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blob: d87962d564913edb29bfadc6fc9df3ababdd6629 [file] [log] [blame]
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
2 "http://www.w3.org/TR/html4/loose.dtd">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3<html>
4<head>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]5 <title>The XML C library for Gnome</title>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]6 <meta name="GENERATOR" content="amaya 5.1">
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]7 <meta http-equiv="Content-Type" content="text/html">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]8</head>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]9
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]10<body bgcolor="#ffffff">
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]11<h1 align="center">The XML C library for Gnome</h1>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]12
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]13<h1>Note: this is the flat content of the <a href="index.html">web
14site</a></h1>
15
Daniel Veillardc9484202001-10-24 12:35:52 +0000[diff] [blame]16<h1 style="text-align: center">libxml, a.k.a. gnome-xml</h1>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]17
18<p></p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]19
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]20<p>Libxml is the XML C library developed for the Gnome project. XML itself
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]21is a metalanguage to design markup languages, i.e. text language where
22semantic and structure are added to the content using extra "markup"
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]23information enclosed between angle brackets. HTML is the most well-known
Daniel Veillard1eb24242002-03-18 11:33:03 +0000[diff] [blame]24markup language. Though the library is written in C <a href="python.html">a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]25variety of language bindings</a> make it available in other environments.</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]26
27<p>Libxml2 implements a number of existing standards related to markup
28languages:</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]29<ul>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]30 <li>the XML standard: <a
31 href="http://www.w3.org/TR/REC-xml">http://www.w3.org/TR/REC-xml</a></li>
32 <li>Namespaces in XML: <a
33 href="http://www.w3.org/TR/REC-xml-names/">http://www.w3.org/TR/REC-xml-names/</a></li>
34 <li>XML Base: <a
35 href="http://www.w3.org/TR/xmlbase/">http://www.w3.org/TR/xmlbase/</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]36 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc2396.txt">RFC 2396</a> :
37 Uniform Resource Identifiers <a
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]38 href="http://www.ietf.org/rfc/rfc2396.txt">http://www.ietf.org/rfc/rfc2396.txt</a></li>
39 <li>XML Path Language (XPath) 1.0: <a
40 href="http://www.w3.org/TR/xpath">http://www.w3.org/TR/xpath</a></li>
41 <li>HTML4 parser: <a
42 href="http://www.w3.org/TR/html401/">http://www.w3.org/TR/html401/</a></li>
43 <li>most of XML Pointer Language (XPointer) Version 1.0: <a
44 href="http://www.w3.org/TR/xptr">http://www.w3.org/TR/xptr</a></li>
45 <li>XML Inclusions (XInclude) Version 1.0: <a
46 href="http://www.w3.org/TR/xinclude/">http://www.w3.org/TR/xinclude/</a></li>
47 <li>[ISO-8859-1], <a
48 href="http://www.cis.ohio-state.edu/rfc/rfc2044.txt">rfc2044</a> [UTF-8]
49 and <a href="http://www.cis.ohio-state.edu/rfc/rfc2781.txt">rfc2781</a>
50 [UTF-16] core encodings</li>
51 <li>part of SGML Open Technical Resolution TR9401:1997</li>
52 <li>XML Catalogs Working Draft 06 August 2001: <a
53 href="http://www.oasis-open.org/committees/entity/spec-2001-08-06.html">http://www.oasis-open.org/committees/entity/spec-2001-08-06.html</a></li>
Daniel Veillard5c396542002-03-15 07:57:50 +0000[diff] [blame]54 <li>Canonical XML Version 1.0: <a
55 href="http://www.w3.org/TR/xml-c14n">http://www.w3.org/TR/xml-c14n</a>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]56 and the Exclusive XML Canonicalization CR draft <a
57 href="http://www.w3.org/TR/xml-exc-c14n">http://www.w3.org/TR/xml-exc-c14n</a></li>
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]58</ul>
59
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]60<p>In most cases libxml tries to implement the specifications in a relatively
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]61strictly compliant way. As of release 2.4.16, libxml2 passes all 1800+ tests
62from the <a
Daniel Veillarda5393562002-02-20 11:40:49 +0000[diff] [blame]63href="http://www.oasis-open.org/committees/xml-conformance/">OASIS XML Tests
64Suite</a>.</p>
Daniel Veillard5b16f582002-02-20 11:38:46 +0000[diff] [blame]65
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]66<p>To some extent libxml2 provides support for the following additional
67specifications but doesn't claim to implement them completely:</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]68<ul>
69 <li>Document Object Model (DOM) <a
70 href="http://www.w3.org/TR/DOM-Level-2-Core/">http://www.w3.org/TR/DOM-Level-2-Core/</a>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]71 it doesn't implement the API itself, gdome2 does this on top of
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]72 libxml2</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]73 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc959.txt">RFC 959</a> :
74 libxml implements a basic FTP client code</li>
75 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc1945.txt">RFC 1945</a> :
76 HTTP/1.0, again a basic HTTP client code</li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]77 <li>SAX: a minimal SAX implementation compatible with early expat
78 versions</li>
79 <li>DocBook SGML v4: libxml2 includes a hackish parser to transition to
80 XML</li>
81</ul>
82
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]83<p>XML Schemas is being worked on but it would be far too early to make any
84conformance statement about it at the moment.</p>
85
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]86<p>Libxml2 is known to be very portable, the library should build and work
87without serious troubles on a variety of systems (Linux, Unix, Windows,
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]88CygWin, MacOS, MacOS X, RISC Os, OS/2, VMS, QNX, MVS, ...)</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]89
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]90<p>Separate documents:</p>
91<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]92 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a> providing an
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]93 implementation of XSLT 1.0 and common extensions like EXSLT for
94 libxml2</li>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]95 <li><a href="http://www.cs.unibo.it/~casarini/gdome2/">the gdome2 page</a>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]96 : a standard DOM2 implementation for libxml2</li>
97 <li><a href="http://www.aleksey.com/xmlsec/">the XMLSec page</a>: an
98 implementation of <a href="http://www.w3.org/TR/xmldsig-core/">W3C XML
99 Digital Signature</a> for libxml2</li>
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]100 <li>also check the related links section below for more related and active
101 projects.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]102</ul>
103
104<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]105
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]106<p>This document describes libxml, the <a
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]107href="http://www.w3.org/XML/">XML</a> C library developed for the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]108href="http://www.gnome.org/">Gnome</a> project. <a
109href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
110structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]111
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]112<p>Here are some key points about libxml:</p>
113<ul>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]114 <li>Libxml exports Push (progressive) and Pull (blocking) type parser
115 interfaces for both XML and HTML.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]116 <li>Libxml can do DTD validation at parse time, using a parsed document
117 instance, or with an arbitrary DTD.</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]118 <li>Libxml includes complete <a
Daniel Veillard8c2ecaf2001-07-10 17:53:07 +0000[diff] [blame]119 href="http://www.w3.org/TR/xpath">XPath</a>, <a
120 href="http://www.w3.org/TR/xptr">XPointer</a> and <a
121 href="http://www.w3.org/TR/xinclude">XInclude</a> implementations.</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]122 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]123 sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]124 Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]125 <li>Basic support for HTTP and FTP client allowing applications to fetch
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]126 remote resources.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]127 <li>The design is modular, most of the extensions can be compiled out.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]128 <li>The internal document representation is as close as possible to the <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]129 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
130 <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]131 like interface</a>; the interface is designed to be compatible with <a
132 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]133 <li>This library is released under the <a
134 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]135 License</a>. See the Copyright file in the distribution for the precise
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]136 wording.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]137</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]138
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]139<p>Warning: unless you are forced to because your application links with a
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]140Gnome-1.X library requiring it, <strong><span
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]141style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
142libxml2</p>
143
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]144<h2><a name="FAQ">FAQ</a></h2>
145
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]146<p>Table of Contents:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]147<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]148 <li><a href="FAQ.html#License">License(s)</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]149 <li><a href="FAQ.html#Installati">Installation</a></li>
150 <li><a href="FAQ.html#Compilatio">Compilation</a></li>
151 <li><a href="FAQ.html#Developer">Developer corner</a></li>
152</ul>
153
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]154<h3><a name="License">License</a>(s)</h3>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]155<ol>
156 <li><em>Licensing Terms for libxml</em>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]157 <p>libxml is released under the <a
158 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]159 License</a>; see the file Copyright in the distribution for the precise
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]160 wording</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]161 </li>
162 <li><em>Can I embed libxml in a proprietary application ?</em>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]163 <p>Yes. The MIT License allows you to keep proprietary the changes you
164 made to libxml, but it would be graceful to send-back bug fixes and
165 improvements as patches for possible incorporation in the main
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]166 development tree.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]167 </li>
168</ol>
169
170<h3><a name="Installati">Installation</a></h3>
171<ol>
172 <li>Unless you are forced to because your application links with a Gnome
173 library requiring it, <strong><span style="background-color: #FF0000">Do
174 Not Use libxml1</span></strong>, use libxml2</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]175 <li><em>Where can I get libxml</em> ?
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]176 <p>The original distribution comes from <a
177 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a
178 href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">gnome.org</a></p>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]179 <p>Most Linux and BSD distributions include libxml, this is probably the
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]180 safer way for end-users to use libxml.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]181 <p>David Doolin provides precompiled Windows versions at <a
182 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
183 </li>
184 <li><em>I see libxml and libxml2 releases, which one should I install ?</em>
185 <ul>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]186 <li>If you are not constrained by backward compatibility issues with
187 existing applications, install libxml2 only</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]188 <li>If you are not doing development, you can safely install both.
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]189 Usually the packages <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]190 href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a
191 href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]192 compatible (this is not the case for development packages).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]193 <li>If you are a developer and your system provides separate packaging
194 for shared libraries and the development components, it is possible
195 to install libxml and libxml2, and also <a
196 href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
197 and <a
198 href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
199 too for libxml2 &gt;= 2.3.0</li>
200 <li>If you are developing a new application, please develop against
201 libxml2(-devel)</li>
202 </ul>
203 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]204 <li><em>I can't install the libxml package, it conflicts with libxml0</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]205 <p>You probably have an old libxml0 package used to provide the shared
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]206 library for libxml.so.0, you can probably safely remove it. The libxml
207 packages provided on <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]208 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provide
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]209 libxml.so.0</p>
210 </li>
211 <li><em>I can't install the libxml(2) RPM package due to failed
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]212 dependencies</em>
213 <p>The most generic solution is to re-fetch the latest src.rpm , and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]214 rebuild it locally with</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]215 <p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code>.</p>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]216 <p>If everything goes well it will generate two binary rpm packages (one
217 providing the shared libs and xmllint, and the other one, the -devel
218 package, providing includes, static libraries and scripts needed to build
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]219 applications with libxml(2)) that you can install locally.</p>
220 </li>
221</ol>
222
223<h3><a name="Compilatio">Compilation</a></h3>
224<ol>
225 <li><em>What is the process to compile libxml ?</em>
226 <p>As most UNIX libraries libxml follows the "standard":</p>
227 <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p>
228 <p><code>cd libxml-xxxx</code></p>
229 <p><code>./configure --help</code></p>
230 <p>to see the options, then the compilation/installation proper</p>
231 <p><code>./configure [possible options]</code></p>
232 <p><code>make</code></p>
233 <p><code>make install</code></p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]234 <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]235 update your list of installed shared libs.</p>
236 </li>
237 <li><em>What other libraries are needed to compile/install libxml ?</em>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]238 <p>Libxml does not require any other library, the normal C ANSI API
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]239 should be sufficient (please report any violation to this rule you may
240 find).</p>
241 <p>However if found at configuration time libxml will detect and use the
242 following libs:</p>
243 <ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]244 <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a> : a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]245 highly portable and available widely compression library.</li>
246 <li>iconv: a powerful character encoding conversion library. It is
247 included by default in recent glibc libraries, so it doesn't need to
248 be installed specifically on Linux. It now seems a <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]249 href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
250 of the official UNIX</a> specification. Here is one <a
251 href="http://clisp.cons.org/~haible/packages-libiconv.html">implementation
252 of the library</a> which source can be found <a
253 href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
254 </ul>
255 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]256 <li><em>Make check fails on some platforms</em>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]257 <p>Sometimes the regression tests' results don't completely match the
258 value produced by the parser, and the makefile uses diff to print the
259 delta. On some platforms the diff return breaks the compilation process;
260 if the diff is small this is probably not a serious problem.</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]261 <p>Sometimes (especially on Solaris) make checks fail due to limitations
Daniel Veillarde46182c2002-02-12 14:29:11 +0000[diff] [blame]262 in make. Try using GNU-make instead.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]263 </li>
264 <li><em>I use the CVS version and there is no configure script</em>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]265 <p>The configure script (and other Makefiles) are generated. Use the
266 autogen.sh script to regenerate the configure script and Makefiles,
267 like:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]268 <p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
269 </li>
270 <li><em>I have troubles when running make tests with gcc-3.0</em>
271 <p>It seems the initial release of gcc-3.0 has a problem with the
272 optimizer which miscompiles the URI module. Please use another
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]273 compiler.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]274 </li>
275</ol>
276
277<h3><a name="Developer">Developer</a> corner</h3>
278<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]279 <li><em>xmlDocDump() generates output on one line.</em>
280 <p>Libxml will not <strong>invent</strong> spaces in the content of a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]281 document since <strong>all spaces in the content of a document are
282 significant</strong>. If you build a tree from the API and want
283 indentation:</p>
284 <ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]285 <li>the correct way is to generate those yourself too.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]286 <li>the dangerous way is to ask libxml to add those blanks to your
287 content <strong>modifying the content of your document in the
288 process</strong>. The result may not be what you expect. There is
289 <strong>NO</strong> way to guarantee that such a modification won't
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]290 affect other parts of the content of your document. See <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]291 href="http://xmlsoft.org/html/libxml-parser.html#XMLKEEPBLANKSDEFAULT">xmlKeepBlanksDefault
292 ()</a> and <a
293 href="http://xmlsoft.org/html/libxml-tree.html#XMLSAVEFORMATFILE">xmlSaveFormatFile
294 ()</a></li>
295 </ol>
296 </li>
297 <li>Extra nodes in the document:
298 <p><em>For a XML file as below:</em></p>
299 <pre>&lt;?xml version="1.0"?&gt;
300&lt;PLAN xmlns="http://www.argus.ca/autotest/1.0/"&gt;
301&lt;NODE CommFlag="0"/&gt;
302&lt;NODE CommFlag="1"/&gt;
303&lt;/PLAN&gt;</pre>
304 <p><em>after parsing it with the function
305 pxmlDoc=xmlParseFile(...);</em></p>
306 <p><em>I want to the get the content of the first node (node with the
307 CommFlag="0")</em></p>
308 <p><em>so I did it as following;</em></p>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]309 <pre>xmlNodePtr pnode;
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]310pnode=pxmlDoc-&gt;children-&gt;children;</pre>
311 <p><em>but it does not work. If I change it to</em></p>
312 <pre>pnode=pxmlDoc-&gt;children-&gt;children-&gt;next;</pre>
313 <p><em>then it works. Can someone explain it to me.</em></p>
314 <p></p>
315 <p>In XML all characters in the content of the document are significant
316 <strong>including blanks and formatting line breaks</strong>.</p>
317 <p>The extra nodes you are wondering about are just that, text nodes with
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]318 the formatting spaces which are part of the document but that people tend
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]319 to forget. There is a function <a
320 href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
321 ()</a> to remove those at parse time, but that's an heuristic, and its
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]322 use should be limited to cases where you are certain there is no
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]323 mixed-content in the document.</p>
324 </li>
325 <li><em>I get compilation errors of existing code like when accessing
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]326 <strong>root</strong> or <strong>child fields</strong> of nodes.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]327 <p>You are compiling code developed for libxml version 1 and using a
328 libxml2 development environment. Either switch back to libxml v1 devel or
329 even better fix the code to compile with libxml2 (or both) by <a
330 href="upgrade.html">following the instructions</a>.</p>
331 </li>
332 <li><em>I get compilation errors about non existing
333 <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]334 fields.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]335 <p>The source code you are using has been <a
336 href="upgrade.html">upgraded</a> to be able to compile with both libxml
337 and libxml2, but you need to install a more recent version:
338 libxml(-devel) &gt;= 1.8.8 or libxml2(-devel) &gt;= 2.1.0</p>
339 </li>
340 <li><em>XPath implementation looks seriously broken</em>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]341 <p>XPath implementation prior to 2.3.0 was really incomplete. Upgrade to
342 a recent version, there are no known bugs in the current version.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]343 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]344 <li><em>The example provided in the web page does not compile.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]345 <p>It's hard to maintain the documentation in sync with the code
346 &lt;grin/&gt; ...</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]347 <p>Check the previous points 1/ and 2/ raised before, and please send
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]348 patches.</p>
349 </li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]350 <li><em>Where can I get more examples and information than privoded on the
351 web page?</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]352 <p>Ideally a libxml book would be nice. I have no such plan ... But you
353 can:</p>
354 <ul>
355 <li>check more deeply the <a href="html/libxml-lib.html">existing
356 generated doc</a></li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]357 <li>look for examples of use for libxml function using the Gnome code.
358 For example the following will query the full Gnome CVS base for the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]359 use of the <strong>xmlAddChild()</strong> function:
360 <p><a
361 href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p>
362 <p>This may be slow, a large hardware donation to the gnome project
363 could cure this :-)</p>
364 </li>
365 <li><a
366 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]367 the libxml source</a> , I try to write code as clean and documented
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]368 as possible, so looking at it may be helpful. In particular the code
369 of xmllint.c and of the various testXXX.c test programs should
370 provide good examples of how to do things with the library.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]371 </ul>
372 </li>
373 <li>What about C++ ?
