blob: 05ddbfb5542d1c25b3fa988d9cb855c0612e9d89 [file] [log] [blame]
Daniel Veillard09ab7e12001-07-10 15:49:44 +00001<!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 +00003<html>
4<head>
Daniel Veillardec78c0f2000-08-25 10:25:23 +00005 <title>The XML C library for Gnome</title>
Daniel Veillardaf43f632002-03-08 15:05:20 +00006 <meta name="GENERATOR" content="amaya 5.1">
Daniel Veillardb24054a1999-12-18 15:32:46 +00007 <meta http-equiv="Content-Type" content="text/html">
Daniel Veillardccb09631998-10-27 06:21:04 +00008</head>
Daniel Veillardccb09631998-10-27 06:21:04 +00009
Daniel Veillardb05deb71999-08-10 19:04:08 +000010<body bgcolor="#ffffff">
Daniel Veillardec78c0f2000-08-25 10:25:23 +000011<h1 align="center">The XML C library for Gnome</h1>
Daniel Veillardb05deb71999-08-10 19:04:08 +000012
Daniel Veillard9c466822001-10-25 12:03:39 +000013<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 +000016<h1 style="text-align: center">libxml, a.k.a. gnome-xml</h1>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +000017
18<p></p>
Daniel Veillard9c466822001-10-25 12:03:39 +000019
Daniel Veillard63d83142002-05-20 06:51:05 +000020<p>Libxml is the XML C library developed for the Gnome project. XML itself
Daniel Veillard9c466822001-10-25 12:03:39 +000021is 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 +000023information enclosed between angle brackets. HTML is the most well-known
Daniel Veillard1eb24242002-03-18 11:33:03 +000024markup language. Though the library is written in C <a href="python.html">a
Daniel Veillard0b28e882002-07-24 23:47:05 +000025variety of language bindings</a> make it available in other environments.</p>
Daniel Veillard9c466822001-10-25 12:03:39 +000026
Daniel Veillard710823b2003-03-04 10:05:52 +000027<p>Libxml2 is known to be very portable, the library should build and work
28without serious troubles on a variety of systems (Linux, Unix, Windows,
29CygWin, MacOS, MacOS X, RISC Os, OS/2, VMS, QNX, MVS, ...)</p>
30
Daniel Veillard9c466822001-10-25 12:03:39 +000031<p>Libxml2 implements a number of existing standards related to markup
32languages:</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +000033<ul>
Daniel Veillard9c466822001-10-25 12:03:39 +000034 <li>the XML standard: <a
35 href="http://www.w3.org/TR/REC-xml">http://www.w3.org/TR/REC-xml</a></li>
36 <li>Namespaces in XML: <a
37 href="http://www.w3.org/TR/REC-xml-names/">http://www.w3.org/TR/REC-xml-names/</a></li>
38 <li>XML Base: <a
39 href="http://www.w3.org/TR/xmlbase/">http://www.w3.org/TR/xmlbase/</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +000040 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc2396.txt">RFC 2396</a> :
41 Uniform Resource Identifiers <a
Daniel Veillard9c466822001-10-25 12:03:39 +000042 href="http://www.ietf.org/rfc/rfc2396.txt">http://www.ietf.org/rfc/rfc2396.txt</a></li>
43 <li>XML Path Language (XPath) 1.0: <a
44 href="http://www.w3.org/TR/xpath">http://www.w3.org/TR/xpath</a></li>
45 <li>HTML4 parser: <a
46 href="http://www.w3.org/TR/html401/">http://www.w3.org/TR/html401/</a></li>
47 <li>most of XML Pointer Language (XPointer) Version 1.0: <a
48 href="http://www.w3.org/TR/xptr">http://www.w3.org/TR/xptr</a></li>
49 <li>XML Inclusions (XInclude) Version 1.0: <a
50 href="http://www.w3.org/TR/xinclude/">http://www.w3.org/TR/xinclude/</a></li>
51 <li>[ISO-8859-1], <a
52 href="http://www.cis.ohio-state.edu/rfc/rfc2044.txt">rfc2044</a> [UTF-8]
53 and <a href="http://www.cis.ohio-state.edu/rfc/rfc2781.txt">rfc2781</a>
54 [UTF-16] core encodings</li>
55 <li>part of SGML Open Technical Resolution TR9401:1997</li>
56 <li>XML Catalogs Working Draft 06 August 2001: <a
57 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 +000058 <li>Canonical XML Version 1.0: <a
59 href="http://www.w3.org/TR/xml-c14n">http://www.w3.org/TR/xml-c14n</a>
Daniel Veillard2d347fa2002-03-17 10:34:11 +000060 and the Exclusive XML Canonicalization CR draft <a
61 href="http://www.w3.org/TR/xml-exc-c14n">http://www.w3.org/TR/xml-exc-c14n</a></li>
Daniel Veillard17bed982003-02-24 20:11:43 +000062 <li>Relax NG Committee Specification 3 December 2001 <a
63 href="http://www.oasis-open.org/committees/relax-ng/spec-20011203.html">http://www.oasis-open.org/committees/relax-ng/spec-20011203.html</a></li>
Daniel Veillard96984452000-08-31 13:50:12 +000064</ul>
65
Daniel Veillard9c466822001-10-25 12:03:39 +000066<p>In most cases libxml tries to implement the specifications in a relatively
Daniel Veillard42766c02002-08-22 20:52:17 +000067strictly compliant way. As of release 2.4.16, libxml2 passes all 1800+ tests
68from the <a
Daniel Veillarda5393562002-02-20 11:40:49 +000069href="http://www.oasis-open.org/committees/xml-conformance/">OASIS XML Tests
70Suite</a>.</p>
Daniel Veillard5b16f582002-02-20 11:38:46 +000071
Daniel Veillard0b28e882002-07-24 23:47:05 +000072<p>To some extent libxml2 provides support for the following additional
73specifications but doesn't claim to implement them completely:</p>
Daniel Veillard9c466822001-10-25 12:03:39 +000074<ul>
75 <li>Document Object Model (DOM) <a
76 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 +000077 it doesn't implement the API itself, gdome2 does this on top of
Daniel Veillard9c466822001-10-25 12:03:39 +000078 libxml2</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +000079 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc959.txt">RFC 959</a> :
80 libxml implements a basic FTP client code</li>
81 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc1945.txt">RFC 1945</a> :
82 HTTP/1.0, again a basic HTTP client code</li>
Daniel Veillard9c466822001-10-25 12:03:39 +000083 <li>SAX: a minimal SAX implementation compatible with early expat
84 versions</li>
85 <li>DocBook SGML v4: libxml2 includes a hackish parser to transition to
86 XML</li>
87</ul>
88
Daniel Veillard72fef162003-02-05 14:31:19 +000089<p>A partial implementation of XML Schemas is being worked on but it would be
90far too early to make any conformance statement about it at the moment.</p>
Daniel Veillarde6d8e202002-05-02 06:11:10 +000091
Daniel Veillard96984452000-08-31 13:50:12 +000092<p>Separate documents:</p>
93<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +000094 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a> providing an
Daniel Veillard2d347fa2002-03-17 10:34:11 +000095 implementation of XSLT 1.0 and common extensions like EXSLT for
96 libxml2</li>
