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Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
2 "http://www.w3.org/TR/html4/loose.dtd">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3<html>
4<head>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]5 <title>The XML C library for Gnome</title>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]6 <meta name="GENERATOR" content="amaya 5.1">
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]7 <meta http-equiv="Content-Type" content="text/html">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]8</head>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]9
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]10<body bgcolor="#ffffff">
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]11<h1 align="center">The XML C library for Gnome</h1>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]12
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]13<h1>Note: this is the flat content of the <a href="index.html">web
14site</a></h1>
15
Daniel Veillardc9484202001-10-24 12:35:52 +0000[diff] [blame]16<h1 style="text-align: center">libxml, a.k.a. gnome-xml</h1>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]17
18<p></p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]19
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]20<p>Libxml is the XML C library developed for the Gnome project. XML itself
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]21is a metalanguage to design markup languages, i.e. text language where
22semantic and structure are added to the content using extra "markup"
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]23information enclosed between angle brackets. HTML is the most well-known
Daniel Veillard1eb24242002-03-18 11:33:03 +0000[diff] [blame]24markup language. Though the library is written in C <a href="python.html">a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]25variety of language bindings</a> make it available in other environments.</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]26
27<p>Libxml2 implements a number of existing standards related to markup
28languages:</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]29<ul>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]30 <li>the XML standard: <a
31 href="http://www.w3.org/TR/REC-xml">http://www.w3.org/TR/REC-xml</a></li>
32 <li>Namespaces in XML: <a
33 href="http://www.w3.org/TR/REC-xml-names/">http://www.w3.org/TR/REC-xml-names/</a></li>
34 <li>XML Base: <a
35 href="http://www.w3.org/TR/xmlbase/">http://www.w3.org/TR/xmlbase/</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]36 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc2396.txt">RFC 2396</a> :
37 Uniform Resource Identifiers <a
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]38 href="http://www.ietf.org/rfc/rfc2396.txt">http://www.ietf.org/rfc/rfc2396.txt</a></li>
39 <li>XML Path Language (XPath) 1.0: <a
40 href="http://www.w3.org/TR/xpath">http://www.w3.org/TR/xpath</a></li>
41 <li>HTML4 parser: <a
42 href="http://www.w3.org/TR/html401/">http://www.w3.org/TR/html401/</a></li>
43 <li>most of XML Pointer Language (XPointer) Version 1.0: <a
44 href="http://www.w3.org/TR/xptr">http://www.w3.org/TR/xptr</a></li>
45 <li>XML Inclusions (XInclude) Version 1.0: <a
46 href="http://www.w3.org/TR/xinclude/">http://www.w3.org/TR/xinclude/</a></li>
47 <li>[ISO-8859-1], <a
48 href="http://www.cis.ohio-state.edu/rfc/rfc2044.txt">rfc2044</a> [UTF-8]
49 and <a href="http://www.cis.ohio-state.edu/rfc/rfc2781.txt">rfc2781</a>
50 [UTF-16] core encodings</li>
51 <li>part of SGML Open Technical Resolution TR9401:1997</li>
52 <li>XML Catalogs Working Draft 06 August 2001: <a
53 href="http://www.oasis-open.org/committees/entity/spec-2001-08-06.html">http://www.oasis-open.org/committees/entity/spec-2001-08-06.html</a></li>
Daniel Veillard5c396542002-03-15 07:57:50 +0000[diff] [blame]54 <li>Canonical XML Version 1.0: <a
55 href="http://www.w3.org/TR/xml-c14n">http://www.w3.org/TR/xml-c14n</a>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]56 and the Exclusive XML Canonicalization CR draft <a
57 href="http://www.w3.org/TR/xml-exc-c14n">http://www.w3.org/TR/xml-exc-c14n</a></li>
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]58</ul>
59
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]60<p>In most cases libxml tries to implement the specifications in a relatively
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]61strictly compliant way. As of release 2.4.16, libxml2 passes all 1800+ tests from the <a
Daniel Veillarda5393562002-02-20 11:40:49 +0000[diff] [blame]62href="http://www.oasis-open.org/committees/xml-conformance/">OASIS XML Tests
63Suite</a>.</p>
Daniel Veillard5b16f582002-02-20 11:38:46 +0000[diff] [blame]64
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]65<p>To some extent libxml2 provides support for the following additional
66specifications but doesn't claim to implement them completely:</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]67<ul>
68 <li>Document Object Model (DOM) <a
69 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^]70 it doesn't implement the API itself, gdome2 does this on top of
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]71 libxml2</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]72 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc959.txt">RFC 959</a> :
73 libxml implements a basic FTP client code</li>
74 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc1945.txt">RFC 1945</a> :
75 HTTP/1.0, again a basic HTTP client code</li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]76 <li>SAX: a minimal SAX implementation compatible with early expat
77 versions</li>
78 <li>DocBook SGML v4: libxml2 includes a hackish parser to transition to
79 XML</li>
80</ul>
81
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]82<p>XML Schemas is being worked on but it would be far too early to make any
83conformance statement about it at the moment.</p>
84
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]85<p>Libxml2 is known to be very portable, the library should build and work
86without serious troubles on a variety of systems (Linux, Unix, Windows,
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]87CygWin, MacOS, MacOS X, RISC Os, OS/2, VMS, QNX, MVS, ...)</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]88
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]89<p>Separate documents:</p>
90<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]91 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a> providing an
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]92 implementation of XSLT 1.0 and common extensions like EXSLT for
93 libxml2</li>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]94 <li><a href="http://www.cs.unibo.it/~casarini/gdome2/">the gdome2 page</a>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]95 : a standard DOM2 implementation for libxml2</li>
96 <li><a href="http://www.aleksey.com/xmlsec/">the XMLSec page</a>: an
97 implementation of <a href="http://www.w3.org/TR/xmldsig-core/">W3C XML
98 Digital Signature</a> for libxml2</li>
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]99 <li>also check the related links section below for more related and active
100 projects.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]101</ul>
102
103<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]104
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]105<p>This document describes libxml, the <a
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]106href="http://www.w3.org/XML/">XML</a> C library developed for the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]107href="http://www.gnome.org/">Gnome</a> project. <a
108href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
109structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]110
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]111<p>Here are some key points about libxml:</p>
112<ul>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]113 <li>Libxml exports Push (progressive) and Pull (blocking) type parser
114 interfaces for both XML and HTML.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]115 <li>Libxml can do DTD validation at parse time, using a parsed document
116 instance, or with an arbitrary DTD.</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]117 <li>Libxml includes complete <a
Daniel Veillard8c2ecaf2001-07-10 17:53:07 +0000[diff] [blame]118 href="http://www.w3.org/TR/xpath">XPath</a>, <a
119 href="http://www.w3.org/TR/xptr">XPointer</a> and <a
120 href="http://www.w3.org/TR/xinclude">XInclude</a> implementations.</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]121 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]122 sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]123 Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]124 <li>Basic support for HTTP and FTP client allowing applications to fetch
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]125 remote resources.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]126 <li>The design is modular, most of the extensions can be compiled out.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]127 <li>The internal document representation is as close as possible to the <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]128 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
129 <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]130 like interface</a>; the interface is designed to be compatible with <a
131 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]132 <li>This library is released under the <a
133 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]134 License</a>. See the Copyright file in the distribution for the precise
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]135 wording.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]136</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]137
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]138<p>Warning: unless you are forced to because your application links with a
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]139Gnome-1.X library requiring it, <strong><span
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]140style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
141libxml2</p>
142
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]143<h2><a name="FAQ">FAQ</a></h2>
144
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]145<p>Table of Contents:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]146<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]147 <li><a href="FAQ.html#License">License(s)</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]148 <li><a href="FAQ.html#Installati">Installation</a></li>
149 <li><a href="FAQ.html#Compilatio">Compilation</a></li>
150 <li><a href="FAQ.html#Developer">Developer corner</a></li>
151</ul>
152
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]153<h3><a name="License">License</a>(s)</h3>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]154<ol>
155 <li><em>Licensing Terms for libxml</em>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]156 <p>libxml is released under the <a
157 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]158 License</a>; see the file Copyright in the distribution for the precise
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]159 wording</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]160 </li>
161 <li><em>Can I embed libxml in a proprietary application ?</em>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]162 <p>Yes. The MIT License allows you to keep proprietary the changes
163 you made to libxml, but it would be graceful to send-back bug fixes
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]164 and improvements as patches for possible incorporation in the main
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]165 development tree.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]166 </li>
167</ol>
168
169<h3><a name="Installati">Installation</a></h3>
170<ol>
171 <li>Unless you are forced to because your application links with a Gnome
172 library requiring it, <strong><span style="background-color: #FF0000">Do
173 Not Use libxml1</span></strong>, use libxml2</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]174 <li><em>Where can I get libxml</em> ?
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]175 <p>The original distribution comes from <a
176 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a
177 href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">gnome.org</a></p>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]178 <p>Most Linux and BSD distributions include libxml, this is probably the
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]179 safer way for end-users to use libxml.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]180 <p>David Doolin provides precompiled Windows versions at <a
181 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
182 </li>
183 <li><em>I see libxml and libxml2 releases, which one should I install ?</em>
184 <ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]185 <li>If you are not constrained by backward compatibility issues
186 with existing applications, install libxml2 only</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]187 <li>If you are not doing development, you can safely install both.
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]188 Usually the packages <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]189 href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a
190 href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]191 compatible (this is not the case for development packages).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]192 <li>If you are a developer and your system provides separate packaging
193 for shared libraries and the development components, it is possible
194 to install libxml and libxml2, and also <a
195 href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
196 and <a
197 href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
198 too for libxml2 &gt;= 2.3.0</li>
199 <li>If you are developing a new application, please develop against
200 libxml2(-devel)</li>
201 </ul>
202 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]203 <li><em>I can't install the libxml package, it conflicts with libxml0</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]204 <p>You probably have an old libxml0 package used to provide the shared
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]205 library for libxml.so.0, you can probably safely remove it. The
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]206 libxml packages provided on <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]207 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provide
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]208 libxml.so.0</p>
209 </li>
210 <li><em>I can't install the libxml(2) RPM package due to failed
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]211 dependencies</em>
212 <p>The most generic solution is to re-fetch the latest src.rpm , and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]213 rebuild it locally with</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]214 <p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code>.</p>
215 <p>If everything goes well it will generate two binary rpm packages (one providing
216 the shared libs and xmllint, and the other one, the -devel package,
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]217 providing includes, static libraries and scripts needed to build
218 applications with libxml(2)) that you can install locally.</p>
219 </li>
220</ol>
221
222<h3><a name="Compilatio">Compilation</a></h3>
223<ol>
224 <li><em>What is the process to compile libxml ?</em>
225 <p>As most UNIX libraries libxml follows the "standard":</p>
226 <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p>
227 <p><code>cd libxml-xxxx</code></p>
228 <p><code>./configure --help</code></p>
229 <p>to see the options, then the compilation/installation proper</p>
230 <p><code>./configure [possible options]</code></p>
231 <p><code>make</code></p>
232 <p><code>make install</code></p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]233 <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]234 update your list of installed shared libs.</p>
235 </li>
236 <li><em>What other libraries are needed to compile/install libxml ?</em>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]237 <p>Libxml does not require any other library, the normal C ANSI API
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]238 should be sufficient (please report any violation to this rule you may
239 find).</p>
240 <p>However if found at configuration time libxml will detect and use the
241 following libs:</p>
242 <ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]243 <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a> : a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]244 highly portable and available widely compression library.</li>
245 <li>iconv: a powerful character encoding conversion library. It is
246 included by default in recent glibc libraries, so it doesn't need to
247 be installed specifically on Linux. It now seems a <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]248 href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
249 of the official UNIX</a> specification. Here is one <a
250 href="http://clisp.cons.org/~haible/packages-libiconv.html">implementation
251 of the library</a> which source can be found <a
252 href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
253 </ul>
254 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]255 <li><em>Make check fails on some platforms</em>
256 <p>Sometimes the regression tests' results don't completely match the value
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]257 produced by the parser, and the makefile uses diff to print the delta. On
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]258 some platforms the diff return breaks the compilation process; if the
Daniel Veillarde46182c2002-02-12 14:29:11 +0000[diff] [blame]259 diff is small this is probably not a serious problem.</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]260 <p>Sometimes (especially on Solaris) make checks fail due to limitations
Daniel Veillarde46182c2002-02-12 14:29:11 +0000[diff] [blame]261 in make. Try using GNU-make instead.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]262 </li>
263 <li><em>I use the CVS version and there is no configure script</em>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]264 <p>The configure script (and other Makefiles) are generated. Use the autogen.sh
265 script to regenerate the configure script and Makefiles, like:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]266 <p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
267 </li>
268 <li><em>I have troubles when running make tests with gcc-3.0</em>
269 <p>It seems the initial release of gcc-3.0 has a problem with the
270 optimizer which miscompiles the URI module. Please use another
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]271 compiler.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]272 </li>
273</ol>
274
275<h3><a name="Developer">Developer</a> corner</h3>
276<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]277 <li><em>xmlDocDump() generates output on one line.</em>
278 <p>Libxml will not <strong>invent</strong> spaces in the content of a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]279 document since <strong>all spaces in the content of a document are
280 significant</strong>. If you build a tree from the API and want
281 indentation:</p>
282 <ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]283 <li>the correct way is to generate those yourself too.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]284 <li>the dangerous way is to ask libxml to add those blanks to your
285 content <strong>modifying the content of your document in the
286 process</strong>. The result may not be what you expect. There is
287 <strong>NO</strong> way to guarantee that such a modification won't
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]288 affect other parts of the content of your document. See <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]289 href="http://xmlsoft.org/html/libxml-parser.html#XMLKEEPBLANKSDEFAULT">xmlKeepBlanksDefault
290 ()</a> and <a
291 href="http://xmlsoft.org/html/libxml-tree.html#XMLSAVEFORMATFILE">xmlSaveFormatFile
292 ()</a></li>
293 </ol>
294 </li>
295 <li>Extra nodes in the document:
296 <p><em>For a XML file as below:</em></p>
297 <pre>&lt;?xml version="1.0"?&gt;
298&lt;PLAN xmlns="http://www.argus.ca/autotest/1.0/"&gt;
299&lt;NODE CommFlag="0"/&gt;
300&lt;NODE CommFlag="1"/&gt;
301&lt;/PLAN&gt;</pre>
302 <p><em>after parsing it with the function
303 pxmlDoc=xmlParseFile(...);</em></p>
304 <p><em>I want to the get the content of the first node (node with the
305 CommFlag="0")</em></p>
306 <p><em>so I did it as following;</em></p>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]307 <pre>xmlNodePtr pnode;
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]308pnode=pxmlDoc-&gt;children-&gt;children;</pre>
309 <p><em>but it does not work. If I change it to</em></p>
310 <pre>pnode=pxmlDoc-&gt;children-&gt;children-&gt;next;</pre>
311 <p><em>then it works. Can someone explain it to me.</em></p>
312 <p></p>
313 <p>In XML all characters in the content of the document are significant
314 <strong>including blanks and formatting line breaks</strong>.</p>
315 <p>The extra nodes you are wondering about are just that, text nodes with
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]316 the formatting spaces which are part of the document but that people tend
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]317 to forget. There is a function <a
318 href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
319 ()</a> to remove those at parse time, but that's an heuristic, and its
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]320 use should be limited to cases where you are certain there is no
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]321 mixed-content in the document.</p>
322 </li>
323 <li><em>I get compilation errors of existing code like when accessing
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]324 <strong>root</strong> or <strong>child fields</strong> of nodes.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]325 <p>You are compiling code developed for libxml version 1 and using a
326 libxml2 development environment. Either switch back to libxml v1 devel or
327 even better fix the code to compile with libxml2 (or both) by <a
328 href="upgrade.html">following the instructions</a>.</p>
329 </li>
330 <li><em>I get compilation errors about non existing
331 <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]332 fields.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]333 <p>The source code you are using has been <a
334 href="upgrade.html">upgraded</a> to be able to compile with both libxml
335 and libxml2, but you need to install a more recent version:
336 libxml(-devel) &gt;= 1.8.8 or libxml2(-devel) &gt;= 2.1.0</p>
337 </li>
338 <li><em>XPath implementation looks seriously broken</em>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]339 <p>XPath implementation prior to 2.3.0 was really incomplete. Upgrade to
340 a recent version, there are no known bugs in the current version.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]341 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]342 <li><em>The example provided in the web page does not compile.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]343 <p>It's hard to maintain the documentation in sync with the code
344 &lt;grin/&gt; ...</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]345 <p>Check the previous points 1/ and 2/ raised before, and please send
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]346 patches.</p>
347 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]348 <li><em>Where can I get more examples and information than privoded on the web
349 page?</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]350 <p>Ideally a libxml book would be nice. I have no such plan ... But you
351 can:</p>
352 <ul>
353 <li>check more deeply the <a href="html/libxml-lib.html">existing
354 generated doc</a></li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]355 <li>look for examples of use for libxml function using the Gnome code.
356 For example the following will query the full Gnome CVS base for the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]357 use of the <strong>xmlAddChild()</strong> function:
358 <p><a
359 href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p>
360 <p>This may be slow, a large hardware donation to the gnome project
361 could cure this :-)</p>
362 </li>
363 <li><a
364 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]365 the libxml source</a> , I try to write code as clean and documented
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]366 as possible, so looking at it may be helpful. In particular the code of
367 xmllint.c and of the various testXXX.c test programs should provide
368 good examples of how to do things with the library.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]369 </ul>
370 </li>
371 <li>What about C++ ?