374 <p>libxml is written in pure C in order to allow easy reuse on a number
375 of platforms, including embedded systems. I don't intend to convert to
376 C++.</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]377 <p>There are however a few C++ wrappers which may fulfill your needs:</p>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]378 <ul>
379 <li>by Ari Johnson &lt;ari@btigate.com&gt;:
380 <p>Website: <a
381 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
382 <p>Download: <a
383 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
384 </li>
385 <li>by Peter Jones &lt;pjones@pmade.org&gt;
386 <p>Website: <a
387 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
388 </li>
389 </ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]390 </li>
391 <li>How to validate a document a posteriori ?
392 <p>It is possible to validate documents which had not been validated at
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]393 initial parsing time or documents which have been built from scratch
394 using the API. Use the <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]395 href="http://xmlsoft.org/html/libxml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]396 function. It is also possible to simply add a DTD to an existing
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]397 document:</p>
398 <pre>xmlDocPtr doc; /* your existing document */
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]399xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
400
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]401 dtd-&gt;name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */
402
403 doc-&gt;intSubset = dtd;
404 if (doc-&gt;children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
405 else xmlAddPrevSibling(doc-&gt;children, (xmlNodePtr)dtd);
406 </pre>
407 </li>
408 <li>etc ...</li>
409</ol>
410
411<p></p>
412
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]413<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]414
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]415<p>There are several on-line resources related to using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]416<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]417 <li>Check the <a href="FAQ.html">FAQ.</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]418 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]419 documentation</a> automatically extracted from code comments (using <a
420 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
421 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]422 <li>Look at the documentation about <a href="encoding.html">libxml
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]423 internationalization support</a>.</li>
Daniel Veillardbc66f852002-01-14 09:49:20 +0000[diff] [blame]424 <li>This page provides a global overview and <a href="example.html">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]425 examples</a> on how to use libxml.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]426 <li>John Fleck's <a href="tutorial/index.html">libxml tutorial</a>.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]427 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]428 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
429 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]430 <li>George Lebl wrote <a
431 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]432 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]433 <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]434 file</a>.</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]435 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>
436 description. If you are starting a new project using libxml you should
437 really use the 2.x version.</li>
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]438 <li>And don't forget to look at the <a
439 href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]440</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]441
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]442<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]443
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]444<p>Well, bugs or missing features are always possible, and I will make a
445point of fixing them in a timely fashion. The best way to report a bug is to
446use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]447bug tracking database</a> (make sure to use the "libxml2" module name). I
448look at reports there regularly and it's good to have a reminder when a bug
449is 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]450
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]451<p>There is also a mailing-list <a
Daniel Veillard3197f162001-04-04 00:40:08 +0000[diff] [blame]452href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
453href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]454href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
455please visit the <a
456href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
457follow the instructions. <strong>Do not send code, I won't debug it</strong>
458(but patches are really appreciated!).</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]459
Daniel Veillard008186f2001-09-13 14:24:44 +0000[diff] [blame]460<p>Check the following <strong><span style="color: #FF0000">before
461posting</span></strong>:</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]462<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]463 <li>Read the <a href="FAQ.html">FAQ</a>.</li>
464 <li>Make sure you are <a href="ftp://xmlsoft.org/">using a recent
465 version</a>, and that the problem still shows up in a recent version.</li>
466 <li>Check the <a href="http://mail.gnome.org/archives/xml/">list
467 archives</a> to see if the problem was reported already. In this case
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]468 there is probably a fix available, similarly check the <a
Daniel Veillarde7ead2d2001-08-22 23:44:09 +0000[diff] [blame]469 href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">registered
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]470 open bugs</a>.</li>
471 <li>Make sure you can reproduce the bug with xmllint or one of the test
472 programs found in source in the distribution.</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]473 <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]474 attachment)</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]475</ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]476
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]477<p>Then send the bug with associated informations to reproduce it to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]478href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]479related I will approve it.. Please do not send mail to me directly, it makes
480things really hard to track and in some cases I am not the best person to
481answer a given question. Ask the list instead.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]482
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]483<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]484probably be processed faster than those without.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]485
486<p>If you're looking for help, a quick look at <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]487href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]488provide the answer. I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]489questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]490documentation</a> is not as polished as I would like (i need to learn more
491about DocBook), but it's a good starting point.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]492
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]493<h2><a name="help">How to help</a></h2>
494
495<p>You can help the project in various ways, the best thing to do first is to
496subscribe to the mailing-list as explained before, check the <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]497href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
498href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]499database</a>:</p>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]500<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]501 <li>Provide patches when you find problems.</li>
502 <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]503 be integrated in all cases but help pinpointing portability problems
504 and</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]505 <li>Provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]506 as HTML diffs).</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]507 <li>Provide new documentations pieces (translations, examples, etc
508 ...).</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]509 <li>Check the TODO file and try to close one of the items.</li>
510 <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]511 provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me
512 </a>before to avoid synchronization problems and check that the suggested
513 fix will fit in nicely :-)</li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]514</ol>
515
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]516<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]517
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]518<p>The latest versions of libxml can be found on <a
Daniel Veillard20c8cf22001-06-26 22:47:36 +0000[diff] [blame]519href="ftp://xmlsoft.org/">xmlsoft.org</a> (<a
520href="ftp://speakeasy.rpmfind.net/pub/libxml/">Seattle</a>, <a
521href="ftp://fr.rpmfind.net/pub/libxml/">France</a>) or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]522href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]523as a <a href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">source
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]524archive</a> or <a
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]525href="ftp://ftp.gnome.org/pub/GNOME/stable/redhat/i386/libxml/">RPM
Daniel Veillard0bfbb422002-04-26 09:21:45 +0000[diff] [blame]526packages</a>, Antonin Sprinzl also provide <a
527href="ftp://gd.tuwien.ac.at/pub/libxml/">a mirror in Austria</a>. (NOTE that
528you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]529href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
530href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]531packages installed to compile applications using libxml.) <a
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]532href="mailto:igor@stud.fh-frankfurt.de">Igor Zlatkovic</a> is now the
533maintainer of the Windows port, <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]534href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]535provides binaries</a>. <a href="mailto:Gary.Pennington@sun.com">Gary
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]536Pennington</a> provides <a href="http://garypennington.net/libxml2/">Solaris
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]537binaries</a>. <a href="mailto:Steve.Ball@zveno.com">Steve Ball</a> provides
538<a href="http://www.zveno.com/open_source/libxml2xslt.html">Mac Os X
539binaries</a>.</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]540
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]541<p><a name="Snapshot">Snapshot:</a></p>
542<ul>
543 <li>Code from the W3C cvs base libxml <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]544 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]545 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]546 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]547</ul>
548
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]549<p><a name="Contribs">Contributions:</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]550
551<p>I do accept external contributions, especially if compiling on another
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]552platform, get in touch with me to upload the package, wrappers for various
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]553languages have been provided, and can be found in the <a
554href="contribs.html">contrib section</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]555
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]556<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]557<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]558 <li><p>The <a
559 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]560 CVS base</a>. Check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]561 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a>
562 page; the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]563 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]564 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]565</ul>
566
567<h2><a name="News">News</a></h2>
568
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]569<h3>CVS only : check the <a
570href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]571for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]572
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]573<p>Items not finished and worked on, get in touch with the list if you want
574to test those</p>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]575<ul>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]576 <li>Finishing up <a href="http://www.w3.org/TR/xmlschema-1/">XML
577 Schemas</a> and <a href="http://www.w3.org/TR/xinclude">XInclude</a></li>
578</ul>
579
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]580<p><strong>2.4.24: Aug 22 2002</strong></p>
581<ul>
582 <li>XPath fixes (William), xf:escape-uri() (Wesley Terpstra)</li>
583 <li>Python binding fixes: makefiles (William), generator, rpm build, x86-64
584 (fcrozat)</li>
585 <li>HTML &lt;style&gt; and boolean attributes serializer fixes</li>
586 <li>C14N improvements by Aleksey</li>
587 <li>doc cleanups: Rick Jones </li>
588 <li>Windows compiler makefile updates: Igor and Elizabeth Barham</li>
589 <li>XInclude: implementation of fallback and xml:base fixup added</li>
590</ul>
591
Daniel Veillard782afda2002-07-08 15:12:49 +0000[diff] [blame]592<h3>2.4.23: July 6 2002</h3>
593<ul>
594 <li>performances patches: Peter Jacobi</li>
595 <li>c14n fixes, testsuite and performances: Aleksey Sanin</li>
596 <li>added xmlDocFormatDump: Chema Celorio</li>
597 <li>new tutorial: John Fleck</li>
598 <li>new hash functions and performances: Sander Vesik, portability fix from
599 Peter Jacobi</li>
600 <li>a number of bug fixes: XPath (William Brack, Richard Jinks), XML and
601 HTML parsers, ID lookup function</li>
602 <li>removal of all remaining sprintf: Aleksey Sanin</li>
603</ul>
604
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]605<h3>2.4.22: May 27 2002</h3>
606<ul>
607 <li>a number of bug fixes: configure scripts, base handling, parser, memory
608 usage, HTML parser, XPath, documentation (Christian Cornelssen),
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]609 indentation, URI parsing</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]610 <li>Optimizations for XMLSec, fixing and making public some of the network
611 protocol handlers (Aleksey)</li>
612 <li>performance patch from Gary Pennington</li>
613 <li>Charles Bozeman provided date and time support for XML Schemas
614 datatypes</li>
615</ul>
616
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]617<h3>2.4.21: Apr 29 2002</h3>
618
619<p>This release is both a bug fix release and also contains the early XML
620Schemas <a href="http://www.w3.org/TR/xmlschema-1/">structures</a> and <a
621href="http://www.w3.org/TR/xmlschema-2/">datatypes</a> code, beware, all
622interfaces are likely to change, there is huge holes, it is clearly a work in
623progress and don't even think of putting this code in a production system,
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]624it's actually not compiled in by default. The real fixes are:</p>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]625<ul>
626 <li>a couple of bugs or limitations introduced in 2.4.20</li>
627 <li>patches for Borland C++ and MSC by Igor</li>
628 <li>some fixes on XPath strings and conformance patches by Richard
629 Jinks</li>
630 <li>patch from Aleksey for the ExcC14N specification</li>
631 <li>OSF/1 bug fix by Bjorn</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]632</ul>
633
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]634<h3>2.4.20: Apr 15 2002</h3>
635<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]636 <li>bug fixes: file descriptor leak, XPath, HTML output, DTD validation</li>
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]637 <li>XPath conformance testing by Richard Jinks</li>
638 <li>Portability fixes: Solaris, MPE/iX, Windows, OSF/1, python bindings,
639 libxml.m4</li>
640</ul>
641
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]642<h3>2.4.19: Mar 25 2002</h3>
643<ul>
644 <li>bug fixes: half a dozen XPath bugs, Validation, ISO-Latin to UTF8
645 encoder</li>
646 <li>portability fixes in the HTTP code</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]647 <li>memory allocation checks using valgrind, and profiling tests</li>
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]648 <li>revamp of the Windows build and Makefiles</li>
649</ul>
650
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]651<h3>2.4.18: Mar 18 2002</h3>
652<ul>
653 <li>bug fixes: tree, SAX, canonicalization, validation, portability,
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]654 XPath</li>
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]655 <li>removed the --with-buffer option it was becoming unmaintainable</li>
656 <li>serious cleanup of the Python makefiles</li>
657 <li>speedup patch to XPath very effective for DocBook stylesheets</li>
658 <li>Fixes for Windows build, cleanup of the documentation</li>
659</ul>
660
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]661<h3>2.4.17: Mar 8 2002</h3>
662<ul>
663 <li>a lot of bug fixes, including "namespace nodes have no parents in
664 XPath"</li>
665 <li>fixed/improved the Python wrappers, added more examples and more
666 regression tests, XPath extension functions can now return node-sets</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]667 <li>added the XML Canonicalization support from Aleksey Sanin</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]668</ul>
669
Daniel Veillard5f4b5992002-02-20 10:22:49 +0000[diff] [blame]670<h3>2.4.16: Feb 20 2002</h3>
671<ul>
672 <li>a lot of bug fixes, most of them were triggered by the XML Testsuite
673 from OASIS and W3C. Compliance has been significantly improved.</li>
674 <li>a couple of portability fixes too.</li>
675</ul>
676
Daniel Veillard397ff112002-02-11 18:27:20 +0000[diff] [blame]677<h3>2.4.15: Feb 11 2002</h3>
678<ul>
679 <li>Fixed the Makefiles, especially the python module ones</li>
680 <li>A few bug fixes and cleanup</li>
681 <li>Includes cleanup</li>
682</ul>
683
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]684<h3>2.4.14: Feb 8 2002</h3>
685<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]686 <li>Change of License to the <a
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]687 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]688 License</a> basically for integration in XFree86 codebase, and removing
689 confusion around the previous dual-licensing</li>
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]690 <li>added Python bindings, beta software but should already be quite
691 complete</li>
692 <li>a large number of fixes and cleanups, especially for all tree
693 manipulations</li>
694 <li>cleanup of the headers, generation of a reference API definition in
695 XML</li>
696</ul>
697
698<h3>2.4.13: Jan 14 2002</h3>
Daniel Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame]699<ul>
700 <li>update of the documentation: John Fleck and Charlie Bozeman</li>
701 <li>cleanup of timing code from Justin Fletcher</li>
702 <li>fixes for Windows and initial thread support on Win32: Igor and Serguei
703 Narojnyi</li>
704 <li>Cygwin patch from Robert Collins</li>
705 <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
706</ul>
707
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]708<h3>2.4.12: Dec 7 2001</h3>
709<ul>
710 <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
711 XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
712 (robert)</li>
713 <li>Eric Lavigne contributed project files for MacOS</li>
714 <li>some makefiles cleanups</li>
715</ul>
716
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]717<h3>2.4.11: Nov 26 2001</h3>
718<ul>
719 <li>fixed a couple of errors in the includes, fixed a few bugs, some code
720 cleanups</li>
721 <li>xmllint man pages improvement by Heiko Rupp</li>
722 <li>updated VMS build instructions from John A Fotheringham</li>
723 <li>Windows Makefiles updates from Igor</li>
724</ul>
725
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]726<h3>2.4.10: Nov 10 2001</h3>
727<ul>
728 <li>URI escaping fix (Joel Young)</li>
729 <li>added xmlGetNodePath() (for paths or XPointers generation)</li>
730 <li>Fixes namespace handling problems when using DTD and validation</li>
731 <li>improvements on xmllint: Morus Walter patches for --format and
732 --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
733 <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
734 <li>fixes to the HTML parser</li>
735</ul>
736
737<h3>2.4.9: Nov 6 2001</h3>
738<ul>
739 <li>fixes more catalog bugs</li>
740 <li>avoid a compilation problem, improve xmlGetLineNo()</li>
741</ul>
742
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]743<h3>2.4.8: Nov 4 2001</h3>
744<ul>
745 <li>fixed SGML catalogs broken in previous release, updated xmlcatalog
746 tool</li>
747 <li>fixed a compile errors and some includes troubles.</li>
748</ul>
749
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]750<h3>2.4.7: Oct 30 2001</h3>
751<ul>
752 <li>exported some debugging interfaces</li>
753 <li>serious rewrite of the catalog code</li>
754 <li>integrated Gary Pennington thread safety patch, added configure option
755 and regression tests</li>
756 <li>removed an HTML parser bug</li>
757 <li>fixed a couple of potentially serious validation bugs</li>
758 <li>integrated the SGML DocBook support in xmllint</li>
759 <li>changed the nanoftp anonymous login passwd</li>
760 <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
761 <li>general bug fixes</li>
762 <li>updated xmllint man page by John Fleck</li>
763 <li>some VMS and Windows updates</li>
764</ul>
765
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]766<h3>2.4.6: Oct 10 2001</h3>
767<ul>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]768 <li>added an updated man pages by John Fleck</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]769 <li>portability and configure fixes</li>
770 <li>an infinite loop on the HTML parser was removed (William)</li>
771 <li>Windows makefile patches from Igor</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]772 <li>fixed half a dozen bugs reported for libxml or libxslt</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]773 <li>updated xmlcatalog to be able to modify SGML super catalogs</li>
774</ul>
775
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]776<h3>2.4.5: Sep 14 2001</h3>
777<ul>
778 <li>Remove a few annoying bugs in 2.4.4</li>
779 <li>forces the HTML serializer to output decimal charrefs since some
780 version of Netscape can't handle hexadecimal ones</li>
781</ul>
782
783<h3>1.8.16: Sep 14 2001</h3>
784<ul>
785 <li>maintenance release of the old libxml1 branch, couple of bug and
786 portability fixes</li>
787</ul>
788
Daniel Veillard04382ae2001-09-12 18:51:30 +0000[diff] [blame]789<h3>2.4.4: Sep 12 2001</h3>
790<ul>
791 <li>added --convert to xmlcatalog, bug fixes and cleanups of XML
792 Catalog</li>
793 <li>a few bug fixes and some portability changes</li>
794 <li>some documentation cleanups</li>
795</ul>
796
Daniel Veillard39936902001-08-24 00:49:01 +0000[diff] [blame]797<h3>2.4.3: Aug 23 2001</h3>
798<ul>
799 <li>XML Catalog support see the doc</li>
800 <li>New NaN/Infinity floating point code</li>
801 <li>A few bug fixes</li>
802</ul>
803
804<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]805<ul>
806 <li>adds xmlLineNumbersDefault() to control line number generation</li>
807 <li>lot of bug fixes</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]808 <li>the Microsoft MSC projects files should now be up to date</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]809 <li>inheritance of namespaces from DTD defaulted attributes</li>
810 <li>fixes a serious potential security bug</li>
811 <li>added a --format option to xmllint</li>
812</ul>
813
814<h3>2.4.1: July 24 2001</h3>
815<ul>
816 <li>possibility to keep line numbers in the tree</li>
817 <li>some computation NaN fixes</li>
818 <li>extension of the XPath API</li>
819 <li>cleanup for alpha and ia64 targets</li>
820 <li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]821</ul>
822
823<h3>2.4.0: July 10 2001</h3>
824<ul>
825 <li>Fixed a few bugs in XPath, validation, and tree handling.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]826 <li>Fixed XML Base implementation, added a couple of examples to the
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]827 regression tests</li>
828 <li>A bit of cleanup</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]829</ul>
830
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]831<h3>2.3.14: July 5 2001</h3>
832<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]833 <li>fixed some entities problems and reduce memory requirement when
834 substituting them</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]835 <li>lots of improvements in the XPath queries interpreter can be
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]836 substantially faster</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]837 <li>Makefiles and configure cleanups</li>
838 <li>Fixes to XPath variable eval, and compare on empty node set</li>
839 <li>HTML tag closing bug fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]840 <li>Fixed an URI reference computation problem when validating</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]841</ul>
842
Daniel Veillard2adbb512001-06-28 16:20:36 +0000[diff] [blame]843<h3>2.3.13: June 28 2001</h3>
844<ul>
845 <li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
846 <li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
847</ul>
848
849<h3>1.8.14: June 28 2001</h3>
850<ul>
851 <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
852 <li>Small Makefile fix</li>
853</ul>
854
Daniel Veillard11648102001-06-26 16:08:24 +0000[diff] [blame]855<h3>2.3.12: June 26 2001</h3>
856<ul>
857 <li>lots of cleanup</li>
858 <li>a couple of validation fix</li>
859 <li>fixed line number counting</li>
860 <li>fixed serious problems in the XInclude processing</li>
861 <li>added support for UTF8 BOM at beginning of entities</li>
862 <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
863 miscompile uri.c (William), Thomas Leitner provided a fix for the
864 optimizer on Tru64</li>
865 <li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
866 compilation on Windows MSC</li>
867 <li>update of libxml-doc.el (Felix Natter)</li>
868 <li>fixed 2 bugs in URI normalization code</li>
869</ul>
870
Daniel Veillarde3c81b52001-06-17 14:50:34 +0000[diff] [blame]871<h3>2.3.11: June 17 2001</h3>
872<ul>