Daniel Veillardc6271d22001-10-27 07:50:58 +000097 <li><a href="http://www.cs.unibo.it/~casarini/gdome2/">the gdome2 page</a>
Daniel Veillard2d347fa2002-03-17 10:34:11 +000098 : a standard DOM2 implementation for libxml2</li>
99 <li><a href="http://www.aleksey.com/xmlsec/">the XMLSec page</a>: an
100 implementation of <a href="http://www.w3.org/TR/xmldsig-core/">W3C XML
101 Digital Signature</a> for libxml2</li>
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000102 <li>also check the related links section below for more related and active
103 projects.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000104</ul>
105
Daniel Veillard806cada2003-03-19 21:58:59 +0000106<p>Results of the <a
107href="http://xmlbench.sourceforge.net/results/benchmark/index.html">xmlbench
108benchmark</a> on sourceforge 19 March 2003 (smaller is better):</p>
Daniel Veillardd8da01c2003-03-24 15:58:23 +0000109
110<p align="center"><img src="benchmark.gif"
111alt="benchmark results for Expat Xerces libxml2 Oracle and Sun toolkits"></p>
Daniel Veillard806cada2003-03-19 21:58:59 +0000112
Daniel Veillarde1662542002-08-28 11:50:59 +0000113<p>Logo designed by <a href="mailto:liyanage@access.ch">Marc Liyanage</a>.</p>
114
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000115<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000116
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000117<p>This document describes libxml, the <a
Daniel Veillard63d83142002-05-20 06:51:05 +0000118href="http://www.w3.org/XML/">XML</a> C library developed for the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000119href="http://www.gnome.org/">Gnome</a> project. <a
120href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
121structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000122
Daniel Veillard0142b842000-01-14 14:45:24 +0000123<p>Here are some key points about libxml:</p>
124<ul>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000125 <li>Libxml exports Push (progressive) and Pull (blocking) type parser
126 interfaces for both XML and HTML.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000127 <li>Libxml can do DTD validation at parse time, using a parsed document
128 instance, or with an arbitrary DTD.</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000129 <li>Libxml includes complete <a
Daniel Veillard8c2ecaf2001-07-10 17:53:07 +0000130 href="http://www.w3.org/TR/xpath">XPath</a>, <a
131 href="http://www.w3.org/TR/xptr">XPointer</a> and <a
132 href="http://www.w3.org/TR/xinclude">XInclude</a> implementations.</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000133 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard189446d2000-10-13 10:23:06 +0000134 sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillardab8500d2000-10-15 21:06:19 +0000135 Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000136 <li>Basic support for HTTP and FTP client allowing applications to fetch
Daniel Veillard0b28e882002-07-24 23:47:05 +0000137 remote resources.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000138 <li>The design is modular, most of the extensions can be compiled out.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000139 <li>The internal document representation is as close as possible to the <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000140 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
141 <li>Libxml also has a <a href="http://www.megginson.com/SAX/index.html">SAX
Daniel Veillard402e8c82000-02-29 22:57:47 +0000142 like interface</a>; the interface is designed to be compatible with <a
143 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillardc575b992002-02-08 13:28:40 +0000144 <li>This library is released under the <a
145 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard0b28e882002-07-24 23:47:05 +0000146 License</a>. See the Copyright file in the distribution for the precise
Daniel Veillardc575b992002-02-08 13:28:40 +0000147 wording.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000148</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000149
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000150<p>Warning: unless you are forced to because your application links with a
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000151Gnome-1.X library requiring it, <strong><span
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000152style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
153libxml2</p>
154
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000155<h2><a name="FAQ">FAQ</a></h2>
156
Daniel Veillard0b28e882002-07-24 23:47:05 +0000157<p>Table of Contents:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000158<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000159 <li><a href="FAQ.html#License">License(s)</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000160 <li><a href="FAQ.html#Installati">Installation</a></li>
161 <li><a href="FAQ.html#Compilatio">Compilation</a></li>
162 <li><a href="FAQ.html#Developer">Developer corner</a></li>
163</ul>
164
Daniel Veillard63d83142002-05-20 06:51:05 +0000165<h3><a name="License">License</a>(s)</h3>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000166<ol>
167 <li><em>Licensing Terms for libxml</em>
Daniel Veillardc575b992002-02-08 13:28:40 +0000168 <p>libxml is released under the <a
169 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard0b28e882002-07-24 23:47:05 +0000170 License</a>; see the file Copyright in the distribution for the precise
Daniel Veillardc575b992002-02-08 13:28:40 +0000171 wording</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000172 </li>
173 <li><em>Can I embed libxml in a proprietary application ?</em>
Daniel Veillard42766c02002-08-22 20:52:17 +0000174 <p>Yes. The MIT License allows you to keep proprietary the changes you
175 made to libxml, but it would be graceful to send-back bug fixes and
176 improvements as patches for possible incorporation in the main
Daniel Veillard0b28e882002-07-24 23:47:05 +0000177 development tree.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000178 </li>
179</ol>
180
181<h3><a name="Installati">Installation</a></h3>
182<ol>
183 <li>Unless you are forced to because your application links with a Gnome
184 library requiring it, <strong><span style="background-color: #FF0000">Do
185 Not Use libxml1</span></strong>, use libxml2</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000186 <li><em>Where can I get libxml</em> ?