372 <p>libxml is written in pure C in order to allow easy reuse on a number
373 of platforms, including embedded systems. I don't intend to convert to
374 C++.</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]375 <p>There are however a few C++ wrappers which may fulfill your needs:</p>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]376 <ul>
377 <li>by Ari Johnson &lt;ari@btigate.com&gt;:
378 <p>Website: <a
379 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
380 <p>Download: <a
381 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
382 </li>
383 <li>by Peter Jones &lt;pjones@pmade.org&gt;
384 <p>Website: <a
385 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
386 </li>
387 </ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]388 </li>
389 <li>How to validate a document a posteriori ?
390 <p>It is possible to validate documents which had not been validated at
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]391 initial parsing time or documents which have been built from scratch using
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]392 the API. Use the <a
393 href="http://xmlsoft.org/html/libxml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]394 function. It is also possible to simply add a DTD to an existing
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]395 document:</p>
396 <pre>xmlDocPtr doc; /* your existing document */
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]397xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
398
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]399 dtd-&gt;name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */
400
401 doc-&gt;intSubset = dtd;
402 if (doc-&gt;children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
403 else xmlAddPrevSibling(doc-&gt;children, (xmlNodePtr)dtd);
404 </pre>
405 </li>
406 <li>etc ...</li>
407</ol>
408
409<p></p>
410
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]411<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]412
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]413<p>There are several on-line resources related to using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]414<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]415 <li>Check the <a href="FAQ.html">FAQ.</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]416 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]417 documentation</a> automatically extracted from code comments (using <a
418 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
419 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]420 <li>Look at the documentation about <a href="encoding.html">libxml
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]421 internationalization support</a>.</li>
Daniel Veillardbc66f852002-01-14 09:49:20 +0000[diff] [blame]422 <li>This page provides a global overview and <a href="example.html">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]423 examples</a> on how to use libxml.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]424 <li>John Fleck's <a href="tutorial/index.html">libxml tutorial</a>.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]425 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]426 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
427 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]428 <li>George Lebl wrote <a
429 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]430 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]431 <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^]432 file</a>.</li>
433 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a> description. If you are
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]434 starting a new project using libxml you should really use the 2.x
435 version.</li>
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]436 <li>And don't forget to look at the <a
437 href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]438</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]439
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]440<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]441
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]442<p>Well, bugs or missing features are always possible, and I will make a
443point of fixing them in a timely fashion. The best way to report a bug is to
444use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome
445bug tracking database</a> (make sure to use the "libxml" module name). I look
446at reports there regularly and it's good to have a reminder when a bug is
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]447still open. Be sure to specify that the bug is for the package libxml.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]448
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]449<p>There is also a mailing-list <a
Daniel Veillard3197f162001-04-04 00:40:08 +0000[diff] [blame]450href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
451href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]452href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
453please visit the <a
454href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
455follow the instructions. <strong>Do not send code, I won't debug it</strong>
456(but patches are really appreciated!).</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]457
Daniel Veillard008186f2001-09-13 14:24:44 +0000[diff] [blame]458<p>Check the following <strong><span style="color: #FF0000">before
459posting</span></strong>:</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]460<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]461 <li>Read the <a href="FAQ.html">FAQ</a>.</li>
462 <li>Make sure you are <a href="ftp://xmlsoft.org/">using a recent
463 version</a>, and that the problem still shows up in a recent version.</li>
464 <li>Check the <a href="http://mail.gnome.org/archives/xml/">list
465 archives</a> to see if the problem was reported already. In this case
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]466 there is probably a fix available, similarly check the <a
Daniel Veillarde7ead2d2001-08-22 23:44:09 +0000[diff] [blame]467 href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">registered
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]468 open bugs</a>.</li>
469 <li>Make sure you can reproduce the bug with xmllint or one of the test
470 programs found in source in the distribution.</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]471 <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]472 attachment)</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]473</ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]474
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]475<p>Then send the bug with associated informations to reproduce it to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]476href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]477related I will approve it.. Please do not send mail to me directly, it makes
478things really hard to track and in some cases I am not the best person to
479answer a given question. Ask the list instead.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]480
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]481<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]482probably be processed faster than those without.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]483
484<p>If you're looking for help, a quick look at <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]485href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]486provide the answer. I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]487questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]488documentation</a> is not as polished as I would like (i need to learn more
489about DocBook), but it's a good starting point.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]490
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]491<h2><a name="help">How to help</a></h2>
492
493<p>You can help the project in various ways, the best thing to do first is to
494subscribe to the mailing-list as explained before, check the <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]495href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
496href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]497database</a>:</p>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]498<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]499 <li>Provide patches when you find problems.</li>
500 <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]501 be integrated in all cases but help pinpointing portability problems
502 and</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]503 <li>Provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]504 as HTML diffs).</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]505 <li>Provide new documentations pieces (translations, examples, etc ...).</li>
506 <li>Check the TODO file and try to close one of the items.</li>
507 <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]508 provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me
509 </a>before to avoid synchronization problems and check that the suggested
510 fix will fit in nicely :-)</li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]511</ol>
512
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]513<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]514
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]515<p>The latest versions of libxml can be found on <a
Daniel Veillard20c8cf22001-06-26 22:47:36 +0000[diff] [blame]516href="ftp://xmlsoft.org/">xmlsoft.org</a> (<a
517href="ftp://speakeasy.rpmfind.net/pub/libxml/">Seattle</a>, <a
518href="ftp://fr.rpmfind.net/pub/libxml/">France</a>) or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]519href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]520as a <a href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">source
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]521archive</a> or <a
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]522href="ftp://ftp.gnome.org/pub/GNOME/stable/redhat/i386/libxml/">RPM
Daniel Veillard0bfbb422002-04-26 09:21:45 +0000[diff] [blame]523packages</a>, Antonin Sprinzl also provide <a
524href="ftp://gd.tuwien.ac.at/pub/libxml/">a mirror in Austria</a>. (NOTE that
525you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]526href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
527href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]528packages installed to compile applications using libxml.) <a
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]529href="mailto:igor@stud.fh-frankfurt.de">Igor Zlatkovic</a> is now the
530maintainer of the Windows port, <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]531href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]532provides binaries</a>. <a href="mailto:Gary.Pennington@sun.com">Gary
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]533Pennington</a> provides <a href="http://garypennington.net/libxml2/">Solaris
Daniel Veillard1175e9c2002-07-18 22:29:28 +0000[diff] [blame]534binaries</a>. <a href="mailto:Steve.Ball@zveno.com">Steve Ball</a> provides <a href="http://www.zveno.com/open_source/libxml2xslt.html">Mac Os X binaries</a>.</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]535
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]536<p><a name="Snapshot">Snapshot:</a></p>
537<ul>
538 <li>Code from the W3C cvs base libxml <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]539 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]540 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]541 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]542</ul>
543
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]544<p><a name="Contribs">Contributions:</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]545
546<p>I do accept external contributions, especially if compiling on another
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]547platform, get in touch with me to upload the package, wrappers for various
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]548languages have been provided, and can be found in the <a
549href="contribs.html">contrib section</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]550
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]551<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]552<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]553 <li><p>The <a
554 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]555 CVS base</a>. Check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]556 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a>
557 page; the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]558 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]559 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]560</ul>
561
562<h2><a name="News">News</a></h2>
563
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]564<h3>CVS only : check the <a
565href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]566for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]567
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]568<p>Items not finished and worked on, get in touch with the list if you want
569to test those</p>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]570<ul>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]571 <li>Finishing up <a href="http://www.w3.org/TR/xmlschema-1/">XML
572 Schemas</a> and <a href="http://www.w3.org/TR/xinclude">XInclude</a></li>
573</ul>
574
Daniel Veillard782afda2002-07-08 15:12:49 +0000[diff] [blame]575<h3>2.4.23: July 6 2002</h3>
576<ul>
577 <li>performances patches: Peter Jacobi</li>
578 <li>c14n fixes, testsuite and performances: Aleksey Sanin</li>
579 <li>added xmlDocFormatDump: Chema Celorio</li>
580 <li>new tutorial: John Fleck</li>
581 <li>new hash functions and performances: Sander Vesik, portability fix from
582 Peter Jacobi</li>
583 <li>a number of bug fixes: XPath (William Brack, Richard Jinks), XML and
584 HTML parsers, ID lookup function</li>
585 <li>removal of all remaining sprintf: Aleksey Sanin</li>
586</ul>
587
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]588<h3>2.4.22: May 27 2002</h3>
589<ul>
590 <li>a number of bug fixes: configure scripts, base handling, parser, memory
591 usage, HTML parser, XPath, documentation (Christian Cornelssen),
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]592 indentation, URI parsing</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]593 <li>Optimizations for XMLSec, fixing and making public some of the network
594 protocol handlers (Aleksey)</li>
595 <li>performance patch from Gary Pennington</li>
596 <li>Charles Bozeman provided date and time support for XML Schemas
597 datatypes</li>
598</ul>
599
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]600<h3>2.4.21: Apr 29 2002</h3>
601
602<p>This release is both a bug fix release and also contains the early XML
603Schemas <a href="http://www.w3.org/TR/xmlschema-1/">structures</a> and <a
604href="http://www.w3.org/TR/xmlschema-2/">datatypes</a> code, beware, all
605interfaces are likely to change, there is huge holes, it is clearly a work in
606progress and don't even think of putting this code in a production system,
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]607it's actually not compiled in by default. The real fixes are:</p>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]608<ul>
609 <li>a couple of bugs or limitations introduced in 2.4.20</li>
610 <li>patches for Borland C++ and MSC by Igor</li>
611 <li>some fixes on XPath strings and conformance patches by Richard
612 Jinks</li>
613 <li>patch from Aleksey for the ExcC14N specification</li>
614 <li>OSF/1 bug fix by Bjorn</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]615</ul>
616
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]617<h3>2.4.20: Apr 15 2002</h3>
618<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]619 <li>bug fixes: file descriptor leak, XPath, HTML output, DTD validation</li>
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]620 <li>XPath conformance testing by Richard Jinks</li>
621 <li>Portability fixes: Solaris, MPE/iX, Windows, OSF/1, python bindings,
622 libxml.m4</li>
623</ul>
624
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]625<h3>2.4.19: Mar 25 2002</h3>
626<ul>
627 <li>bug fixes: half a dozen XPath bugs, Validation, ISO-Latin to UTF8
628 encoder</li>
629 <li>portability fixes in the HTTP code</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]630 <li>memory allocation checks using valgrind, and profiling tests</li>
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]631 <li>revamp of the Windows build and Makefiles</li>
632</ul>
633
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]634<h3>2.4.18: Mar 18 2002</h3>
635<ul>
636 <li>bug fixes: tree, SAX, canonicalization, validation, portability,
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]637 XPath</li>
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]638 <li>removed the --with-buffer option it was becoming unmaintainable</li>
639 <li>serious cleanup of the Python makefiles</li>
640 <li>speedup patch to XPath very effective for DocBook stylesheets</li>
641 <li>Fixes for Windows build, cleanup of the documentation</li>
642</ul>
643
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]644<h3>2.4.17: Mar 8 2002</h3>
645<ul>
646 <li>a lot of bug fixes, including "namespace nodes have no parents in
647 XPath"</li>
648 <li>fixed/improved the Python wrappers, added more examples and more
649 regression tests, XPath extension functions can now return node-sets</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]650 <li>added the XML Canonicalization support from Aleksey Sanin</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]651</ul>
652
Daniel Veillard5f4b5992002-02-20 10:22:49 +0000[diff] [blame]653<h3>2.4.16: Feb 20 2002</h3>
654<ul>
655 <li>a lot of bug fixes, most of them were triggered by the XML Testsuite
656 from OASIS and W3C. Compliance has been significantly improved.</li>
657 <li>a couple of portability fixes too.</li>
658</ul>
659
Daniel Veillard397ff112002-02-11 18:27:20 +0000[diff] [blame]660<h3>2.4.15: Feb 11 2002</h3>
661<ul>
662 <li>Fixed the Makefiles, especially the python module ones</li>
663 <li>A few bug fixes and cleanup</li>
664 <li>Includes cleanup</li>
665</ul>
666
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]667<h3>2.4.14: Feb 8 2002</h3>
668<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]669 <li>Change of License to the <a
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]670 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]671 License</a> basically for integration in XFree86 codebase, and removing
672 confusion around the previous dual-licensing</li>
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]673 <li>added Python bindings, beta software but should already be quite
674 complete</li>
675 <li>a large number of fixes and cleanups, especially for all tree
676 manipulations</li>
677 <li>cleanup of the headers, generation of a reference API definition in
678 XML</li>
679</ul>
680
681<h3>2.4.13: Jan 14 2002</h3>
Daniel Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame]682<ul>
683 <li>update of the documentation: John Fleck and Charlie Bozeman</li>
684 <li>cleanup of timing code from Justin Fletcher</li>
685 <li>fixes for Windows and initial thread support on Win32: Igor and Serguei
686 Narojnyi</li>
687 <li>Cygwin patch from Robert Collins</li>
688 <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
689</ul>
690
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]691<h3>2.4.12: Dec 7 2001</h3>
692<ul>
693 <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
694 XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
695 (robert)</li>
696 <li>Eric Lavigne contributed project files for MacOS</li>
697 <li>some makefiles cleanups</li>
698</ul>
699
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]700<h3>2.4.11: Nov 26 2001</h3>
701<ul>
702 <li>fixed a couple of errors in the includes, fixed a few bugs, some code
703 cleanups</li>
704 <li>xmllint man pages improvement by Heiko Rupp</li>
705 <li>updated VMS build instructions from John A Fotheringham</li>
706 <li>Windows Makefiles updates from Igor</li>
707</ul>
708
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]709<h3>2.4.10: Nov 10 2001</h3>
710<ul>
711 <li>URI escaping fix (Joel Young)</li>
712 <li>added xmlGetNodePath() (for paths or XPointers generation)</li>
713 <li>Fixes namespace handling problems when using DTD and validation</li>
714 <li>improvements on xmllint: Morus Walter patches for --format and
715 --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
716 <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
717 <li>fixes to the HTML parser</li>
718</ul>
719
720<h3>2.4.9: Nov 6 2001</h3>
721<ul>
722 <li>fixes more catalog bugs</li>
723 <li>avoid a compilation problem, improve xmlGetLineNo()</li>
724</ul>
725
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]726<h3>2.4.8: Nov 4 2001</h3>
727<ul>
728 <li>fixed SGML catalogs broken in previous release, updated xmlcatalog
729 tool</li>
730 <li>fixed a compile errors and some includes troubles.</li>
731</ul>
732
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]733<h3>2.4.7: Oct 30 2001</h3>
734<ul>
735 <li>exported some debugging interfaces</li>
736 <li>serious rewrite of the catalog code</li>
737 <li>integrated Gary Pennington thread safety patch, added configure option
738 and regression tests</li>
739 <li>removed an HTML parser bug</li>
740 <li>fixed a couple of potentially serious validation bugs</li>
741 <li>integrated the SGML DocBook support in xmllint</li>
742 <li>changed the nanoftp anonymous login passwd</li>
743 <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
744 <li>general bug fixes</li>
745 <li>updated xmllint man page by John Fleck</li>
746 <li>some VMS and Windows updates</li>
747</ul>
748
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]749<h3>2.4.6: Oct 10 2001</h3>
750<ul>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]751 <li>added an updated man pages by John Fleck</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]752 <li>portability and configure fixes</li>
753 <li>an infinite loop on the HTML parser was removed (William)</li>
754 <li>Windows makefile patches from Igor</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]755 <li>fixed half a dozen bugs reported for libxml or libxslt</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]756 <li>updated xmlcatalog to be able to modify SGML super catalogs</li>
757</ul>
758
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]759<h3>2.4.5: Sep 14 2001</h3>
760<ul>
761 <li>Remove a few annoying bugs in 2.4.4</li>
762 <li>forces the HTML serializer to output decimal charrefs since some
763 version of Netscape can't handle hexadecimal ones</li>
764</ul>
765
766<h3>1.8.16: Sep 14 2001</h3>
767<ul>
768 <li>maintenance release of the old libxml1 branch, couple of bug and
769 portability fixes</li>
770</ul>
771
Daniel Veillard04382ae2001-09-12 18:51:30 +0000[diff] [blame]772<h3>2.4.4: Sep 12 2001</h3>
773<ul>
774 <li>added --convert to xmlcatalog, bug fixes and cleanups of XML
775 Catalog</li>
776 <li>a few bug fixes and some portability changes</li>
777 <li>some documentation cleanups</li>
778</ul>
779
Daniel Veillard39936902001-08-24 00:49:01 +0000[diff] [blame]780<h3>2.4.3: Aug 23 2001</h3>
781<ul>
782 <li>XML Catalog support see the doc</li>
783 <li>New NaN/Infinity floating point code</li>
784 <li>A few bug fixes</li>
785</ul>
786
787<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]788<ul>
789 <li>adds xmlLineNumbersDefault() to control line number generation</li>
790 <li>lot of bug fixes</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]791 <li>the Microsoft MSC projects files should now be up to date</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]792 <li>inheritance of namespaces from DTD defaulted attributes</li>
793 <li>fixes a serious potential security bug</li>
794 <li>added a --format option to xmllint</li>
795</ul>
796
797<h3>2.4.1: July 24 2001</h3>
798<ul>
799 <li>possibility to keep line numbers in the tree</li>
800 <li>some computation NaN fixes</li>
801 <li>extension of the XPath API</li>
802 <li>cleanup for alpha and ia64 targets</li>
803 <li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]804</ul>
805
806<h3>2.4.0: July 10 2001</h3>
807<ul>
808 <li>Fixed a few bugs in XPath, validation, and tree handling.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]809 <li>Fixed XML Base implementation, added a couple of examples to the
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]810 regression tests</li>
811 <li>A bit of cleanup</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]812</ul>
813
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]814<h3>2.3.14: July 5 2001</h3>
815<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]816 <li>fixed some entities problems and reduce memory requirement when
817 substituting them</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]818 <li>lots of improvements in the XPath queries interpreter can be
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]819 substantially faster</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]820 <li>Makefiles and configure cleanups</li>
821 <li>Fixes to XPath variable eval, and compare on empty node set</li>
822 <li>HTML tag closing bug fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]823 <li>Fixed an URI reference computation problem when validating</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]824</ul>
825
Daniel Veillard2adbb512001-06-28 16:20:36 +0000[diff] [blame]826<h3>2.3.13: June 28 2001</h3>
827<ul>
828 <li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
829 <li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