873 <li>updates to trio, Makefiles and configure should fix some portability
874 problems (alpha)</li>
875 <li>fixed some HTML serialization problems (pre, script, and block/inline
876 handling), added encoding aware APIs, cleanup of this code</li>
877 <li>added xmlHasNsProp()</li>
878 <li>implemented a specific PI for encoding support in the DocBook SGML
879 parser</li>
880 <li>some XPath fixes (-Infinity, / as a function parameter and namespaces
881 node selection)</li>
882 <li>fixed a performance problem and an error in the validation code</li>
883 <li>fixed XInclude routine to implement the recursive behaviour</li>
884 <li>fixed xmlFreeNode problem when libxml is included statically twice</li>
885 <li>added --version to xmllint for bug reports</li>
886</ul>
887
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]888<h3>2.3.10: June 1 2001</h3>
889<ul>
890 <li>fixed the SGML catalog support</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]891 <li>a number of reported bugs got fixed, in XPath, iconv detection,
892 XInclude processing</li>
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]893 <li>XPath string function should now handle unicode correctly</li>
894</ul>
895
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]896<h3>2.3.9: May 19 2001</h3>
897
898<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
899<ul>
900 <li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]901 <li>some serious speed optimization again</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]902 <li>some documentation cleanups</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]903 <li>trying to get better linking on Solaris (-R)</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]904 <li>XPath API cleanup from Thomas Broyer</li>
905 <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
906 xmlValidGetValidElements()</li>
907 <li>Added an INSTALL file</li>
908 <li>Attribute removal added to API: #54433</li>
909 <li>added a basic support for SGML catalogs</li>
910 <li>fixed xmlKeepBlanksDefault(0) API</li>
911 <li>bugfix in xmlNodeGetLang()</li>
912 <li>fixed a small configure portability problem</li>
913 <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
914</ul>
915
Daniel Veillarda265af72001-05-14 11:13:58 +0000[diff] [blame]916<h3>1.8.13: May 14 2001</h3>
917<ul>
918 <li>bugfixes release of the old libxml1 branch used by Gnome</li>
919</ul>
920
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]921<h3>2.3.8: May 3 2001</h3>
922<ul>
923 <li>Integrated an SGML DocBook parser for the Gnome project</li>
924 <li>Fixed a few things in the HTML parser</li>
925 <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
926 point portability issue</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]927 <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
928 DOM+validation using the XML REC as input and a 700MHz celeron).</li>
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]929 <li>incorporated more Windows cleanup</li>
930 <li>added xmlSaveFormatFile()</li>
931 <li>fixed problems in copying nodes with entities references (gdome)</li>
932 <li>removed some troubles surrounding the new validation module</li>
933</ul>
934
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]935<h3>2.3.7: April 22 2001</h3>
936<ul>
937 <li>lots of small bug fixes, corrected XPointer</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]938 <li>Non deterministic content model validation support</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]939 <li>added xmlDocCopyNode for gdome2</li>
940 <li>revamped the way the HTML parser handles end of tags</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]941 <li>XPath: corrections of namespaces support and number formatting</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]942 <li>Windows: Igor Zlatkovic patches for MSC compilation</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]943 <li>HTML output fixes from P C Chow and William M. Brack</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]944 <li>Improved validation speed sensible for DocBook</li>
945 <li>fixed a big bug with ID declared in external parsed entities</li>
946 <li>portability fixes, update of Trio from Bjorn Reese</li>
947</ul>
948
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]949<h3>2.3.6: April 8 2001</h3>
950<ul>
951 <li>Code cleanup using extreme gcc compiler warning options, found and
952 cleared half a dozen potential problem</li>
953 <li>the Eazel team found an XML parser bug</li>
954 <li>cleaned up the user of some of the string formatting function. used the
955 trio library code to provide the one needed when the platform is missing
956 them</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]957 <li>xpath: removed a memory leak and fixed the predicate evaluation
958 problem, extended the testsuite and cleaned up the result. XPointer seems
959 broken ...</li>
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]960</ul>
961
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame]962<h3>2.3.5: Mar 23 2001</h3>
963<ul>
964 <li>Biggest change is separate parsing and evaluation of XPath expressions,
965 there is some new APIs for this too</li>
966 <li>included a number of bug fixes(XML push parser, 51876, notations,
967 52299)</li>
968 <li>Fixed some portability issues</li>
969</ul>
970
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]971<h3>2.3.4: Mar 10 2001</h3>
972<ul>
973 <li>Fixed bugs #51860 and #51861</li>
974 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
975 size to be application tunable.</li>
976 <li>Some cleanup in the validation code, still a bug left and this part
977 should probably be rewritten to support ambiguous content model :-\</li>
978 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
979 parser</li>
980 <li>Fixed another bug in xmlNodeGetContent()</li>
981 <li>Bjorn fixed XPath node collection and Number formatting</li>
982 <li>Fixed a loop reported in the HTML parsing</li>
983 <li>blank space are reported even if the Dtd content model proves that they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]984 are formatting spaces, this is for XML conformance</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]985</ul>
986
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]987<h3>2.3.3: Mar 1 2001</h3>
988<ul>
989 <li>small change in XPath for XSLT</li>
990 <li>documentation cleanups</li>
991 <li>fix in validation by Gary Pennington</li>
992 <li>serious parsing performances improvements</li>
993</ul>
994
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]995<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]996<ul>
997 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
998 <li>fixed a Dtd parsing bug</li>
999 <li>fixed a bug in xmlNodeGetContent</li>
1000 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
1001</ul>
1002
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1003<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1004<ul>
1005 <li>some XPath and HTML bug fixes for XSLT</li>
1006 <li>small extension of the hash table interfaces for DOM gdome2
1007 implementation</li>
1008 <li>A few bug fixes</li>
1009</ul>
1010
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1011<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]1012<ul>
1013 <li>Lots of XPath bug fixes</li>
1014 <li>Add a mode with Dtd lookup but without validation error reporting for
1015 XSLT</li>
1016 <li>Add support for text node without escaping (XSLT)</li>
1017 <li>bug fixes for xmlCheckFilename</li>
1018 <li>validation code bug fixes from Gary Pennington</li>
1019 <li>Patch from Paul D. Smith correcting URI path normalization</li>
1020 <li>Patch to allow simultaneous install of libxml-devel and
1021 libxml2-devel</li>
1022 <li>the example Makefile is now fixed</li>
1023 <li>added HTML to the RPM packages</li>
1024 <li>tree copying bugfixes</li>
1025 <li>updates to Windows makefiles</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1026 <li>optimization patch from Bjorn Reese</li>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1027</ul>
1028
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1029<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]1030<ul>
1031 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
1032 <li>added htmlHandleOmittedElem()</li>
1033 <li>Applied Bjorn Reese's IPV6 first patch</li>
1034 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1035 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]1036</ul>
1037
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]1038<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]1039<ul>
1040 <li>Fix the Windows problems of 2.2.8</li>
1041 <li>integrate OpenVMS patches</li>
1042 <li>better handling of some nasty HTML input</li>
1043 <li>Improved the XPointer implementation</li>
1044 <li>integrate a number of provided patches</li>
1045</ul>
1046
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]1047<h3>2.2.9: Nov 25 2000</h3>
1048<ul>
1049 <li>erroneous release :-(</li>
1050</ul>
1051
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]1052<h3>2.2.8: Nov 13 2000</h3>
1053<ul>
1054 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
1055 support</li>
1056 <li>Patch in conditional section handling</li>
1057 <li>updated MS compiler project</li>
1058 <li>fixed some XPath problems</li>
1059 <li>added an URI escaping function</li>
1060 <li>some other bug fixes</li>
1061</ul>
1062
1063<h3>2.2.7: Oct 31 2000</h3>
1064<ul>
1065 <li>added message redirection</li>
1066 <li>XPath improvements (thanks TOM !)</li>
1067 <li>xmlIOParseDTD() added</li>
1068 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
1069 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
1070</ul>
1071
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]1072<h3>2.2.6: Oct 25 2000:</h3>
1073<ul>
1074 <li>Added an hash table module, migrated a number of internal structure to
1075 those</li>
1076 <li>Fixed a posteriori validation problems</li>
1077 <li>HTTP module cleanups</li>
1078 <li>HTML parser improvements (tag errors, script/style handling, attribute
1079 normalization)</li>
1080 <li>coalescing of adjacent text nodes</li>
1081 <li>couple of XPath bug fixes, exported the internal API</li>
1082</ul>
1083
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1084<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1085<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1086 <li>XPointer implementation and testsuite</li>
1087 <li>Lot of XPath fixes, added variable and functions registration, more
1088 tests</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1089 <li>Portability fixes, lots of enhancements toward an easy Windows build
1090 and release</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1091 <li>Late validation fixes</li>
1092 <li>Integrated a lot of contributed patches</li>
1093 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1094 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1095</ul>
1096
1097<h3>2.2.4: Oct 1 2000:</h3>
1098<ul>
1099 <li>main XPath problem fixed</li>
1100 <li>Integrated portability patches for Windows</li>
1101 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1102</ul>
1103
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1104<h3>2.2.3: Sep 17 2000</h3>
1105<ul>
1106 <li>bug fixes</li>
1107 <li>cleanup of entity handling code</li>
1108 <li>overall review of all loops in the parsers, all sprintf usage has been
1109 checked too</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1110 <li>Far better handling of larges Dtd. Validating against DocBook XML Dtd
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1111 works smoothly now.</li>
1112</ul>
1113
1114<h3>1.8.10: Sep 6 2000</h3>
1115<ul>
1116 <li>bug fix release for some Gnome projects</li>
1117</ul>
1118
1119<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1120<ul>
1121 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]1122 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1123</ul>
1124
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1125<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1126<ul>
1127 <li>a purely bug fixes release</li>
1128 <li>fixed an encoding support problem when parsing from a memory block</li>
1129 <li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1130 <li>removed a bug in the function allowing to override the memory
1131 allocation routines</li>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1132</ul>
1133
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1134<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]1135<ul>
1136 <li>applied a lot of portability fixes</li>
1137 <li>better encoding support/cleanup and saving (content is now always
1138 encoded in UTF-8)</li>
1139 <li>the HTML parser now correctly handles encodings</li>
1140 <li>added xmlHasProp()</li>
1141 <li>fixed a serious problem with &amp;#38;</li>
1142 <li>propagated the fix to FTP client</li>
1143 <li>cleanup, bugfixes, etc ...</li>
1144 <li>Added a page about <a href="encoding.html">libxml Internationalization
1145 support</a></li>
1146</ul>
1147
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1148<h3>1.8.9: July 9 2000</h3>
1149<ul>
1150 <li>fixed the spec the RPMs should be better</li>
1151 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
1152 rpmfind users problem</li>
1153</ul>
1154
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]1155<h3>2.1.1: July 1 2000</h3>
1156<ul>
1157 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
1158 <li>improvements on the HTML parser</li>
1159</ul>
1160
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1161<h3>2.1.0 and 1.8.8: June 29 2000</h3>
1162<ul>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1163 <li>1.8.8 is mostly a commodity package for upgrading to libxml2 according
1164 to <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1165 about &amp;#38; charref parsing</li>
1166 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
1167 also contains numerous fixes and enhancements:
1168 <ul>
1169 <li>added xmlStopParser() to stop parsing</li>
1170 <li>improved a lot parsing speed when there is large CDATA blocs</li>
1171 <li>includes XPath patches provided by Picdar Technology</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1172 <li>tried to fix as much as possible DTD validation and namespace
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1173 related problems</li>
1174 <li>output to a given encoding has been added/tested</li>
1175 <li>lot of various fixes</li>
1176 </ul>
1177 </li>
1178</ul>
1179
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1180<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1181<ul>
1182 <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]1183 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initially
1184 scheduled for Apr 3 the release occurred only on Apr 12 due to massive
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1185 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1186 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1187 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1188 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1189 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1190 <pre>#include "xxx.h"</pre>
1191 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]1192 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
1193 <li>the memory allocation routines used by libxml can now be overloaded
1194 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1195 <li>The previously CVS only tool tester has been renamed
1196 <strong>xmllint</strong> and is now installed as part of the libxml2
1197 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1198 <li>The I/O interface has been revamped. There is now ways to plug in
1199 specific I/O modules, either at the URI scheme detection level using
1200 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
1201 parser context using xmlCreateIOParserCtxt()</li>
1202 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
1203 number of the libxml module in use</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1204 <li>a number of optional features of libxml can now be excluded at
1205 configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1206</ul>
1207
1208<h3>2.0.0beta: Mar 14 2000</h3>
1209<ul>
1210 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1211 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
1212 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
1213 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1214 <li>This version is now the head in the Gnome CVS base, the old one is
1215 available under the tag LIB_XML_1_X</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1216 <li>This includes a very large set of changes. From a programmatic point
1217 of view applications should not have to be modified too much, check the
1218 <a href="upgrade.html">upgrade page</a></li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1219 <li>Some interfaces may changes (especially a bit about encoding).</li>
1220 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1221 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1222 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
1223 handled now</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1224 <li>Better handling of entities, especially well-formedness checking
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1225 and proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1226 <li>DTD conditional sections</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1227 <li>Validation now correctly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1228 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1229 structures to accommodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1230 </ul>
1231 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1232 <li>Serious progress were made toward compliance, <a
1233 href="conf/result.html">here are the result of the test</a> against the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1234 OASIS testsuite (except the Japanese tests since I don't support that
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1235 encoding yet). This URL is rebuilt every couple of hours using the CVS
1236 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1237</ul>
1238
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1239<h3>1.8.7: Mar 6 2000</h3>
1240<ul>
1241 <li>This is a bug fix release:</li>
1242 <li>It is possible to disable the ignorable blanks heuristic used by
1243 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1244 that for adherence to XML spec, this behaviour will be disabled by
1245 default in 2.x . The same function will allow to keep compatibility for
1246 old code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1247 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
1248 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1249 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
1250 compilation on some platforms has been fixed</li>
1251 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
1252 URIs</li>
1253</ul>
1254
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1255<h3>1.8.6: Jan 31 2000</h3>
1256<ul>
1257 <li>added a nanoFTP transport module, debugged until the new version of <a
1258 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
1259 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]1260</ul>
1261
1262<h3>1.8.5: Jan 21 2000</h3>
1263<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1264 <li>adding APIs to parse a well balanced chunk of XML (production <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1265 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
1266 XML spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1267 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1268 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
1269 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1270 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
1271 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1272</ul>
1273
1274<h3>1.8.4: Jan 13 2000</h3>
1275<ul>
1276 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
1277 <li>all exit() call should have been removed from libxml</li>
1278 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
1279 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1280</ul>
1281
1282<h3>1.8.3: Jan 5 2000</h3>
1283<ul>
1284 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1285 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1286 <li>lots of bug fixes and improvement added over XMas holidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1287 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1288 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
1289 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1290 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1291 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1292 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1293</ul>
1294
1295<h3>1.8.2: Dec 21 1999</h3>
1296<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1297 <li>I got another problem with includes and C++, I hope this issue is fixed
1298 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1299 <li>Added a few tree modification functions: xmlReplaceNode,
1300 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
1301 xmlDocSetRootElement</li>
1302 <li>Tried to improve the HTML output with help from <a
1303 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1304</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1305
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1306<h3>1.8.1: Dec 18 1999</h3>
1307<ul>
1308 <li>various patches to avoid troubles when using libxml with C++ compilers
1309 the "namespace" keyword and C escaping in include files</li>
1310 <li>a problem in one of the core macros IS_CHAR was corrected</li>
1311 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
1312 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]1313 <li>fixed a posteriori validation (validation after parsing, or by using a
1314 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1315 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]1316</ul>
1317
1318<h3>1.8.0: Dec 12 1999</h3>
1319<ul>
1320 <li>cleanup, especially memory wise</li>
1321 <li>the parser should be more reliable, especially the HTML one, it should
1322 not crash, whatever the input !</li>
1323 <li>Integrated various patches, especially a speedup improvement for large
1324 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
1325 configure with --with-buffers to enable them.</li>
1326 <li>attribute normalization, oops should have been added long ago !</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1327 <li>attributes defaulted from DTDs should be available, xmlSetProp() now
1328 does entities escaping by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1329</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1330
1331<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1332<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1333 <li>Lots of HTML improvement</li>
1334 <li>Fixed some errors when saving both XML and HTML</li>
1335 <li>More examples, the regression tests should now look clean</li>
1336 <li>Fixed a bug with contiguous charref</li>
1337</ul>
1338
1339<h3>1.7.3: Sep 29 1999</h3>
1340<ul>
1341 <li>portability problems fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1342 <li>snprintf was used unconditionally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1343 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1344</ul>
1345
1346<h3>1.7.1: Sep 24 1999</h3>
1347<ul>
1348 <li>The basic type for strings manipulated by libxml has been renamed in
1349 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1350 is that CHAR was conflicting with a predefined type on Windows. However
1351 on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1352 <strong>#define </strong>.</li>
1353 <li>Changed another error : the use of a structure field called errno, and
1354 leading to troubles on platforms where it's a macro</li>
1355</ul>
1356
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1357<h3>1.7.0: Sep 23 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1358<ul>
1359 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1360 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1361 <li>Added an errno to report errors by another mean than a simple printf
1362 like callback</li>
1363 <li>Finished ID/IDREF support and checking when validation</li>
1364 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1365 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1366 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
1367 implementation</li>
1368 <li>Added an HTML parser front-end</li>
1369</ul>
1370
1371<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1372
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1373<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]1374markup-based structured documents. Here is <a name="example">an example XML
1375document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1376<pre>&lt;?xml version="1.0"?&gt;
1377&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
1378 &lt;head&gt;
1379 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
1380 &lt;/head&gt;
1381 &lt;chapter&gt;
1382 &lt;title&gt;The Linux adventure&lt;/title&gt;
1383 &lt;p&gt;bla bla bla ...&lt;/p&gt;
1384 &lt;image href="linus.gif"/&gt;
1385 &lt;p&gt;...&lt;/p&gt;
1386 &lt;/chapter&gt;
1387&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1388
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1389<p>The first line specifies that it is an XML document and gives useful
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]1390information about its encoding. Then the rest of the document is a text
1391format whose structure is specified by tags between brackets. <strong>Each
1392tag opened has to be closed</strong>. XML is pedantic about this. However, if
1393a tag is empty (no content), a single tag can serve as both the opening and
1394closing tag if it ends with <code>/&gt;</code> rather than with
1395<code>&gt;</code>. Note that, for example, the image tag has no content (just
1396an attribute) and is closed by ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1397
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]1398<p>XML can be applied successfully to a wide range of tasks, ranging from
1399long term structured document maintenance (where it follows the steps of
1400SGML) to simple data encoding mechanisms like configuration file formatting
1401(glade), spreadsheets (gnumeric), or even shorter lived documents such as
1402WebDAV where it is used to encode remote calls between a client and a
1403server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1404
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1405<h2><a name="XSLT">XSLT</a></h2>
1406
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1407<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
1408
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1409<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
1410language for transforming XML documents into other XML documents (or
1411HTML/textual output).</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1412
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]1413<p>A separate library called libxslt is being developed on top of libxml2.