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000187 <p>The original distribution comes from <a
188 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a
Daniel Veillard6581e1b2003-02-09 22:21:43 +0000189 href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.5/">gnome.org</a></p>
Daniel Veillard63d83142002-05-20 06:51:05 +0000190 <p>Most Linux and BSD distributions include libxml, this is probably the
Daniel Veillard0b28e882002-07-24 23:47:05 +0000191 safer way for end-users to use libxml.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000192 <p>David Doolin provides precompiled Windows versions at <a
193 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
194 </li>
195 <li><em>I see libxml and libxml2 releases, which one should I install ?</em>
196 <ul>
Daniel Veillard42766c02002-08-22 20:52:17 +0000197 <li>If you are not constrained by backward compatibility issues with
198 existing applications, install libxml2 only</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000199 <li>If you are not doing development, you can safely install both.
Daniel Veillard0b28e882002-07-24 23:47:05 +0000200 Usually the packages <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000201 href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a
202 href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
Daniel Veillard0b28e882002-07-24 23:47:05 +0000203 compatible (this is not the case for development packages).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000204 <li>If you are a developer and your system provides separate packaging
205 for shared libraries and the development components, it is possible
206 to install libxml and libxml2, and also <a
207 href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
208 and <a
209 href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
210 too for libxml2 &gt;= 2.3.0</li>
211 <li>If you are developing a new application, please develop against
212 libxml2(-devel)</li>
213 </ul>
214 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000215 <li><em>I can't install the libxml package, it conflicts with libxml0</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000216 <p>You probably have an old libxml0 package used to provide the shared
Daniel Veillard42766c02002-08-22 20:52:17 +0000217 library for libxml.so.0, you can probably safely remove it. The libxml
218 packages provided on <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000219 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provide
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000220 libxml.so.0</p>
221 </li>
222 <li><em>I can't install the libxml(2) RPM package due to failed
Daniel Veillard63d83142002-05-20 06:51:05 +0000223 dependencies</em>
224 <p>The most generic solution is to re-fetch the latest src.rpm , and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000225 rebuild it locally with</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000226 <p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code>.</p>
Daniel Veillard42766c02002-08-22 20:52:17 +0000227 <p>If everything goes well it will generate two binary rpm packages (one
228 providing the shared libs and xmllint, and the other one, the -devel
229 package, providing includes, static libraries and scripts needed to build
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000230 applications with libxml(2)) that you can install locally.</p>
231 </li>
232</ol>
233
234<h3><a name="Compilatio">Compilation</a></h3>
235<ol>
236 <li><em>What is the process to compile libxml ?</em>
237 <p>As most UNIX libraries libxml follows the "standard":</p>
238 <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p>
239 <p><code>cd libxml-xxxx</code></p>
240 <p><code>./configure --help</code></p>
241 <p>to see the options, then the compilation/installation proper</p>
242 <p><code>./configure [possible options]</code></p>
243 <p><code>make</code></p>
244 <p><code>make install</code></p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000245 <p>At that point you may have to rerun ldconfig or a similar utility to
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000246 update your list of installed shared libs.</p>
247 </li>
248 <li><em>What other libraries are needed to compile/install libxml ?</em>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000249 <p>Libxml does not require any other library, the normal C ANSI API
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000250 should be sufficient (please report any violation to this rule you may
251 find).</p>
252 <p>However if found at configuration time libxml will detect and use the
253 following libs:</p>
254 <ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000255 <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a> : a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000256 highly portable and available widely compression library.</li>
257 <li>iconv: a powerful character encoding conversion library. It is
258 included by default in recent glibc libraries, so it doesn't need to
259 be installed specifically on Linux. It now seems a <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000260 href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
261 of the official UNIX</a> specification. Here is one <a
Daniel Veillarddad3f682002-11-17 16:47:27 +0000262 href="http://www.gnu.org/software/libiconv/">implementation of the
263 library</a> which source can be found <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000264 href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
265 </ul>
266 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000267 <li><em>Make check fails on some platforms</em>
Daniel Veillard42766c02002-08-22 20:52:17 +0000268 <p>Sometimes the regression tests' results don't completely match the
269 value produced by the parser, and the makefile uses diff to print the
270 delta. On some platforms the diff return breaks the compilation process;
271 if the diff is small this is probably not a serious problem.</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000272 <p>Sometimes (especially on Solaris) make checks fail due to limitations