830</ul>
831
832<h3>1.8.14: June 28 2001</h3>
833<ul>
834 <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
835 <li>Small Makefile fix</li>
836</ul>
837
Daniel Veillard11648102001-06-26 16:08:24 +0000[diff] [blame]838<h3>2.3.12: June 26 2001</h3>
839<ul>
840 <li>lots of cleanup</li>
841 <li>a couple of validation fix</li>
842 <li>fixed line number counting</li>
843 <li>fixed serious problems in the XInclude processing</li>
844 <li>added support for UTF8 BOM at beginning of entities</li>
845 <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
846 miscompile uri.c (William), Thomas Leitner provided a fix for the
847 optimizer on Tru64</li>
848 <li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
849 compilation on Windows MSC</li>
850 <li>update of libxml-doc.el (Felix Natter)</li>
851 <li>fixed 2 bugs in URI normalization code</li>
852</ul>
853
Daniel Veillarde3c81b52001-06-17 14:50:34 +0000[diff] [blame]854<h3>2.3.11: June 17 2001</h3>
855<ul>
856 <li>updates to trio, Makefiles and configure should fix some portability
857 problems (alpha)</li>
858 <li>fixed some HTML serialization problems (pre, script, and block/inline
859 handling), added encoding aware APIs, cleanup of this code</li>
860 <li>added xmlHasNsProp()</li>
861 <li>implemented a specific PI for encoding support in the DocBook SGML
862 parser</li>
863 <li>some XPath fixes (-Infinity, / as a function parameter and namespaces
864 node selection)</li>
865 <li>fixed a performance problem and an error in the validation code</li>
866 <li>fixed XInclude routine to implement the recursive behaviour</li>
867 <li>fixed xmlFreeNode problem when libxml is included statically twice</li>
868 <li>added --version to xmllint for bug reports</li>
869</ul>
870
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]871<h3>2.3.10: June 1 2001</h3>
872<ul>
873 <li>fixed the SGML catalog support</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]874 <li>a number of reported bugs got fixed, in XPath, iconv detection,
875 XInclude processing</li>
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]876 <li>XPath string function should now handle unicode correctly</li>
877</ul>
878
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]879<h3>2.3.9: May 19 2001</h3>
880
881<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
882<ul>
883 <li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]884 <li>some serious speed optimization again</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]885 <li>some documentation cleanups</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]886 <li>trying to get better linking on Solaris (-R)</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]887 <li>XPath API cleanup from Thomas Broyer</li>
888 <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
889 xmlValidGetValidElements()</li>
890 <li>Added an INSTALL file</li>
891 <li>Attribute removal added to API: #54433</li>
892 <li>added a basic support for SGML catalogs</li>
893 <li>fixed xmlKeepBlanksDefault(0) API</li>
894 <li>bugfix in xmlNodeGetLang()</li>
895 <li>fixed a small configure portability problem</li>
896 <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
897</ul>
898
Daniel Veillarda265af72001-05-14 11:13:58 +0000[diff] [blame]899<h3>1.8.13: May 14 2001</h3>
900<ul>
901 <li>bugfixes release of the old libxml1 branch used by Gnome</li>
902</ul>
903
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]904<h3>2.3.8: May 3 2001</h3>
905<ul>
906 <li>Integrated an SGML DocBook parser for the Gnome project</li>
907 <li>Fixed a few things in the HTML parser</li>
908 <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
909 point portability issue</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]910 <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
911 DOM+validation using the XML REC as input and a 700MHz celeron).</li>
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]912 <li>incorporated more Windows cleanup</li>
913 <li>added xmlSaveFormatFile()</li>
914 <li>fixed problems in copying nodes with entities references (gdome)</li>
915 <li>removed some troubles surrounding the new validation module</li>
916</ul>
917
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]918<h3>2.3.7: April 22 2001</h3>
919<ul>
920 <li>lots of small bug fixes, corrected XPointer</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]921 <li>Non deterministic content model validation support</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]922 <li>added xmlDocCopyNode for gdome2</li>
923 <li>revamped the way the HTML parser handles end of tags</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]924 <li>XPath: corrections of namespaces support and number formatting</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]925 <li>Windows: Igor Zlatkovic patches for MSC compilation</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]926 <li>HTML output fixes from P C Chow and William M. Brack</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]927 <li>Improved validation speed sensible for DocBook</li>
928 <li>fixed a big bug with ID declared in external parsed entities</li>
929 <li>portability fixes, update of Trio from Bjorn Reese</li>
930</ul>
931
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]932<h3>2.3.6: April 8 2001</h3>
933<ul>
934 <li>Code cleanup using extreme gcc compiler warning options, found and
935 cleared half a dozen potential problem</li>
936 <li>the Eazel team found an XML parser bug</li>
937 <li>cleaned up the user of some of the string formatting function. used the
938 trio library code to provide the one needed when the platform is missing
939 them</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]940 <li>xpath: removed a memory leak and fixed the predicate evaluation
941 problem, extended the testsuite and cleaned up the result. XPointer seems
942 broken ...</li>
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]943</ul>
944
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame]945<h3>2.3.5: Mar 23 2001</h3>
946<ul>
947 <li>Biggest change is separate parsing and evaluation of XPath expressions,
948 there is some new APIs for this too</li>
949 <li>included a number of bug fixes(XML push parser, 51876, notations,
950 52299)</li>
951 <li>Fixed some portability issues</li>
952</ul>
953
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]954<h3>2.3.4: Mar 10 2001</h3>
955<ul>
956 <li>Fixed bugs #51860 and #51861</li>
957 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
958 size to be application tunable.</li>
959 <li>Some cleanup in the validation code, still a bug left and this part
960 should probably be rewritten to support ambiguous content model :-\</li>
961 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
962 parser</li>
963 <li>Fixed another bug in xmlNodeGetContent()</li>
964 <li>Bjorn fixed XPath node collection and Number formatting</li>
965 <li>Fixed a loop reported in the HTML parsing</li>
966 <li>blank space are reported even if the Dtd content model proves that they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]967 are formatting spaces, this is for XML conformance</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]968</ul>
969
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]970<h3>2.3.3: Mar 1 2001</h3>
971<ul>
972 <li>small change in XPath for XSLT</li>
973 <li>documentation cleanups</li>
974 <li>fix in validation by Gary Pennington</li>
975 <li>serious parsing performances improvements</li>
976</ul>
977
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]978<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]979<ul>
980 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
981 <li>fixed a Dtd parsing bug</li>
982 <li>fixed a bug in xmlNodeGetContent</li>
983 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
984</ul>
985
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]986<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]987<ul>
988 <li>some XPath and HTML bug fixes for XSLT</li>
989 <li>small extension of the hash table interfaces for DOM gdome2
990 implementation</li>
991 <li>A few bug fixes</li>
992</ul>
993
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]994<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]995<ul>
996 <li>Lots of XPath bug fixes</li>
997 <li>Add a mode with Dtd lookup but without validation error reporting for
998 XSLT</li>
999 <li>Add support for text node without escaping (XSLT)</li>
1000 <li>bug fixes for xmlCheckFilename</li>
1001 <li>validation code bug fixes from Gary Pennington</li>
1002 <li>Patch from Paul D. Smith correcting URI path normalization</li>
1003 <li>Patch to allow simultaneous install of libxml-devel and
1004 libxml2-devel</li>
1005 <li>the example Makefile is now fixed</li>
1006 <li>added HTML to the RPM packages</li>
1007 <li>tree copying bugfixes</li>
1008 <li>updates to Windows makefiles</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1009 <li>optimization patch from Bjorn Reese</li>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1010</ul>
1011
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1012<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]1013<ul>
1014 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
1015 <li>added htmlHandleOmittedElem()</li>
1016 <li>Applied Bjorn Reese's IPV6 first patch</li>
1017 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1018 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]1019</ul>
1020
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]1021<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]1022<ul>
1023 <li>Fix the Windows problems of 2.2.8</li>
1024 <li>integrate OpenVMS patches</li>
1025 <li>better handling of some nasty HTML input</li>
1026 <li>Improved the XPointer implementation</li>
1027 <li>integrate a number of provided patches</li>
1028</ul>
1029
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]1030<h3>2.2.9: Nov 25 2000</h3>
1031<ul>
1032 <li>erroneous release :-(</li>
1033</ul>
1034
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]1035<h3>2.2.8: Nov 13 2000</h3>
1036<ul>
1037 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
1038 support</li>
1039 <li>Patch in conditional section handling</li>
1040 <li>updated MS compiler project</li>
1041 <li>fixed some XPath problems</li>
1042 <li>added an URI escaping function</li>
1043 <li>some other bug fixes</li>
1044</ul>
1045
1046<h3>2.2.7: Oct 31 2000</h3>
1047<ul>
1048 <li>added message redirection</li>
1049 <li>XPath improvements (thanks TOM !)</li>
1050 <li>xmlIOParseDTD() added</li>
1051 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
1052 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
1053</ul>
1054
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]1055<h3>2.2.6: Oct 25 2000:</h3>
1056<ul>
1057 <li>Added an hash table module, migrated a number of internal structure to
1058 those</li>
1059 <li>Fixed a posteriori validation problems</li>
1060 <li>HTTP module cleanups</li>
1061 <li>HTML parser improvements (tag errors, script/style handling, attribute
1062 normalization)</li>
1063 <li>coalescing of adjacent text nodes</li>
1064 <li>couple of XPath bug fixes, exported the internal API</li>
1065</ul>
1066
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1067<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1068<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1069 <li>XPointer implementation and testsuite</li>
1070 <li>Lot of XPath fixes, added variable and functions registration, more
1071 tests</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1072 <li>Portability fixes, lots of enhancements toward an easy Windows build
1073 and release</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1074 <li>Late validation fixes</li>
1075 <li>Integrated a lot of contributed patches</li>
1076 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1077 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1078</ul>
1079
1080<h3>2.2.4: Oct 1 2000:</h3>
1081<ul>
1082 <li>main XPath problem fixed</li>
1083 <li>Integrated portability patches for Windows</li>
1084 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1085</ul>
1086
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1087<h3>2.2.3: Sep 17 2000</h3>
1088<ul>
1089 <li>bug fixes</li>
1090 <li>cleanup of entity handling code</li>
1091 <li>overall review of all loops in the parsers, all sprintf usage has been
1092 checked too</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1093 <li>Far better handling of larges Dtd. Validating against DocBook XML Dtd
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1094 works smoothly now.</li>
1095</ul>
1096
1097<h3>1.8.10: Sep 6 2000</h3>
1098<ul>
1099 <li>bug fix release for some Gnome projects</li>
1100</ul>
1101
1102<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1103<ul>
1104 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]1105 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1106</ul>
1107
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1108<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1109<ul>
1110 <li>a purely bug fixes release</li>
1111 <li>fixed an encoding support problem when parsing from a memory block</li>
1112 <li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1113 <li>removed a bug in the function allowing to override the memory
1114 allocation routines</li>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1115</ul>
1116
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1117<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]1118<ul>
1119 <li>applied a lot of portability fixes</li>
1120 <li>better encoding support/cleanup and saving (content is now always
1121 encoded in UTF-8)</li>
1122 <li>the HTML parser now correctly handles encodings</li>
1123 <li>added xmlHasProp()</li>
1124 <li>fixed a serious problem with &amp;#38;</li>
1125 <li>propagated the fix to FTP client</li>
1126 <li>cleanup, bugfixes, etc ...</li>
1127 <li>Added a page about <a href="encoding.html">libxml Internationalization
1128 support</a></li>
1129</ul>
1130
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1131<h3>1.8.9: July 9 2000</h3>
1132<ul>
1133 <li>fixed the spec the RPMs should be better</li>
1134 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
1135 rpmfind users problem</li>
1136</ul>
1137
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]1138<h3>2.1.1: July 1 2000</h3>
1139<ul>
1140 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
1141 <li>improvements on the HTML parser</li>
1142</ul>
1143
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1144<h3>2.1.0 and 1.8.8: June 29 2000</h3>
1145<ul>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1146 <li>1.8.8 is mostly a commodity package for upgrading to libxml2 according
1147 to <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1148 about &amp;#38; charref parsing</li>
1149 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
1150 also contains numerous fixes and enhancements:
1151 <ul>
1152 <li>added xmlStopParser() to stop parsing</li>
1153 <li>improved a lot parsing speed when there is large CDATA blocs</li>
1154 <li>includes XPath patches provided by Picdar Technology</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1155 <li>tried to fix as much as possible DTD validation and namespace
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1156 related problems</li>
1157 <li>output to a given encoding has been added/tested</li>
1158 <li>lot of various fixes</li>
1159 </ul>
1160 </li>
1161</ul>
1162
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1163<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1164<ul>
1165 <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]1166 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initially
1167 scheduled for Apr 3 the release occurred only on Apr 12 due to massive
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1168 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1169 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1170 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1171 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1172 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1173 <pre>#include "xxx.h"</pre>
1174 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]1175 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
1176 <li>the memory allocation routines used by libxml can now be overloaded
1177 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1178 <li>The previously CVS only tool tester has been renamed
1179 <strong>xmllint</strong> and is now installed as part of the libxml2
1180 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1181 <li>The I/O interface has been revamped. There is now ways to plug in
1182 specific I/O modules, either at the URI scheme detection level using
1183 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
1184 parser context using xmlCreateIOParserCtxt()</li>
1185 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
1186 number of the libxml module in use</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1187 <li>a number of optional features of libxml can now be excluded at
1188 configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1189</ul>
1190
1191<h3>2.0.0beta: Mar 14 2000</h3>
1192<ul>
1193 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1194 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
1195 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
1196 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1197 <li>This version is now the head in the Gnome CVS base, the old one is
1198 available under the tag LIB_XML_1_X</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1199 <li>This includes a very large set of changes. From a programmatic point
1200 of view applications should not have to be modified too much, check the
1201 <a href="upgrade.html">upgrade page</a></li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1202 <li>Some interfaces may changes (especially a bit about encoding).</li>
1203 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1204 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1205 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
1206 handled now</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1207 <li>Better handling of entities, especially well-formedness checking
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1208 and proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1209 <li>DTD conditional sections</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1210 <li>Validation now correctly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1211 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1212 structures to accommodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1213 </ul>
1214 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1215 <li>Serious progress were made toward compliance, <a
1216 href="conf/result.html">here are the result of the test</a> against the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1217 OASIS testsuite (except the Japanese tests since I don't support that
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1218 encoding yet). This URL is rebuilt every couple of hours using the CVS
1219 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1220</ul>
1221
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1222<h3>1.8.7: Mar 6 2000</h3>
1223<ul>
1224 <li>This is a bug fix release:</li>
1225 <li>It is possible to disable the ignorable blanks heuristic used by
1226 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1227 that for adherence to XML spec, this behaviour will be disabled by
1228 default in 2.x . The same function will allow to keep compatibility for
1229 old code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1230 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
1231 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1232 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
1233 compilation on some platforms has been fixed</li>
1234 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
1235 URIs</li>
1236</ul>
1237
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1238<h3>1.8.6: Jan 31 2000</h3>
1239<ul>
1240 <li>added a nanoFTP transport module, debugged until the new version of <a
1241 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
1242 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]1243</ul>
1244
1245<h3>1.8.5: Jan 21 2000</h3>
1246<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1247 <li>adding APIs to parse a well balanced chunk of XML (production <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1248 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
1249 XML spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1250 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1251 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
1252 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1253 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
1254 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1255</ul>
1256
1257<h3>1.8.4: Jan 13 2000</h3>
1258<ul>
1259 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
1260 <li>all exit() call should have been removed from libxml</li>
1261 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
1262 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1263</ul>
1264
1265<h3>1.8.3: Jan 5 2000</h3>
1266<ul>
1267 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1268 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1269 <li>lots of bug fixes and improvement added over XMas holidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1270 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1271 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
1272 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1273 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1274 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1275 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1276</ul>
1277
1278<h3>1.8.2: Dec 21 1999</h3>
1279<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1280 <li>I got another problem with includes and C++, I hope this issue is fixed
1281 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1282 <li>Added a few tree modification functions: xmlReplaceNode,
1283 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
1284 xmlDocSetRootElement</li>
1285 <li>Tried to improve the HTML output with help from <a
1286 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1287</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1288
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1289<h3>1.8.1: Dec 18 1999</h3>
1290<ul>
1291 <li>various patches to avoid troubles when using libxml with C++ compilers
1292 the "namespace" keyword and C escaping in include files</li>
1293 <li>a problem in one of the core macros IS_CHAR was corrected</li>
1294 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
1295 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]1296 <li>fixed a posteriori validation (validation after parsing, or by using a
1297 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1298 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]1299</ul>
1300
1301<h3>1.8.0: Dec 12 1999</h3>
1302<ul>
1303 <li>cleanup, especially memory wise</li>
1304 <li>the parser should be more reliable, especially the HTML one, it should
1305 not crash, whatever the input !</li>
1306 <li>Integrated various patches, especially a speedup improvement for large
1307 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
1308 configure with --with-buffers to enable them.</li>
1309 <li>attribute normalization, oops should have been added long ago !</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1310 <li>attributes defaulted from DTDs should be available, xmlSetProp() now
1311 does entities escaping by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1312</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1313
1314<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1315<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1316 <li>Lots of HTML improvement</li>
1317 <li>Fixed some errors when saving both XML and HTML</li>
1318 <li>More examples, the regression tests should now look clean</li>
1319 <li>Fixed a bug with contiguous charref</li>
1320</ul>
1321
1322<h3>1.7.3: Sep 29 1999</h3>
1323<ul>
1324 <li>portability problems fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1325 <li>snprintf was used unconditionally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1326 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1327</ul>
1328
1329<h3>1.7.1: Sep 24 1999</h3>
1330<ul>
1331 <li>The basic type for strings manipulated by libxml has been renamed in
1332 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1333 is that CHAR was conflicting with a predefined type on Windows. However
1334 on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1335 <strong>#define </strong>.</li>
1336 <li>Changed another error : the use of a structure field called errno, and
1337 leading to troubles on platforms where it's a macro</li>
1338</ul>
1339
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1340<h3>1.7.0: Sep 23 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1341<ul>
1342 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1343 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1344 <li>Added an errno to report errors by another mean than a simple printf
1345 like callback</li>
1346 <li>Finished ID/IDREF support and checking when validation</li>
1347 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1348 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1349 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
1350 implementation</li>
1351 <li>Added an HTML parser front-end</li>
1352</ul>
1353
1354<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1355
