
2519
2520<h2><a name="IO">I/O Interfaces</a></h2>
2521
2522<p>Table of Content:</p>
2523<ol>
2524 <li><a href="#General1">General overview</a></li>
2525 <li><a href="#basic">The basic buffer type</a></li>
2526 <li><a href="#Input">Input I/O handlers</a></li>
2527 <li><a href="#Output">Output I/O handlers</a></li>
2528 <li><a href="#entities">The entities loader</a></li>
2529 <li><a href="#Example2">Example of customized I/O</a></li>
2530</ol>
2531
2532<h3><a name="General1">General overview</a></h3>
2533
2534<p>The module <code><a
2535href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
2536the interfaces to the libxml I/O system. This consists of 4 main parts:</p>
2537<ul>
2538 <li>Entities loader, this is a routine which tries to fetch the entities
2539 (files) based on their PUBLIC and SYSTEM identifiers. The default loader
2540 don't look at the public identifier since libxml do not maintain a
2541 catalog. You can redefine you own entity loader by using
2542 <code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2543 <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
2544 example</a>.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2545 <li>Input I/O buffers which are a commodity structure used by the parser(s)
2546 input layer to handle fetching the informations to feed the parser. This
2547 provides buffering and is also a placeholder where the encoding
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2548 converters to UTF8 are piggy-backed.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2549 <li>Output I/O buffers are similar to the Input ones and fulfill similar
2550 task but when generating a serialization from a tree.</li>
2551 <li>A mechanism to register sets of I/O callbacks and associate them with
2552 specific naming schemes like the protocol part of the URIs.
2553 <p>This affect the default I/O operations and allows to use specific I/O
2554 handlers for certain names.</p>
2555 </li>
2556</ul>
2557
2558<p>The general mechanism used when loading http://rpmfind.net/xml.html for
2559example in the HTML parser is the following:</p>
2560<ol>
2561 <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
2562 the parsing context and the URI string.</li>
2563 <li>the URI string is checked against the existing registered handlers
2564 using their match() callback function, if the HTTP module was compiled
2565 in, it is registered and its match() function will succeeds</li>
2566 <li>the open() function of the handler is called and if successful will
2567 return an I/O Input buffer</li>
2568 <li>the parser will the start reading from this buffer and progressively
2569 fetch information from the resource, calling the read() function of the
2570 handler until the resource is exhausted</li>
2571 <li>if an encoding change is detected it will be installed on the input
2572 buffer, providing buffering and efficient use of the conversion
2573 routines</li>
2574 <li>once the parser has finished, the close() function of the handler is
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2575 called once and the Input buffer and associated resources are
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2576 deallocated.</li>
2577</ol>
2578
2579<p>The user defined callbacks are checked first to allow overriding of the
2580default libxml I/O routines.</p>
2581
2582<h3><a name="basic">The basic buffer type</a></h3>
2583
2584<p>All the buffer manipulation handling is done using the
2585<code>xmlBuffer</code> type define in <code><a
2586href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
2587resizable memory buffer. The buffer allocation strategy can be selected to be
2588either best-fit or use an exponential doubling one (CPU vs. memory use
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2589trade-off). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2590<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
2591system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
2592of functions allows to manipulate buffers with names starting with the
2593<code>xmlBuffer...</code> prefix.</p>
2594
2595<h3><a name="Input">Input I/O handlers</a></h3>
2596
2597<p>An Input I/O handler is a simple structure
2598<code>xmlParserInputBuffer</code> containing a context associated to the
2599resource (file descriptor, or pointer to a protocol handler), the read() and
2600close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
2601encoding handler are also present to support charset conversion when
2602needed.</p>
2603
2604<h3><a name="Output">Output I/O handlers</a></h3>
2605
2606<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
2607Input one except the callbacks are write() and close().</p>
2608
2609<h3><a name="entities">The entities loader</a></h3>
2610
2611<p>The entity loader resolves requests for new entities and create inputs for
2612the parser. Creating an input from a filename or an URI string is done
2613through the xmlNewInputFromFile() routine. The default entity loader do not
2614handle the PUBLIC identifier associated with an entity (if any). So it just
2615calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
2616XML).</p>
2617
2618<p>If you want to hook up a catalog mechanism then you simply need to
2619override the default entity loader, here is an example:</p>
2620<pre>#include &lt;libxml/xmlIO.h&gt;
2621
2622xmlExternalEntityLoader defaultLoader = NULL;
2623
2624xmlParserInputPtr
2625xmlMyExternalEntityLoader(const char *URL, const char *ID,
2626 xmlParserCtxtPtr ctxt) {
2627 xmlParserInputPtr ret;
2628 const char *fileID = NULL;
2629 /* lookup for the fileID depending on ID */
2630
2631 ret = xmlNewInputFromFile(ctxt, fileID);
2632 if (ret != NULL)
2633 return(ret);
2634 if (defaultLoader != NULL)
2635 ret = defaultLoader(URL, ID, ctxt);
2636 return(ret);
2637}
2638
2639int main(..) {
2640 ...
2641
2642 /*
2643 * Install our own entity loader
2644 */
2645 defaultLoader = xmlGetExternalEntityLoader();
2646 xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
2647
2648 ...