Daniel Veillarde46182c2002-02-12 14:29:11 +0000273 in make. Try using GNU-make instead.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000274 </li>
275 <li><em>I use the CVS version and there is no configure script</em>
Daniel Veillard42766c02002-08-22 20:52:17 +0000276 <p>The configure script (and other Makefiles) are generated. Use the
277 autogen.sh script to regenerate the configure script and Makefiles,
278 like:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000279 <p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
280 </li>
281 <li><em>I have troubles when running make tests with gcc-3.0</em>
282 <p>It seems the initial release of gcc-3.0 has a problem with the
283 optimizer which miscompiles the URI module. Please use another
Daniel Veillard0b28e882002-07-24 23:47:05 +0000284 compiler.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000285 </li>
286</ol>
287
288<h3><a name="Developer">Developer</a> corner</h3>
289<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000290 <li><em>xmlDocDump() generates output on one line.</em>
291 <p>Libxml will not <strong>invent</strong> spaces in the content of a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000292 document since <strong>all spaces in the content of a document are
293 significant</strong>. If you build a tree from the API and want
294 indentation:</p>
295 <ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000296 <li>the correct way is to generate those yourself too.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000297 <li>the dangerous way is to ask libxml to add those blanks to your
298 content <strong>modifying the content of your document in the
299 process</strong>. The result may not be what you expect. There is
300 <strong>NO</strong> way to guarantee that such a modification won't
Daniel Veillard0b28e882002-07-24 23:47:05 +0000301 affect other parts of the content of your document. See <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000302 href="http://xmlsoft.org/html/libxml-parser.html#XMLKEEPBLANKSDEFAULT">xmlKeepBlanksDefault
303 ()</a> and <a
304 href="http://xmlsoft.org/html/libxml-tree.html#XMLSAVEFORMATFILE">xmlSaveFormatFile
305 ()</a></li>
306 </ol>
307 </li>
308 <li>Extra nodes in the document:
309 <p><em>For a XML file as below:</em></p>
310 <pre>&lt;?xml version="1.0"?&gt;
311&lt;PLAN xmlns="http://www.argus.ca/autotest/1.0/"&gt;
312&lt;NODE CommFlag="0"/&gt;
313&lt;NODE CommFlag="1"/&gt;
314&lt;/PLAN&gt;</pre>
315 <p><em>after parsing it with the function
316 pxmlDoc=xmlParseFile(...);</em></p>
317 <p><em>I want to the get the content of the first node (node with the
318 CommFlag="0")</em></p>
319 <p><em>so I did it as following;</em></p>
Daniel Veillard63d83142002-05-20 06:51:05 +0000320 <pre>xmlNodePtr pnode;
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000321pnode=pxmlDoc-&gt;children-&gt;children;</pre>
322 <p><em>but it does not work. If I change it to</em></p>
323 <pre>pnode=pxmlDoc-&gt;children-&gt;children-&gt;next;</pre>
324 <p><em>then it works. Can someone explain it to me.</em></p>
325 <p></p>
326 <p>In XML all characters in the content of the document are significant
327 <strong>including blanks and formatting line breaks</strong>.</p>
328 <p>The extra nodes you are wondering about are just that, text nodes with
Daniel Veillard63d83142002-05-20 06:51:05 +0000329 the formatting spaces which are part of the document but that people tend
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000330 to forget. There is a function <a
331 href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
332 ()</a> to remove those at parse time, but that's an heuristic, and its
Daniel Veillard0b28e882002-07-24 23:47:05 +0000333 use should be limited to cases where you are certain there is no
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000334 mixed-content in the document.</p>
335 </li>
336 <li><em>I get compilation errors of existing code like when accessing
Daniel Veillard0b28e882002-07-24 23:47:05 +0000337 <strong>root</strong> or <strong>child fields</strong> of nodes.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000338 <p>You are compiling code developed for libxml version 1 and using a
339 libxml2 development environment. Either switch back to libxml v1 devel or
340 even better fix the code to compile with libxml2 (or both) by <a
341 href="upgrade.html">following the instructions</a>.</p>
342 </li>
343 <li><em>I get compilation errors about non existing
344 <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000345 fields.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000346 <p>The source code you are using has been <a
347 href="upgrade.html">upgraded</a> to be able to compile with both libxml
348 and libxml2, but you need to install a more recent version:
349 libxml(-devel) &gt;= 1.8.8 or libxml2(-devel) &gt;= 2.1.0</p>
350 </li>
351 <li><em>XPath implementation looks seriously broken</em>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000352 <p>XPath implementation prior to 2.3.0 was really incomplete. Upgrade to
353 a recent version, there are no known bugs in the current version.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000354 </li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000355 <li><em>The example provided in the web page does not compile.</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000356 <p>It's hard to maintain the documentation in sync with the code
357 &lt;grin/&gt; ...</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000358 <p>Check the previous points 1/ and 2/ raised before, and please send
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000359 patches.</p>
360 </li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000361 <li><em>Where can I get more examples and information than privoded on the
362 web page?</em>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000363 <p>Ideally a libxml book would be nice. I have no such plan ... But you
364 can:</p>
365 <ul>
366 <li>check more deeply the <a href="html/libxml-lib.html">existing
367 generated doc</a></li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000368 <li>look for examples of use for libxml function using the Gnome code.