1414This module "libxslt" too can be found in the Gnome CVS base.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1415
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]1416<p>You can check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1417href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
1418supported and the progresses on the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1419href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog"
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1420name="Changelog">Changelog</a>.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1421
1422<h2><a name="Python">Python and bindings</a></h2>
1423
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]1424<p>There are a number of language bindings and wrappers available for
1425libxml2, the list below is not exhaustive. Please contact the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1426href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a>
1427(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in
1428order to get updates to this list or to discuss the specific topic of libxml2
1429or libxslt wrappers or bindings:</p>
1430<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1431 <li><a href="mailto:ari@lusis.org">Ari Johnson</a> provides a C++ wrapper
1432 for libxml:<br>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1433 Website: <a
1434 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a><br>
1435 Download: <a
1436 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></li>
1437 <li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1438 based on the gdome2 bindings</a> maintained by Tobias Peters.</li>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]1439 <li>and a third C++ wrapper by Peter Jones &lt;pjones@pmade.org&gt;
1440 <p>Website: <a
1441 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
1442 </li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1443 <li><a
1444 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1445 Sergeant</a> developed <a
1446 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1447 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1448 application server</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]1449 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides an
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1450 earlier version of the libxml/libxslt <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1451 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]1452 <li>Gopal.V and Peter Minten develop <a
1453 href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1454 C# libxml2 bindings.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1455 <li>Petr Kozelka provides <a
1456 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1457 libxml2</a> with Kylix, Delphi and other Pascal compilers.</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]1458 <li>Uwe Fechner also provides <a
1459 href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1460 implementation for Kylix2/D5/D6 from Borland.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1461 <li>Wai-Sun "Squidster" Chia provides <a
1462 href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and
1463 libxml2 bindings are also available in Ruby through the <a
1464 href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module
1465 maintained by Tobias Peters.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1466 <li>Steve Ball and contributors maintains <a
1467 href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1468 Tcl</a>.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1469 <li>There is support for libxml2 in the DOM module of PHP.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1470</ul>
1471
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1472<p>The distribution includes a set of Python bindings, which are guaranteed
1473to be maintained as part of the library in the future, though the Python
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1474interface have not yet reached the maturity of the C API.</p>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1475
1476<p>To install the Python bindings there are 2 options:</p>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1477<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1478 <li>If you use an RPM based distribution, simply install the <a
1479 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python
1480 RPM</a> (and if needed the <a
1481 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python
1482 RPM</a>).</li>
1483 <li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python
1484 module distribution</a> corresponding to your installed version of
1485 libxml2 and libxslt. Note that to install it you will need both libxml2
1486 and libxslt installed and run "python setup.py build install" in the
1487 module tree.</li>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1488</ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1489
1490<p>The distribution includes a set of examples and regression tests for the
1491python bindings in the <code>python/tests</code> directory. Here are some
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1492excerpts from those tests:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1493
1494<h3>tst.py:</h3>
1495
1496<p>This is a basic test of the file interface and DOM navigation:</p>
1497<pre>import libxml2
1498
1499doc = libxml2.parseFile("tst.xml")
1500if doc.name != "tst.xml":
1501 print "doc.name failed"
1502 sys.exit(1)
1503root = doc.children
1504if root.name != "doc":
1505 print "root.name failed"
1506 sys.exit(1)
1507child = root.children
1508if child.name != "foo":
1509 print "child.name failed"
1510 sys.exit(1)
1511doc.freeDoc()</pre>
1512
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1513<p>The Python module is called libxml2; parseFile is the equivalent of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1514xmlParseFile (most of the bindings are automatically generated, and the xml
1515prefix is removed and the casing convention are kept). All node seen at the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1516binding level share the same subset of accessors:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1517<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1518 <li><code>name</code> : returns the node name</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1519 <li><code>type</code> : returns a string indicating the node type</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1520 <li><code>content</code> : returns the content of the node, it is based on
1521 xmlNodeGetContent() and hence is recursive.</li>
1522 <li><code>parent</code> , <code>children</code>, <code>last</code>,
1523 <code>next</code>, <code>prev</code>, <code>doc</code>,
1524 <code>properties</code>: pointing to the associated element in the tree,
1525 those may return None in case no such link exists.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1526</ul>
1527
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1528<p>Also note the need to explicitly deallocate documents with freeDoc() .
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1529Reference counting for libxml2 trees would need quite a lot of work to
1530function properly, and rather than risk memory leaks if not implemented
1531correctly it sounds safer to have an explicit function to free a tree. The
1532wrapper python objects like doc, root or child are them automatically garbage
1533collected.</p>
1534
1535<h3>validate.py:</h3>
1536
1537<p>This test check the validation interfaces and redirection of error
1538messages:</p>
1539<pre>import libxml2
1540
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1541#deactivate error messages from the validation
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1542def noerr(ctx, str):
1543 pass
1544
1545libxml2.registerErrorHandler(noerr, None)
1546
1547ctxt = libxml2.createFileParserCtxt("invalid.xml")
1548ctxt.validate(1)
1549ctxt.parseDocument()
1550doc = ctxt.doc()
1551valid = ctxt.isValid()
1552doc.freeDoc()
1553if valid != 0:
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1554 print "validity check failed"</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1555
1556<p>The first thing to notice is the call to registerErrorHandler(), it
1557defines a new error handler global to the library. It is used to avoid seeing
1558the error messages when trying to validate the invalid document.</p>
1559
1560<p>The main interest of that test is the creation of a parser context with
1561createFileParserCtxt() and how the behaviour can be changed before calling
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1562parseDocument() . Similarly the informations resulting from the parsing phase
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1563are also available using context methods.</p>
1564
1565<p>Contexts like nodes are defined as class and the libxml2 wrappers maps the
1566C function interfaces in terms of objects method as much as possible. The
1567best to get a complete view of what methods are supported is to look at the
1568libxml2.py module containing all the wrappers.</p>
1569
1570<h3>push.py:</h3>
1571
1572<p>This test show how to activate the push parser interface:</p>
1573<pre>import libxml2
1574
1575ctxt = libxml2.createPushParser(None, "&lt;foo", 4, "test.xml")
1576ctxt.parseChunk("/&gt;", 2, 1)
1577doc = ctxt.doc()
1578
1579doc.freeDoc()</pre>
1580
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1581<p>The context is created with a special call based on the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1582xmlCreatePushParser() from the C library. The first argument is an optional
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1583SAX callback object, then the initial set of data, the length and the name of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1584the resource in case URI-References need to be computed by the parser.</p>
1585
1586<p>Then the data are pushed using the parseChunk() method, the last call
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1587setting the third argument terminate to 1.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1588
1589<h3>pushSAX.py:</h3>
1590
1591<p>this test show the use of the event based parsing interfaces. In this case
1592the parser does not build a document, but provides callback information as
1593the parser makes progresses analyzing the data being provided:</p>
1594<pre>import libxml2
1595log = ""
1596
1597class callback:
1598 def startDocument(self):
1599 global log
1600 log = log + "startDocument:"
1601
1602 def endDocument(self):
1603 global log
1604 log = log + "endDocument:"
1605
1606 def startElement(self, tag, attrs):
1607 global log
1608 log = log + "startElement %s %s:" % (tag, attrs)
1609
1610 def endElement(self, tag):
1611 global log
1612 log = log + "endElement %s:" % (tag)
1613
1614 def characters(self, data):
1615 global log
1616 log = log + "characters: %s:" % (data)
1617
1618 def warning(self, msg):
1619 global log
1620 log = log + "warning: %s:" % (msg)
1621
1622 def error(self, msg):
1623 global log
1624 log = log + "error: %s:" % (msg)
1625
1626 def fatalError(self, msg):
1627 global log
1628 log = log + "fatalError: %s:" % (msg)
1629
1630handler = callback()
1631
1632ctxt = libxml2.createPushParser(handler, "&lt;foo", 4, "test.xml")
1633chunk = " url='tst'&gt;b"
1634ctxt.parseChunk(chunk, len(chunk), 0)
1635chunk = "ar&lt;/foo&gt;"
1636ctxt.parseChunk(chunk, len(chunk), 1)
1637
Daniel Veillardfcbfa2d2002-02-21 17:54:27 +0000[diff] [blame]1638reference = "startDocument:startElement foo {'url': 'tst'}:" + \
1639 "characters: bar:endElement foo:endDocument:"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1640if log != reference:
1641 print "Error got: %s" % log
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1642 print "Expected: %s" % reference</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1643
1644<p>The key object in that test is the handler, it provides a number of entry
1645points which can be called by the parser as it makes progresses to indicate
1646the information set obtained. The full set of callback is larger than what
1647the callback class in that specific example implements (see the SAX
1648definition for a complete list). The wrapper will only call those supplied by
1649the object when activated. The startElement receives the names of the element
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1650and a dictionary containing the attributes carried by this element.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1651
1652<p>Also note that the reference string generated from the callback shows a
1653single character call even though the string "bar" is passed to the parser
1654from 2 different call to parseChunk()</p>
1655
1656<h3>xpath.py:</h3>
1657
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1658<p>This is a basic test of XPath wrappers support</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1659<pre>import libxml2
1660
1661doc = libxml2.parseFile("tst.xml")
1662ctxt = doc.xpathNewContext()
1663res = ctxt.xpathEval("//*")
1664if len(res) != 2:
1665 print "xpath query: wrong node set size"
1666 sys.exit(1)
1667if res[0].name != "doc" or res[1].name != "foo":
1668 print "xpath query: wrong node set value"
1669 sys.exit(1)
1670doc.freeDoc()
1671ctxt.xpathFreeContext()</pre>
1672
1673<p>This test parses a file, then create an XPath context to evaluate XPath
1674expression on it. The xpathEval() method execute an XPath query and returns
1675the result mapped in a Python way. String and numbers are natively converted,
1676and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1677the document, the XPath context need to be freed explicitly, also not that
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1678the result of the XPath query may point back to the document tree and hence
1679the document must be freed after the result of the query is used.</p>
1680
1681<h3>xpathext.py:</h3>
1682
1683<p>This test shows how to extend the XPath engine with functions written in
1684python:</p>
1685<pre>import libxml2
1686
1687def foo(ctx, x):
1688 return x + 1
1689
1690doc = libxml2.parseFile("tst.xml")
1691ctxt = doc.xpathNewContext()
1692libxml2.registerXPathFunction(ctxt._o, "foo", None, foo)
1693res = ctxt.xpathEval("foo(1)")
1694if res != 2:
1695 print "xpath extension failure"
1696doc.freeDoc()
1697ctxt.xpathFreeContext()</pre>
1698
1699<p>Note how the extension function is registered with the context (but that
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1700part is not yet finalized, this may change slightly in the future).</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1701
1702<h3>tstxpath.py:</h3>
1703
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1704<p>This test is similar to the previous one but shows how the extension
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1705function can access the XPath evaluation context:</p>
1706<pre>def foo(ctx, x):
1707 global called
1708
1709 #
1710 # test that access to the XPath evaluation contexts
1711 #
1712 pctxt = libxml2.xpathParserContext(_obj=ctx)
1713 ctxt = pctxt.context()
1714 called = ctxt.function()
1715 return x + 1</pre>
1716
1717<p>All the interfaces around the XPath parser(or rather evaluation) context
1718are not finalized, but it should be sufficient to do contextual work at the
1719evaluation point.</p>
1720
1721<h3>Memory debugging:</h3>
1722
1723<p>last but not least, all tests starts with the following prologue:</p>
1724<pre>#memory debug specific
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1725libxml2.debugMemory(1)</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1726
1727<p>and ends with the following epilogue:</p>
1728<pre>#memory debug specific
1729libxml2.cleanupParser()
1730if libxml2.debugMemory(1) == 0:
1731 print "OK"
1732else:
1733 print "Memory leak %d bytes" % (libxml2.debugMemory(1))
1734 libxml2.dumpMemory()</pre>
1735
1736<p>Those activate the memory debugging interface of libxml2 where all
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1737allocated block in the library are tracked. The prologue then cleans up the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1738library state and checks that all allocated memory has been freed. If not it
1739calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1740
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1741<h2><a name="architecture">libxml architecture</a></h2>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1742
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1743<p>Libxml is made of multiple components; some of them are optional, and most
1744of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1745<ul>
1746 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1747 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1748 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1749 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1750 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1751 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1752 <li>a SAX tree module to build an in-memory DOM representation</li>
1753 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1754 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1755 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1756 (optional)</li>
1757 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1758</ul>
1759
1760<p>Graphically this gives the following:</p>
1761
1762<p><img src="libxml.gif" alt="a graphical view of the various"></p>
1763
1764<p></p>
1765
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1766<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1767
1768<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1769returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1770<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1771as the file name, the document type, and a <strong>children</strong> pointer
1772which is the root of the document (or more exactly the first child under the
1773root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1774chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1775relationship. An xmlNode can also carry properties (a chain of xmlAttr
1776structures). An attribute may have a value which is a list of TEXT or
1777ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1778
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1779<p>Here is an example (erroneous with respect to the XML spec since there
1780should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1781
1782<p><img src="structure.gif" alt=" structure.gif "></p>
1783
1784<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1785called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1786prints them back as parsed. This is useful for detecting errors both in XML
1787code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1788which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1789result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1790<pre>DOCUMENT
1791version=1.0
1792standalone=true
1793 ELEMENT EXAMPLE
1794 ATTRIBUTE prop1
1795 TEXT
1796 content=gnome is great
1797 ATTRIBUTE prop2
1798 ENTITY_REF
1799 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1800 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1801 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1802 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1803 TEXT
1804 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1805 ELEMENT chapter
1806 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1807 TEXT
1808 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1809 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1810 TEXT
1811 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1812 ELEMENT image
1813 ATTRIBUTE href
1814 TEXT
1815 content=linus.gif
1816 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1817 TEXT
1818 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1819
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1820<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1821
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1822<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1823
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1824<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1825memory. 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]1826loaded using libxml), it's better to use the SAX interface of libxml. SAX is
1827a <strong>callback-based interface</strong> to the parser. Before parsing,
1828the application layer registers a customized set of callbacks which are
1829called by the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1830
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1831<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]1832libxml, see the <a
1833href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
1834documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1835Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1836
1837<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
1838program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1839binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1840distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1841testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1842<pre>SAX.setDocumentLocator()
1843SAX.startDocument()
1844SAX.getEntity(amp)
1845SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
1846SAX.characters( , 3)
1847SAX.startElement(head)
1848SAX.characters( , 4)
1849SAX.startElement(title)
1850SAX.characters(Welcome to Gnome, 16)
1851SAX.endElement(title)
1852SAX.characters( , 3)
1853SAX.endElement(head)
1854SAX.characters( , 3)
1855SAX.startElement(chapter)
1856SAX.characters( , 4)
1857SAX.startElement(title)
1858SAX.characters(The Linux adventure, 19)
1859SAX.endElement(title)
1860SAX.characters( , 4)
1861SAX.startElement(p)
1862SAX.characters(bla bla bla ..., 15)
1863SAX.endElement(p)
1864SAX.characters( , 4)
1865SAX.startElement(image, href='linus.gif')
1866SAX.endElement(image)
1867SAX.characters( , 4)
1868SAX.startElement(p)
1869SAX.characters(..., 3)
1870SAX.endElement(p)
1871SAX.characters( , 3)
1872SAX.endElement(chapter)
1873SAX.characters( , 1)
1874SAX.endElement(EXAMPLE)
1875SAX.endDocument()</pre>
1876
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1877<p>Most of the other interfaces of libxml are based on the DOM tree-building
1878facility, so nearly everything up to the end of this document presupposes the
1879use of the standard DOM tree build. Note that the DOM tree itself is built by
1880a set of registered default callbacks, without internal specific
1881interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1882
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1883<h2><a name="Validation">Validation &amp; DTDs</a></h2>
1884
1885<p>Table of Content:</p>
1886<ol>
1887 <li><a href="#General5">General overview</a></li>
1888 <li><a href="#definition">The definition</a></li>
1889 <li><a href="#Simple">Simple rules</a>
1890 <ol>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]1891 <li><a href="#reference">How to reference a DTD from a document</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1892 <li><a href="#Declaring">Declaring elements</a></li>
1893 <li><a href="#Declaring1">Declaring attributes</a></li>
1894 </ol>
1895 </li>
1896 <li><a href="#Some">Some examples</a></li>
1897 <li><a href="#validate">How to validate</a></li>
1898 <li><a href="#Other">Other resources</a></li>
1899</ol>
1900
1901<h3><a name="General5">General overview</a></h3>
1902
1903<p>Well what is validation and what is a DTD ?</p>
1904
1905<p>DTD is the acronym for Document Type Definition. This is a description of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1906the 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]1907specification, and allows one to describe and verify that a given document
1908instance conforms to the set of rules detailing its structure and content.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1909
1910<p>Validation is the process of checking a document against a DTD (more
1911generally against a set of construction rules).</p>
1912
1913<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1914of the XML life cycle. Briefly a DTD defines all the possible elements to be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1915found within your document, what is the formal shape of your document tree