2649}</pre>
2650
2651<h3><a name="Example2">Example of customized I/O</a></h3>
2652
2653<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
2654real use case</a>, xmlDocDump() closes the FILE * passed by the application
2655and this was a problem. The <a
2656href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
2657new output handler with the closing call deactivated:</p>
2658<ol>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2659 <li>First define a new I/O output allocator where the output don't close
2660 the file:
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2661 <pre>xmlOutputBufferPtr
2662xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
2663    xmlOutputBufferPtr ret;
2664    
2665    if (xmlOutputCallbackInitialized == 0)
2666        xmlRegisterDefaultOutputCallbacks();
2667
2668    if (file == NULL) return(NULL);
2669    ret = xmlAllocOutputBuffer(encoder);
2670    if (ret != NULL) {
2671        ret-&gt;context = file;
2672        ret-&gt;writecallback = xmlFileWrite;
2673        ret-&gt;closecallback = NULL; /* No close callback */
2674    }
2675    return(ret); <br>
Daniel Veillard1eb24242002-03-18 11:33:03 +0000[diff] [blame]2676
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]2677
2678
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]2679
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]2680
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2681
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]2682
Daniel Veillard0bfbb422002-04-26 09:21:45 +0000[diff] [blame]2683
Daniel Veillard93d3a472002-04-26 14:04:55 +0000[diff] [blame]2684
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]2685
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]2686
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]2687
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2688
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]2689
Daniel Veillard782afda2002-07-08 15:12:49 +0000[diff] [blame]2690
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]2691
Daniel Veillarde1662542002-08-28 11:50:59 +0000[diff] [blame]2692
Daniel Veillarde16b5742002-09-26 17:50:03 +0000[diff] [blame]2693
Daniel Veillard321be0c2002-10-08 21:26:42 +0000[diff] [blame^]2694
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2695} </pre>
2696 </li>
2697 <li>And then use it to save the document:
2698 <pre>FILE *f;
2699xmlOutputBufferPtr output;
2700xmlDocPtr doc;
2701int res;
2702
2703f = ...
2704doc = ....
2705
2706output = xmlOutputBufferCreateOwn(f, NULL);
2707res = xmlSaveFileTo(output, doc, NULL);
2708 </pre>
2709 </li>
2710</ol>
2711
2712<h2><a name="Catalog">Catalog support</a></h2>
2713
2714<p>Table of Content:</p>
2715<ol>
2716 <li><a href="General2">General overview</a></li>
2717 <li><a href="#definition">The definition</a></li>
2718 <li><a href="#Simple">Using catalogs</a></li>
2719 <li><a href="#Some">Some examples</a></li>
2720 <li><a href="#reference">How to tune catalog usage</a></li>
2721 <li><a href="#validate">How to debug catalog processing</a></li>
2722 <li><a href="#Declaring">How to create and maintain catalogs</a></li>
2723 <li><a href="#implemento">The implementor corner quick review of the
2724 API</a></li>
2725 <li><a href="#Other">Other resources</a></li>
2726</ol>
2727
2728<h3><a name="General2">General overview</a></h3>
2729
2730<p>What is a catalog? Basically it's a lookup mechanism used when an entity
2731(a file or a remote resource) references another entity. The catalog lookup
2732is inserted between the moment the reference is recognized by the software
2733(XML parser, stylesheet processing, or even images referenced for inclusion
2734in a rendering) and the time where loading that resource is actually
2735started.</p>
2736
2737<p>It is basically used for 3 things:</p>
2738<ul>
2739 <li>mapping from "logical" names, the public identifiers and a more
2740 concrete name usable for download (and URI). For example it can associate
2741 the logical name
2742 <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
2743 <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
2744 downloaded</p>
2745 <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
2746 </li>
2747 <li>remapping from a given URL to another one, like an HTTP indirection
2748 saying that
2749 <p>"http://www.oasis-open.org/committes/tr.xsl"</p>
2750 <p>should really be looked at</p>
2751 <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
2752 </li>
2753 <li>providing a local cache mechanism allowing to load the entities
2754 associated to public identifiers or remote resources, this is a really
2755 important feature for any significant deployment of XML or SGML since it
2756 allows to avoid the aleas and delays associated to fetching remote
2757 resources.</li>
2758</ul>
2759
2760<h3><a name="definition">The definitions</a></h3>
2761
2762<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
2763<ul>
2764 <li>the older SGML catalogs, the official spec is SGML Open Technical
2765 Resolution TR9401:1997, but is better understood by reading <a
2766 href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
2767 James Clark. This is relatively old and not the preferred mode of
2768 operation of libxml.</li>
2769 <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2770 Catalogs</a> is far more flexible, more recent, uses an XML syntax and
2771 should scale quite better. This is the default option of libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2772</ul>
2773
2774<p></p>
2775
2776<h3><a name="Simple">Using catalog</a></h3>
2777
2778<p>In a normal environment libxml will by default check the presence of a
2779catalog in /etc/xml/catalog, and assuming it has been correctly populated,
2780the processing is completely transparent to the document user. To take a
2781concrete example, suppose you are authoring a DocBook document, this one
2782starts with the following DOCTYPE definition:</p>
2783<pre>&lt;?xml version='1.0'?&gt;
2784&lt;!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
2785 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"&gt;</pre>
2786
2787<p>When validating the document with libxml, the catalog will be
2788automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
2789DocBk XML V3.1.4//EN" and the system identifier
2790"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
2791been installed on your system and the catalogs actually point to them, libxml
2792will fetch them from the local disk.</p>
2793
2794<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
2795DOCTYPE example it's a really old version, but is fine as an example.</p>
2796
2797<p>Libxml will check the catalog each time that it is requested to load an
2798entity, this includes DTD, external parsed entities, stylesheets, etc ... If
2799your system is correctly configured all the authoring phase and processing
2800should use only local files, even if your document stays portable because it
2801uses the canonical public and system ID, referencing the remote document.</p>
2802
2803<h3><a name="Some">Some examples:</a></h3>
2804
2805<p>Here is a couple of fragments from XML Catalogs used in libxml early
2806regression tests in <code>test/catalogs</code> :</p>
2807<pre>&lt;?xml version="1.0"?&gt;
2808&lt;!DOCTYPE catalog PUBLIC
2809 "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2810 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2811&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2812 &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2813 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2814...</pre>
2815
2816<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
2817written in XML, there is a specific namespace for catalog elements
2818"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
2819catalog is a <code>public</code> mapping it allows to associate a Public
2820Identifier with an URI.</p>
2821<pre>...