369 For example the following will query the full Gnome CVS base for the
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000370 use of the <strong>xmlAddChild()</strong> function:
371 <p><a
372 href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p>
373 <p>This may be slow, a large hardware donation to the gnome project
374 could cure this :-)</p>
375 </li>
376 <li><a
377 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gnome-xml">Browse
Daniel Veillardaf43f632002-03-08 15:05:20 +0000378 the libxml source</a> , I try to write code as clean and documented
Daniel Veillard42766c02002-08-22 20:52:17 +0000379 as possible, so looking at it may be helpful. In particular the code
380 of xmllint.c and of the various testXXX.c test programs should
381 provide good examples of how to do things with the library.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000382 </ul>
383 </li>
384 <li>What about C++ ?
385 <p>libxml is written in pure C in order to allow easy reuse on a number
386 of platforms, including embedded systems. I don't intend to convert to
387 C++.</p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000388 <p>There are however a few C++ wrappers which may fulfill your needs:</p>
Daniel Veillard9b6fd302002-05-13 12:06:47 +0000389 <ul>
390 <li>by Ari Johnson &lt;ari@btigate.com&gt;:
391 <p>Website: <a
392 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
393 <p>Download: <a
394 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
395 </li>
396 <li>by Peter Jones &lt;pjones@pmade.org&gt;
397 <p>Website: <a
398 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
399 </li>
400 </ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000401 </li>
402 <li>How to validate a document a posteriori ?
403 <p>It is possible to validate documents which had not been validated at
Daniel Veillard42766c02002-08-22 20:52:17 +0000404 initial parsing time or documents which have been built from scratch
405 using the API. Use the <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000406 href="http://xmlsoft.org/html/libxml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a>
Daniel Veillard63d83142002-05-20 06:51:05 +0000407 function. It is also possible to simply add a DTD to an existing
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000408 document:</p>
409 <pre>xmlDocPtr doc; /* your existing document */
Daniel Veillard0b28e882002-07-24 23:47:05 +0000410xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
411
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000412 dtd-&gt;name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */
413
414 doc-&gt;intSubset = dtd;
415 if (doc-&gt;children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
416 else xmlAddPrevSibling(doc-&gt;children, (xmlNodePtr)dtd);
417 </pre>
418 </li>
Daniel Veillarddad3f682002-11-17 16:47:27 +0000419 <li>So what is this funky "xmlChar" used all the time?
420 <p>It is a null terminated sequence of utf-8 characters. And only utf-8!
421 You need to convert strings encoded in different ways to utf-8 before
422 passing them to the API. This can be accomplished with the iconv library
423 for instance.</p>
John Fleck61f6fb62002-10-31 15:23:29 +0000424 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000425 <li>etc ...</li>
426</ol>
427
428<p></p>
429
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000430<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000431
Daniel Veillard0b28e882002-07-24 23:47:05 +0000432<p>There are several on-line resources related to using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000433<ol>
Daniel Veillard321be0c2002-10-08 21:26:42 +0000434 <li>Use the <a href="search.php">search engine</a> to lookup
435 informations.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000436 <li>Check the <a href="FAQ.html">FAQ.</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000437 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000438 documentation</a> automatically extracted from code comments (using <a
439 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
440 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000441 <li>Look at the documentation about <a href="encoding.html">libxml
Daniel Veillard0b28e882002-07-24 23:47:05 +0000442 internationalization support</a>.</li>
Daniel Veillardbc66f852002-01-14 09:49:20 +0000443 <li>This page provides a global overview and <a href="example.html">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000444 examples</a> on how to use libxml.</li>
Daniel Veillarddad3f682002-11-17 16:47:27 +0000445 <li>John Fleck's libxml tutorial: <a href="tutorial/index.html">html</a> or
446 <a href="tutorial/xmltutorial.pdf">pdf</a>.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000447 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
Daniel Veillard402e8c82000-02-29 22:57:47 +0000448 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
449 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000450 <li>George Lebl wrote <a
451 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000452 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000453 <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO
Daniel Veillard0b28e882002-07-24 23:47:05 +0000454 file</a>.</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000455 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>
456 description. If you are starting a new project using libxml you should
457 really use the 2.x version.</li>
Daniel Veillard845cce42002-01-09 11:51:37 +0000458 <li>And don't forget to look at the <a
459 href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000460</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000461
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000462<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000463
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000464<p>Well, bugs or missing features are always possible, and I will make a
465point of fixing them in a timely fashion. The best way to report a bug is to
466use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome
Daniel Veillard42766c02002-08-22 20:52:17 +0000467bug tracking database</a> (make sure to use the "libxml2" module name). I
468look at reports there regularly and it's good to have a reminder when a bug
469is still open. Be sure to specify that the bug is for the package libxml2.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000470
Daniel Veillard0142b842000-01-14 14:45:24 +0000471<p>There is also a mailing-list <a
Daniel Veillard3197f162001-04-04 00:40:08 +0000472href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
473href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000474href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
475please visit the <a
476href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
477follow the instructions. <strong>Do not send code, I won't debug it</strong>
478(but patches are really appreciated!).</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000479
Daniel Veillard008186f2001-09-13 14:24:44 +0000480<p>Check the following <strong><span style="color: #FF0000">before
481posting</span></strong>:</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000482<ul>
Daniel Veillard321be0c2002-10-08 21:26:42 +0000483 <li>Read the <a href="FAQ.html">FAQ</a> and <a href="search.php">use the