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1916(by defining the allowed content of an element; either text, a regular
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1917expression for the allowed list of children, or mixed content i.e. both text
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]1918and children). The DTD also defines the valid attributes for all elements and
1919the types of those attributes.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1920
1921<h3><a name="definition1">The definition</a></h3>
1922
1923<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
1924href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
1925Rev1</a>):</p>
1926<ul>
1927 <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
1928 elements</a></li>
1929 <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
1930 attributes</a></li>
1931</ul>
1932
1933<p>(unfortunately) all this is inherited from the SGML world, the syntax is
1934ancient...</p>
1935
1936<h3><a name="Simple1">Simple rules</a></h3>
1937
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]1938<p>Writing DTDs can be done in many ways. The rules to build them if you need
1939something permanent or something which can evolve over time can be radically
1940different. Really complex DTDs like DocBook ones are flexible but quite
1941harder 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]1942structure. It is just a set of basic rules, and definitely not exhaustive nor
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1943usable for complex DTD design.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1944
1945<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
1946
1947<p>Assuming the top element of the document is <code>spec</code> and the dtd
1948is placed in the file <code>mydtd</code> in the subdirectory
1949<code>dtds</code> of the directory from where the document were loaded:</p>
1950
1951<p><code>&lt;!DOCTYPE spec SYSTEM "dtds/mydtd"&gt;</code></p>
1952
1953<p>Notes:</p>
1954<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1955 <li>The system string is actually an URI-Reference (as defined in <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1956 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]1957 full URL string indicating the location of your DTD on the Web. This is a
1958 really good thing to do if you want others to validate your document.</li>
1959 <li>It is also possible to associate a <code>PUBLIC</code> identifier (a
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1960 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]1961 without having to locate it on the web.</li>
1962 <li>A DTD contains a set of element and attribute declarations, but they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1963 don't define what the root of the document should be. This is explicitly
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1964 told to the parser/validator as the first element of the
1965 <code>DOCTYPE</code> declaration.</li>
1966</ul>
1967
1968<h4><a name="Declaring2">Declaring elements</a>:</h4>
1969
1970<p>The following declares an element <code>spec</code>:</p>
1971
1972<p><code>&lt;!ELEMENT spec (front, body, back?)&gt;</code></p>
1973
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1974<p>It also expresses that the spec element contains one <code>front</code>,
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1975one <code>body</code> and one optional <code>back</code> children elements in
1976this order. The declaration of one element of the structure and its content
1977are done in a single declaration. Similarly the following declares
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1978<code>div1</code> elements:</p>
1979
Daniel Veillard51737272002-01-23 23:10:38 +0000[diff] [blame]1980<p><code>&lt;!ELEMENT div1 (head, (p | list | note)*, div2?)&gt;</code></p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1981
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]1982<p>which means div1 contains one <code>head</code> then a series of optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1983<code>p</code>, <code>list</code>s and <code>note</code>s and then an
1984optional <code>div2</code>. And last but not least an element can contain
1985text:</p>
1986
1987<p><code>&lt;!ELEMENT b (#PCDATA)&gt;</code></p>
1988
1989<p><code>b</code> contains text or being of mixed content (text and elements
1990in no particular order):</p>
1991
1992<p><code>&lt;!ELEMENT p (#PCDATA|a|ul|b|i|em)*&gt;</code></p>
1993
1994<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
1995<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
1996order.</p>
1997
1998<h4><a name="Declaring1">Declaring attributes</a>:</h4>
1999
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2000<p>Again the attributes declaration includes their content definition:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2001
2002<p><code>&lt;!ATTLIST termdef name CDATA #IMPLIED&gt;</code></p>
2003
2004<p>means that the element <code>termdef</code> can have a <code>name</code>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2005attribute containing text (<code>CDATA</code>) and which is optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2006(<code>#IMPLIED</code>). The attribute value can also be defined within a
2007set:</p>
2008
2009<p><code>&lt;!ATTLIST list type (bullets|ordered|glossary)
2010"ordered"&gt;</code></p>
2011
2012<p>means <code>list</code> element have a <code>type</code> attribute with 3
2013allowed values "bullets", "ordered" or "glossary" and which default to
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2014"ordered" if the attribute is not explicitly specified.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2015
2016<p>The content type of an attribute can be text (<code>CDATA</code>),
2017anchor/reference/references
2018(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
2019(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
2020(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
2021<code>chapter</code> element can have an optional <code>id</code> attribute
2022of type <code>ID</code>, usable for reference from attribute of type
2023IDREF:</p>
2024
2025<p><code>&lt;!ATTLIST chapter id ID #IMPLIED&gt;</code></p>
2026
2027<p>The last value of an attribute definition can be <code>#REQUIRED
2028</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
2029meaning that it is optional, or the default value (possibly prefixed by
2030<code>#FIXED</code> if it is the only allowed).</p>
2031
2032<p>Notes:</p>
2033<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2034 <li>Usually the attributes pertaining to a given element are declared in a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2035 single expression, but it is just a convention adopted by a lot of DTD
2036 writers:
2037 <pre>&lt;!ATTLIST termdef
2038 id ID #REQUIRED
2039 name CDATA #IMPLIED&gt;</pre>
2040 <p>The previous construct defines both <code>id</code> and
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2041 <code>name</code> attributes for the element <code>termdef</code>.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2042 </li>
2043</ul>
2044
2045<h3><a name="Some1">Some examples</a></h3>
2046
2047<p>The directory <code>test/valid/dtds/</code> in the libxml distribution
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]2048contains some complex DTD examples. The example in the file
2049<code>test/valid/dia.xml</code> shows an XML file where the simple DTD is
2050directly included within the document.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2051
2052<h3><a name="validate1">How to validate</a></h3>
2053
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2054<p>The simplest way is to use the xmllint program included with libxml. The
2055<code>--valid</code> option turns-on validation of the files given as input.
2056For example the following validates a copy of the first revision of the XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]20571.0 specification:</p>
2058
2059<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
2060
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]2061<p>the -- noout is used to disable output of the resulting tree.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2062
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]2063<p>The <code>--dtdvalid dtd</code> allows validation of the document(s)
2064against a given DTD.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2065
2066<p>Libxml exports an API to handle DTDs and validation, check the <a
2067href="http://xmlsoft.org/html/libxml-valid.html">associated
2068description</a>.</p>
2069
2070<h3><a name="Other1">Other resources</a></h3>
2071
2072<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
2073will just list one for now, others pointers welcome:</p>
2074<ul>
2075 <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
2076</ul>
2077
2078<p>I suggest looking at the examples found under test/valid/dtd and any of
2079the large number of books available on XML. The dia example in test/valid
2080should be both simple and complete enough to allow you to build your own.</p>
2081
2082<p></p>
2083
2084<h2><a name="Memory">Memory Management</a></h2>
2085
2086<p>Table of Content:</p>
2087<ol>
2088 <li><a href="#General3">General overview</a></li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2089 <li><a href="#setting">Setting libxml set of memory routines</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2090 <li><a href="#cleanup">Cleaning up after parsing</a></li>
2091 <li><a href="#Debugging">Debugging routines</a></li>
2092 <li><a href="#General4">General memory requirements</a></li>
2093</ol>
2094
2095<h3><a name="General3">General overview</a></h3>
2096
2097<p>The module <code><a
2098href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
2099provides the interfaces to the libxml memory system:</p>
2100<ul>
2101 <li>libxml does not use the libc memory allocator directly but xmlFree(),
2102 xmlMalloc() and xmlRealloc()</li>
2103 <li>those routines can be reallocated to a specific set of routine, by
2104 default the libc ones i.e. free(), malloc() and realloc()</li>
2105 <li>the xmlmemory.c module includes a set of debugging routine</li>
2106</ul>
2107
2108<h3><a name="setting">Setting libxml set of memory routines</a></h3>
2109
2110<p>It is sometimes useful to not use the default memory allocator, either for
2111debugging, analysis or to implement a specific behaviour on memory management
2112(like on embedded systems). Two function calls are available to do so:</p>
2113<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2114 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet
2115 ()</a> which return the current set of functions in use by the parser</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2116 <li><a
2117 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2118 which allow to set up a new set of memory allocation functions</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2119</ul>
2120
2121<p>Of course a call to xmlMemSetup() should probably be done before calling
2122any other libxml routines (unless you are sure your allocations routines are
2123compatibles).</p>
2124
2125<h3><a name="cleanup">Cleaning up after parsing</a></h3>
2126
2127<p>Libxml is not stateless, there is a few set of memory structures needing
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2128allocation before the parser is fully functional (some encoding structures
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2129for example). This also mean that once parsing is finished there is a tiny
2130amount of memory (a few hundred bytes) which can be recollected if you don't
2131reuse the parser immediately:</p>
2132<ul>
2133 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2134 ()</a> is a centralized routine to free the parsing states. Note that it
2135 won't deallocate any produced tree if any (use the xmlFreeDoc() and
2136 related routines for this).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2137 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2138 ()</a> is the dual routine allowing to preallocate the parsing state
2139 which can be useful for example to avoid initialization reentrancy
2140 problems when using libxml in multithreaded applications</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2141</ul>
2142
2143<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
2144at the next invocation of parser routines, but be careful of the consequences
2145in multithreaded applications.</p>
2146
2147<h3><a name="Debugging">Debugging routines</a></h3>
2148
2149<p>When configured using --with-mem-debug flag (off by default), libxml uses
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2150a set of memory allocation debugging routines keeping track of all allocated
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2151blocks and the location in the code where the routine was called. A couple of
2152other debugging routines allow to dump the memory allocated infos to a file
2153or call a specific routine when a given block number is allocated:</p>
2154<ul>
2155 <li><a
2156 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2157 <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2158 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
2159 and <a
2160 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
2161 are the memory debugging replacement allocation routines</li>
2162 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2163 ()</a> dumps all the informations about the allocated memory block lefts
2164 in the <code>.memdump</code> file</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2165</ul>
2166
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2167<p>When developing libxml memory debug is enabled, the tests programs call
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2168xmlMemoryDump () and the "make test" regression tests will check for any
2169memory leak during the full regression test sequence, this helps a lot
2170ensuring that libxml does not leak memory and bullet proof memory
2171allocations use (some libc implementations are known to be far too permissive
2172resulting in major portability problems!).</p>
2173
2174<p>If the .memdump reports a leak, it displays the allocation function and
2175also tries to give some informations about the content and structure of the
2176allocated blocks left. This is sufficient in most cases to find the culprit,
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2177but not always. Assuming the allocation problem is reproducible, it is
2178possible to find more easily:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2179<ol>
2180 <li>write down the block number xxxx not allocated</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2181 <li>export the environment variable XML_MEM_BREAKPOINT=xxxx , the easiest
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2182 when using GDB is to simply give the command
2183 <p><code>set environment XML_MEM_BREAKPOINT xxxx</code></p>
2184 <p>before running the program.</p>
2185 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2186 <li>run the program under a debugger and set a breakpoint on
2187 xmlMallocBreakpoint() a specific function called when this precise block
2188 is allocated</li>
2189 <li>when the breakpoint is reached you can then do a fine analysis of the
2190 allocation an step to see the condition resulting in the missing
2191 deallocation.</li>
2192</ol>
2193
2194<p>I used to use a commercial tool to debug libxml memory problems but after
2195noticing that it was not detecting memory leaks that simple mechanism was
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2196used and proved extremely efficient until now. Lately I have also used <a
2197href="http://developer.kde.org/~sewardj/">valgrind</a> with quite some
2198success, it is tied to the i386 architecture since it works by emulating the
2199processor and instruction set, it is slow but extremely efficient, i.e. it
2200spot memory usage errors in a very precise way.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2201
2202<h3><a name="General4">General memory requirements</a></h3>
2203
2204<p>How much libxml memory require ? It's hard to tell in average it depends
2205of a number of things:</p>
2206<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2207 <li>the parser itself should work in a fixed amount of memory, except for
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2208 information maintained about the stacks of names and entities locations.
2209 The I/O and encoding handlers will probably account for a few KBytes.
2210 This is true for both the XML and HTML parser (though the HTML parser
2211 need more state).</li>
2212 <li>If you are generating the DOM tree then memory requirements will grow
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2213 nearly linear with the size of the data. In general for a balanced
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2214 textual document the internal memory requirement is about 4 times the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2215 size of the UTF8 serialization of this document (example the XML-1.0
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2216 recommendation is a bit more of 150KBytes and takes 650KBytes of main
2217 memory when parsed). Validation will add a amount of memory required for
2218 maintaining the external Dtd state which should be linear with the
2219 complexity of the content model defined by the Dtd</li>
2220 <li>If you don't care about the advanced features of libxml like
2221 validation, DOM, XPath or XPointer, but really need to work fixed memory
2222 requirements, then the SAX interface should be used.</li>
2223</ul>
2224
2225<p></p>
2226
2227<h2><a name="Encodings">Encodings support</a></h2>
2228
2229<p>Table of Content:</p>
2230<ol>
2231 <li><a href="encoding.html#What">What does internationalization support
2232 mean ?</a></li>
2233 <li><a href="encoding.html#internal">The internal encoding, how and
2234 why</a></li>
2235 <li><a href="encoding.html#implemente">How is it implemented ?</a></li>
2236 <li><a href="encoding.html#Default">Default supported encodings</a></li>
2237 <li><a href="encoding.html#extend">How to extend the existing
2238 support</a></li>
2239</ol>
2240
2241<h3><a name="What">What does internationalization support mean ?</a></h3>
2242
2243<p>XML was designed from the start to allow the support of any character set
2244by using Unicode. Any conformant XML parser has to support the UTF-8 and
2245UTF-16 default encodings which can both express the full unicode ranges. UTF8
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2246is a variable length encoding whose greatest points are to reuse the same
2247encoding for ASCII and to save space for Western encodings, but it is a bit
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2248more complex to handle in practice. UTF-16 use 2 bytes per characters (and
2249sometimes combines two pairs), it makes implementation easier, but looks a
2250bit overkill for Western languages encoding. Moreover the XML specification
2251allows document to be encoded in other encodings at the condition that they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2252are clearly labeled as such. For example the following is a wellformed XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2253document encoded in ISO-8859 1 and using accentuated letter that we French
2254likes for both markup and content:</p>
2255<pre>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2256&lt;très&gt;là&lt;/très&gt;</pre>
2257
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2258<p>Having internationalization support in libxml means the following:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2259<ul>
2260 <li>the document is properly parsed</li>
2261 <li>informations about it's encoding are saved</li>
2262 <li>it can be modified</li>
2263 <li>it can be saved in its original encoding</li>
2264 <li>it can also be saved in another encoding supported by libxml (for
2265 example straight UTF8 or even an ASCII form)</li>
2266</ul>
2267
2268<p>Another very important point is that the whole libxml API, with the
2269exception of a few routines to read with a specific encoding or save to a
2270specific encoding, is completely agnostic about the original encoding of the
2271document.</p>
2272
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2273<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]2274the same rules too, the following document will be (as of 2.2.2) handled in
2275an internationalized fashion by libxml too:</p>
2276<pre>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
2277 "http://www.w3.org/TR/REC-html40/loose.dtd"&gt;
2278&lt;html lang="fr"&gt;
2279&lt;head&gt;
2280 &lt;META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&gt;
2281&lt;/head&gt;
2282&lt;body&gt;
2283&lt;p&gt;W3C crée des standards pour le Web.&lt;/body&gt;
2284&lt;/html&gt;</pre>
2285
2286<h3><a name="internal">The internal encoding, how and why</a></h3>
2287
2288<p>One of the core decision was to force all documents to be converted to a
2289default internal encoding, and that encoding to be UTF-8, here are the
2290rationale for those choices:</p>
2291<ul>
2292 <li>keeping the native encoding in the internal form would force the libxml
2293 users (or the code associated) to be fully aware of the encoding of the
2294 original document, for examples when adding a text node to a document,
2295 the content would have to be provided in the document encoding, i.e. the
2296 client code would have to check it before hand, make sure it's conformant
2297 to the encoding, etc ... Very hard in practice, though in some specific
2298 cases this may make sense.</li>
2299 <li>the second decision was which encoding. From the XML spec only UTF8 and
2300 UTF16 really makes sense as being the two only encodings for which there
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2301 is mandatory support. UCS-4 (32 bits fixed size encoding) could be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2302 considered an intelligent choice too since it's a direct Unicode mapping
2303 support. I selected UTF-8 on the basis of efficiency and compatibility
2304 with surrounding software:
2305 <ul>
2306 <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
2307 more costly to import and export CPU wise) is also far more compact
2308 than UTF-16 (and UCS-4) for a majority of the documents I see it used
2309 for right now (RPM RDF catalogs, advogato data, various configuration
2310 file formats, etc.) and the key point for today's computer
2311 architecture is efficient uses of caches. If one nearly double the
2312 memory requirement to store the same amount of data, this will trash
2313 caches (main memory/external caches/internal caches) and my take is
2314 that this harms the system far more than the CPU requirements needed
2315 for the conversion to UTF-8</li>
2316 <li>Most of libxml version 1 users were using it with straight ASCII
2317 most of the time, doing the conversion with an internal encoding
2318 requiring all their code to be rewritten was a serious show-stopper
2319 for using UTF-16 or UCS-4.</li>
2320 <li>UTF-8 is being used as the de-facto internal encoding standard for
2321 related code like the <a href="http://www.pango.org/">pango</a>
2322 upcoming Gnome text widget, and a lot of Unix code (yep another place
2323 where Unix programmer base takes a different approach from Microsoft
2324 - they are using UTF-16)</li>
2325 </ul>
2326 </li>
2327</ul>
2328
2329<p>What does this mean in practice for the libxml user:</p>
2330<ul>
2331 <li>xmlChar, the libxml data type is a byte, those bytes must be assembled
2332 as UTF-8 valid strings. The proper way to terminate an xmlChar * string
2333 is simply to append 0 byte, as usual.</li>
2334 <li>One just need to make sure that when using chars outside the ASCII set,
2335 the values has been properly converted to UTF-8</li>
2336</ul>
2337
2338<h3><a name="implemente">How is it implemented ?</a></h3>
2339
2340<p>Let's describe how all this works within libxml, basically the I18N
2341(internationalization) support get triggered only during I/O operation, i.e.