2822 &lt;rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2823 rewritePrefix="file:///usr/share/xml/docbook/"/&gt;
2824...</pre>
2825
2826<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
2827any URI starting with a given prefix should be looked at another URI
2828constructed by replacing the prefix with an new one. In effect this acts like
2829a cache system for a full area of the Web. In practice it is extremely useful
2830with a file prefix if you have installed a copy of those resources on your
2831local system.</p>
2832<pre>...
2833&lt;delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
2834 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2835&lt;delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
2836 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2837&lt;delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
2838 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2839&lt;delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2840 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2841&lt;delegateURI uriStartString="http://www.oasis-open.org/docbook/"
2842 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2843...</pre>
2844
2845<p>Delegation is the core features which allows to build a tree of catalogs,
2846easier to maintain than a single catalog, based on Public Identifier, System
2847Identifier or URI prefixes it instructs the catalog software to look up
2848entries in another resource. This feature allow to build hierarchies of
2849catalogs, the set of entries presented should be sufficient to redirect the
2850resolution of all DocBook references to the specific catalog in
2851<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
2852references for DocBook 4.2.1 to a specific catalog installed at the same time
2853as the DocBook resources on the local machine.</p>
2854
2855<h3><a name="reference">How to tune catalog usage:</a></h3>
2856
2857<p>The user can change the default catalog behaviour by redirecting queries
2858to its own set of catalogs, this can be done by setting the
2859<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
2860empty one should deactivate loading the default <code>/etc/xml/catalog</code>
2861default catalog</p>
2862
2863<h3><a name="validate">How to debug catalog processing:</a></h3>
2864
2865<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
2866make libxml output debugging informations for each catalog operations, for
2867example:</p>
2868<pre>orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2869warning: failed to load external entity "title.xml"
2870orchis:~/XML -&gt; export XML_DEBUG_CATALOG=
2871orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2872Failed to parse catalog /etc/xml/catalog
2873Failed to parse catalog /etc/xml/catalog
2874warning: failed to load external entity "title.xml"
2875Catalogs cleanup
2876orchis:~/XML -&gt; </pre>
2877
2878<p>The test/ent2 references an entity, running the parser from memory makes
2879the base URI unavailable and the the "title.xml" entity cannot be loaded.
2880Setting up the debug environment variable allows to detect that an attempt is
2881made to load the <code>/etc/xml/catalog</code> but since it's not present the
2882resolution fails.</p>
2883
2884<p>But the most advanced way to debug XML catalog processing is to use the
2885<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
2886catalogs and make resolution queries to see what is going on. This is also
2887used for the regression tests:</p>
2888<pre>orchis:~/XML -&gt; ./xmlcatalog test/catalogs/docbook.xml \
2889 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2890http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2891orchis:~/XML -&gt; </pre>
2892
2893<p>For debugging what is going on, adding one -v flags increase the verbosity
2894level to indicate the processing done (adding a second flag also indicate
2895what elements are recognized at parsing):</p>
2896<pre>orchis:~/XML -&gt; ./xmlcatalog -v test/catalogs/docbook.xml \
2897 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2898Parsing catalog test/catalogs/docbook.xml's content
2899Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
2900http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2901Catalogs cleanup
2902orchis:~/XML -&gt; </pre>
2903
2904<p>A shell interface is also available to debug and process multiple queries
2905(and for regression tests):</p>
2906<pre>orchis:~/XML -&gt; ./xmlcatalog -shell test/catalogs/docbook.xml \
2907 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2908&gt; help
2909Commands available:
2910public PublicID: make a PUBLIC identifier lookup
2911system SystemID: make a SYSTEM identifier lookup
2912resolve PublicID SystemID: do a full resolver lookup
2913add 'type' 'orig' 'replace' : add an entry
2914del 'values' : remove values
2915dump: print the current catalog state
2916debug: increase the verbosity level
2917quiet: decrease the verbosity level
2918exit: quit the shell
2919&gt; public "-//OASIS//DTD DocBook XML V4.1.2//EN"
2920http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2921&gt; quit
2922orchis:~/XML -&gt; </pre>
2923
2924<p>This should be sufficient for most debugging purpose, this was actually
2925used heavily to debug the XML Catalog implementation itself.</p>
2926
2927<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
2928
2929<p>Basically XML Catalogs are XML files, you can either use XML tools to
2930manage them or use <strong>xmlcatalog</strong> for this. The basic step is
2931to create a catalog the -create option provide this facility:</p>
2932<pre>orchis:~/XML -&gt; ./xmlcatalog --create tst.xml
2933&lt;?xml version="1.0"?&gt;
2934&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2935 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2936&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2937orchis:~/XML -&gt; </pre>
2938
2939<p>By default xmlcatalog does not overwrite the original catalog and save the
2940result on the standard output, this can be overridden using the -noout
2941option. The <code>-add</code> command allows to add entries in the
2942catalog:</p>
2943<pre>orchis:~/XML -&gt; ./xmlcatalog --noout --create --add "public" \
2944 "-//OASIS//DTD DocBook XML V4.1.2//EN" \
2945 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
2946orchis:~/XML -&gt; cat tst.xml
2947&lt;?xml version="1.0"?&gt;
2948&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
2949 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2950&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2951&lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2952 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2953&lt;/catalog&gt;
2954orchis:~/XML -&gt; </pre>
2955
2956<p>The <code>-add</code> option will always take 3 parameters even if some of
2957the XML Catalog constructs (like nextCatalog) will have only a single
2958argument, just pass a third empty string, it will be ignored.</p>
2959
2960<p>Similarly the <code>-del</code> option remove matching entries from the
2961catalog:</p>
2962<pre>orchis:~/XML -&gt; ./xmlcatalog --del \
2963 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
2964&lt;?xml version="1.0"?&gt;