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1356<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]1357markup-based structured documents. Here is <a name="example">an example XML
1358document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1359<pre>&lt;?xml version="1.0"?&gt;
1360&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
1361 &lt;head&gt;
1362 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
1363 &lt;/head&gt;
1364 &lt;chapter&gt;
1365 &lt;title&gt;The Linux adventure&lt;/title&gt;
1366 &lt;p&gt;bla bla bla ...&lt;/p&gt;
1367 &lt;image href="linus.gif"/&gt;
1368 &lt;p&gt;...&lt;/p&gt;
1369 &lt;/chapter&gt;
1370&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1371
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1372<p>The first line specifies that it is an XML document and gives useful
1373information about its encoding. Then the rest of the document is a text format whose
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1374structure is specified by tags between brackets. <strong>Each tag opened has
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1375to be closed</strong>. XML is pedantic about this. However, if a tag is empty
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1376(no content), a single tag can serve as both the opening and closing tag if
1377it ends with <code>/&gt;</code> rather than with <code>&gt;</code>. Note
1378that, for example, the image tag has no content (just an attribute) and is
1379closed by ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1380
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1381<p>XML can be applied successfully to a wide range of tasks, ranging from long term
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1382structured document maintenance (where it follows the steps of SGML) to
1383simple data encoding mechanisms like configuration file formatting (glade),
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1384spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where
1385it is used to encode remote calls between a client and a server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1386
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1387<h2><a name="XSLT">XSLT</a></h2>
1388
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1389<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
1390
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1391<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
1392language for transforming XML documents into other XML documents (or
1393HTML/textual output).</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1394
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1395<p>A separate library called libxslt is being developed on top of libxml2. This
1396module "libxslt" too can be found in the Gnome CVS base.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1397
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]1398<p>You can check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1399href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
1400supported and the progresses on the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1401href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog"
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1402name="Changelog">Changelog</a>.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1403
1404<h2><a name="Python">Python and bindings</a></h2>
1405
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1406<p>There are a number of language bindings and wrappers available for libxml2,
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1407the list below is not exhaustive. Please contact the <a
1408href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a>
1409(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in
1410order to get updates to this list or to discuss the specific topic of libxml2
1411or libxslt wrappers or bindings:</p>
1412<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1413 <li><a href="mailto:ari@lusis.org">Ari Johnson</a> provides a C++ wrapper
1414 for libxml:<br>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1415 Website: <a
1416 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a><br>
1417 Download: <a
1418 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></li>
1419 <li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1420 based on the gdome2 bindings</a> maintained by Tobias Peters.</li>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]1421 <li>and a third C++ wrapper by Peter Jones &lt;pjones@pmade.org&gt;
1422 <p>Website: <a
1423 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
1424 </li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1425 <li><a
1426 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1427 Sergeant</a> developed <a
1428 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1429 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1430 application server</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]1431 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides an
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1432 earlier version of the libxml/libxslt <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1433 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]1434 <li>Gopal.V and Peter Minten develop <a
1435 href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1436 C# libxml2 bindings.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1437 <li>Petr Kozelka provides <a
1438 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1439 libxml2</a> with Kylix, Delphi and other Pascal compilers.</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]1440 <li>Uwe Fechner also provides <a
1441 href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1442 implementation for Kylix2/D5/D6 from Borland.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1443 <li>Wai-Sun "Squidster" Chia provides <a
1444 href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and
1445 libxml2 bindings are also available in Ruby through the <a
1446 href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module
1447 maintained by Tobias Peters.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1448 <li>Steve Ball and contributors maintains <a
1449 href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1450 Tcl</a>.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1451 <li>There is support for libxml2 in the DOM module of PHP.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1452</ul>
1453
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1454<p>The distribution includes a set of Python bindings, which are guaranteed
1455to be maintained as part of the library in the future, though the Python
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1456interface have not yet reached the maturity of the C API.</p>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1457
1458<p>To install the Python bindings there are 2 options:</p>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1459<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1460 <li>If you use an RPM based distribution, simply install the <a
1461 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python
1462 RPM</a> (and if needed the <a
1463 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python
1464 RPM</a>).</li>
1465 <li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python
1466 module distribution</a> corresponding to your installed version of
1467 libxml2 and libxslt. Note that to install it you will need both libxml2
1468 and libxslt installed and run "python setup.py build install" in the
1469 module tree.</li>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1470</ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1471
1472<p>The distribution includes a set of examples and regression tests for the
1473python bindings in the <code>python/tests</code> directory. Here are some
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1474excerpts from those tests:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1475
1476<h3>tst.py:</h3>
1477
1478<p>This is a basic test of the file interface and DOM navigation:</p>
1479<pre>import libxml2
1480
1481doc = libxml2.parseFile("tst.xml")
1482if doc.name != "tst.xml":
1483 print "doc.name failed"
1484 sys.exit(1)
1485root = doc.children
1486if root.name != "doc":
1487 print "root.name failed"
1488 sys.exit(1)
1489child = root.children
1490if child.name != "foo":
1491 print "child.name failed"
1492 sys.exit(1)
1493doc.freeDoc()</pre>
1494
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1495<p>The Python module is called libxml2; parseFile is the equivalent of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1496xmlParseFile (most of the bindings are automatically generated, and the xml
1497prefix is removed and the casing convention are kept). All node seen at the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1498binding level share the same subset of accessors:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1499<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1500 <li><code>name</code> : returns the node name</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1501 <li><code>type</code> : returns a string indicating the node type</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1502 <li><code>content</code> : returns the content of the node, it is based on
1503 xmlNodeGetContent() and hence is recursive.</li>
1504 <li><code>parent</code> , <code>children</code>, <code>last</code>,
1505 <code>next</code>, <code>prev</code>, <code>doc</code>,
1506 <code>properties</code>: pointing to the associated element in the tree,
1507 those may return None in case no such link exists.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1508</ul>
1509
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1510<p>Also note the need to explicitly deallocate documents with freeDoc() .
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1511Reference counting for libxml2 trees would need quite a lot of work to
1512function properly, and rather than risk memory leaks if not implemented
1513correctly it sounds safer to have an explicit function to free a tree. The
1514wrapper python objects like doc, root or child are them automatically garbage
1515collected.</p>
1516
1517<h3>validate.py:</h3>
1518
1519<p>This test check the validation interfaces and redirection of error
1520messages:</p>
1521<pre>import libxml2
1522
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1523#deactivate error messages from the validation
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1524def noerr(ctx, str):
1525 pass
1526
1527libxml2.registerErrorHandler(noerr, None)
1528
1529ctxt = libxml2.createFileParserCtxt("invalid.xml")
1530ctxt.validate(1)
1531ctxt.parseDocument()
1532doc = ctxt.doc()
1533valid = ctxt.isValid()
1534doc.freeDoc()
1535if valid != 0:
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1536 print "validity check failed"</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1537
1538<p>The first thing to notice is the call to registerErrorHandler(), it
1539defines a new error handler global to the library. It is used to avoid seeing
1540the error messages when trying to validate the invalid document.</p>
1541
1542<p>The main interest of that test is the creation of a parser context with
1543createFileParserCtxt() and how the behaviour can be changed before calling
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1544parseDocument() . Similarly the informations resulting from the parsing phase
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1545are also available using context methods.</p>
1546
1547<p>Contexts like nodes are defined as class and the libxml2 wrappers maps the
1548C function interfaces in terms of objects method as much as possible. The
1549best to get a complete view of what methods are supported is to look at the
1550libxml2.py module containing all the wrappers.</p>
1551
1552<h3>push.py:</h3>
1553
1554<p>This test show how to activate the push parser interface:</p>
1555<pre>import libxml2
1556
1557ctxt = libxml2.createPushParser(None, "&lt;foo", 4, "test.xml")
1558ctxt.parseChunk("/&gt;", 2, 1)
1559doc = ctxt.doc()
1560
1561doc.freeDoc()</pre>
1562
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1563<p>The context is created with a special call based on the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1564xmlCreatePushParser() from the C library. The first argument is an optional
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1565SAX callback object, then the initial set of data, the length and the name of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1566the resource in case URI-References need to be computed by the parser.</p>
1567
1568<p>Then the data are pushed using the parseChunk() method, the last call
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1569setting the third argument terminate to 1.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1570
1571<h3>pushSAX.py:</h3>
1572
1573<p>this test show the use of the event based parsing interfaces. In this case
1574the parser does not build a document, but provides callback information as
1575the parser makes progresses analyzing the data being provided:</p>
1576<pre>import libxml2
1577log = ""
1578
1579class callback:
1580 def startDocument(self):
1581 global log
1582 log = log + "startDocument:"
1583
1584 def endDocument(self):
1585 global log
1586 log = log + "endDocument:"
1587
1588 def startElement(self, tag, attrs):
1589 global log
1590 log = log + "startElement %s %s:" % (tag, attrs)
1591
1592 def endElement(self, tag):
1593 global log
1594 log = log + "endElement %s:" % (tag)
1595
1596 def characters(self, data):
1597 global log
1598 log = log + "characters: %s:" % (data)
1599
1600 def warning(self, msg):
1601 global log
1602 log = log + "warning: %s:" % (msg)
1603
1604 def error(self, msg):
1605 global log
1606 log = log + "error: %s:" % (msg)
1607
1608 def fatalError(self, msg):
1609 global log
1610 log = log + "fatalError: %s:" % (msg)
1611
1612handler = callback()
1613
1614ctxt = libxml2.createPushParser(handler, "&lt;foo", 4, "test.xml")
1615chunk = " url='tst'&gt;b"
1616ctxt.parseChunk(chunk, len(chunk), 0)
1617chunk = "ar&lt;/foo&gt;"
1618ctxt.parseChunk(chunk, len(chunk), 1)
1619
Daniel Veillardfcbfa2d2002-02-21 17:54:27 +0000[diff] [blame]1620reference = "startDocument:startElement foo {'url': 'tst'}:" + \
1621 "characters: bar:endElement foo:endDocument:"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1622if log != reference:
1623 print "Error got: %s" % log
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1624 print "Expected: %s" % reference</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1625
1626<p>The key object in that test is the handler, it provides a number of entry
1627points which can be called by the parser as it makes progresses to indicate
1628the information set obtained. The full set of callback is larger than what
1629the callback class in that specific example implements (see the SAX
1630definition for a complete list). The wrapper will only call those supplied by
1631the object when activated. The startElement receives the names of the element
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1632and a dictionary containing the attributes carried by this element.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1633
1634<p>Also note that the reference string generated from the callback shows a
1635single character call even though the string "bar" is passed to the parser
1636from 2 different call to parseChunk()</p>
1637
1638<h3>xpath.py:</h3>
1639
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1640<p>This is a basic test of XPath wrappers support</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1641<pre>import libxml2
1642
1643doc = libxml2.parseFile("tst.xml")
1644ctxt = doc.xpathNewContext()
1645res = ctxt.xpathEval("//*")
1646if len(res) != 2:
1647 print "xpath query: wrong node set size"
1648 sys.exit(1)
1649if res[0].name != "doc" or res[1].name != "foo":
1650 print "xpath query: wrong node set value"
1651 sys.exit(1)
1652doc.freeDoc()
1653ctxt.xpathFreeContext()</pre>
1654
1655<p>This test parses a file, then create an XPath context to evaluate XPath
1656expression on it. The xpathEval() method execute an XPath query and returns
1657the result mapped in a Python way. String and numbers are natively converted,
1658and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1659the document, the XPath context need to be freed explicitly, also not that
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1660the result of the XPath query may point back to the document tree and hence
1661the document must be freed after the result of the query is used.</p>
1662
1663<h3>xpathext.py:</h3>
1664
1665<p>This test shows how to extend the XPath engine with functions written in
1666python:</p>
1667<pre>import libxml2
1668
1669def foo(ctx, x):
1670 return x + 1
1671
1672doc = libxml2.parseFile("tst.xml")
1673ctxt = doc.xpathNewContext()
1674libxml2.registerXPathFunction(ctxt._o, "foo", None, foo)
1675res = ctxt.xpathEval("foo(1)")
1676if res != 2:
1677 print "xpath extension failure"
1678doc.freeDoc()
1679ctxt.xpathFreeContext()</pre>
1680
1681<p>Note how the extension function is registered with the context (but that
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1682part is not yet finalized, this may change slightly in the future).</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1683
1684<h3>tstxpath.py:</h3>
1685
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1686<p>This test is similar to the previous one but shows how the extension
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1687function can access the XPath evaluation context:</p>
1688<pre>def foo(ctx, x):
1689 global called
1690
1691 #
1692 # test that access to the XPath evaluation contexts
1693 #
1694 pctxt = libxml2.xpathParserContext(_obj=ctx)
1695 ctxt = pctxt.context()
1696 called = ctxt.function()
1697 return x + 1</pre>
1698
1699<p>All the interfaces around the XPath parser(or rather evaluation) context
1700are not finalized, but it should be sufficient to do contextual work at the
1701evaluation point.</p>
1702
1703<h3>Memory debugging:</h3>
1704
1705<p>last but not least, all tests starts with the following prologue:</p>
1706<pre>#memory debug specific
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1707libxml2.debugMemory(1)</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1708
1709<p>and ends with the following epilogue:</p>
1710<pre>#memory debug specific
1711libxml2.cleanupParser()
1712if libxml2.debugMemory(1) == 0:
1713 print "OK"
1714else:
1715 print "Memory leak %d bytes" % (libxml2.debugMemory(1))
1716 libxml2.dumpMemory()</pre>
1717
1718<p>Those activate the memory debugging interface of libxml2 where all
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1719allocated block in the library are tracked. The prologue then cleans up the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1720library state and checks that all allocated memory has been freed. If not it
1721calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1722
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1723<h2><a name="architecture">libxml architecture</a></h2>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1724
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1725<p>Libxml is made of multiple components; some of them are optional, and most
1726of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1727<ul>
1728 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1729 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1730 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1731 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1732 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1733 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1734 <li>a SAX tree module to build an in-memory DOM representation</li>
1735 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1736 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1737 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1738 (optional)</li>
1739 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1740</ul>
1741
1742<p>Graphically this gives the following:</p>
1743
1744<p><img src="libxml.gif" alt="a graphical view of the various"></p>
1745
1746<p></p>
1747
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1748<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1749
1750<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1751returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1752<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1753as the file name, the document type, and a <strong>children</strong> pointer
1754which is the root of the document (or more exactly the first child under the
1755root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1756chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1757relationship. An xmlNode can also carry properties (a chain of xmlAttr
1758structures). An attribute may have a value which is a list of TEXT or
1759ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1760
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1761<p>Here is an example (erroneous with respect to the XML spec since there
1762should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1763
1764<p><img src="structure.gif" alt=" structure.gif "></p>
1765
1766<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1767called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1768prints them back as parsed. This is useful for detecting errors both in XML
1769code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1770which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1771result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1772<pre>DOCUMENT
1773version=1.0
1774standalone=true
1775 ELEMENT EXAMPLE
1776 ATTRIBUTE prop1
1777 TEXT
1778 content=gnome is great
1779 ATTRIBUTE prop2
1780 ENTITY_REF
1781 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1782 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1783 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1784 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1785 TEXT
1786 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1787 ELEMENT chapter
1788 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1789 TEXT
1790 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1791 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1792 TEXT
1793 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1794 ELEMENT image
1795 ATTRIBUTE href
1796 TEXT
1797 content=linus.gif
1798 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1799 TEXT
1800 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1801
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1802<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1803
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1804<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1805
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1806<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1807memory. 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]1808loaded using libxml), it's better to use the SAX interface of libxml. SAX is
1809a <strong>callback-based interface</strong> to the parser. Before parsing,
1810the application layer registers a customized set of callbacks which are
1811called by the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1812
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1813<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]1814libxml, see the <a
1815href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
1816documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1817Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1818
1819<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
1820program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1821binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1822distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1823testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1824<pre>SAX.setDocumentLocator()
1825SAX.startDocument()
1826SAX.getEntity(amp)
1827SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
1828SAX.characters( , 3)
1829SAX.startElement(head)
1830SAX.characters( , 4)
1831SAX.startElement(title)
1832SAX.characters(Welcome to Gnome, 16)
1833SAX.endElement(title)
1834SAX.characters( , 3)
1835SAX.endElement(head)
1836SAX.characters( , 3)
1837SAX.startElement(chapter)
1838SAX.characters( , 4)
1839SAX.startElement(title)
1840SAX.characters(The Linux adventure, 19)
1841SAX.endElement(title)
1842SAX.characters( , 4)
1843SAX.startElement(p)
1844SAX.characters(bla bla bla ..., 15)
1845SAX.endElement(p)
1846SAX.characters( , 4)
1847SAX.startElement(image, href='linus.gif')
1848SAX.endElement(image)
1849SAX.characters( , 4)
1850SAX.startElement(p)
1851SAX.characters(..., 3)
1852SAX.endElement(p)
1853SAX.characters( , 3)
1854SAX.endElement(chapter)
1855SAX.characters( , 1)
1856SAX.endElement(EXAMPLE)
1857SAX.endDocument()</pre>
1858
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1859<p>Most of the other interfaces of libxml are based on the DOM tree-building
1860facility, so nearly everything up to the end of this document presupposes the
1861use of the standard DOM tree build. Note that the DOM tree itself is built by
1862a set of registered default callbacks, without internal specific
1863interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1864
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1865<h2><a name="Validation">Validation &amp; DTDs</a></h2>
1866
1867<p>Table of Content:</p>
1868<ol>
1869 <li><a href="#General5">General overview</a></li>
1870 <li><a href="#definition">The definition</a></li>
1871 <li><a href="#Simple">Simple rules</a>