2342when reading a document or saving one. Let's look first at the reading
2343sequence:</p>
2344<ol>
2345 <li>when a document is processed, we usually don't know the encoding, a
2346 simple heuristic allows to detect UTF-18 and UCS-4 from whose where the
2347 ASCII range (0-0x7F) maps with ASCII</li>
2348 <li>the xml declaration if available is parsed, including the encoding
2349 declaration. At that point, if the autodetected encoding is different
2350 from the one declared a call to xmlSwitchEncoding() is issued.</li>
2351 <li>If there is no encoding declaration, then the input has to be in either
2352 UTF-8 or UTF-16, if it is not then at some point when processing the
2353 input, the converter/checker of UTF-8 form will raise an encoding error.
2354 You may end-up with a garbled document, or no document at all ! Example:
2355 <pre>~/XML -&gt; ./xmllint err.xml
2356err.xml:1: error: Input is not proper UTF-8, indicate encoding !
2357&lt;très&gt;là&lt;/très&gt;
2358 ^
2359err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
2360&lt;très&gt;là&lt;/très&gt;
2361 ^</pre>
2362 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2363 <li>xmlSwitchEncoding() does an encoding name lookup, canonicalize it, and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2364 then search the default registered encoding converters for that encoding.
2365 If it's not within the default set and iconv() support has been compiled
2366 it, it will ask iconv for such an encoder. If this fails then the parser
2367 will report an error and stops processing:
2368 <pre>~/XML -&gt; ./xmllint err2.xml
2369err2.xml:1: error: Unsupported encoding UnsupportedEnc
2370&lt;?xml version="1.0" encoding="UnsupportedEnc"?&gt;
2371 ^</pre>
2372 </li>
Daniel Veillard46c5c1d2002-05-20 07:15:54 +0000[diff] [blame]2373 <li>From that point the encoder processes progressively the input (it is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2374 plugged as a front-end to the I/O module) for that entity. It captures
2375 and convert on-the-fly the document to be parsed to UTF-8. The parser
2376 itself just does UTF-8 checking of this input and process it
2377 transparently. The only difference is that the encoding information has
2378 been added to the parsing context (more precisely to the input
2379 corresponding to this entity).</li>
2380 <li>The result (when using DOM) is an internal form completely in UTF-8
2381 with just an encoding information on the document node.</li>
2382</ol>
2383
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2384<p>Ok then what happens when saving the document (assuming you
2385collected/built an xmlDoc DOM like structure) ? It depends on the function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2386called, xmlSaveFile() will just try to save in the original encoding, while
2387xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
2388encoding:</p>
2389<ol>
2390 <li>if no encoding is given, libxml will look for an encoding value
2391 associated to the document and if it exists will try to save to that
2392 encoding,
2393 <p>otherwise everything is written in the internal form, i.e. UTF-8</p>
2394 </li>
2395 <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]2396 document, libxml will again canonicalize the encoding name, lookup for a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2397 converter in the registered set or through iconv. If not found the
2398 function will return an error code</li>
2399 <li>the converter is placed before the I/O buffer layer, as another kind of
2400 buffer, then libxml will simply push the UTF-8 serialization to through
2401 that buffer, which will then progressively be converted and pushed onto
2402 the I/O layer.</li>
2403 <li>It is possible that the converter code fails on some input, for example
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2404 trying to push an UTF-8 encoded Chinese character through the UTF-8 to
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2405 ISO-8859-1 converter won't work. Since the encoders are progressive they
2406 will just report the error and the number of bytes converted, at that
2407 point libxml will decode the offending character, remove it from the
2408 buffer and replace it with the associated charRef encoding &amp;#123; and
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2409 resume the conversion. This guarantees that any document will be saved
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2410 without losses (except for markup names where this is not legal, this is
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2411 a problem in the current version, in practice avoid using non-ascii
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2412 characters for tags or attributes names @@). A special "ascii" encoding
2413 name is used to save documents to a pure ascii form can be used when
2414 portability is really crucial</li>
2415</ol>
2416
2417<p>Here is a few examples based on the same test document:</p>
2418<pre>~/XML -&gt; ./xmllint isolat1
2419&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2420&lt;très&gt;là&lt;/très&gt;
2421~/XML -&gt; ./xmllint --encode UTF-8 isolat1
2422&lt;?xml version="1.0" encoding="UTF-8"?&gt;
2423&lt;très&gt;là  &lt;/très&gt;
2424~/XML -&gt; </pre>
2425
2426<p>The same processing is applied (and reuse most of the code) for HTML I18N
2427processing. Looking up and modifying the content encoding is a bit more
2428difficult since it is located in a &lt;meta&gt; tag under the &lt;head&gt;,
2429so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
2430been provided. The parser also attempts to switch encoding on the fly when
2431detecting such a tag on input. Except for that the processing is the same
2432(and again reuses the same code).</p>
2433
2434<h3><a name="Default">Default supported encodings</a></h3>
2435
2436<p>libxml has a set of default converters for the following encodings
2437(located in encoding.c):</p>
2438<ol>
2439 <li>UTF-8 is supported by default (null handlers)</li>
2440 <li>UTF-16, both little and big endian</li>
2441 <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
2442 <li>ASCII, useful mostly for saving</li>
2443 <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
2444 predefined entities like &amp;copy; for the Copyright sign.</li>
2445</ol>
2446
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2447<p>More over when compiled on an Unix platform with iconv support the full
2448set of encodings supported by iconv can be instantly be used by libxml. On a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2449linux machine with glibc-2.1 the list of supported encodings and aliases fill
24503 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
2451various Japanese ones.</p>
2452
2453<h4>Encoding aliases</h4>
2454
2455<p>From 2.2.3, libxml has support to register encoding names aliases. The
2456goal is to be able to parse document whose encoding is supported but where
2457the name differs (for example from the default set of names accepted by
2458iconv). The following functions allow to register and handle new aliases for
2459existing encodings. Once registered libxml will automatically lookup the
2460aliases when handling a document:</p>
2461<ul>
2462 <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li>
2463 <li>int xmlDelEncodingAlias(const char *alias);</li>
2464 <li>const char * xmlGetEncodingAlias(const char *alias);</li>
2465 <li>void xmlCleanupEncodingAliases(void);</li>
2466</ul>
2467
2468<h3><a name="extend">How to extend the existing support</a></h3>
2469
2470<p>Well adding support for new encoding, or overriding one of the encoders
2471(assuming it is buggy) should not be hard, just write an input and output
2472conversion routines to/from UTF-8, and register them using
2473xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
2474called automatically if the parser(s) encounter such an encoding name
2475(register it uppercase, this will help). The description of the encoders,
2476their arguments and expected return values are described in the encoding.h
2477header.</p>
2478
2479<p>A quick note on the topic of subverting the parser to use a different
2480internal encoding than UTF-8, in some case people will absolutely want to
2481keep the internal encoding different, I think it's still possible (but the
2482encoding must be compliant with ASCII on the same subrange) though I didn't
2483tried it. The key is to override the default conversion routines (by
2484registering null encoders/decoders for your charsets), and bypass the UTF-8
2485checking of the parser by setting the parser context charset
2486(ctxt-&gt;charset) to something different than XML_CHAR_ENCODING_UTF8, but
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2487there is no guarantee that this will work. You may also have some troubles
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2488saving back.</p>
2489
2490<p>Basically proper I18N support is important, this requires at least
2491libxml-2.0.0, but a lot of features and corrections are really available only
2492starting 2.2.</p>
2493
2494<h2><a name="IO">I/O Interfaces</a></h2>
2495
2496<p>Table of Content:</p>
2497<ol>
2498 <li><a href="#General1">General overview</a></li>
2499 <li><a href="#basic">The basic buffer type</a></li>
2500 <li><a href="#Input">Input I/O handlers</a></li>
2501 <li><a href="#Output">Output I/O handlers</a></li>
2502 <li><a href="#entities">The entities loader</a></li>
2503 <li><a href="#Example2">Example of customized I/O</a></li>
2504</ol>
2505
2506<h3><a name="General1">General overview</a></h3>
2507
2508<p>The module <code><a
2509href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
2510the interfaces to the libxml I/O system. This consists of 4 main parts:</p>
2511<ul>
2512 <li>Entities loader, this is a routine which tries to fetch the entities
2513 (files) based on their PUBLIC and SYSTEM identifiers. The default loader
2514 don't look at the public identifier since libxml do not maintain a
2515 catalog. You can redefine you own entity loader by using
2516 <code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2517 <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
2518 example</a>.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2519 <li>Input I/O buffers which are a commodity structure used by the parser(s)
2520 input layer to handle fetching the informations to feed the parser. This
2521 provides buffering and is also a placeholder where the encoding
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2522 converters to UTF8 are piggy-backed.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2523 <li>Output I/O buffers are similar to the Input ones and fulfill similar
2524 task but when generating a serialization from a tree.</li>
2525 <li>A mechanism to register sets of I/O callbacks and associate them with
2526 specific naming schemes like the protocol part of the URIs.
2527 <p>This affect the default I/O operations and allows to use specific I/O
2528 handlers for certain names.</p>
2529 </li>
2530</ul>
2531
2532<p>The general mechanism used when loading http://rpmfind.net/xml.html for
2533example in the HTML parser is the following:</p>
2534<ol>
2535 <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
2536 the parsing context and the URI string.</li>
2537 <li>the URI string is checked against the existing registered handlers
2538 using their match() callback function, if the HTTP module was compiled
2539 in, it is registered and its match() function will succeeds</li>
2540 <li>the open() function of the handler is called and if successful will
2541 return an I/O Input buffer</li>
2542 <li>the parser will the start reading from this buffer and progressively
2543 fetch information from the resource, calling the read() function of the
2544 handler until the resource is exhausted</li>
2545 <li>if an encoding change is detected it will be installed on the input
2546 buffer, providing buffering and efficient use of the conversion
2547 routines</li>
2548 <li>once the parser has finished, the close() function of the handler is
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2549 called once and the Input buffer and associated resources are
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2550 deallocated.</li>
2551</ol>
2552
2553<p>The user defined callbacks are checked first to allow overriding of the
2554default libxml I/O routines.</p>
2555
2556<h3><a name="basic">The basic buffer type</a></h3>
2557
2558<p>All the buffer manipulation handling is done using the
2559<code>xmlBuffer</code> type define in <code><a
2560href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
2561resizable memory buffer. The buffer allocation strategy can be selected to be
2562either best-fit or use an exponential doubling one (CPU vs. memory use
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2563trade-off). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2564<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
2565system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
2566of functions allows to manipulate buffers with names starting with the
2567<code>xmlBuffer...</code> prefix.</p>
2568
2569<h3><a name="Input">Input I/O handlers</a></h3>
2570
2571<p>An Input I/O handler is a simple structure
2572<code>xmlParserInputBuffer</code> containing a context associated to the
2573resource (file descriptor, or pointer to a protocol handler), the read() and
2574close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
2575encoding handler are also present to support charset conversion when
2576needed.</p>
2577
2578<h3><a name="Output">Output I/O handlers</a></h3>
2579
2580<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
2581Input one except the callbacks are write() and close().</p>
2582
2583<h3><a name="entities">The entities loader</a></h3>
2584
2585<p>The entity loader resolves requests for new entities and create inputs for
2586the parser. Creating an input from a filename or an URI string is done
2587through the xmlNewInputFromFile() routine. The default entity loader do not
2588handle the PUBLIC identifier associated with an entity (if any). So it just
2589calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
2590XML).</p>
2591
2592<p>If you want to hook up a catalog mechanism then you simply need to
2593override the default entity loader, here is an example:</p>
2594<pre>#include &lt;libxml/xmlIO.h&gt;
2595
2596xmlExternalEntityLoader defaultLoader = NULL;
2597
2598xmlParserInputPtr
2599xmlMyExternalEntityLoader(const char *URL, const char *ID,
2600 xmlParserCtxtPtr ctxt) {
2601 xmlParserInputPtr ret;
2602 const char *fileID = NULL;
2603 /* lookup for the fileID depending on ID */
2604
2605 ret = xmlNewInputFromFile(ctxt, fileID);
2606 if (ret != NULL)
2607 return(ret);
2608 if (defaultLoader != NULL)
2609 ret = defaultLoader(URL, ID, ctxt);
2610 return(ret);
2611}
2612
2613int main(..) {
2614 ...
2615
2616 /*
2617 * Install our own entity loader
2618 */
2619 defaultLoader = xmlGetExternalEntityLoader();
2620 xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
2621
2622 ...
2623}</pre>
2624
2625<h3><a name="Example2">Example of customized I/O</a></h3>
2626
2627<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
2628real use case</a>, xmlDocDump() closes the FILE * passed by the application
2629and this was a problem. The <a
2630href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
2631new output handler with the closing call deactivated:</p>
2632<ol>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2633 <li>First define a new I/O output allocator where the output don't close
2634 the file:
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2635 <pre>xmlOutputBufferPtr
2636xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
2637    xmlOutputBufferPtr ret;
2638    
2639    if (xmlOutputCallbackInitialized == 0)
2640        xmlRegisterDefaultOutputCallbacks();
2641
2642    if (file == NULL) return(NULL);
2643    ret = xmlAllocOutputBuffer(encoder);
2644    if (ret != NULL) {
2645        ret-&gt;context = file;
2646        ret-&gt;writecallback = xmlFileWrite;
2647        ret-&gt;closecallback = NULL; /* No close callback */
2648    }
2649    return(ret); <br>
Daniel Veillard1eb24242002-03-18 11:33:03 +0000[diff] [blame]2650
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]2651
2652
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]2653
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]2654
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2655
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]2656
Daniel Veillard0bfbb422002-04-26 09:21:45 +0000[diff] [blame]2657
Daniel Veillard93d3a472002-04-26 14:04:55 +0000[diff] [blame]2658
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]2659
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]2660
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]2661
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2662
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]2663
Daniel Veillard782afda2002-07-08 15:12:49 +0000[diff] [blame]2664
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame^]2665
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2666} </pre>
2667 </li>
2668 <li>And then use it to save the document:
2669 <pre>FILE *f;
2670xmlOutputBufferPtr output;
2671xmlDocPtr doc;
2672int res;
2673
2674f = ...
2675doc = ....