2965&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2966 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2967&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2968orchis:~/XML -&gt; </pre>
2969
2970<p>The catalog is now empty. Note that the matching of <code>-del</code> is
2971exact and would have worked in a similar fashion with the Public ID
2972string.</p>
2973
2974<p>This is rudimentary but should be sufficient to manage a not too complex
2975catalog tree of resources.</p>
2976
2977<h3><a name="implemento">The implementor corner quick review of the
2978API:</a></h3>
2979
2980<p>First, and like for every other module of libxml, there is an
2981automatically generated <a href="html/libxml-catalog.html">API page for
2982catalog support</a>.</p>
2983
2984<p>The header for the catalog interfaces should be included as:</p>
2985<pre>#include &lt;libxml/catalog.h&gt;</pre>
2986
2987<p>The API is voluntarily kept very simple. First it is not obvious that
2988applications really need access to it since it is the default behaviour of
2989libxml (Note: it is possible to completely override libxml default catalog by
2990using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
2991plug an application specific resolver).</p>
2992
2993<p>Basically libxml support 2 catalog lists:</p>
2994<ul>
2995 <li>the default one, global shared by all the application</li>
2996 <li>a per-document catalog, this one is built if the document uses the
2997 <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
2998 associated to the parser context and destroyed when the parsing context
2999 is destroyed.</li>
3000</ul>
3001
3002<p>the document one will be used first if it exists.</p>
3003
3004<h4>Initialization routines:</h4>
3005
3006<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
3007used at startup to initialize the catalog, if the catalog should be
3008initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
3009should be called before xmlInitializeCatalog() which would otherwise do a
3010default initialization first.</p>
3011
3012<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
3013own catalog list if needed.</p>
3014
3015<h4>Preferences setup:</h4>
3016
3017<p>The XML Catalog spec requires the possibility to select default
3018preferences between public and system delegation,
3019xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
3020xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
3021be forbidden, allowed for global catalog, for document catalog or both, the
3022default is to allow both.</p>
3023
3024<p>And of course xmlCatalogSetDebug() allows to generate debug messages
3025(through the xmlGenericError() mechanism).</p>
3026
3027<h4>Querying routines:</h4>
3028
3029<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
3030and xmlCatalogResolveURI() are relatively explicit if you read the XML
3031Catalog specification they correspond to section 7 algorithms, they should
3032also work if you have loaded an SGML catalog with a simplified semantic.</p>
3033
3034<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
3035operate on the document catalog list</p>
3036
3037<h4>Cleanup and Miscellaneous:</h4>
3038
3039<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
3040the per-document equivalent.</p>
3041
3042<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
3043first catalog in the global list, and xmlCatalogDump() allows to dump a
3044catalog state, those routines are primarily designed for xmlcatalog, I'm not
3045sure that exposing more complex interfaces (like navigation ones) would be
3046really useful.</p>
3047
3048<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
3049it's similar as xmlParseFile() except it bypass all catalog lookups, it's
3050provided because this functionality may be useful for client tools.</p>
3051
3052<h4>threaded environments:</h4>
3053
3054<p>Since the catalog tree is built progressively, some care has been taken to
3055try to avoid troubles in multithreaded environments. The code is now thread
3056safe assuming that the libxml library has been compiled with threads
3057support.</p>
3058
3059<p></p>
3060
3061<h3><a name="Other">Other resources</a></h3>
3062
3063<p>The XML Catalog specification is relatively recent so there isn't much
3064literature to point at:</p>
3065<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3066 <li>You can find a good rant from Norm Walsh about <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3067 href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
3068 need for catalogs</a>, it provides a lot of context informations even if
Daniel Veillard93d3a472002-04-26 14:04:55 +0000[diff] [blame]3069 I don't agree with everything presented. Norm also wrote a more recent
3070 article <a
3071 href="http://wwws.sun.com/software/xml/developers/resolver/article/">XML
3072 entities and URI resolvers</a> describing them.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3073 <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
3074 catalog proposal</a> from John Cowan</li>
3075 <li>The <a href="http://www.rddl.org/">Resource Directory Description
3076 Language</a> (RDDL) another catalog system but more oriented toward
3077 providing metadata for XML namespaces.</li>
3078 <li>the page from the OASIS Technical <a
3079 href="http://www.oasis-open.org/committees/entity/">Committee on Entity
3080 Resolution</a> who maintains XML Catalog, you will find pointers to the
3081 specification update, some background and pointers to others tools
3082 providing XML Catalog support</li>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3083 <li>Here is a <a href="buildDocBookCatalog">shell script</a> to generate
3084 XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
3085 directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
3086 the resources found on the system. Otherwise it will just create
3087 ~/xmlcatalog and ~/dbkxmlcatalog and doing:
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]3088 <p><code>export XMLCATALOG=$HOME/xmlcatalog</code></p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3089 <p>should allow to process DocBook documentations without requiring
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3090 network accesses for the DTD or stylesheets</p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3091 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3092 <li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3093 small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
3094 to work fine for me too</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3095 <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
3096 manual page</a></li>
3097</ul>
3098
3099<p>If you have suggestions for corrections or additions, simply contact
3100me:</p>
3101
3102<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3103
3104<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3105using the XML library from the C language. It is not intended to be
3106extensive. I hope the automatically generated documents will provide the
3107completeness required, but as a separate set of documents. The interfaces of
3108the XML library are by principle low level, there is nearly zero abstraction.