484 search engine</a> to get informations related to your problem.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000485 <li>Make sure you are <a href="ftp://xmlsoft.org/">using a recent
486 version</a>, and that the problem still shows up in a recent version.</li>
487 <li>Check the <a href="http://mail.gnome.org/archives/xml/">list
488 archives</a> to see if the problem was reported already. In this case
Daniel Veillard63d83142002-05-20 06:51:05 +0000489 there is probably a fix available, similarly check the <a
Daniel Veillarde7ead2d2001-08-22 23:44:09 +0000490 href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">registered
Daniel Veillard0b28e882002-07-24 23:47:05 +0000491 open bugs</a>.</li>
492 <li>Make sure you can reproduce the bug with xmllint or one of the test
493 programs found in source in the distribution.</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000494 <li>Please send the command showing the error as well as the input (as an
Daniel Veillard63d83142002-05-20 06:51:05 +0000495 attachment)</li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000496</ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000497
Daniel Veillarddadd0872001-09-15 09:21:44 +0000498<p>Then send the bug with associated informations to reproduce it to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000499href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillard98d071d2003-01-10 09:22:44 +0000500related I will approve it. Please do not send mail to me directly, it makes
Daniel Veillard0b28e882002-07-24 23:47:05 +0000501things really hard to track and in some cases I am not the best person to
Daniel Veillard98d071d2003-01-10 09:22:44 +0000502answer a given question, ask on the list.</p>
503
504<p>To <span style="color: #E50000">be really clear about support</span>:</p>
505<ul>
506 <li>Support or help <span style="color: #E50000">request MUST be sent to
507 the list or on bugzilla</span> in case of problems, so that the Question
508 and Answers can be shared publicly. Failing to do so carries the implicit
509 message "I want free support but I don't want to share the benefits with
Daniel Veillard831e8fd2003-01-25 11:45:34 +0000510 others" and is not welcome. I will automatically Carbon-Copy the
511 xml@gnome.org mailing list for any technical reply made about libxml2 or
512 libxslt.</li>
Daniel Veillard98d071d2003-01-10 09:22:44 +0000513 <li>There is <span style="color: #E50000">no garantee for support</span>,
514 if your question remains unanswered after a week, repost it, making sure
515 you gave all the detail needed and the informations requested.</li>
516 <li>Failing to provide informations as requested or double checking first
517 for prior feedback also carries the implicit message "the time of the
518 library maintainers is less valuable than my time" and might not be
519 welcome.</li>
520</ul>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000521
Daniel Veillard91e9d582001-02-26 07:31:12 +0000522<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillard0b28e882002-07-24 23:47:05 +0000523probably be processed faster than those without.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000524
525<p>If you're looking for help, a quick look at <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000526href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually
Daniel Veillard0b28e882002-07-24 23:47:05 +0000527provide the answer. I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000528questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillard63d83142002-05-20 06:51:05 +0000529documentation</a> is not as polished as I would like (i need to learn more
530about DocBook), but it's a good starting point.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000531
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000532<h2><a name="help">How to help</a></h2>
533
534<p>You can help the project in various ways, the best thing to do first is to
535subscribe to the mailing-list as explained before, check the <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000536href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
537href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
Daniel Veillard0b28e882002-07-24 23:47:05 +0000538database</a>:</p>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000539<ol>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000540 <li>Provide patches when you find problems.</li>
541 <li>Provide the diffs when you port libxml to a new platform. They may not
Daniel Veillardab8500d2000-10-15 21:06:19 +0000542 be integrated in all cases but help pinpointing portability problems
543 and</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000544 <li>Provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000545 as HTML diffs).</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000546 <li>Provide new documentations pieces (translations, examples, etc
547 ...).</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000548 <li>Check the TODO file and try to close one of the items.</li>
549 <li>Take one of the points raised in the archive or the bug database and
Daniel Veillarde7ead2d2001-08-22 23:44:09 +0000550 provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me
551 </a>before to avoid synchronization problems and check that the suggested
552 fix will fit in nicely :-)</li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000553</ol>
554
Daniel Veillard10a2c651999-12-12 13:03:50 +0000555<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000556
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000557<p>The latest versions of libxml can be found on <a
Daniel Veillard20c8cf22001-06-26 22:47:36 +0000558href="ftp://xmlsoft.org/">xmlsoft.org</a> (<a
559href="ftp://speakeasy.rpmfind.net/pub/libxml/">Seattle</a>, <a
560href="ftp://fr.rpmfind.net/pub/libxml/">France</a>) or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000561href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard6581e1b2003-02-09 22:21:43 +0000562as a <a href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.5/">source
MDT 2002 John Fleck30c70542002-09-24 14:24:54 +0000563archive</a><!-- commenting this out because they seem to have disappeared or <a
Daniel Veillarda41123c2001-04-22 19:31:20 +0000564href="ftp://ftp.gnome.org/pub/GNOME/stable/redhat/i386/libxml/">RPM
Daniel Veillarde16b5742002-09-26 17:50:03 +0000565packages</a> -->
Daniel Veillard321be0c2002-10-08 21:26:42 +0000566 , Antonin Sprinzl also provide <a href="ftp://gd.tuwien.ac.at/pub/libxml/">a
Daniel Veillarde16b5742002-09-26 17:50:03 +0000567mirror in Austria</a>. (NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000568href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
569href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard95189532001-07-26 18:30:26 +0000570packages installed to compile applications using libxml.) <a
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000571href="mailto:igor@zlatkovic.com">Igor Zlatkovic</a> is now the maintainer of
572the Windows port, <a
573href="http://www.zlatkovic.com/projects/libxml/index.html">he provides
574binaries</a>. <a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a>
575provides <a href="http://garypennington.net/libxml2/">Solaris binaries</a>.