2676
2677output = xmlOutputBufferCreateOwn(f, NULL);
2678res = xmlSaveFileTo(output, doc, NULL);
2679 </pre>
2680 </li>
2681</ol>
2682
2683<h2><a name="Catalog">Catalog support</a></h2>
2684
2685<p>Table of Content:</p>
2686<ol>
2687 <li><a href="General2">General overview</a></li>
2688 <li><a href="#definition">The definition</a></li>
2689 <li><a href="#Simple">Using catalogs</a></li>
2690 <li><a href="#Some">Some examples</a></li>
2691 <li><a href="#reference">How to tune catalog usage</a></li>
2692 <li><a href="#validate">How to debug catalog processing</a></li>
2693 <li><a href="#Declaring">How to create and maintain catalogs</a></li>
2694 <li><a href="#implemento">The implementor corner quick review of the
2695 API</a></li>
2696 <li><a href="#Other">Other resources</a></li>
2697</ol>
2698
2699<h3><a name="General2">General overview</a></h3>
2700
2701<p>What is a catalog? Basically it's a lookup mechanism used when an entity
2702(a file or a remote resource) references another entity. The catalog lookup
2703is inserted between the moment the reference is recognized by the software
2704(XML parser, stylesheet processing, or even images referenced for inclusion
2705in a rendering) and the time where loading that resource is actually
2706started.</p>
2707
2708<p>It is basically used for 3 things:</p>
2709<ul>
2710 <li>mapping from "logical" names, the public identifiers and a more
2711 concrete name usable for download (and URI). For example it can associate
2712 the logical name
2713 <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
2714 <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
2715 downloaded</p>
2716 <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
2717 </li>
2718 <li>remapping from a given URL to another one, like an HTTP indirection
2719 saying that
2720 <p>"http://www.oasis-open.org/committes/tr.xsl"</p>
2721 <p>should really be looked at</p>
2722 <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
2723 </li>
2724 <li>providing a local cache mechanism allowing to load the entities
2725 associated to public identifiers or remote resources, this is a really
2726 important feature for any significant deployment of XML or SGML since it
2727 allows to avoid the aleas and delays associated to fetching remote
2728 resources.</li>
2729</ul>
2730
2731<h3><a name="definition">The definitions</a></h3>
2732
2733<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
2734<ul>
2735 <li>the older SGML catalogs, the official spec is SGML Open Technical
2736 Resolution TR9401:1997, but is better understood by reading <a
2737 href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
2738 James Clark. This is relatively old and not the preferred mode of
2739 operation of libxml.</li>
2740 <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2741 Catalogs</a> is far more flexible, more recent, uses an XML syntax and
2742 should scale quite better. This is the default option of libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2743</ul>
2744
2745<p></p>
2746
2747<h3><a name="Simple">Using catalog</a></h3>
2748
2749<p>In a normal environment libxml will by default check the presence of a
2750catalog in /etc/xml/catalog, and assuming it has been correctly populated,
2751the processing is completely transparent to the document user. To take a
2752concrete example, suppose you are authoring a DocBook document, this one
2753starts with the following DOCTYPE definition:</p>
2754<pre>&lt;?xml version='1.0'?&gt;
2755&lt;!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
2756 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"&gt;</pre>
2757
2758<p>When validating the document with libxml, the catalog will be
2759automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
2760DocBk XML V3.1.4//EN" and the system identifier
2761"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
2762been installed on your system and the catalogs actually point to them, libxml
2763will fetch them from the local disk.</p>
2764
2765<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
2766DOCTYPE example it's a really old version, but is fine as an example.</p>
2767
2768<p>Libxml will check the catalog each time that it is requested to load an
2769entity, this includes DTD, external parsed entities, stylesheets, etc ... If
2770your system is correctly configured all the authoring phase and processing
2771should use only local files, even if your document stays portable because it
2772uses the canonical public and system ID, referencing the remote document.</p>
2773
2774<h3><a name="Some">Some examples:</a></h3>
2775
2776<p>Here is a couple of fragments from XML Catalogs used in libxml early
2777regression tests in <code>test/catalogs</code> :</p>
2778<pre>&lt;?xml version="1.0"?&gt;
2779&lt;!DOCTYPE catalog PUBLIC
2780 "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2781 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2782&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2783 &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2784 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2785...</pre>
2786
2787<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
2788written in XML, there is a specific namespace for catalog elements
2789"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
2790catalog is a <code>public</code> mapping it allows to associate a Public
2791Identifier with an URI.</p>
2792<pre>...
2793 &lt;rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2794 rewritePrefix="file:///usr/share/xml/docbook/"/&gt;
2795...</pre>
2796
2797<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
2798any URI starting with a given prefix should be looked at another URI
2799constructed by replacing the prefix with an new one. In effect this acts like
2800a cache system for a full area of the Web. In practice it is extremely useful
2801with a file prefix if you have installed a copy of those resources on your
2802local system.</p>
2803<pre>...
2804&lt;delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
2805 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2806&lt;delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
2807 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2808&lt;delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
2809 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2810&lt;delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2811 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2812&lt;delegateURI uriStartString="http://www.oasis-open.org/docbook/"
2813 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2814...</pre>
2815
2816<p>Delegation is the core features which allows to build a tree of catalogs,
2817easier to maintain than a single catalog, based on Public Identifier, System
2818Identifier or URI prefixes it instructs the catalog software to look up
2819entries in another resource. This feature allow to build hierarchies of
2820catalogs, the set of entries presented should be sufficient to redirect the
2821resolution of all DocBook references to the specific catalog in
2822<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
2823references for DocBook 4.2.1 to a specific catalog installed at the same time
2824as the DocBook resources on the local machine.</p>
2825
2826<h3><a name="reference">How to tune catalog usage:</a></h3>
2827
2828<p>The user can change the default catalog behaviour by redirecting queries
2829to its own set of catalogs, this can be done by setting the
2830<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
2831empty one should deactivate loading the default <code>/etc/xml/catalog</code>
2832default catalog</p>
2833
2834<h3><a name="validate">How to debug catalog processing:</a></h3>
2835
2836<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
2837make libxml output debugging informations for each catalog operations, for
2838example:</p>
2839<pre>orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2840warning: failed to load external entity "title.xml"
2841orchis:~/XML -&gt; export XML_DEBUG_CATALOG=
2842orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2843Failed to parse catalog /etc/xml/catalog
2844Failed to parse catalog /etc/xml/catalog
2845warning: failed to load external entity "title.xml"
2846Catalogs cleanup
2847orchis:~/XML -&gt; </pre>
2848
2849<p>The test/ent2 references an entity, running the parser from memory makes
2850the base URI unavailable and the the "title.xml" entity cannot be loaded.
2851Setting up the debug environment variable allows to detect that an attempt is
2852made to load the <code>/etc/xml/catalog</code> but since it's not present the
2853resolution fails.</p>
2854
2855<p>But the most advanced way to debug XML catalog processing is to use the
2856<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
2857catalogs and make resolution queries to see what is going on. This is also
2858used for the regression tests:</p>
2859<pre>orchis:~/XML -&gt; ./xmlcatalog test/catalogs/docbook.xml \
2860 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2861http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2862orchis:~/XML -&gt; </pre>
2863
2864<p>For debugging what is going on, adding one -v flags increase the verbosity
2865level to indicate the processing done (adding a second flag also indicate
2866what elements are recognized at parsing):</p>
2867<pre>orchis:~/XML -&gt; ./xmlcatalog -v test/catalogs/docbook.xml \
2868 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2869Parsing catalog test/catalogs/docbook.xml's content
2870Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
2871http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2872Catalogs cleanup
2873orchis:~/XML -&gt; </pre>
2874
2875<p>A shell interface is also available to debug and process multiple queries
2876(and for regression tests):</p>
2877<pre>orchis:~/XML -&gt; ./xmlcatalog -shell test/catalogs/docbook.xml \
2878 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2879&gt; help
2880Commands available:
2881public PublicID: make a PUBLIC identifier lookup
2882system SystemID: make a SYSTEM identifier lookup
2883resolve PublicID SystemID: do a full resolver lookup
2884add 'type' 'orig' 'replace' : add an entry
2885del 'values' : remove values
2886dump: print the current catalog state
2887debug: increase the verbosity level
2888quiet: decrease the verbosity level
2889exit: quit the shell
2890&gt; public "-//OASIS//DTD DocBook XML V4.1.2//EN"
2891http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2892&gt; quit
2893orchis:~/XML -&gt; </pre>
2894
2895<p>This should be sufficient for most debugging purpose, this was actually
2896used heavily to debug the XML Catalog implementation itself.</p>
2897
2898<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
2899
2900<p>Basically XML Catalogs are XML files, you can either use XML tools to
2901manage them or use <strong>xmlcatalog</strong> for this. The basic step is
2902to create a catalog the -create option provide this facility:</p>
2903<pre>orchis:~/XML -&gt; ./xmlcatalog --create tst.xml
2904&lt;?xml version="1.0"?&gt;
2905&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2906 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2907&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2908orchis:~/XML -&gt; </pre>
2909
2910<p>By default xmlcatalog does not overwrite the original catalog and save the
2911result on the standard output, this can be overridden using the -noout
2912option. The <code>-add</code> command allows to add entries in the
2913catalog:</p>
2914<pre>orchis:~/XML -&gt; ./xmlcatalog --noout --create --add "public" \
2915 "-//OASIS//DTD DocBook XML V4.1.2//EN" \
2916 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
2917orchis:~/XML -&gt; cat tst.xml
2918&lt;?xml version="1.0"?&gt;
2919&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
2920 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2921&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2922&lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2923 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2924&lt;/catalog&gt;
2925orchis:~/XML -&gt; </pre>
2926
2927<p>The <code>-add</code> option will always take 3 parameters even if some of
2928the XML Catalog constructs (like nextCatalog) will have only a single
2929argument, just pass a third empty string, it will be ignored.</p>
2930
2931<p>Similarly the <code>-del</code> option remove matching entries from the
2932catalog:</p>
2933<pre>orchis:~/XML -&gt; ./xmlcatalog --del \
2934 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
2935&lt;?xml version="1.0"?&gt;
2936&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2937 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2938&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2939orchis:~/XML -&gt; </pre>
2940
2941<p>The catalog is now empty. Note that the matching of <code>-del</code> is
2942exact and would have worked in a similar fashion with the Public ID
2943string.</p>
2944
2945<p>This is rudimentary but should be sufficient to manage a not too complex
2946catalog tree of resources.</p>
2947
2948<h3><a name="implemento">The implementor corner quick review of the
2949API:</a></h3>
2950
2951<p>First, and like for every other module of libxml, there is an
2952automatically generated <a href="html/libxml-catalog.html">API page for
2953catalog support</a>.</p>
2954
2955<p>The header for the catalog interfaces should be included as:</p>
2956<pre>#include &lt;libxml/catalog.h&gt;</pre>
2957
2958<p>The API is voluntarily kept very simple. First it is not obvious that
2959applications really need access to it since it is the default behaviour of
2960libxml (Note: it is possible to completely override libxml default catalog by
2961using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
2962plug an application specific resolver).</p>
2963
2964<p>Basically libxml support 2 catalog lists:</p>
2965<ul>
2966 <li>the default one, global shared by all the application</li>
2967 <li>a per-document catalog, this one is built if the document uses the
2968 <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
2969 associated to the parser context and destroyed when the parsing context
2970 is destroyed.</li>
2971</ul>
2972
2973<p>the document one will be used first if it exists.</p>
2974
2975<h4>Initialization routines:</h4>
2976
2977<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
2978used at startup to initialize the catalog, if the catalog should be
2979initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
2980should be called before xmlInitializeCatalog() which would otherwise do a
2981default initialization first.</p>
2982
2983<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
2984own catalog list if needed.</p>
2985
2986<h4>Preferences setup:</h4>
2987
2988<p>The XML Catalog spec requires the possibility to select default
2989preferences between public and system delegation,
2990xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
2991xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
2992be forbidden, allowed for global catalog, for document catalog or both, the
2993default is to allow both.</p>
2994
2995<p>And of course xmlCatalogSetDebug() allows to generate debug messages
2996(through the xmlGenericError() mechanism).</p>
2997
2998<h4>Querying routines:</h4>
2999
3000<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
3001and xmlCatalogResolveURI() are relatively explicit if you read the XML
3002Catalog specification they correspond to section 7 algorithms, they should
3003also work if you have loaded an SGML catalog with a simplified semantic.</p>
3004
3005<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
3006operate on the document catalog list</p>
3007
3008<h4>Cleanup and Miscellaneous:</h4>
3009
3010<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
3011the per-document equivalent.</p>
3012
3013<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
3014first catalog in the global list, and xmlCatalogDump() allows to dump a
3015catalog state, those routines are primarily designed for xmlcatalog, I'm not
3016sure that exposing more complex interfaces (like navigation ones) would be
3017really useful.</p>
3018
3019<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
3020it's similar as xmlParseFile() except it bypass all catalog lookups, it's
3021provided because this functionality may be useful for client tools.</p>
3022
3023<h4>threaded environments:</h4>
3024
3025<p>Since the catalog tree is built progressively, some care has been taken to
3026try to avoid troubles in multithreaded environments. The code is now thread
3027safe assuming that the libxml library has been compiled with threads
3028support.</p>
3029
3030<p></p>
3031
3032<h3><a name="Other">Other resources</a></h3>
3033
3034<p>The XML Catalog specification is relatively recent so there isn't much
3035literature to point at:</p>
3036<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3037 <li>You can find a good rant from Norm Walsh about <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3038 href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
3039 need for catalogs</a>, it provides a lot of context informations even if
Daniel Veillard93d3a472002-04-26 14:04:55 +0000[diff] [blame]3040 I don't agree with everything presented. Norm also wrote a more recent
3041 article <a
3042 href="http://wwws.sun.com/software/xml/developers/resolver/article/">XML
3043 entities and URI resolvers</a> describing them.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3044 <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
3045 catalog proposal</a> from John Cowan</li>
3046 <li>The <a href="http://www.rddl.org/">Resource Directory Description
3047 Language</a> (RDDL) another catalog system but more oriented toward
3048 providing metadata for XML namespaces.</li>
3049 <li>the page from the OASIS Technical <a
3050 href="http://www.oasis-open.org/committees/entity/">Committee on Entity
3051 Resolution</a> who maintains XML Catalog, you will find pointers to the
3052 specification update, some background and pointers to others tools
3053 providing XML Catalog support</li>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3054 <li>Here is a <a href="buildDocBookCatalog">shell script</a> to generate
3055 XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
3056 directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
3057 the resources found on the system. Otherwise it will just create
3058 ~/xmlcatalog and ~/dbkxmlcatalog and doing:
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]3059 <p><code>export XMLCATALOG=$HOME/xmlcatalog</code></p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3060 <p>should allow to process DocBook documentations without requiring
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3061 network accesses for the DTD or stylesheets</p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3062 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3063 <li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3064 small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
3065 to work fine for me too</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3066 <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
3067 manual page</a></li>
3068</ul>
3069
3070<p>If you have suggestions for corrections or additions, simply contact
3071me:</p>
3072
3073<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3074
3075<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3076using the XML library from the C language. It is not intended to be
3077extensive. I hope the automatically generated documents will provide the
3078completeness required, but as a separate set of documents. The interfaces of
3079the XML library are by principle low level, there is nearly zero abstraction.
3080Those interested in a higher level API should <a href="#DOM">look at
3081DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3082
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3083<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
3084separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3085interfaces</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]3086
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3087<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3088
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3089<p>Usually, the first thing to do is to read an XML input. The parser accepts
3090documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3091defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3092<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3093 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3094 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3095 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3096</dl>
3097<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3098 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3099 <dd><p>Parse an XML document contained in a (possibly compressed)
3100 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3101 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3102</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3103
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3104<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]3105failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3106
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3107<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3108
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3109<p>In order for the application to keep the control when the document is
3110being fetched (which is common for GUI based programs) libxml provides a push
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3111interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3112<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
3113 void *user_data,
3114 const char *chunk,
3115 int size,
3116 const char *filename);
3117int xmlParseChunk (xmlParserCtxtPtr ctxt,
3118 const char *chunk,
3119 int size,
3120 int terminate);</pre>
3121
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3122<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3123<pre> FILE *f;
3124
3125 f = fopen(filename, "r");
3126 if (f != NULL) {
3127 int res, size = 1024;
3128 char chars[1024];
3129 xmlParserCtxtPtr ctxt;
3130
3131 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3132 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3133 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
3134 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3135 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3136 xmlParseChunk(ctxt, chars, res, 0);
3137 }
3138 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3139 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3140 xmlFreeParserCtxt(ctxt);
3141 }
3142 }</pre>
3143
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3144<p>The HTML parser embedded into libxml also has a push interface; the
3145functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3146
3147<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
3148
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3149<p>The tree-building interface makes the parser memory-hungry, first loading
3150the document in memory and then building the tree itself. Reading a document
3151without building the tree is possible using the SAX interfaces (see SAX.h and
3152<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]3153Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3154limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3155<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3156
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3157<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3158
3159<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]3160there is a set of functions dedicated to building new elements. (These are
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3161also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of
3162code that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3163<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3164 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3165 xmlNodePtr tree, subtree;
3166
3167 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3168 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
3169 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
3170 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
3171 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3172 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3173 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3174 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
3175 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
3176 subtree = xmlNewChild(tree, NULL, "image", NULL);
3177 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3178
3179<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3180
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3181<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3182
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3183<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3184code has access to the internal structure of all the elements of the tree.