3109Those interested in a higher level API should <a href="#DOM">look at
3110DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3111
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3112<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
3113separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3114interfaces</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]3115
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3116<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3117
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3118<p>Usually, the first thing to do is to read an XML input. The parser accepts
3119documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3120defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3121<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3122 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3123 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3124 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3125</dl>
3126<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3127 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3128 <dd><p>Parse an XML document contained in a (possibly compressed)
3129 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3130 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3131</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3132
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3133<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]3134failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3135
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3136<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3137
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3138<p>In order for the application to keep the control when the document is
3139being fetched (which is common for GUI based programs) libxml provides a push
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3140interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3141<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
3142 void *user_data,
3143 const char *chunk,
3144 int size,
3145 const char *filename);
3146int xmlParseChunk (xmlParserCtxtPtr ctxt,
3147 const char *chunk,
3148 int size,
3149 int terminate);</pre>
3150
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3151<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3152<pre> FILE *f;
3153
3154 f = fopen(filename, "r");
3155 if (f != NULL) {
3156 int res, size = 1024;
3157 char chars[1024];
3158 xmlParserCtxtPtr ctxt;
3159
3160 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3161 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3162 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
3163 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3164 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3165 xmlParseChunk(ctxt, chars, res, 0);
3166 }
3167 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3168 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3169 xmlFreeParserCtxt(ctxt);
3170 }
3171 }</pre>
3172
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3173<p>The HTML parser embedded into libxml also has a push interface; the
3174functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3175
3176<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
3177
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3178<p>The tree-building interface makes the parser memory-hungry, first loading
3179the document in memory and then building the tree itself. Reading a document
3180without building the tree is possible using the SAX interfaces (see SAX.h and
3181<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]3182Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3183limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3184<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3185
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3186<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3187
3188<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]3189there is a set of functions dedicated to building new elements. (These are
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3190also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of
3191code that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3192<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3193 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3194 xmlNodePtr tree, subtree;
3195
3196 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3197 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
3198 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
3199 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
3200 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3201 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3202 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3203 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
3204 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
3205 subtree = xmlNewChild(tree, NULL, "image", NULL);
3206 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3207
3208<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3209
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3210<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3211
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3212<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3213code has access to the internal structure of all the elements of the tree.
3214The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]3215<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3216<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3217example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3218<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3219
3220<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3221<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3222
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3223<p>points to the text node containing the chapter title "The Linux
3224adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3225
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3226<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]3227present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3228to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]3229<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3230
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3231<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3232
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3233<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3234is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3235<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3236 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
3237 xmlChar *value);</code></dt>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3238 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
3239 The value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3240 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3241</dl>
3242<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3243 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3244 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]3245 <dd><p>This function returns a pointer to new copy of the property
3246 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3247 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3248</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3249
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3250<p>Two functions are provided for reading and writing the text associated
3251with elements:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3252<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3253 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3254 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3255 <dd><p>This function takes an "external" string and converts it to one
3256 text node or possibly to a list of entity and text nodes. All
3257 non-predefined entity references like &amp;Gnome; will be stored
3258 internally as entity nodes, hence the result of the function may not be
3259 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3260 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3261</dl>
3262<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3263 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3264 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3265 <dd><p>This function is the inverse of
3266 <code>xmlStringGetNodeList()</code>. It generates a new string
3267 containing the content of the text and entity nodes. Note the extra
3268 argument inLine. If this argument is set to 1, the function will expand
3269 entity references. For example, instead of returning the &amp;Gnome;
3270 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3271 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3272 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3273</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3274
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3275<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3276
3277<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3278<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3279 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3280 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3281 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3282 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3283</dl>
3284<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3285 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3286 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3287 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3288</dl>
3289<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3290 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3291 <dd><p>Saves the document to a file. In this case, the compression
3292 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3293 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3294</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3295
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3296<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3297
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3298<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3299accesses. The level of compression on saves can be turned on either globally
3300or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3301<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3302 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3303 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3304 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3305</dl>