576<a href="mailto:Steve.Ball@zveno.com">Steve Ball</a> provides <a
577href="http://www.zveno.com/open_source/libxml2xslt.html">Mac Os X
Daniel Veillard42766c02002-08-22 20:52:17 +0000578binaries</a>.</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000579
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000580<p><a name="Snapshot">Snapshot:</a></p>
581<ul>
582 <li>Code from the W3C cvs base libxml <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000583 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000584 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard0b28e882002-07-24 23:47:05 +0000585 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a>.</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000586</ul>
587
Daniel Veillardc6271d22001-10-27 07:50:58 +0000588<p><a name="Contribs">Contributions:</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000589
590<p>I do accept external contributions, especially if compiling on another
Daniel Veillardc6271d22001-10-27 07:50:58 +0000591platform, get in touch with me to upload the package, wrappers for various
Daniel Veillard51095312001-10-28 18:51:57 +0000592languages have been provided, and can be found in the <a
593href="contribs.html">contrib section</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000594
Daniel Veillard82687162001-01-22 15:32:01 +0000595<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000596<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000597 <li><p>The <a
598 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gnome-xml">Gnome
Daniel Veillard402e8c82000-02-29 22:57:47 +0000599 CVS base</a>. Check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000600 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a>
601 page; the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000602 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000603 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000604</ul>
605
606<h2><a name="News">News</a></h2>
607
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000608<h3>CVS only : check the <a
609href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000610for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000611
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000612<p>Items not finished and worked on, get in touch with the list if you want
613to test those</p>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000614<ul>
Daniel Veillard72fef162003-02-05 14:31:19 +0000615 <li>More testing on RelaxNG</li>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000616 <li>Finishing up <a href="http://www.w3.org/TR/xmlschema-1/">XML
Daniel Veillard72fef162003-02-05 14:31:19 +0000617 Schemas</a></li>
618</ul>
619
Daniel Veillardc2d4a932003-04-01 11:13:05 +0000620<h3>2.5.6: Apr 1 2003</h3>
621<ul>
622 <li>Fixed W3C XML Schemas datatype, should be compliant now except for
623 binHex and base64 which are not supported yet.</li>
624 <li>bug fixes: non-ASCII IDs, HTML output, XInclude on large docs and
625 XInclude entities handling, encoding detection on external subsets, XML
626 Schemas bugs and memory leaks, HTML parser (James Bursa)</li>
627 <li>portability: python/trio (Albert Chin), Sun compiler warnings</li>
628 <li>documentation: added --relaxng option to xmllint man page (John)</li>
629 <li>improved error reporting: xml:space, start/end tag mismatches, Relax NG
630 errors</li>
631</ul>
632
633<h3>2.5.5: Mar 24 2003</h3>
Daniel Veillardd8da01c2003-03-24 15:58:23 +0000634<ul>
635 <li>Lot of fixes on the Relax NG implementation. More testing including
636 DocBook and TEI examples.</li>
637 <li>Increased the support for W3C XML Schemas datatype</li>
638 <li>Several bug fixes in the URI handling layer</li>
639 <li>Bug fixes: HTML parser, xmlReader, DTD validation, XPath, encoding
640 conversion, line counting in the parser.</li>
641 <li>Added support for $XMLLINT_INDENT environment variable, FTP delete</li>
642 <li>Fixed the RPM spec file name</li>
643</ul>
644
Daniel Veillard17bed982003-02-24 20:11:43 +0000645<h3>2.5.4: Feb 20 2003</h3>
646<ul>
647 <li>Conformance testing and lot of fixes on Relax NG and XInclude
648 implementation</li>
649 <li>Implementation of XPointer element() scheme</li>
650 <li>Bug fixes: XML parser, XInclude entities merge, validity checking on
651 namespaces,
652 <p>2 serialization bugs, node info generation problems, a DTD regexp
653 generation problem.</p>
654 </li>
655 <li>Portability: windows updates and path canonicalization (Igor)</li>
656 <li>A few typo fixes (Kjartan Maraas)</li>
657 <li>Python bindings generator fixes (Stephane Bidoul)</li>
658</ul>
659
Daniel Veillard1d788d22003-02-10 16:21:58 +0000660<h3>2.5.3: Feb 10 2003</h3>
661<ul>
662 <li>RelaxNG and XML Schemas datatypes improvements, and added a first
663 version of RelaxNG Python bindings</li>
664 <li>Fixes: XLink (Sean Chittenden), XInclude (Sean Chittenden), API fix for
665 serializing namespace nodes, encoding conversion bug, XHTML1
666 serialization</li>
667 <li>Portability fixes: Windows (Igor), AMD 64bits RPM spec file</li>
668</ul>
669
Daniel Veillard72fef162003-02-05 14:31:19 +0000670<h3>2.5.2: Feb 5 2003</h3>
671<ul>
672 <li>First implementation of RelaxNG, added --relaxng flag to xmllint</li>
673 <li>Schemas support now compiled in by default.</li>
674 <li>Bug fixes: DTD validation, namespace checking, XInclude and entities,