1872 <ol>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]1873 <li><a href="#reference">How to reference a DTD from a document</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1874 <li><a href="#Declaring">Declaring elements</a></li>
1875 <li><a href="#Declaring1">Declaring attributes</a></li>
1876 </ol>
1877 </li>
1878 <li><a href="#Some">Some examples</a></li>
1879 <li><a href="#validate">How to validate</a></li>
1880 <li><a href="#Other">Other resources</a></li>
1881</ol>
1882
1883<h3><a name="General5">General overview</a></h3>
1884
1885<p>Well what is validation and what is a DTD ?</p>
1886
1887<p>DTD is the acronym for Document Type Definition. This is a description of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1888the 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^]1889specification, and allows one to describe and verify that a given document
1890instance conforms to the set of rules detailing its structure and content.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1891
1892<p>Validation is the process of checking a document against a DTD (more
1893generally against a set of construction rules).</p>
1894
1895<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1896of the XML life cycle. Briefly a DTD defines all the possible elements to be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1897found within your document, what is the formal shape of your document tree
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1898(by defining the allowed content of an element; either text, a regular
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1899expression for the allowed list of children, or mixed content i.e. both text
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1900and children). The DTD also defines the valid attributes for all elements
1901and the types of those attributes.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1902
1903<h3><a name="definition1">The definition</a></h3>
1904
1905<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
1906href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
1907Rev1</a>):</p>
1908<ul>
1909 <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
1910 elements</a></li>
1911 <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
1912 attributes</a></li>
1913</ul>
1914
1915<p>(unfortunately) all this is inherited from the SGML world, the syntax is
1916ancient...</p>
1917
1918<h3><a name="Simple1">Simple rules</a></h3>
1919
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1920<p>Writing DTDs can be done in many ways. The rules to build them if you
1921need something permanent or something which can evolve over time can be radically
1922different. Really complex DTDs like DocBook ones are flexible but quite harder
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1923to design. I will just focus on DTDs for a formats with a fixed simple
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1924structure. It is just a set of basic rules, and definitely not exhaustive nor
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1925usable for complex DTD design.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1926
1927<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
1928
1929<p>Assuming the top element of the document is <code>spec</code> and the dtd
1930is placed in the file <code>mydtd</code> in the subdirectory
1931<code>dtds</code> of the directory from where the document were loaded:</p>
1932
1933<p><code>&lt;!DOCTYPE spec SYSTEM "dtds/mydtd"&gt;</code></p>
1934
1935<p>Notes:</p>
1936<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1937 <li>The system string is actually an URI-Reference (as defined in <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1938 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^]1939 full URL string indicating the location of your DTD on the Web. This is a
1940 really good thing to do if you want others to validate your document.</li>
1941 <li>It is also possible to associate a <code>PUBLIC</code> identifier (a
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1942 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^]1943 without having to locate it on the web.</li>
1944 <li>A DTD contains a set of element and attribute declarations, but they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1945 don't define what the root of the document should be. This is explicitly
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1946 told to the parser/validator as the first element of the
1947 <code>DOCTYPE</code> declaration.</li>
1948</ul>
1949
1950<h4><a name="Declaring2">Declaring elements</a>:</h4>
1951
1952<p>The following declares an element <code>spec</code>:</p>
1953
1954<p><code>&lt;!ELEMENT spec (front, body, back?)&gt;</code></p>
1955
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1956<p>It also expresses that the spec element contains one <code>front</code>,
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]1957one <code>body</code> and one optional <code>back</code> children elements in
1958this order. The declaration of one element of the structure and its content
1959are done in a single declaration. Similarly the following declares
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1960<code>div1</code> elements:</p>
1961
Daniel Veillard51737272002-01-23 23:10:38 +0000[diff] [blame]1962<p><code>&lt;!ELEMENT div1 (head, (p | list | note)*, div2?)&gt;</code></p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1963
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1964<p>which means div1 contains one <code>head</code> then a series of optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1965<code>p</code>, <code>list</code>s and <code>note</code>s and then an
1966optional <code>div2</code>. And last but not least an element can contain
1967text:</p>
1968
1969<p><code>&lt;!ELEMENT b (#PCDATA)&gt;</code></p>
1970
1971<p><code>b</code> contains text or being of mixed content (text and elements
1972in no particular order):</p>
1973
1974<p><code>&lt;!ELEMENT p (#PCDATA|a|ul|b|i|em)*&gt;</code></p>
1975
1976<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
1977<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
1978order.</p>
1979
1980<h4><a name="Declaring1">Declaring attributes</a>:</h4>
1981
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]1982<p>Again the attributes declaration includes their content definition:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1983
1984<p><code>&lt;!ATTLIST termdef name CDATA #IMPLIED&gt;</code></p>
1985
1986<p>means that the element <code>termdef</code> can have a <code>name</code>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1987attribute containing text (<code>CDATA</code>) and which is optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1988(<code>#IMPLIED</code>). The attribute value can also be defined within a
1989set:</p>
1990
1991<p><code>&lt;!ATTLIST list type (bullets|ordered|glossary)
1992"ordered"&gt;</code></p>
1993
1994<p>means <code>list</code> element have a <code>type</code> attribute with 3
1995allowed values "bullets", "ordered" or "glossary" and which default to
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]1996"ordered" if the attribute is not explicitly specified.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1997
1998<p>The content type of an attribute can be text (<code>CDATA</code>),
1999anchor/reference/references
2000(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
2001(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
2002(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
2003<code>chapter</code> element can have an optional <code>id</code> attribute
2004of type <code>ID</code>, usable for reference from attribute of type
2005IDREF:</p>
2006
2007<p><code>&lt;!ATTLIST chapter id ID #IMPLIED&gt;</code></p>
2008
2009<p>The last value of an attribute definition can be <code>#REQUIRED
2010</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
2011meaning that it is optional, or the default value (possibly prefixed by
2012<code>#FIXED</code> if it is the only allowed).</p>
2013
2014<p>Notes:</p>
2015<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]2016 <li>Usually the attributes pertaining to a given element are declared in a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2017 single expression, but it is just a convention adopted by a lot of DTD
2018 writers:
2019 <pre>&lt;!ATTLIST termdef
2020 id ID #REQUIRED
2021 name CDATA #IMPLIED&gt;</pre>
2022 <p>The previous construct defines both <code>id</code> and
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]2023 <code>name</code> attributes for the element <code>termdef</code>.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2024 </li>
2025</ul>
2026
2027<h3><a name="Some1">Some examples</a></h3>
2028
2029<p>The directory <code>test/valid/dtds/</code> in the libxml distribution
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]2030contains some complex DTD examples. The example in the file <code>test/valid/dia.xml</code>
2031shows an XML file where the simple DTD is directly included within
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2032the document.</p>
2033
2034<h3><a name="validate1">How to validate</a></h3>
2035
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]2036<p>The simplest way is to use the xmllint program included with libxml. The
2037<code>--valid</code> option turns-on validation of the files given as input.
2038For example the following validates a copy of the first revision of the XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]20391.0 specification:</p>
2040
2041<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
2042
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]2043<p>the -- noout is used to disable output of the resulting tree.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2044
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame^]2045<p>The <code>--dtdvalid dtd</code> allows validation of the document(s) against
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2046a given DTD.</p>
2047
2048<p>Libxml exports an API to handle DTDs and validation, check the <a
2049href="http://xmlsoft.org/html/libxml-valid.html">associated
2050description</a>.</p>
2051
2052<h3><a name="Other1">Other resources</a></h3>
2053
2054<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
2055will just list one for now, others pointers welcome:</p>
2056<ul>
2057 <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
2058</ul>
2059
2060<p>I suggest looking at the examples found under test/valid/dtd and any of
2061the large number of books available on XML. The dia example in test/valid
2062should be both simple and complete enough to allow you to build your own.</p>
2063
2064<p></p>
2065
2066<h2><a name="Memory">Memory Management</a></h2>
2067
2068<p>Table of Content:</p>
2069<ol>
2070 <li><a href="#General3">General overview</a></li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2071 <li><a href="#setting">Setting libxml set of memory routines</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2072 <li><a href="#cleanup">Cleaning up after parsing</a></li>
2073 <li><a href="#Debugging">Debugging routines</a></li>
2074 <li><a href="#General4">General memory requirements</a></li>
2075</ol>
2076
2077<h3><a name="General3">General overview</a></h3>
2078
2079<p>The module <code><a
2080href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
2081provides the interfaces to the libxml memory system:</p>
2082<ul>
2083 <li>libxml does not use the libc memory allocator directly but xmlFree(),
2084 xmlMalloc() and xmlRealloc()</li>
2085 <li>those routines can be reallocated to a specific set of routine, by
2086 default the libc ones i.e. free(), malloc() and realloc()</li>
2087 <li>the xmlmemory.c module includes a set of debugging routine</li>
2088</ul>
2089
2090<h3><a name="setting">Setting libxml set of memory routines</a></h3>
2091
2092<p>It is sometimes useful to not use the default memory allocator, either for
2093debugging, analysis or to implement a specific behaviour on memory management
2094(like on embedded systems). Two function calls are available to do so:</p>
2095<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2096 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet
2097 ()</a> which return the current set of functions in use by the parser</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2098 <li><a
2099 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2100 which allow to set up a new set of memory allocation functions</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2101</ul>
2102
2103<p>Of course a call to xmlMemSetup() should probably be done before calling
2104any other libxml routines (unless you are sure your allocations routines are
2105compatibles).</p>
2106
2107<h3><a name="cleanup">Cleaning up after parsing</a></h3>
2108
2109<p>Libxml is not stateless, there is a few set of memory structures needing
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2110allocation before the parser is fully functional (some encoding structures
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2111for example). This also mean that once parsing is finished there is a tiny
2112amount of memory (a few hundred bytes) which can be recollected if you don't
2113reuse the parser immediately:</p>
2114<ul>
2115 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2116 ()</a> is a centralized routine to free the parsing states. Note that it
2117 won't deallocate any produced tree if any (use the xmlFreeDoc() and
2118 related routines for this).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2119 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2120 ()</a> is the dual routine allowing to preallocate the parsing state
2121 which can be useful for example to avoid initialization reentrancy
2122 problems when using libxml in multithreaded applications</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2123</ul>
2124
2125<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
2126at the next invocation of parser routines, but be careful of the consequences
2127in multithreaded applications.</p>
2128
2129<h3><a name="Debugging">Debugging routines</a></h3>
2130
2131<p>When configured using --with-mem-debug flag (off by default), libxml uses
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2132a set of memory allocation debugging routines keeping track of all allocated
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2133blocks and the location in the code where the routine was called. A couple of
2134other debugging routines allow to dump the memory allocated infos to a file
2135or call a specific routine when a given block number is allocated:</p>
2136<ul>
2137 <li><a
2138 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2139 <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2140 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
2141 and <a
2142 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
2143 are the memory debugging replacement allocation routines</li>
2144 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2145 ()</a> dumps all the informations about the allocated memory block lefts
2146 in the <code>.memdump</code> file</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2147</ul>
2148
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2149<p>When developing libxml memory debug is enabled, the tests programs call
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2150xmlMemoryDump () and the "make test" regression tests will check for any
2151memory leak during the full regression test sequence, this helps a lot
2152ensuring that libxml does not leak memory and bullet proof memory
2153allocations use (some libc implementations are known to be far too permissive
2154resulting in major portability problems!).</p>
2155
2156<p>If the .memdump reports a leak, it displays the allocation function and
2157also tries to give some informations about the content and structure of the
2158allocated blocks left. This is sufficient in most cases to find the culprit,
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2159but not always. Assuming the allocation problem is reproducible, it is
2160possible to find more easily:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2161<ol>
2162 <li>write down the block number xxxx not allocated</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2163 <li>export the environment variable XML_MEM_BREAKPOINT=xxxx , the easiest
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2164 when using GDB is to simply give the command
2165 <p><code>set environment XML_MEM_BREAKPOINT xxxx</code></p>
2166 <p>before running the program.</p>
2167 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2168 <li>run the program under a debugger and set a breakpoint on
2169 xmlMallocBreakpoint() a specific function called when this precise block
2170 is allocated</li>
2171 <li>when the breakpoint is reached you can then do a fine analysis of the
2172 allocation an step to see the condition resulting in the missing
2173 deallocation.</li>
2174</ol>
2175
2176<p>I used to use a commercial tool to debug libxml memory problems but after
2177noticing that it was not detecting memory leaks that simple mechanism was
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2178used and proved extremely efficient until now. Lately I have also used <a
2179href="http://developer.kde.org/~sewardj/">valgrind</a> with quite some
2180success, it is tied to the i386 architecture since it works by emulating the
2181processor and instruction set, it is slow but extremely efficient, i.e. it
2182spot memory usage errors in a very precise way.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2183
2184<h3><a name="General4">General memory requirements</a></h3>
2185
2186<p>How much libxml memory require ? It's hard to tell in average it depends
2187of a number of things:</p>
2188<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2189 <li>the parser itself should work in a fixed amount of memory, except for
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2190 information maintained about the stacks of names and entities locations.
2191 The I/O and encoding handlers will probably account for a few KBytes.
2192 This is true for both the XML and HTML parser (though the HTML parser
2193 need more state).</li>
2194 <li>If you are generating the DOM tree then memory requirements will grow
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2195 nearly linear with the size of the data. In general for a balanced
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2196 textual document the internal memory requirement is about 4 times the
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2197 size of the UTF8 serialization of this document (example the XML-1.0
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2198 recommendation is a bit more of 150KBytes and takes 650KBytes of main
2199 memory when parsed). Validation will add a amount of memory required for
2200 maintaining the external Dtd state which should be linear with the
2201 complexity of the content model defined by the Dtd</li>
2202 <li>If you don't care about the advanced features of libxml like
2203 validation, DOM, XPath or XPointer, but really need to work fixed memory
2204 requirements, then the SAX interface should be used.</li>
2205</ul>
2206
2207<p></p>
2208
2209<h2><a name="Encodings">Encodings support</a></h2>
2210
2211<p>Table of Content:</p>
2212<ol>
2213 <li><a href="encoding.html#What">What does internationalization support
2214 mean ?</a></li>
2215 <li><a href="encoding.html#internal">The internal encoding, how and
2216 why</a></li>
2217 <li><a href="encoding.html#implemente">How is it implemented ?</a></li>
2218 <li><a href="encoding.html#Default">Default supported encodings</a></li>
2219 <li><a href="encoding.html#extend">How to extend the existing
2220 support</a></li>
2221</ol>
2222
2223<h3><a name="What">What does internationalization support mean ?</a></h3>
2224
2225<p>XML was designed from the start to allow the support of any character set
2226by using Unicode. Any conformant XML parser has to support the UTF-8 and
2227UTF-16 default encodings which can both express the full unicode ranges. UTF8
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2228is a variable length encoding whose greatest points are to reuse the same
2229encoding for ASCII and to save space for Western encodings, but it is a bit
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2230more complex to handle in practice. UTF-16 use 2 bytes per characters (and
2231sometimes combines two pairs), it makes implementation easier, but looks a
2232bit overkill for Western languages encoding. Moreover the XML specification
2233allows document to be encoded in other encodings at the condition that they
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2234are clearly labeled as such. For example the following is a wellformed XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2235document encoded in ISO-8859 1 and using accentuated letter that we French
2236likes for both markup and content:</p>
2237<pre>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2238&lt;très&gt;là&lt;/très&gt;</pre>
2239
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2240<p>Having internationalization support in libxml means the following:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2241<ul>
2242 <li>the document is properly parsed</li>
2243 <li>informations about it's encoding are saved</li>
2244 <li>it can be modified</li>
2245 <li>it can be saved in its original encoding</li>
2246 <li>it can also be saved in another encoding supported by libxml (for
2247 example straight UTF8 or even an ASCII form)</li>
2248</ul>
2249
2250<p>Another very important point is that the whole libxml API, with the
2251exception of a few routines to read with a specific encoding or save to a
2252specific encoding, is completely agnostic about the original encoding of the
2253document.</p>
2254
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2255<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]2256the same rules too, the following document will be (as of 2.2.2) handled in
2257an internationalized fashion by libxml too:</p>
2258<pre>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
2259 "http://www.w3.org/TR/REC-html40/loose.dtd"&gt;
2260&lt;html lang="fr"&gt;
2261&lt;head&gt;
2262 &lt;META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&gt;
2263&lt;/head&gt;
2264&lt;body&gt;
2265&lt;p&gt;W3C crée des standards pour le Web.&lt;/body&gt;
2266&lt;/html&gt;</pre>
2267
2268<h3><a name="internal">The internal encoding, how and why</a></h3>
2269
2270<p>One of the core decision was to force all documents to be converted to a
2271default internal encoding, and that encoding to be UTF-8, here are the
2272rationale for those choices:</p>
2273<ul>
2274 <li>keeping the native encoding in the internal form would force the libxml
2275 users (or the code associated) to be fully aware of the encoding of the
2276 original document, for examples when adding a text node to a document,
2277 the content would have to be provided in the document encoding, i.e. the
2278 client code would have to check it before hand, make sure it's conformant
2279 to the encoding, etc ... Very hard in practice, though in some specific
2280 cases this may make sense.</li>
2281 <li>the second decision was which encoding. From the XML spec only UTF8 and
2282 UTF16 really makes sense as being the two only encodings for which there
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2283 is mandatory support. UCS-4 (32 bits fixed size encoding) could be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2284 considered an intelligent choice too since it's a direct Unicode mapping
2285 support. I selected UTF-8 on the basis of efficiency and compatibility
2286 with surrounding software:
2287 <ul>
2288 <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
2289 more costly to import and export CPU wise) is also far more compact
2290 than UTF-16 (and UCS-4) for a majority of the documents I see it used
2291 for right now (RPM RDF catalogs, advogato data, various configuration
2292 file formats, etc.) and the key point for today's computer
2293 architecture is efficient uses of caches. If one nearly double the
2294 memory requirement to store the same amount of data, this will trash
2295 caches (main memory/external caches/internal caches) and my take is
2296 that this harms the system far more than the CPU requirements needed
2297 for the conversion to UTF-8</li>
2298 <li>Most of libxml version 1 users were using it with straight ASCII
2299 most of the time, doing the conversion with an internal encoding
2300 requiring all their code to be rewritten was a serious show-stopper
2301 for using UTF-16 or UCS-4.</li>
2302 <li>UTF-8 is being used as the de-facto internal encoding standard for
2303 related code like the <a href="http://www.pango.org/">pango</a>
2304 upcoming Gnome text widget, and a lot of Unix code (yep another place
2305 where Unix programmer base takes a different approach from Microsoft
2306 - they are using UTF-16)</li>
2307 </ul>
2308 </li>
2309</ul>
2310
2311<p>What does this mean in practice for the libxml user:</p>
2312<ul>
2313 <li>xmlChar, the libxml data type is a byte, those bytes must be assembled
2314 as UTF-8 valid strings. The proper way to terminate an xmlChar * string
2315 is simply to append 0 byte, as usual.</li>
2316 <li>One just need to make sure that when using chars outside the ASCII set,
2317 the values has been properly converted to UTF-8</li>
2318</ul>
2319
2320<h3><a name="implemente">How is it implemented ?</a></h3>
2321
2322<p>Let's describe how all this works within libxml, basically the I18N
2323(internationalization) support get triggered only during I/O operation, i.e.