3306<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3307 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3308 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3309 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3310</dl>
3311<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3312 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3313 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3314 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3315</dl>
3316<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3317 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3318 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3319 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3320</dl>
3321
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3322<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3323
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3324<p>Entities in principle are similar to simple C macros. An entity defines an
3325abbreviation for a given string that you can reuse many times throughout the
3326content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3327may occur frequently within a document, or to confine the change needed to a
3328document to a restricted area in the internal subset of the document (at the
3329beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3330<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]33312 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]33323 &lt;!ENTITY xml "Extensible Markup Language"&gt;
33334 ]&gt;
33345 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]33356 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]33367 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3337
3338<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]3339its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3340are 5 predefined entities in libxml allowing you to escape characters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3341predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3342<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3343for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3344<strong>&amp;quot;</strong> for the character '"', and
3345<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3346
3347<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]3348substitute an entity's content so that you can see the replacement text in
3349your application. Or you may prefer to keep entity references as such in the
3350content to be able to save the document back without losing this usually
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3351precious information (if the user went through the pain of explicitly
3352defining entities, he may have a a rather negative attitude if you blindly
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3353substitute them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3354href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3355function allows you to check and change the behaviour, which is to not
3356substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3357
3358<p>Here is the DOM tree built by libxml for the previous document in the
3359default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3360<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3361DOCUMENT
3362version=1.0
3363 ELEMENT EXAMPLE
3364 TEXT
3365 content=
3366 ENTITY_REF
3367 INTERNAL_GENERAL_ENTITY xml
3368 content=Extensible Markup Language
3369 TEXT
3370 content=</pre>
3371
3372<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3373<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3374DOCUMENT
3375version=1.0
3376 ELEMENT EXAMPLE
3377 TEXT
3378 content= Extensible Markup Language</pre>
3379
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3380<p>So, entities or no entities? Basically, it depends on your use case. I
3381suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3382entities in your XML document or data if you are not willing to handle the
3383entity references elements in the DOM tree.</p>
3384
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3385<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3386entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3387transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3388reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3389finding them in the input).</p>
3390
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3391<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3392on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3393non-predefined entities in your documents, then the learning curve to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3394then 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]3395strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]3396deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3397
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3398<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3399
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3400<p>The libxml library implements <a
3401href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3402recognizing namespace constructs in the input, and does namespace lookup
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3403automatically when building the DOM tree. A namespace declaration is
3404associated with an in-memory structure and all elements or attributes within
3405that namespace point to it. Hence testing the namespace is a simple and fast
3406equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3407
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3408<p>I suggest that people using libxml use a namespace, and declare it in the
3409root element of their document as the default namespace. Then they don't need
3410to 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]3411refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3412the size of the XML output significantly, but significantly increases its
3413value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3414<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
3415 &lt;elem1&gt;...&lt;/elem1&gt;
3416 &lt;elem2&gt;...&lt;/elem2&gt;
3417&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3418
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3419<p>The namespace value has to be an absolute URL, but the URL doesn't have to
3420point to any existing resource on the Web. It will bind all the element and
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3421attributes with that URL. I suggest to use an URL within a domain you
3422control, and that the URL should contain some kind of version information if
3423possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a
3424good namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3425
3426<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3427version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3428and if the version information don't match something you know, warn the user
3429and 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]3430namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3431same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3432associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3433just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3434<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3435prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3436
3437<p>@@Interfaces@@</p>
3438
3439<p>@@Examples@@</p>
3440
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3441<p>Usually people object to using namespaces together with validity checking.
3442I will try to make sure that using namespaces won't break validity checking,
3443so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3444suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3445<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3446flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3447from multiple DTDs will certainly break current validation schemes. I will
3448try to provide ways to do this, but this may not be portable or
3449standardized.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3450
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3451<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3452
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3453<p>Incompatible changes:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3454
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3455<p>Version 2 of libxml is the first version introducing serious backward
3456incompatible changes. The main goals were:</p>
3457<ul>
3458 <li>a general cleanup. A number of mistakes inherited from the very early
3459 versions couldn't be changed due to compatibility constraints. Example
3460 the "childs" element in the nodes.</li>
3461 <li>Uniformization of the various nodes, at least for their header and link
3462 parts (doc, parent, children, prev, next), the goal is a simpler
3463 programming model and simplifying the task of the DOM implementors.</li>
3464 <li>better conformances to the XML specification, for example version 1.x
3465 had an heuristic to try to detect ignorable white spaces. As a result the
3466 SAX event generated were ignorableWhitespace() while the spec requires
3467 character() in that case. This also mean that a number of DOM node
3468 containing blank text may populate the DOM tree which were not present
3469 before.</li>
3470</ul>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3471
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3472<h3>How to fix libxml-1.x code:</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3473
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3474<p>So client code of libxml designed to run with version 1.x may have to be
3475changed to compile against version 2.x of libxml. Here is a list of changes
3476that I have collected, they may not be sufficient, so in case you find other
3477change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
3478mail</a>:</p>
3479<ol>
3480 <li>The package name have changed from libxml to libxml2, the library name
3481 is now -lxml2 . There is a new xml2-config script which should be used to
3482 select the right parameters libxml2</li>
3483 <li>Node <strong>childs</strong> field has been renamed
3484 <strong>children</strong> so s/childs/children/g should be applied
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3485 (probability of having "childs" anywhere else is close to 0+</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3486 <li>The document don't have anymore a <strong>root</strong> element it has
3487 been replaced by <strong>children</strong> and usually you will get a
3488 list of element here. For example a Dtd element for the internal subset
3489 and it's declaration may be found in that list, as well as processing
3490 instructions or comments found before or after the document root element.