3185The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]3186<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3187<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3188example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3189<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3190
3191<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3192<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3193
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3194<p>points to the text node containing the chapter title "The Linux
3195adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3196
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3197<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]3198present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3199to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]3200<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3201
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3202<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3203
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3204<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3205is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3206<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3207 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
3208 xmlChar *value);</code></dt>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3209 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
3210 The value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3211 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3212</dl>
3213<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3214 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3215 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]3216 <dd><p>This function returns a pointer to new copy of the property
3217 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3218 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3219</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3220
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3221<p>Two functions are provided for reading and writing the text associated
3222with elements:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3223<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3224 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3225 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3226 <dd><p>This function takes an "external" string and converts it to one
3227 text node or possibly to a list of entity and text nodes. All
3228 non-predefined entity references like &amp;Gnome; will be stored
3229 internally as entity nodes, hence the result of the function may not be
3230 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3231 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3232</dl>
3233<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3234 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3235 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3236 <dd><p>This function is the inverse of
3237 <code>xmlStringGetNodeList()</code>. It generates a new string
3238 containing the content of the text and entity nodes. Note the extra
3239 argument inLine. If this argument is set to 1, the function will expand
3240 entity references. For example, instead of returning the &amp;Gnome;
3241 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3242 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3243 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3244</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3245
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3246<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3247
3248<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3249<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3250 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3251 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3252 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3253 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3254</dl>
3255<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3256 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3257 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3258 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3259</dl>
3260<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3261 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3262 <dd><p>Saves the document to a file. In this case, the compression
3263 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3264 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3265</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3266
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3267<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3268
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3269<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3270accesses. The level of compression on saves can be turned on either globally
3271or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3272<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3273 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3274 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3275 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3276</dl>
3277<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3278 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3279 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3280 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3281</dl>
3282<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3283 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3284 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3285 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3286</dl>
3287<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3288 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3289 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3290 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3291</dl>
3292
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3293<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3294
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3295<p>Entities in principle are similar to simple C macros. An entity defines an
3296abbreviation for a given string that you can reuse many times throughout the
3297content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3298may occur frequently within a document, or to confine the change needed to a
3299document to a restricted area in the internal subset of the document (at the
3300beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3301<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]33022 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]33033 &lt;!ENTITY xml "Extensible Markup Language"&gt;
33044 ]&gt;
33055 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]33066 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]33077 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3308
3309<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]3310its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3311are 5 predefined entities in libxml allowing you to escape characters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3312predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3313<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3314for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3315<strong>&amp;quot;</strong> for the character '"', and
3316<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3317
3318<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]3319substitute an entity's content so that you can see the replacement text in
3320your application. Or you may prefer to keep entity references as such in the
3321content to be able to save the document back without losing this usually
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3322precious information (if the user went through the pain of explicitly
3323defining entities, he may have a a rather negative attitude if you blindly
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3324substitute them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3325href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3326function allows you to check and change the behaviour, which is to not
3327substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3328
3329<p>Here is the DOM tree built by libxml for the previous document in the
3330default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3331<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3332DOCUMENT
3333version=1.0
3334 ELEMENT EXAMPLE
3335 TEXT
3336 content=
3337 ENTITY_REF
3338 INTERNAL_GENERAL_ENTITY xml
3339 content=Extensible Markup Language
3340 TEXT
3341 content=</pre>
3342
3343<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3344<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3345DOCUMENT
3346version=1.0
3347 ELEMENT EXAMPLE
3348 TEXT
3349 content= Extensible Markup Language</pre>
3350
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3351<p>So, entities or no entities? Basically, it depends on your use case. I
3352suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3353entities in your XML document or data if you are not willing to handle the
3354entity references elements in the DOM tree.</p>
3355
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3356<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3357entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3358transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3359reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3360finding them in the input).</p>
3361
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3362<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3363on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3364non-predefined entities in your documents, then the learning curve to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3365then 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]3366strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]3367deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3368
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3369<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3370
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3371<p>The libxml library implements <a
3372href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3373recognizing namespace constructs in the input, and does namespace lookup
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3374automatically when building the DOM tree. A namespace declaration is
3375associated with an in-memory structure and all elements or attributes within
3376that namespace point to it. Hence testing the namespace is a simple and fast
3377equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3378
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3379<p>I suggest that people using libxml use a namespace, and declare it in the
3380root element of their document as the default namespace. Then they don't need
3381to 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]3382refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3383the size of the XML output significantly, but significantly increases its
3384value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3385<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
3386 &lt;elem1&gt;...&lt;/elem1&gt;
3387 &lt;elem2&gt;...&lt;/elem2&gt;
3388&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3389
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3390<p>The namespace value has to be an absolute URL, but the URL doesn't have to
3391point to any existing resource on the Web. It will bind all the element and
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3392attributes with that URL. I suggest to use an URL within a domain you
3393control, and that the URL should contain some kind of version information if
3394possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a
3395good namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3396
3397<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3398version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3399and if the version information don't match something you know, warn the user
3400and 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]3401namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3402same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3403associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3404just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3405<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3406prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3407
3408<p>@@Interfaces@@</p>
3409
3410<p>@@Examples@@</p>
3411
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3412<p>Usually people object to using namespaces together with validity checking.
3413I will try to make sure that using namespaces won't break validity checking,
3414so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3415suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3416<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3417flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3418from multiple DTDs will certainly break current validation schemes. I will
3419try to provide ways to do this, but this may not be portable or
3420standardized.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3421
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3422<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3423
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3424<p>Incompatible changes:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3425
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3426<p>Version 2 of libxml is the first version introducing serious backward
3427incompatible changes. The main goals were:</p>
3428<ul>
3429 <li>a general cleanup. A number of mistakes inherited from the very early
3430 versions couldn't be changed due to compatibility constraints. Example
3431 the "childs" element in the nodes.</li>
3432 <li>Uniformization of the various nodes, at least for their header and link
3433 parts (doc, parent, children, prev, next), the goal is a simpler
3434 programming model and simplifying the task of the DOM implementors.</li>
3435 <li>better conformances to the XML specification, for example version 1.x
3436 had an heuristic to try to detect ignorable white spaces. As a result the
3437 SAX event generated were ignorableWhitespace() while the spec requires
3438 character() in that case. This also mean that a number of DOM node
3439 containing blank text may populate the DOM tree which were not present
3440 before.</li>
3441</ul>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3442
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3443<h3>How to fix libxml-1.x code:</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3444
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3445<p>So client code of libxml designed to run with version 1.x may have to be
3446changed to compile against version 2.x of libxml. Here is a list of changes
3447that I have collected, they may not be sufficient, so in case you find other
3448change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
3449mail</a>:</p>
3450<ol>
3451 <li>The package name have changed from libxml to libxml2, the library name
3452 is now -lxml2 . There is a new xml2-config script which should be used to
3453 select the right parameters libxml2</li>
3454 <li>Node <strong>childs</strong> field has been renamed
3455 <strong>children</strong> so s/childs/children/g should be applied
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3456 (probability of having "childs" anywhere else is close to 0+</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3457 <li>The document don't have anymore a <strong>root</strong> element it has
3458 been replaced by <strong>children</strong> and usually you will get a
3459 list of element here. For example a Dtd element for the internal subset
3460 and it's declaration may be found in that list, as well as processing
3461 instructions or comments found before or after the document root element.
3462 Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3463 a document. Alternatively if you are sure to not reference DTDs nor have
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3464 PIs or comments before or after the root element
3465 s/-&gt;root/-&gt;children/g will probably do it.</li>
3466 <li>The white space issue, this one is more complex, unless special case of
3467 validating parsing, the line breaks and spaces usually used for indenting
3468 and formatting the document content becomes significant. So they are
3469 reported by SAX and if your using the DOM tree, corresponding nodes are
3470 generated. Too approach can be taken:
3471 <ol>
3472 <li>lazy one, use the compatibility call
3473 <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
3474 relying on a special (and possibly broken) set of heuristics of
3475 libxml to detect ignorable blanks. Don't complain if it breaks or
3476 make your application not 100% clean w.r.t. to it's input.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3477 <li>the Right Way: change you code to accept possibly insignificant
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3478 blanks characters, or have your tree populated with weird blank text
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3479 nodes. You can spot them using the commodity function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3480 <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
3481 nodes.</li>
3482 </ol>
3483 <p>Note also that with the new default the output functions don't add any
3484 extra indentation when saving a tree in order to be able to round trip
3485 (read and save) without inflating the document with extra formatting
3486 chars.</p>
3487 </li>
3488 <li>The include path has changed to $prefix/libxml/ and the includes
3489 themselves uses this new prefix in includes instructions... If you are
3490 using (as expected) the
3491 <pre>xml2-config --cflags</pre>
3492 <p>output to generate you compile commands this will probably work out of
3493 the box</p>
3494 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3495 <li>xmlDetectCharEncoding takes an extra argument indicating the length in
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3496 byte of the head of the document available for character detection.</li>
3497</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3498
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3499<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3500
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3501<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]3502to allow smooth upgrade of existing libxml v1code while retaining
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3503compatibility. They offers the following:</p>
3504<ol>
3505 <li>similar include naming, one should use
3506 <strong>#include&lt;libxml/...&gt;</strong> in both cases.</li>
3507 <li>similar identifiers defined via macros for the child and root fields:
3508 respectively <strong>xmlChildrenNode</strong> and
3509 <strong>xmlRootNode</strong></li>
3510 <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
3511 inserted once in the client code</li>
3512</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3513
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3514<p>So the roadmap to upgrade your existing libxml applications is the
3515following:</p>
3516<ol>
3517 <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]3518 <li>find all occurrences where the xmlDoc <strong>root</strong> field is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3519 used and change it to <strong>xmlRootNode</strong></li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3520 <li>similarly find all occurrences where the xmlNode
3521 <strong>childs</strong> field is used and change it to
3522 <strong>xmlChildrenNode</strong></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3523 <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
3524 <strong>main()</strong> or in the library init entry point</li>
3525 <li>Recompile, check compatibility, it should still work</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3526 <li>Change your configure script to look first for xml2-config and fall
3527 back using xml-config . Use the --cflags and --libs output of the command
3528 as the Include and Linking parameters needed to use libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3529 <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
3530 libxml-devel-1.8.y can be kept simultaneously)</li>
3531 <li>remove your config.cache, relaunch your configuration mechanism, and
3532 recompile, if steps 2 and 3 were done right it should compile as-is</li>
3533 <li>Test that your application is still running correctly, if not this may
3534 be due to extra empty nodes due to formating spaces being kept in libxml2
3535 contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
3536 code before calling the parser (next to
3537 <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
3538</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3539
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3540<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]3541
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3542<p>Let me put some emphasis on the fact that there is far more changes from
3543libxml 1.x to 2.x than the ones you may have to patch for. The overall code
3544has been considerably cleaned up and the conformance to the XML specification
3545has been drastically improved too. Don't take those changes as an excuse to
3546not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3547
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3548<h2><a name="Thread">Thread safety</a></h2>
3549
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3550<p>Starting with 2.4.7, libxml makes provisions to ensure that concurrent
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3551threads can safely work in parallel parsing different documents. There is
3552however a couple of things to do to ensure it:</p>
3553<ul>
3554 <li>configure the library accordingly using the --with-threads options</li>
3555 <li>call xmlInitParser() in the "main" thread before using any of the
3556 libxml API (except possibly selecting a different memory allocator)</li>
3557</ul>
3558
3559<p>Note that the thread safety cannot be ensured for multiple threads sharing
3560the same document, the locking must be done at the application level, libxml
3561exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
3562The parts of the library checked for thread safety are:</p>
3563<ul>
3564 <li>concurrent loading</li>
3565 <li>file access resolution</li>
3566 <li>catalog access</li>
3567 <li>catalog building</li>
3568 <li>entities lookup/accesses</li>
3569 <li>validation</li>
3570 <li>global variables per-thread override</li>
3571 <li>memory handling</li>
3572</ul>
3573
3574<p>XPath is supposed to be thread safe now, but this wasn't tested
3575seriously.</p>
3576
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3577<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3578
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3579<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
3580Object Model</em>; this is an API for accessing XML or HTML structured
3581documents. Native support for DOM in Gnome is on the way (module gnome-dom),
3582and will be based on gnome-xml. This will be a far cleaner interface to
3583manipulate XML files within Gnome since it won't expose the internal
3584structure.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3585
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3586<p>The current DOM implementation on top of libxml is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame]3587href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
3588is a full DOM interface, thanks to Paolo Casarini, check the <a
3589href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
3590informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3591
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3592<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3593
3594<p>Here is a real size example, where the actual content of the application
3595data 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]3596a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3597storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
3598base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3599<pre>&lt;?xml version="1.0"?&gt;
3600&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
3601 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3602
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3603 &lt;gjob:Job&gt;
3604 &lt;gjob:Project ID="3"/&gt;
3605 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
3606 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3607
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3608 &lt;gjob:Update&gt;
3609 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
3610 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
3611 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
3612 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3613
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3614 &lt;gjob:Developers&gt;
3615 &lt;gjob:Developer&gt;
3616 &lt;/gjob:Developer&gt;
3617 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3618
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3619 &lt;gjob:Contact&gt;
3620 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
3621 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
3622 &lt;gjob:Company&gt;
3623 &lt;/gjob:Company&gt;
3624 &lt;gjob:Organisation&gt;
3625 &lt;/gjob:Organisation&gt;
3626 &lt;gjob:Webpage&gt;
3627 &lt;/gjob:Webpage&gt;
3628 &lt;gjob:Snailmail&gt;
3629 &lt;/gjob:Snailmail&gt;
3630 &lt;gjob:Phone&gt;
3631 &lt;/gjob:Phone&gt;
3632 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3633
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3634 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3635 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3636 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3637
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3638 &lt;gjob:Skills&gt;
3639 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3640
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3641 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3642 A GNOME based system that will allow a superuser to configure
3643 compressed and uncompressed files and/or file systems to be backed
3644 up with a supported media in the system. This should be able to
3645 perform via find commands generating a list of files that are passed
3646 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
3647 or via operations performed on the filesystem itself. Email
3648 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3649 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3650
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3651 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3652
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3653 &lt;/gjob:Jobs&gt;
3654&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3655
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3656<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]3657calling only a couple of functions, browsing the tree to gather the data and
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3658generate the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3659
3660<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3661structure. For example, the ordering of the attributes is not significant,
3662the 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]3663depend on the order of the children of a given node, unless it really makes
3664things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3665<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3666 * A person record
3667 */
3668typedef struct person {
3669 char *name;
3670 char *email;
3671 char *company;
3672 char *organisation;
3673 char *smail;
3674 char *webPage;
3675 char *phone;
3676} person, *personPtr;
3677
3678/*
3679 * And the code needed to parse it
3680 */
3681personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3682 personPtr ret = NULL;
3683
3684DEBUG("parsePerson\n");
3685 /*
3686 * allocate the struct
3687 */
3688 ret = (personPtr) malloc(sizeof(person));
3689 if (ret == NULL) {
3690 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3691 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3692 }
3693 memset(ret, 0, sizeof(person));
3694
3695 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3696 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3697 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3698 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
3699 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3700 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
3701 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3702 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3703 }
3704
3705 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3706}</pre>
3707
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3708<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3709<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3710 <li>Usually a recursive parsing style is the more convenient one: XML data
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3711 is by nature subject to repetitive constructs and usually exhibits highly
3712 structured patterns.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3713 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
3714 i.e. the pointer to the global XML document and the namespace reserved to
3715 the application. Document wide information are needed for example to
3716 decode entities and it's a good coding practice to define a namespace for
3717 your application set of data and test that the element and attributes
3718 you're analyzing actually pertains to your application space. This is
3719 done by a simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3720 <li>To retrieve text and attributes value, you can use the function
3721 <em>xmlNodeListGetString</em> to gather all the text and entity reference
3722 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3723</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3724
3725<p>Here is another piece of code used to parse another level of the
3726structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3727<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3728/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3729 * a Description for a Job
3730 */
3731typedef struct job {
3732 char *projectID;
3733 char *application;
3734 char *category;
3735 personPtr contact;
3736 int nbDevelopers;
3737 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
3738} job, *jobPtr;
3739
3740/*
3741 * And the code needed to parse it
3742 */
3743jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3744 jobPtr ret = NULL;
3745
3746DEBUG("parseJob\n");
3747 /*
3748 * allocate the struct
3749 */
3750 ret = (jobPtr) malloc(sizeof(job));
3751 if (ret == NULL) {
3752 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3753 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3754 }
3755 memset(ret, 0, sizeof(job));
3756
3757 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3758 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3759 while (cur != NULL) {
3760
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3761 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
3762 ret-&gt;projectID = xmlGetProp(cur, "ID");
3763 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3764 fprintf(stderr, "Project has no ID\n");
3765 }
3766 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3767 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
3768 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3769 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
3770 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3771 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
3772 ret-&gt;contact = parsePerson(doc, ns, cur);
3773 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3774 }
3775
3776 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3777}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3778
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3779<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]3780boring. Ultimately, it could be possible to write stubbers taking either C
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3781data structure definitions, a set of XML examples or an XML DTD and produce
3782the code needed to import and export the content between C data and XML
3783storage. This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3784
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]3785<p>Feel free to use <a href="example/gjobread.c">the code for the full C
3786parsing example</a> as a template, it is also available with Makefile in the
3787Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3788
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3789<h2><a name="Contributi">Contributions</a></h2>
3790<ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3791 <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
3792 patches, Gary Pennington worked on the validation API, threading support
3793 and Solaris port.</li>
3794 <li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]3795 <li><a href="mailto:igor@stud.fh-frankfurt.de">Igor Zlatkovic</a> is now
3796 the maintainer of the Windows port, <a
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]3797 href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
3798 provides binaries</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3799 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
3800 <a href="http://garypennington.net/libxml2/">Solaris binaries</a></li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]3801 <li><a
3802 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3803 Sergeant</a> developed <a
3804 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3805 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
3806 application server</a></li>
3807 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> and <a
3808 href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillardca989762001-06-23 17:39:29 +0000[diff] [blame]3809 href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]3810 documentation</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3811 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
3812 href="http://xmlsoft.org/messages/0488.html">man pages</a></li>
Daniel Veillard5168dbf2001-07-07 00:18:23 +0000[diff] [blame]3813 <li>there is a module for <a
3814 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
3815 in OpenNSD/AOLServer</a></li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]3816 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provided the
3817 first version of libxml/libxslt <a
3818 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li>
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]3819 <li>Petr Kozelka provides <a
3820 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
3821 libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]3822 <li><a href="mailto:aleksey@aleksey.com">Aleksey Sanin</a> implemented the
3823 <a href="http://www.w3.org/Signature/">XML Canonicalization and XML
3824 Digital Signature</a> <a
3825 href="http://www.aleksey.com/xmlsec/">implementations for libxml2</a></li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3826</ul>
3827
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3828<p></p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3829</body>
3830</html>