2324when reading a document or saving one. Let's look first at the reading
2325sequence:</p>
2326<ol>
2327 <li>when a document is processed, we usually don't know the encoding, a
2328 simple heuristic allows to detect UTF-18 and UCS-4 from whose where the
2329 ASCII range (0-0x7F) maps with ASCII</li>
2330 <li>the xml declaration if available is parsed, including the encoding
2331 declaration. At that point, if the autodetected encoding is different
2332 from the one declared a call to xmlSwitchEncoding() is issued.</li>
2333 <li>If there is no encoding declaration, then the input has to be in either
2334 UTF-8 or UTF-16, if it is not then at some point when processing the
2335 input, the converter/checker of UTF-8 form will raise an encoding error.
2336 You may end-up with a garbled document, or no document at all ! Example:
2337 <pre>~/XML -&gt; ./xmllint err.xml
2338err.xml:1: error: Input is not proper UTF-8, indicate encoding !
2339&lt;très&gt;là&lt;/très&gt;
2340 ^
2341err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
2342&lt;très&gt;là&lt;/très&gt;
2343 ^</pre>
2344 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2345 <li>xmlSwitchEncoding() does an encoding name lookup, canonicalize it, and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2346 then search the default registered encoding converters for that encoding.
2347 If it's not within the default set and iconv() support has been compiled
2348 it, it will ask iconv for such an encoder. If this fails then the parser
2349 will report an error and stops processing:
2350 <pre>~/XML -&gt; ./xmllint err2.xml
2351err2.xml:1: error: Unsupported encoding UnsupportedEnc
2352&lt;?xml version="1.0" encoding="UnsupportedEnc"?&gt;
2353 ^</pre>
2354 </li>
Daniel Veillard46c5c1d2002-05-20 07:15:54 +0000[diff] [blame]2355 <li>From that point the encoder processes progressively the input (it is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2356 plugged as a front-end to the I/O module) for that entity. It captures
2357 and convert on-the-fly the document to be parsed to UTF-8. The parser
2358 itself just does UTF-8 checking of this input and process it
2359 transparently. The only difference is that the encoding information has
2360 been added to the parsing context (more precisely to the input
2361 corresponding to this entity).</li>
2362 <li>The result (when using DOM) is an internal form completely in UTF-8
2363 with just an encoding information on the document node.</li>
2364</ol>
2365
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2366<p>Ok then what happens when saving the document (assuming you
2367collected/built an xmlDoc DOM like structure) ? It depends on the function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2368called, xmlSaveFile() will just try to save in the original encoding, while
2369xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
2370encoding:</p>
2371<ol>
2372 <li>if no encoding is given, libxml will look for an encoding value
2373 associated to the document and if it exists will try to save to that
2374 encoding,
2375 <p>otherwise everything is written in the internal form, i.e. UTF-8</p>
2376 </li>
2377 <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]2378 document, libxml will again canonicalize the encoding name, lookup for a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2379 converter in the registered set or through iconv. If not found the
2380 function will return an error code</li>
2381 <li>the converter is placed before the I/O buffer layer, as another kind of
2382 buffer, then libxml will simply push the UTF-8 serialization to through
2383 that buffer, which will then progressively be converted and pushed onto
2384 the I/O layer.</li>
2385 <li>It is possible that the converter code fails on some input, for example
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2386 trying to push an UTF-8 encoded Chinese character through the UTF-8 to
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2387 ISO-8859-1 converter won't work. Since the encoders are progressive they
2388 will just report the error and the number of bytes converted, at that
2389 point libxml will decode the offending character, remove it from the
2390 buffer and replace it with the associated charRef encoding &amp;#123; and
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2391 resume the conversion. This guarantees that any document will be saved
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2392 without losses (except for markup names where this is not legal, this is
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2393 a problem in the current version, in practice avoid using non-ascii
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2394 characters for tags or attributes names @@). A special "ascii" encoding
2395 name is used to save documents to a pure ascii form can be used when
2396 portability is really crucial</li>
2397</ol>
2398
2399<p>Here is a few examples based on the same test document:</p>
2400<pre>~/XML -&gt; ./xmllint isolat1
2401&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2402&lt;très&gt;là&lt;/très&gt;
2403~/XML -&gt; ./xmllint --encode UTF-8 isolat1
2404&lt;?xml version="1.0" encoding="UTF-8"?&gt;
2405&lt;très&gt;là  &lt;/très&gt;
2406~/XML -&gt; </pre>
2407
2408<p>The same processing is applied (and reuse most of the code) for HTML I18N
2409processing. Looking up and modifying the content encoding is a bit more
2410difficult since it is located in a &lt;meta&gt; tag under the &lt;head&gt;,
2411so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
2412been provided. The parser also attempts to switch encoding on the fly when
2413detecting such a tag on input. Except for that the processing is the same
2414(and again reuses the same code).</p>
2415
2416<h3><a name="Default">Default supported encodings</a></h3>
2417
2418<p>libxml has a set of default converters for the following encodings
2419(located in encoding.c):</p>
2420<ol>
2421 <li>UTF-8 is supported by default (null handlers)</li>
2422 <li>UTF-16, both little and big endian</li>
2423 <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
2424 <li>ASCII, useful mostly for saving</li>
2425 <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
2426 predefined entities like &amp;copy; for the Copyright sign.</li>
2427</ol>
2428
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2429<p>More over when compiled on an Unix platform with iconv support the full
2430set of encodings supported by iconv can be instantly be used by libxml. On a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2431linux machine with glibc-2.1 the list of supported encodings and aliases fill
24323 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
2433various Japanese ones.</p>
2434
2435<h4>Encoding aliases</h4>
2436
2437<p>From 2.2.3, libxml has support to register encoding names aliases. The
2438goal is to be able to parse document whose encoding is supported but where
2439the name differs (for example from the default set of names accepted by
2440iconv). The following functions allow to register and handle new aliases for
2441existing encodings. Once registered libxml will automatically lookup the
2442aliases when handling a document:</p>
2443<ul>
2444 <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li>
2445 <li>int xmlDelEncodingAlias(const char *alias);</li>
2446 <li>const char * xmlGetEncodingAlias(const char *alias);</li>
2447 <li>void xmlCleanupEncodingAliases(void);</li>
2448</ul>
2449
2450<h3><a name="extend">How to extend the existing support</a></h3>
2451
2452<p>Well adding support for new encoding, or overriding one of the encoders
2453(assuming it is buggy) should not be hard, just write an input and output
2454conversion routines to/from UTF-8, and register them using
2455xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
2456called automatically if the parser(s) encounter such an encoding name
2457(register it uppercase, this will help). The description of the encoders,
2458their arguments and expected return values are described in the encoding.h
2459header.</p>
2460
2461<p>A quick note on the topic of subverting the parser to use a different
2462internal encoding than UTF-8, in some case people will absolutely want to
2463keep the internal encoding different, I think it's still possible (but the
2464encoding must be compliant with ASCII on the same subrange) though I didn't
2465tried it. The key is to override the default conversion routines (by
2466registering null encoders/decoders for your charsets), and bypass the UTF-8
2467checking of the parser by setting the parser context charset
2468(ctxt-&gt;charset) to something different than XML_CHAR_ENCODING_UTF8, but
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2469there is no guarantee that this will work. You may also have some troubles
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2470saving back.</p>
2471
2472<p>Basically proper I18N support is important, this requires at least
2473libxml-2.0.0, but a lot of features and corrections are really available only
2474starting 2.2.</p>
2475
2476<h2><a name="IO">I/O Interfaces</a></h2>
2477
2478<p>Table of Content:</p>
2479<ol>
2480 <li><a href="#General1">General overview</a></li>
2481 <li><a href="#basic">The basic buffer type</a></li>
2482 <li><a href="#Input">Input I/O handlers</a></li>
2483 <li><a href="#Output">Output I/O handlers</a></li>
2484 <li><a href="#entities">The entities loader</a></li>
2485 <li><a href="#Example2">Example of customized I/O</a></li>
2486</ol>
2487
2488<h3><a name="General1">General overview</a></h3>
2489
2490<p>The module <code><a
2491href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
2492the interfaces to the libxml I/O system. This consists of 4 main parts:</p>
2493<ul>
2494 <li>Entities loader, this is a routine which tries to fetch the entities
2495 (files) based on their PUBLIC and SYSTEM identifiers. The default loader
2496 don't look at the public identifier since libxml do not maintain a
2497 catalog. You can redefine you own entity loader by using
2498 <code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2499 <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
2500 example</a>.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2501 <li>Input I/O buffers which are a commodity structure used by the parser(s)
2502 input layer to handle fetching the informations to feed the parser. This
2503 provides buffering and is also a placeholder where the encoding
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2504 converters to UTF8 are piggy-backed.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2505 <li>Output I/O buffers are similar to the Input ones and fulfill similar
2506 task but when generating a serialization from a tree.</li>
2507 <li>A mechanism to register sets of I/O callbacks and associate them with
2508 specific naming schemes like the protocol part of the URIs.
2509 <p>This affect the default I/O operations and allows to use specific I/O
2510 handlers for certain names.</p>
2511 </li>
2512</ul>
2513
2514<p>The general mechanism used when loading http://rpmfind.net/xml.html for
2515example in the HTML parser is the following:</p>
2516<ol>
2517 <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
2518 the parsing context and the URI string.</li>
2519 <li>the URI string is checked against the existing registered handlers
2520 using their match() callback function, if the HTTP module was compiled
2521 in, it is registered and its match() function will succeeds</li>
2522 <li>the open() function of the handler is called and if successful will
2523 return an I/O Input buffer</li>
2524 <li>the parser will the start reading from this buffer and progressively
2525 fetch information from the resource, calling the read() function of the
2526 handler until the resource is exhausted</li>
2527 <li>if an encoding change is detected it will be installed on the input
2528 buffer, providing buffering and efficient use of the conversion
2529 routines</li>
2530 <li>once the parser has finished, the close() function of the handler is
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2531 called once and the Input buffer and associated resources are
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2532 deallocated.</li>
2533</ol>
2534
2535<p>The user defined callbacks are checked first to allow overriding of the
2536default libxml I/O routines.</p>
2537
2538<h3><a name="basic">The basic buffer type</a></h3>
2539
2540<p>All the buffer manipulation handling is done using the
2541<code>xmlBuffer</code> type define in <code><a
2542href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
2543resizable memory buffer. The buffer allocation strategy can be selected to be
2544either best-fit or use an exponential doubling one (CPU vs. memory use
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]2545trade-off). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2546<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
2547system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
2548of functions allows to manipulate buffers with names starting with the
2549<code>xmlBuffer...</code> prefix.</p>
2550
2551<h3><a name="Input">Input I/O handlers</a></h3>
2552
2553<p>An Input I/O handler is a simple structure
2554<code>xmlParserInputBuffer</code> containing a context associated to the
2555resource (file descriptor, or pointer to a protocol handler), the read() and
2556close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
2557encoding handler are also present to support charset conversion when
2558needed.</p>
2559
2560<h3><a name="Output">Output I/O handlers</a></h3>
2561
2562<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
2563Input one except the callbacks are write() and close().</p>
2564
2565<h3><a name="entities">The entities loader</a></h3>
2566
2567<p>The entity loader resolves requests for new entities and create inputs for
2568the parser. Creating an input from a filename or an URI string is done
2569through the xmlNewInputFromFile() routine. The default entity loader do not
2570handle the PUBLIC identifier associated with an entity (if any). So it just
2571calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
2572XML).</p>
2573
2574<p>If you want to hook up a catalog mechanism then you simply need to
2575override the default entity loader, here is an example:</p>
2576<pre>#include &lt;libxml/xmlIO.h&gt;
2577
2578xmlExternalEntityLoader defaultLoader = NULL;
2579
2580xmlParserInputPtr
2581xmlMyExternalEntityLoader(const char *URL, const char *ID,
2582 xmlParserCtxtPtr ctxt) {
2583 xmlParserInputPtr ret;
2584 const char *fileID = NULL;
2585 /* lookup for the fileID depending on ID */
2586
2587 ret = xmlNewInputFromFile(ctxt, fileID);
2588 if (ret != NULL)
2589 return(ret);
2590 if (defaultLoader != NULL)
2591 ret = defaultLoader(URL, ID, ctxt);
2592 return(ret);
2593}
2594
2595int main(..) {
2596 ...
2597
2598 /*
2599 * Install our own entity loader
2600 */
2601 defaultLoader = xmlGetExternalEntityLoader();
2602 xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
2603
2604 ...
2605}</pre>
2606
2607<h3><a name="Example2">Example of customized I/O</a></h3>
2608
2609<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
2610real use case</a>, xmlDocDump() closes the FILE * passed by the application
2611and this was a problem. The <a
2612href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
2613new output handler with the closing call deactivated:</p>
2614<ol>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2615 <li>First define a new I/O output allocator where the output don't close
2616 the file:
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2617 <pre>xmlOutputBufferPtr
2618xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
2619    xmlOutputBufferPtr ret;
2620    
2621    if (xmlOutputCallbackInitialized == 0)
2622        xmlRegisterDefaultOutputCallbacks();
2623
2624    if (file == NULL) return(NULL);
2625    ret = xmlAllocOutputBuffer(encoder);
2626    if (ret != NULL) {
2627        ret-&gt;context = file;
2628        ret-&gt;writecallback = xmlFileWrite;
2629        ret-&gt;closecallback = NULL; /* No close callback */
2630    }
2631    return(ret); <br>
Daniel Veillard1eb24242002-03-18 11:33:03 +0000[diff] [blame]2632
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]2633
2634
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]2635
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]2636
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2637
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]2638
Daniel Veillard0bfbb422002-04-26 09:21:45 +0000[diff] [blame]2639
Daniel Veillard93d3a472002-04-26 14:04:55 +0000[diff] [blame]2640
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]2641
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame]2642
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000[diff] [blame]2643
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]2644
Daniel Veillard21473672002-06-17 07:29:22 +0000[diff] [blame]2645
Daniel Veillard782afda2002-07-08 15:12:49 +0000[diff] [blame]2646
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2647} </pre>
2648 </li>
2649 <li>And then use it to save the document:
2650 <pre>FILE *f;
2651xmlOutputBufferPtr output;
2652xmlDocPtr doc;
2653int res;
2654
2655f = ...
2656doc = ....