3491 Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3492 a document. Alternatively if you are sure to not reference DTDs nor have
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3493 PIs or comments before or after the root element
3494 s/-&gt;root/-&gt;children/g will probably do it.</li>
3495 <li>The white space issue, this one is more complex, unless special case of
3496 validating parsing, the line breaks and spaces usually used for indenting
3497 and formatting the document content becomes significant. So they are
3498 reported by SAX and if your using the DOM tree, corresponding nodes are
3499 generated. Too approach can be taken:
3500 <ol>
3501 <li>lazy one, use the compatibility call
3502 <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
3503 relying on a special (and possibly broken) set of heuristics of
3504 libxml to detect ignorable blanks. Don't complain if it breaks or
3505 make your application not 100% clean w.r.t. to it's input.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3506 <li>the Right Way: change you code to accept possibly insignificant
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3507 blanks characters, or have your tree populated with weird blank text
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3508 nodes. You can spot them using the commodity function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3509 <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
3510 nodes.</li>
3511 </ol>
3512 <p>Note also that with the new default the output functions don't add any
3513 extra indentation when saving a tree in order to be able to round trip
3514 (read and save) without inflating the document with extra formatting
3515 chars.</p>
3516 </li>
3517 <li>The include path has changed to $prefix/libxml/ and the includes
3518 themselves uses this new prefix in includes instructions... If you are
3519 using (as expected) the
3520 <pre>xml2-config --cflags</pre>
3521 <p>output to generate you compile commands this will probably work out of
3522 the box</p>
3523 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3524 <li>xmlDetectCharEncoding takes an extra argument indicating the length in
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3525 byte of the head of the document available for character detection.</li>
3526</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3527
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3528<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3529
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3530<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]3531to allow smooth upgrade of existing libxml v1code while retaining
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3532compatibility. They offers the following:</p>
3533<ol>
3534 <li>similar include naming, one should use
3535 <strong>#include&lt;libxml/...&gt;</strong> in both cases.</li>
3536 <li>similar identifiers defined via macros for the child and root fields:
3537 respectively <strong>xmlChildrenNode</strong> and
3538 <strong>xmlRootNode</strong></li>
3539 <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
3540 inserted once in the client code</li>
3541</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3542
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3543<p>So the roadmap to upgrade your existing libxml applications is the
3544following:</p>
3545<ol>
3546 <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]3547 <li>find all occurrences where the xmlDoc <strong>root</strong> field is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3548 used and change it to <strong>xmlRootNode</strong></li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3549 <li>similarly find all occurrences where the xmlNode
3550 <strong>childs</strong> field is used and change it to
3551 <strong>xmlChildrenNode</strong></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3552 <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
3553 <strong>main()</strong> or in the library init entry point</li>
3554 <li>Recompile, check compatibility, it should still work</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3555 <li>Change your configure script to look first for xml2-config and fall
3556 back using xml-config . Use the --cflags and --libs output of the command
3557 as the Include and Linking parameters needed to use libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3558 <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
3559 libxml-devel-1.8.y can be kept simultaneously)</li>
3560 <li>remove your config.cache, relaunch your configuration mechanism, and
3561 recompile, if steps 2 and 3 were done right it should compile as-is</li>
3562 <li>Test that your application is still running correctly, if not this may
3563 be due to extra empty nodes due to formating spaces being kept in libxml2
3564 contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
3565 code before calling the parser (next to
3566 <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
3567</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3568
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3569<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]3570
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3571<p>Let me put some emphasis on the fact that there is far more changes from
3572libxml 1.x to 2.x than the ones you may have to patch for. The overall code
3573has been considerably cleaned up and the conformance to the XML specification
3574has been drastically improved too. Don't take those changes as an excuse to
3575not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3576
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3577<h2><a name="Thread">Thread safety</a></h2>
3578
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3579<p>Starting with 2.4.7, libxml makes provisions to ensure that concurrent
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3580threads can safely work in parallel parsing different documents. There is
3581however a couple of things to do to ensure it:</p>
3582<ul>
3583 <li>configure the library accordingly using the --with-threads options</li>
3584 <li>call xmlInitParser() in the "main" thread before using any of the
3585 libxml API (except possibly selecting a different memory allocator)</li>
3586</ul>
3587
3588<p>Note that the thread safety cannot be ensured for multiple threads sharing
3589the same document, the locking must be done at the application level, libxml
3590exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
3591The parts of the library checked for thread safety are:</p>
3592<ul>
3593 <li>concurrent loading</li>
3594 <li>file access resolution</li>
3595 <li>catalog access</li>
3596 <li>catalog building</li>
3597 <li>entities lookup/accesses</li>
3598 <li>validation</li>
3599 <li>global variables per-thread override</li>
3600 <li>memory handling</li>
3601</ul>
3602
3603<p>XPath is supposed to be thread safe now, but this wasn't tested
3604seriously.</p>
3605
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3606<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3607
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3608<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
3609Object Model</em>; this is an API for accessing XML or HTML structured
3610documents. Native support for DOM in Gnome is on the way (module gnome-dom),
3611and will be based on gnome-xml. This will be a far cleaner interface to
3612manipulate XML files within Gnome since it won't expose the internal
3613structure.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3614
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3615<p>The current DOM implementation on top of libxml is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame]3616href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
3617is a full DOM interface, thanks to Paolo Casarini, check the <a
3618href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
3619informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3620
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3621<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3622
3623<p>Here is a real size example, where the actual content of the application
3624data 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]3625a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3626storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
3627base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3628<pre>&lt;?xml version="1.0"?&gt;
3629&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
3630 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3631
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3632 &lt;gjob:Job&gt;
3633 &lt;gjob:Project ID="3"/&gt;
3634 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
3635 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3636
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3637 &lt;gjob:Update&gt;
3638 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
3639 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
3640 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
3641 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3642
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3643 &lt;gjob:Developers&gt;
3644 &lt;gjob:Developer&gt;
3645 &lt;/gjob:Developer&gt;
3646 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3647
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3648 &lt;gjob:Contact&gt;
3649 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
3650 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
3651 &lt;gjob:Company&gt;
3652 &lt;/gjob:Company&gt;
3653 &lt;gjob:Organisation&gt;
3654 &lt;/gjob:Organisation&gt;
3655 &lt;gjob:Webpage&gt;
3656 &lt;/gjob:Webpage&gt;
3657 &lt;gjob:Snailmail&gt;
3658 &lt;/gjob:Snailmail&gt;
3659 &lt;gjob:Phone&gt;
3660 &lt;/gjob:Phone&gt;