2657
2658output = xmlOutputBufferCreateOwn(f, NULL);
2659res = xmlSaveFileTo(output, doc, NULL);
2660 </pre>
2661 </li>
2662</ol>
2663
2664<h2><a name="Catalog">Catalog support</a></h2>
2665
2666<p>Table of Content:</p>
2667<ol>
2668 <li><a href="General2">General overview</a></li>
2669 <li><a href="#definition">The definition</a></li>
2670 <li><a href="#Simple">Using catalogs</a></li>
2671 <li><a href="#Some">Some examples</a></li>
2672 <li><a href="#reference">How to tune catalog usage</a></li>
2673 <li><a href="#validate">How to debug catalog processing</a></li>
2674 <li><a href="#Declaring">How to create and maintain catalogs</a></li>
2675 <li><a href="#implemento">The implementor corner quick review of the
2676 API</a></li>
2677 <li><a href="#Other">Other resources</a></li>
2678</ol>
2679
2680<h3><a name="General2">General overview</a></h3>
2681
2682<p>What is a catalog? Basically it's a lookup mechanism used when an entity
2683(a file or a remote resource) references another entity. The catalog lookup
2684is inserted between the moment the reference is recognized by the software
2685(XML parser, stylesheet processing, or even images referenced for inclusion
2686in a rendering) and the time where loading that resource is actually
2687started.</p>
2688
2689<p>It is basically used for 3 things:</p>
2690<ul>
2691 <li>mapping from "logical" names, the public identifiers and a more
2692 concrete name usable for download (and URI). For example it can associate
2693 the logical name
2694 <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
2695 <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
2696 downloaded</p>
2697 <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
2698 </li>
2699 <li>remapping from a given URL to another one, like an HTTP indirection
2700 saying that
2701 <p>"http://www.oasis-open.org/committes/tr.xsl"</p>
2702 <p>should really be looked at</p>
2703 <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
2704 </li>
2705 <li>providing a local cache mechanism allowing to load the entities
2706 associated to public identifiers or remote resources, this is a really
2707 important feature for any significant deployment of XML or SGML since it
2708 allows to avoid the aleas and delays associated to fetching remote
2709 resources.</li>
2710</ul>
2711
2712<h3><a name="definition">The definitions</a></h3>
2713
2714<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
2715<ul>
2716 <li>the older SGML catalogs, the official spec is SGML Open Technical
2717 Resolution TR9401:1997, but is better understood by reading <a
2718 href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
2719 James Clark. This is relatively old and not the preferred mode of
2720 operation of libxml.</li>
2721 <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2722 Catalogs</a> is far more flexible, more recent, uses an XML syntax and
2723 should scale quite better. This is the default option of libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2724</ul>
2725
2726<p></p>
2727
2728<h3><a name="Simple">Using catalog</a></h3>
2729
2730<p>In a normal environment libxml will by default check the presence of a
2731catalog in /etc/xml/catalog, and assuming it has been correctly populated,
2732the processing is completely transparent to the document user. To take a
2733concrete example, suppose you are authoring a DocBook document, this one
2734starts with the following DOCTYPE definition:</p>
2735<pre>&lt;?xml version='1.0'?&gt;
2736&lt;!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
2737 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"&gt;</pre>
2738
2739<p>When validating the document with libxml, the catalog will be
2740automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
2741DocBk XML V3.1.4//EN" and the system identifier
2742"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
2743been installed on your system and the catalogs actually point to them, libxml
2744will fetch them from the local disk.</p>
2745
2746<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
2747DOCTYPE example it's a really old version, but is fine as an example.</p>
2748
2749<p>Libxml will check the catalog each time that it is requested to load an
2750entity, this includes DTD, external parsed entities, stylesheets, etc ... If
2751your system is correctly configured all the authoring phase and processing
2752should use only local files, even if your document stays portable because it
2753uses the canonical public and system ID, referencing the remote document.</p>
2754
2755<h3><a name="Some">Some examples:</a></h3>
2756
2757<p>Here is a couple of fragments from XML Catalogs used in libxml early
2758regression tests in <code>test/catalogs</code> :</p>
2759<pre>&lt;?xml version="1.0"?&gt;
2760&lt;!DOCTYPE catalog PUBLIC
2761 "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2762 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2763&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2764 &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2765 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2766...</pre>
2767
2768<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
2769written in XML, there is a specific namespace for catalog elements
2770"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
2771catalog is a <code>public</code> mapping it allows to associate a Public
2772Identifier with an URI.</p>
2773<pre>...
2774 &lt;rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2775 rewritePrefix="file:///usr/share/xml/docbook/"/&gt;
2776...</pre>
2777
2778<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
2779any URI starting with a given prefix should be looked at another URI
2780constructed by replacing the prefix with an new one. In effect this acts like
2781a cache system for a full area of the Web. In practice it is extremely useful
2782with a file prefix if you have installed a copy of those resources on your
2783local system.</p>
2784<pre>...
2785&lt;delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
2786 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2787&lt;delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
2788 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2789&lt;delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
2790 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2791&lt;delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2792 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2793&lt;delegateURI uriStartString="http://www.oasis-open.org/docbook/"
2794 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2795...</pre>
2796
2797<p>Delegation is the core features which allows to build a tree of catalogs,
2798easier to maintain than a single catalog, based on Public Identifier, System
2799Identifier or URI prefixes it instructs the catalog software to look up
2800entries in another resource. This feature allow to build hierarchies of
2801catalogs, the set of entries presented should be sufficient to redirect the
2802resolution of all DocBook references to the specific catalog in
2803<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
2804references for DocBook 4.2.1 to a specific catalog installed at the same time
2805as the DocBook resources on the local machine.</p>
2806
2807<h3><a name="reference">How to tune catalog usage:</a></h3>
2808
2809<p>The user can change the default catalog behaviour by redirecting queries
2810to its own set of catalogs, this can be done by setting the
2811<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
2812empty one should deactivate loading the default <code>/etc/xml/catalog</code>
2813default catalog</p>
2814
2815<h3><a name="validate">How to debug catalog processing:</a></h3>
2816
2817<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
2818make libxml output debugging informations for each catalog operations, for
2819example:</p>
2820<pre>orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2821warning: failed to load external entity "title.xml"
2822orchis:~/XML -&gt; export XML_DEBUG_CATALOG=
2823orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2824Failed to parse catalog /etc/xml/catalog
2825Failed to parse catalog /etc/xml/catalog
2826warning: failed to load external entity "title.xml"
2827Catalogs cleanup
2828orchis:~/XML -&gt; </pre>
2829
2830<p>The test/ent2 references an entity, running the parser from memory makes
2831the base URI unavailable and the the "title.xml" entity cannot be loaded.
2832Setting up the debug environment variable allows to detect that an attempt is
2833made to load the <code>/etc/xml/catalog</code> but since it's not present the
2834resolution fails.</p>
2835
2836<p>But the most advanced way to debug XML catalog processing is to use the
2837<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
2838catalogs and make resolution queries to see what is going on. This is also
2839used for the regression tests:</p>
2840<pre>orchis:~/XML -&gt; ./xmlcatalog test/catalogs/docbook.xml \
2841 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2842http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2843orchis:~/XML -&gt; </pre>
2844
2845<p>For debugging what is going on, adding one -v flags increase the verbosity
2846level to indicate the processing done (adding a second flag also indicate
2847what elements are recognized at parsing):</p>
2848<pre>orchis:~/XML -&gt; ./xmlcatalog -v test/catalogs/docbook.xml \
2849 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2850Parsing catalog test/catalogs/docbook.xml's content
2851Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
2852http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2853Catalogs cleanup
2854orchis:~/XML -&gt; </pre>
2855
2856<p>A shell interface is also available to debug and process multiple queries
2857(and for regression tests):</p>
2858<pre>orchis:~/XML -&gt; ./xmlcatalog -shell test/catalogs/docbook.xml \
2859 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2860&gt; help
2861Commands available:
2862public PublicID: make a PUBLIC identifier lookup
2863system SystemID: make a SYSTEM identifier lookup
2864resolve PublicID SystemID: do a full resolver lookup
2865add 'type' 'orig' 'replace' : add an entry
2866del 'values' : remove values
2867dump: print the current catalog state
2868debug: increase the verbosity level
2869quiet: decrease the verbosity level
2870exit: quit the shell
2871&gt; public "-//OASIS//DTD DocBook XML V4.1.2//EN"
2872http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2873&gt; quit
2874orchis:~/XML -&gt; </pre>
2875
2876<p>This should be sufficient for most debugging purpose, this was actually
2877used heavily to debug the XML Catalog implementation itself.</p>
2878
2879<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
2880
2881<p>Basically XML Catalogs are XML files, you can either use XML tools to
2882manage them or use <strong>xmlcatalog</strong> for this. The basic step is
2883to create a catalog the -create option provide this facility:</p>
2884<pre>orchis:~/XML -&gt; ./xmlcatalog --create tst.xml
2885&lt;?xml version="1.0"?&gt;
2886&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2887 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2888&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2889orchis:~/XML -&gt; </pre>
2890
2891<p>By default xmlcatalog does not overwrite the original catalog and save the
2892result on the standard output, this can be overridden using the -noout
2893option. The <code>-add</code> command allows to add entries in the
2894catalog:</p>
2895<pre>orchis:~/XML -&gt; ./xmlcatalog --noout --create --add "public" \
2896 "-//OASIS//DTD DocBook XML V4.1.2//EN" \
2897 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
2898orchis:~/XML -&gt; cat tst.xml
2899&lt;?xml version="1.0"?&gt;
2900&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
2901 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2902&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2903&lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2904 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2905&lt;/catalog&gt;
2906orchis:~/XML -&gt; </pre>
2907
2908<p>The <code>-add</code> option will always take 3 parameters even if some of
2909the XML Catalog constructs (like nextCatalog) will have only a single
2910argument, just pass a third empty string, it will be ignored.</p>
2911
2912<p>Similarly the <code>-del</code> option remove matching entries from the
2913catalog:</p>
2914<pre>orchis:~/XML -&gt; ./xmlcatalog --del \
2915 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
2916&lt;?xml version="1.0"?&gt;
2917&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2918 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2919&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2920orchis:~/XML -&gt; </pre>
2921
2922<p>The catalog is now empty. Note that the matching of <code>-del</code> is
2923exact and would have worked in a similar fashion with the Public ID
2924string.</p>
2925
2926<p>This is rudimentary but should be sufficient to manage a not too complex
2927catalog tree of resources.</p>
2928
2929<h3><a name="implemento">The implementor corner quick review of the
2930API:</a></h3>
2931
2932<p>First, and like for every other module of libxml, there is an
2933automatically generated <a href="html/libxml-catalog.html">API page for
2934catalog support</a>.</p>
2935
2936<p>The header for the catalog interfaces should be included as:</p>
2937<pre>#include &lt;libxml/catalog.h&gt;</pre>
2938
2939<p>The API is voluntarily kept very simple. First it is not obvious that
2940applications really need access to it since it is the default behaviour of
2941libxml (Note: it is possible to completely override libxml default catalog by
2942using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
2943plug an application specific resolver).</p>
2944
2945<p>Basically libxml support 2 catalog lists:</p>
2946<ul>
2947 <li>the default one, global shared by all the application</li>
2948 <li>a per-document catalog, this one is built if the document uses the
2949 <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
2950 associated to the parser context and destroyed when the parsing context
2951 is destroyed.</li>
2952</ul>
2953
2954<p>the document one will be used first if it exists.</p>
2955
2956<h4>Initialization routines:</h4>
2957
2958<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
2959used at startup to initialize the catalog, if the catalog should be
2960initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
2961should be called before xmlInitializeCatalog() which would otherwise do a
2962default initialization first.</p>
2963
2964<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
2965own catalog list if needed.</p>
2966
2967<h4>Preferences setup:</h4>
2968
2969<p>The XML Catalog spec requires the possibility to select default
2970preferences between public and system delegation,
2971xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
2972xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
2973be forbidden, allowed for global catalog, for document catalog or both, the
2974default is to allow both.</p>
2975
2976<p>And of course xmlCatalogSetDebug() allows to generate debug messages
2977(through the xmlGenericError() mechanism).</p>
2978
2979<h4>Querying routines:</h4>
2980
2981<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
2982and xmlCatalogResolveURI() are relatively explicit if you read the XML
2983Catalog specification they correspond to section 7 algorithms, they should
2984also work if you have loaded an SGML catalog with a simplified semantic.</p>
2985
2986<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
2987operate on the document catalog list</p>
2988
2989<h4>Cleanup and Miscellaneous:</h4>
2990
2991<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
2992the per-document equivalent.</p>
2993
2994<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
2995first catalog in the global list, and xmlCatalogDump() allows to dump a
2996catalog state, those routines are primarily designed for xmlcatalog, I'm not
2997sure that exposing more complex interfaces (like navigation ones) would be
2998really useful.</p>
2999
3000<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
3001it's similar as xmlParseFile() except it bypass all catalog lookups, it's
3002provided because this functionality may be useful for client tools.</p>
3003
3004<h4>threaded environments:</h4>
3005
3006<p>Since the catalog tree is built progressively, some care has been taken to
3007try to avoid troubles in multithreaded environments. The code is now thread
3008safe assuming that the libxml library has been compiled with threads
3009support.</p>
3010
3011<p></p>
3012
3013<h3><a name="Other">Other resources</a></h3>
3014
3015<p>The XML Catalog specification is relatively recent so there isn't much
3016literature to point at:</p>
3017<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3018 <li>You can find a good rant from Norm Walsh about <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3019 href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
3020 need for catalogs</a>, it provides a lot of context informations even if
Daniel Veillard93d3a472002-04-26 14:04:55 +0000[diff] [blame]3021 I don't agree with everything presented. Norm also wrote a more recent
3022 article <a
3023 href="http://wwws.sun.com/software/xml/developers/resolver/article/">XML
3024 entities and URI resolvers</a> describing them.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3025 <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
3026 catalog proposal</a> from John Cowan</li>
3027 <li>The <a href="http://www.rddl.org/">Resource Directory Description
3028 Language</a> (RDDL) another catalog system but more oriented toward
3029 providing metadata for XML namespaces.</li>
3030 <li>the page from the OASIS Technical <a
3031 href="http://www.oasis-open.org/committees/entity/">Committee on Entity
3032 Resolution</a> who maintains XML Catalog, you will find pointers to the
3033 specification update, some background and pointers to others tools
3034 providing XML Catalog support</li>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3035 <li>Here is a <a href="buildDocBookCatalog">shell script</a> to generate
3036 XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
3037 directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
3038 the resources found on the system. Otherwise it will just create
3039 ~/xmlcatalog and ~/dbkxmlcatalog and doing:
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]3040 <p><code>export XMLCATALOG=$HOME/xmlcatalog</code></p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3041 <p>should allow to process DocBook documentations without requiring
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3042 network accesses for the DTD or stylesheets</p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3043 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3044 <li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3045 small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
3046 to work fine for me too</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3047 <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
3048 manual page</a></li>
3049</ul>
3050
3051<p>If you have suggestions for corrections or additions, simply contact
3052me:</p>
3053
3054<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3055
3056<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3057using the XML library from the C language. It is not intended to be
3058extensive. I hope the automatically generated documents will provide the
3059completeness required, but as a separate set of documents. The interfaces of
3060the XML library are by principle low level, there is nearly zero abstraction.
3061Those interested in a higher level API should <a href="#DOM">look at
3062DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3063
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3064<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
3065separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3066interfaces</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]3067
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3068<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3069
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3070<p>Usually, the first thing to do is to read an XML input. The parser accepts
3071documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3072defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3073<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3074 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3075 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3076 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3077</dl>
3078<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3079 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3080 <dd><p>Parse an XML document contained in a (possibly compressed)
3081 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3082 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3083</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3084
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3085<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]3086failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3087
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3088<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3089
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3090<p>In order for the application to keep the control when the document is
3091being fetched (which is common for GUI based programs) libxml provides a push
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3092interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3093<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
3094 void *user_data,
3095 const char *chunk,
3096 int size,
3097 const char *filename);
3098int xmlParseChunk (xmlParserCtxtPtr ctxt,
3099 const char *chunk,
3100 int size,
3101 int terminate);</pre>
3102
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3103<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3104<pre> FILE *f;
3105
3106 f = fopen(filename, "r");
3107 if (f != NULL) {
3108 int res, size = 1024;
3109 char chars[1024];
3110 xmlParserCtxtPtr ctxt;
3111
3112 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3113 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3114 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
3115 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3116 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3117 xmlParseChunk(ctxt, chars, res, 0);
3118 }
3119 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3120 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3121 xmlFreeParserCtxt(ctxt);
3122 }
3123 }</pre>
3124
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3125<p>The HTML parser embedded into libxml also has a push interface; the
3126functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3127
3128<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
3129
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3130<p>The tree-building interface makes the parser memory-hungry, first loading
3131the document in memory and then building the tree itself. Reading a document
3132without building the tree is possible using the SAX interfaces (see SAX.h and
3133<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]3134Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3135limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3136<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3137
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3138<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3139
3140<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]3141there is a set of functions dedicated to building new elements. (These are
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3142also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of
3143code that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3144<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3145 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3146 xmlNodePtr tree, subtree;
3147
3148 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3149 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
3150 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
3151 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
3152 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3153 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3154 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3155 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
3156 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
3157 subtree = xmlNewChild(tree, NULL, "image", NULL);
3158 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3159
3160<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3161
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3162<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3163
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3164<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3165code has access to the internal structure of all the elements of the tree.
3166The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]3167<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3168<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3169example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3170<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3171
3172<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3173<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3174
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3175<p>points to the text node containing the chapter title "The Linux
3176adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3177
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3178<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]3179present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3180to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]3181<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3182
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3183<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3184
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3185<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3186is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3187<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3188 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
3189 xmlChar *value);</code></dt>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3190 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
3191 The value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3192 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3193</dl>
3194<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3195 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3196 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]3197 <dd><p>This function returns a pointer to new copy of the property
3198 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3199 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3200</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3201
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3202<p>Two functions are provided for reading and writing the text associated
3203with elements:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3204<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3205 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3206 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3207 <dd><p>This function takes an "external" string and converts it to one
3208 text node or possibly to a list of entity and text nodes. All
3209 non-predefined entity references like &amp;Gnome; will be stored
3210 internally as entity nodes, hence the result of the function may not be
3211 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3212 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3213</dl>
3214<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3215 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3216 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3217 <dd><p>This function is the inverse of
3218 <code>xmlStringGetNodeList()</code>. It generates a new string
3219 containing the content of the text and entity nodes. Note the extra
3220 argument inLine. If this argument is set to 1, the function will expand
3221 entity references. For example, instead of returning the &amp;Gnome;
3222 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3223 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3224 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3225</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3226
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3227<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3228
3229<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3230<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3231 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3232 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3233 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3234 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3235</dl>
3236<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3237 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3238 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3239 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3240</dl>
3241<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3242 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3243 <dd><p>Saves the document to a file. In this case, the compression
3244 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3245 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3246</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3247
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3248<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3249
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3250<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3251accesses. The level of compression on saves can be turned on either globally
3252or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3253<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3254 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3255 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3256 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3257</dl>
3258<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3259 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3260 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3261 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3262</dl>
3263<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3264 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3265 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3266 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3267</dl>
3268<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3269 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3270 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3271 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3272</dl>
3273
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3274<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3275
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3276<p>Entities in principle are similar to simple C macros. An entity defines an
3277abbreviation for a given string that you can reuse many times throughout the
3278content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3279may occur frequently within a document, or to confine the change needed to a
3280document to a restricted area in the internal subset of the document (at the
3281beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3282<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]32832 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]32843 &lt;!ENTITY xml "Extensible Markup Language"&gt;
32854 ]&gt;
32865 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]32876 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]32887 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3289
3290<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]3291its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3292are 5 predefined entities in libxml allowing you to escape characters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3293predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3294<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3295for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3296<strong>&amp;quot;</strong> for the character '"', and
3297<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3298
3299<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]3300substitute an entity's content so that you can see the replacement text in
3301your application. Or you may prefer to keep entity references as such in the
3302content to be able to save the document back without losing this usually
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3303precious information (if the user went through the pain of explicitly
3304defining entities, he may have a a rather negative attitude if you blindly
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3305substitute them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3306href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3307function allows you to check and change the behaviour, which is to not
3308substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3309
3310<p>Here is the DOM tree built by libxml for the previous document in the
3311default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3312<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3313DOCUMENT
3314version=1.0
3315 ELEMENT EXAMPLE
3316 TEXT
3317 content=
3318 ENTITY_REF
3319 INTERNAL_GENERAL_ENTITY xml
3320 content=Extensible Markup Language
3321 TEXT
3322 content=</pre>
3323
3324<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3325<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3326DOCUMENT
3327version=1.0
3328 ELEMENT EXAMPLE
3329 TEXT
3330 content= Extensible Markup Language</pre>
3331
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3332<p>So, entities or no entities? Basically, it depends on your use case. I
3333suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3334entities in your XML document or data if you are not willing to handle the
3335entity references elements in the DOM tree.</p>
3336
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3337<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3338entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3339transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3340reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3341finding them in the input).</p>
3342
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3343<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3344on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3345non-predefined entities in your documents, then the learning curve to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3346then 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]3347strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]3348deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3349
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3350<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3351
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3352<p>The libxml library implements <a
3353href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3354recognizing namespace constructs in the input, and does namespace lookup
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3355automatically when building the DOM tree. A namespace declaration is
3356associated with an in-memory structure and all elements or attributes within
3357that namespace point to it. Hence testing the namespace is a simple and fast
3358equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3359
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3360<p>I suggest that people using libxml use a namespace, and declare it in the
3361root element of their document as the default namespace. Then they don't need
3362to 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]3363refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3364the size of the XML output significantly, but significantly increases its
3365value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3366<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
3367 &lt;elem1&gt;...&lt;/elem1&gt;
3368 &lt;elem2&gt;...&lt;/elem2&gt;
3369&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3370
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3371<p>The namespace value has to be an absolute URL, but the URL doesn't have to
3372point to any existing resource on the Web. It will bind all the element and
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3373attributes with that URL. I suggest to use an URL within a domain you
3374control, and that the URL should contain some kind of version information if
3375possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a
3376good namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3377
3378<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3379version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3380and if the version information don't match something you know, warn the user
3381and 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]3382namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3383same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3384associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3385just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3386<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3387prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3388
3389<p>@@Interfaces@@</p>
3390
3391<p>@@Examples@@</p>
3392
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3393<p>Usually people object to using namespaces together with validity checking.
3394I will try to make sure that using namespaces won't break validity checking,
3395so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3396suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3397<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3398flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3399from multiple DTDs will certainly break current validation schemes. I will
3400try to provide ways to do this, but this may not be portable or
3401standardized.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3402
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3403<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3404
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3405<p>Incompatible changes:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3406
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3407<p>Version 2 of libxml is the first version introducing serious backward
3408incompatible changes. The main goals were:</p>
3409<ul>
3410 <li>a general cleanup. A number of mistakes inherited from the very early
3411 versions couldn't be changed due to compatibility constraints. Example
3412 the "childs" element in the nodes.</li>
3413 <li>Uniformization of the various nodes, at least for their header and link
3414 parts (doc, parent, children, prev, next), the goal is a simpler
3415 programming model and simplifying the task of the DOM implementors.</li>
3416 <li>better conformances to the XML specification, for example version 1.x
3417 had an heuristic to try to detect ignorable white spaces. As a result the
3418 SAX event generated were ignorableWhitespace() while the spec requires
3419 character() in that case. This also mean that a number of DOM node
3420 containing blank text may populate the DOM tree which were not present
3421 before.</li>
3422</ul>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3423
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3424<h3>How to fix libxml-1.x code:</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3425
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3426<p>So client code of libxml designed to run with version 1.x may have to be
3427changed to compile against version 2.x of libxml. Here is a list of changes
3428that I have collected, they may not be sufficient, so in case you find other
3429change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
3430mail</a>:</p>
3431<ol>
3432 <li>The package name have changed from libxml to libxml2, the library name
3433 is now -lxml2 . There is a new xml2-config script which should be used to
3434 select the right parameters libxml2</li>
3435 <li>Node <strong>childs</strong> field has been renamed
3436 <strong>children</strong> so s/childs/children/g should be applied
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3437 (probability of having "childs" anywhere else is close to 0+</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3438 <li>The document don't have anymore a <strong>root</strong> element it has
3439 been replaced by <strong>children</strong> and usually you will get a
3440 list of element here. For example a Dtd element for the internal subset
3441 and it's declaration may be found in that list, as well as processing
3442 instructions or comments found before or after the document root element.
3443 Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3444 a document. Alternatively if you are sure to not reference DTDs nor have
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3445 PIs or comments before or after the root element
3446 s/-&gt;root/-&gt;children/g will probably do it.</li>
3447 <li>The white space issue, this one is more complex, unless special case of
3448 validating parsing, the line breaks and spaces usually used for indenting
3449 and formatting the document content becomes significant. So they are
3450 reported by SAX and if your using the DOM tree, corresponding nodes are
3451 generated. Too approach can be taken:
3452 <ol>
3453 <li>lazy one, use the compatibility call
3454 <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
3455 relying on a special (and possibly broken) set of heuristics of
3456 libxml to detect ignorable blanks. Don't complain if it breaks or
3457 make your application not 100% clean w.r.t. to it's input.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3458 <li>the Right Way: change you code to accept possibly insignificant
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3459 blanks characters, or have your tree populated with weird blank text
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3460 nodes. You can spot them using the commodity function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3461 <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
3462 nodes.</li>
3463 </ol>
3464 <p>Note also that with the new default the output functions don't add any
3465 extra indentation when saving a tree in order to be able to round trip
3466 (read and save) without inflating the document with extra formatting
3467 chars.</p>
3468 </li>
3469 <li>The include path has changed to $prefix/libxml/ and the includes
3470 themselves uses this new prefix in includes instructions... If you are
3471 using (as expected) the
3472 <pre>xml2-config --cflags</pre>
3473 <p>output to generate you compile commands this will probably work out of
3474 the box</p>
3475 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3476 <li>xmlDetectCharEncoding takes an extra argument indicating the length in
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3477 byte of the head of the document available for character detection.</li>
3478</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3479
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3480<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3481
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3482<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]3483to allow smooth upgrade of existing libxml v1code while retaining
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3484compatibility. They offers the following:</p>
3485<ol>
3486 <li>similar include naming, one should use
3487 <strong>#include&lt;libxml/...&gt;</strong> in both cases.</li>
3488 <li>similar identifiers defined via macros for the child and root fields:
3489 respectively <strong>xmlChildrenNode</strong> and
3490 <strong>xmlRootNode</strong></li>
3491 <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
3492 inserted once in the client code</li>
3493</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3494
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3495<p>So the roadmap to upgrade your existing libxml applications is the
3496following:</p>
3497<ol>
3498 <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]3499 <li>find all occurrences where the xmlDoc <strong>root</strong> field is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3500 used and change it to <strong>xmlRootNode</strong></li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3501 <li>similarly find all occurrences where the xmlNode
3502 <strong>childs</strong> field is used and change it to
3503 <strong>xmlChildrenNode</strong></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3504 <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
3505 <strong>main()</strong> or in the library init entry point</li>
3506 <li>Recompile, check compatibility, it should still work</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]3507 <li>Change your configure script to look first for xml2-config and fall
3508 back using xml-config . Use the --cflags and --libs output of the command
3509 as the Include and Linking parameters needed to use libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3510 <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
3511 libxml-devel-1.8.y can be kept simultaneously)</li>
3512 <li>remove your config.cache, relaunch your configuration mechanism, and
3513 recompile, if steps 2 and 3 were done right it should compile as-is</li>
3514 <li>Test that your application is still running correctly, if not this may
3515 be due to extra empty nodes due to formating spaces being kept in libxml2
3516 contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
3517 code before calling the parser (next to
3518 <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
3519</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3520
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3521<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]3522
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3523<p>Let me put some emphasis on the fact that there is far more changes from
3524libxml 1.x to 2.x than the ones you may have to patch for. The overall code
3525has been considerably cleaned up and the conformance to the XML specification
3526has been drastically improved too. Don't take those changes as an excuse to
3527not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3528
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3529<h2><a name="Thread">Thread safety</a></h2>
3530
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3531<p>Starting with 2.4.7, libxml makes provisions to ensure that concurrent
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3532threads can safely work in parallel parsing different documents. There is
3533however a couple of things to do to ensure it:</p>
3534<ul>
3535 <li>configure the library accordingly using the --with-threads options</li>
3536 <li>call xmlInitParser() in the "main" thread before using any of the
3537 libxml API (except possibly selecting a different memory allocator)</li>
3538</ul>
3539
3540<p>Note that the thread safety cannot be ensured for multiple threads sharing
3541the same document, the locking must be done at the application level, libxml
3542exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
3543The parts of the library checked for thread safety are:</p>
3544<ul>
3545 <li>concurrent loading</li>
3546 <li>file access resolution</li>
3547 <li>catalog access</li>
3548 <li>catalog building</li>
3549 <li>entities lookup/accesses</li>
3550 <li>validation</li>
3551 <li>global variables per-thread override</li>
3552 <li>memory handling</li>
3553</ul>
3554
3555<p>XPath is supposed to be thread safe now, but this wasn't tested
3556seriously.</p>
3557
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3558<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3559
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3560<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
3561Object Model</em>; this is an API for accessing XML or HTML structured
3562documents. Native support for DOM in Gnome is on the way (module gnome-dom),
3563and will be based on gnome-xml. This will be a far cleaner interface to
3564manipulate XML files within Gnome since it won't expose the internal
3565structure.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3566
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3567<p>The current DOM implementation on top of libxml is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame]3568href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
3569is a full DOM interface, thanks to Paolo Casarini, check the <a
3570href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
3571informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3572
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3573<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3574
3575<p>Here is a real size example, where the actual content of the application
3576data 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]3577a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3578storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
3579base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3580<pre>&lt;?xml version="1.0"?&gt;
3581&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
3582 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3583
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3584 &lt;gjob:Job&gt;
3585 &lt;gjob:Project ID="3"/&gt;
3586 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
3587 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3588
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3589 &lt;gjob:Update&gt;
3590 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
3591 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
3592 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
3593 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3594
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3595 &lt;gjob:Developers&gt;
3596 &lt;gjob:Developer&gt;
3597 &lt;/gjob:Developer&gt;
3598 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3599
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3600 &lt;gjob:Contact&gt;
3601 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
3602 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
3603 &lt;gjob:Company&gt;
3604 &lt;/gjob:Company&gt;
3605 &lt;gjob:Organisation&gt;
3606 &lt;/gjob:Organisation&gt;
3607 &lt;gjob:Webpage&gt;
3608 &lt;/gjob:Webpage&gt;
3609 &lt;gjob:Snailmail&gt;
3610 &lt;/gjob:Snailmail&gt;
3611 &lt;gjob:Phone&gt;
3612 &lt;/gjob:Phone&gt;
3613 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3614
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3615 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3616 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3617 &lt;/gjob:Requirements&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:Skills&gt;
3620 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3621
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3622 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3623 A GNOME based system that will allow a superuser to configure
3624 compressed and uncompressed files and/or file systems to be backed
3625 up with a supported media in the system. This should be able to
3626 perform via find commands generating a list of files that are passed
3627 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
3628 or via operations performed on the filesystem itself. Email
3629 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3630 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3631
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3632 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3633
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3634 &lt;/gjob:Jobs&gt;
3635&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3636
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3637<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]3638calling only a couple of functions, browsing the tree to gather the data and
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3639generate the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3640
3641<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3642structure. For example, the ordering of the attributes is not significant,
3643the 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]3644depend on the order of the children of a given node, unless it really makes
3645things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3646<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3647 * A person record
3648 */
3649typedef struct person {
3650 char *name;
3651 char *email;
3652 char *company;
3653 char *organisation;
3654 char *smail;
3655 char *webPage;
3656 char *phone;
3657} person, *personPtr;
3658
3659/*
3660 * And the code needed to parse it
3661 */
3662personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3663 personPtr ret = NULL;
3664
3665DEBUG("parsePerson\n");
3666 /*
3667 * allocate the struct
3668 */
3669 ret = (personPtr) malloc(sizeof(person));
3670 if (ret == NULL) {
3671 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3672 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3673 }
3674 memset(ret, 0, sizeof(person));
3675
3676 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3677 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3678 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3679 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
3680 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3681 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
3682 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3683 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3684 }
3685
3686 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3687}</pre>
3688
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3689<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3690<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3691 <li>Usually a recursive parsing style is the more convenient one: XML data
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3692 is by nature subject to repetitive constructs and usually exhibits highly
3693 structured patterns.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3694 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
3695 i.e. the pointer to the global XML document and the namespace reserved to
3696 the application. Document wide information are needed for example to
3697 decode entities and it's a good coding practice to define a namespace for
3698 your application set of data and test that the element and attributes
3699 you're analyzing actually pertains to your application space. This is
3700 done by a simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3701 <li>To retrieve text and attributes value, you can use the function
3702 <em>xmlNodeListGetString</em> to gather all the text and entity reference
3703 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3704</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3705
3706<p>Here is another piece of code used to parse another level of the
3707structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3708<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3709/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3710 * a Description for a Job
3711 */
3712typedef struct job {
3713 char *projectID;
3714 char *application;
3715 char *category;
3716 personPtr contact;
3717 int nbDevelopers;
3718 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
3719} job, *jobPtr;
3720
3721/*
3722 * And the code needed to parse it
3723 */
3724jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3725 jobPtr ret = NULL;
3726
3727DEBUG("parseJob\n");
3728 /*
3729 * allocate the struct
3730 */
3731 ret = (jobPtr) malloc(sizeof(job));
3732 if (ret == NULL) {
3733 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3734 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3735 }
3736 memset(ret, 0, sizeof(job));
3737
3738 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3739 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3740 while (cur != NULL) {
3741
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3742 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
3743 ret-&gt;projectID = xmlGetProp(cur, "ID");
3744 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3745 fprintf(stderr, "Project has no ID\n");
3746 }
3747 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3748 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
3749 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3750 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
3751 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3752 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
3753 ret-&gt;contact = parsePerson(doc, ns, cur);
3754 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3755 }
3756
3757 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3758}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3759
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3760<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]3761boring. Ultimately, it could be possible to write stubbers taking either C
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3762data structure definitions, a set of XML examples or an XML DTD and produce
3763the code needed to import and export the content between C data and XML
3764storage. This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3765
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]3766<p>Feel free to use <a href="example/gjobread.c">the code for the full C
3767parsing example</a> as a template, it is also available with Makefile in the
3768Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3769
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3770<h2><a name="Contributi">Contributions</a></h2>
3771<ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3772 <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
3773 patches, Gary Pennington worked on the validation API, threading support
3774 and Solaris port.</li>
3775 <li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]3776 <li><a href="mailto:igor@stud.fh-frankfurt.de">Igor Zlatkovic</a> is now
3777 the maintainer of the Windows port, <a
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]3778 href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
3779 provides binaries</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3780 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
3781 <a href="http://garypennington.net/libxml2/">Solaris binaries</a></li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]3782 <li><a
3783 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]3784 Sergeant</a> developed <a
3785 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3786 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
3787 application server</a></li>
3788 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> and <a
3789 href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillardca989762001-06-23 17:39:29 +0000[diff] [blame]3790 href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]3791 documentation</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3792 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
3793 href="http://xmlsoft.org/messages/0488.html">man pages</a></li>
Daniel Veillard5168dbf2001-07-07 00:18:23 +0000[diff] [blame]3794 <li>there is a module for <a
3795 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
3796 in OpenNSD/AOLServer</a></li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]3797 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provided the
3798 first version of libxml/libxslt <a
3799 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li>
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]3800 <li>Petr Kozelka provides <a
3801 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
3802 libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]3803 <li><a href="mailto:aleksey@aleksey.com">Aleksey Sanin</a> implemented the
3804 <a href="http://www.w3.org/Signature/">XML Canonicalization and XML
3805 Digital Signature</a> <a
3806 href="http://www.aleksey.com/xmlsec/">implementations for libxml2</a></li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3807</ul>
3808
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3809<p></p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3810</body>
3811</html>