3661 &lt;/gjob:Contact&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:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3664 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3665 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3666
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3667 &lt;gjob:Skills&gt;
3668 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3669
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3670 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3671 A GNOME based system that will allow a superuser to configure
3672 compressed and uncompressed files and/or file systems to be backed
3673 up with a supported media in the system. This should be able to
3674 perform via find commands generating a list of files that are passed
3675 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
3676 or via operations performed on the filesystem itself. Email
3677 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3678 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3679
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3680 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3681
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3682 &lt;/gjob:Jobs&gt;
3683&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3684
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3685<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]3686calling only a couple of functions, browsing the tree to gather the data and
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3687generate the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3688
3689<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3690structure. For example, the ordering of the attributes is not significant,
3691the 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]3692depend on the order of the children of a given node, unless it really makes
3693things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3694<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3695 * A person record
3696 */
3697typedef struct person {
3698 char *name;
3699 char *email;
3700 char *company;
3701 char *organisation;
3702 char *smail;
3703 char *webPage;
3704 char *phone;
3705} person, *personPtr;
3706
3707/*
3708 * And the code needed to parse it
3709 */
3710personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3711 personPtr ret = NULL;
3712
3713DEBUG("parsePerson\n");
3714 /*
3715 * allocate the struct
3716 */
3717 ret = (personPtr) malloc(sizeof(person));
3718 if (ret == NULL) {
3719 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3720 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3721 }
3722 memset(ret, 0, sizeof(person));
3723
3724 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3725 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3726 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3727 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
3728 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3729 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
3730 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3731 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3732 }
3733
3734 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3735}</pre>
3736
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3737<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3738<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3739 <li>Usually a recursive parsing style is the more convenient one: XML data
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3740 is by nature subject to repetitive constructs and usually exhibits highly
3741 structured patterns.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3742 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
3743 i.e. the pointer to the global XML document and the namespace reserved to
3744 the application. Document wide information are needed for example to
3745 decode entities and it's a good coding practice to define a namespace for
3746 your application set of data and test that the element and attributes
3747 you're analyzing actually pertains to your application space. This is
3748 done by a simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3749 <li>To retrieve text and attributes value, you can use the function
3750 <em>xmlNodeListGetString</em> to gather all the text and entity reference
3751 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3752</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3753
3754<p>Here is another piece of code used to parse another level of the
3755structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3756<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3757/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3758 * a Description for a Job
3759 */
3760typedef struct job {
3761 char *projectID;
3762 char *application;
3763 char *category;
3764 personPtr contact;
3765 int nbDevelopers;
3766 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
3767} job, *jobPtr;
3768
3769/*
3770 * And the code needed to parse it
3771 */
3772jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3773 jobPtr ret = NULL;
3774
3775DEBUG("parseJob\n");
3776 /*
3777 * allocate the struct
3778 */
3779 ret = (jobPtr) malloc(sizeof(job));
3780 if (ret == NULL) {
3781 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3782 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3783 }
3784 memset(ret, 0, sizeof(job));
3785
3786 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3787 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3788 while (cur != NULL) {
3789
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3790 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
3791 ret-&gt;projectID = xmlGetProp(cur, "ID");
3792 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3793 fprintf(stderr, "Project has no ID\n");
3794 }
3795 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3796 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
3797 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3798 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
3799 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3800 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
3801 ret-&gt;contact = parsePerson(doc, ns, cur);
3802 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3803 }
3804
3805 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3806}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3807
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3808<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]3809boring. Ultimately, it could be possible to write stubbers taking either C
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3810data structure definitions, a set of XML examples or an XML DTD and produce
3811the code needed to import and export the content between C data and XML
3812storage. This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3813
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]3814<p>Feel free to use <a href="example/gjobread.c">the code for the full C
3815parsing example</a> as a template, it is also available with Makefile in the
3816Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3817
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3818<h2><a name="Contributi">Contributions</a></h2>
3819<ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3820 <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
3821 patches, Gary Pennington worked on the validation API, threading support
3822 and Solaris port.</li>
3823 <li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]3824 <li><a href="mailto:igor@stud.fh-frankfurt.de">Igor Zlatkovic</a> is now
3825 the maintainer of the Windows port, <a
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]3826 href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
3827 provides binaries</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3828 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
3829 <a href="http://garypennington.net/libxml2/">Solaris binaries</a></li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]3830 <li><a
3831 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3832 Sergeant</a> developed <a
3833 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3834 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
3835 application server</a></li>
3836 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> and <a
3837 href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillardca989762001-06-23 17:39:29 +0000[diff] [blame]3838 href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]3839 documentation</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3840 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
3841 href="http://xmlsoft.org/messages/0488.html">man pages</a></li>
Daniel Veillard5168dbf2001-07-07 00:18:23 +0000[diff] [blame]3842 <li>there is a module for <a
3843 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
3844 in OpenNSD/AOLServer</a></li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]3845 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provided the
3846 first version of libxml/libxslt <a
3847 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li>
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]3848 <li>Petr Kozelka provides <a
3849 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
3850 libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]3851 <li><a href="mailto:aleksey@aleksey.com">Aleksey Sanin</a> implemented the
3852 <a href="http://www.w3.org/Signature/">XML Canonicalization and XML
3853 Digital Signature</a> <a
3854 href="http://www.aleksey.com/xmlsec/">implementations for libxml2</a></li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3855</ul>
3856
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3857<p></p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3858</body>
3859</html>