675 delegateURI in XML Catalogs, HTML parser, XML reader (Stéphane Bidoul),
676 XPath parser and evaluation, UTF8ToUTF8 serialization, XML reader memory
677 consumption, HTML parser, HTML serialization in the presence of
678 namespaces</li>
679 <li>added an HTML API to check elements and attributes.</li>
680 <li>Documentation improvement, PDF for the tutorial (John Fleck), doc
681 patches (Stefan Kost)</li>
682 <li>Portability fixes: NetBSD (Julio Merino), Windows (Igor Zlatkovic)</li>
683 <li>Added python bindings for XPointer, contextual error reporting
684 (Stéphane Bidoul)</li>
685 <li>URI/file escaping problems (Stefano Zacchiroli)</li>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000686</ul>
687
Daniel Veillarde2830f12003-01-08 17:47:49 +0000688<h3>2.5.1: Jan 8 2003</h3>
689<ul>
690 <li>Fixes a memory leak and configuration/compilation problems in 2.5.0</li>
691 <li>documentation updates (John)</li>
692 <li>a couple of XmlTextReader fixes</li>
693</ul>
694
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000695<h3>2.5.0: Jan 6 2003</h3>
696<ul>
697 <li>New <a href="xmlreader.html">XmltextReader interface</a> based on C#
698 API (with help of Stéphane Bidoul)</li>
699 <li>Windows: more exports, including the new API (Igor)</li>
700 <li>XInclude fallback fix</li>
701 <li>Python: bindings for the new API, packaging (Stéphane Bidoul),
702 drv_libxml2.py Python xml.sax driver (Stéphane Bidoul), fixes, speedup
703 and iterators for Python-2.2 (Hannu Krosing)</li>
704 <li>Tutorial fixes (john Fleck and Niraj Tolia) xmllint man update
705 (John)</li>
706 <li>Fix an XML parser bug raised by Vyacheslav Pindyura</li>
707 <li>Fix for VMS serialization (Nigel Hall) and config (Craig A. Berry)</li>
708 <li>Entities handling fixes</li>
709 <li>new API to optionally track node creation and deletion (Lukas
710 Schroeder)</li>
711 <li>Added documentation for the XmltextReader interface and some <a
712 href="guidelines.html">XML guidelines</a></li>
713</ul>
714
Daniel Veillardc1eed322002-12-12 11:01:32 +0000715<h3>2.4.30: Dec 12 2002</h3>
716<ul>
717 <li>2.4.29 broke the python bindings, rereleasing</li>
718 <li>Improvement/fixes of the XML API generator, and couple of minor code
719 fixes.</li>
720</ul>
721
Daniel Veillard9b4bb4d2002-12-11 19:28:47 +0000722<h3>2.4.29: Dec 11 2002</h3>
723<ul>
724 <li>Windows fixes (Igor): Windows CE port, pthread linking, python bindings
725 (Stéphane Bidoul), Mingw (Magnus Henoch), and export list updates</li>
726 <li>Fix for prev in python bindings (ERDI Gergo)</li>
727 <li>Fix for entities handling (Marcus Clarke)</li>
728 <li>Refactored the XML and HTML dumps to a single code path, fixed XHTML1
729 dump</li>
730 <li>Fix for URI parsing when handling URNs with fragment identifiers</li>
731 <li>Fix for HTTP URL escaping problem</li>
732 <li>added an TextXmlReader (C#) like API (work in progress)</li>
733 <li>Rewrote the API in XML generation script, includes a C parser and saves
734 more informations needed for C# bindings</li>
735</ul>
736
Daniel Veillardf9c4cad2002-11-22 15:57:07 +0000737<h3>2.4.28: Nov 22 2002</h3>
738<ul>
739 <li>a couple of python binding fixes</li>
740 <li>2 bug fixes in the XML push parser</li>
741 <li>potential memory leak removed (Martin Stoilov)</li>
742 <li>fix to the configure script for Unix (Dimitri Papadopoulos)</li>
743 <li>added encoding support for XInclude parse="text"</li>
744 <li>autodetection of XHTML1 and specific serialization rules added</li>
Daniel Veillard9b4bb4d2002-12-11 19:28:47 +0000745 <li>nasty threading bug fixed (William Brack)</li>
Daniel Veillardf9c4cad2002-11-22 15:57:07 +0000746</ul>
747
Daniel Veillarddad3f682002-11-17 16:47:27 +0000748<h3>2.4.27: Nov 17 2002</h3>
749<ul>
750 <li>fixes for the Python bindings</li>
751 <li>a number of bug fixes: SGML catalogs, xmlParseBalancedChunkMemory(),
752 HTML parser, Schemas (Charles Bozeman), document fragment support
753 (Christian Glahn), xmlReconciliateNs (Brian Stafford), XPointer,
754 xmlFreeNode(), xmlSAXParseMemory (Peter Jones), xmlGetNodePath (Petr
755 Pajas), entities processing</li>
756 <li>added grep to xmllint --shell</li>
757 <li>VMS update patch from Craig A. Berry</li>
758 <li>cleanup of the Windows build with support for more compilers (Igor),
759 better thread support on Windows</li>
760 <li>cleanup of Unix Makefiles and spec file</li>
761 <li>Improvements to the documentation (John Fleck)</li>
762</ul>
763
Daniel Veillard48267432002-10-18 11:21:38 +0000764<h3>2.4.26: Oct 18 2002</h3>
765<ul>
766 <li>Patches for Windows CE port, improvements on Windows paths handling</li>
767 <li>Fixes to the validation code (DTD and Schemas), xmlNodeGetPath() ,
768 HTML serialization, Namespace compliance, and a number of small
769 problems</li>
770</ul>
771
Daniel Veillarde16b5742002-09-26 17:50:03 +0000772<h3>2.4.25: Sep 26 2002</h3>
773<ul>
774 <li>A number of bug fixes: XPath, validation, Python bindings, DOM and
775 tree, xmlI/O, Html</li>
776 <li>Serious rewrite of XInclude</li>
777 <li>Made XML Schemas regexp part of the default build and APIs, small fix
778 and improvement of the regexp core</li>
779 <li>Changed the validation code to reuse XML Schemas regexp APIs</li>
780 <li>Better handling of Windows file paths, improvement of Makefiles (Igor,
781 Daniel Gehriger, Mark Vakoc)</li>
782 <li>Improved the python I/O bindings, the tests, added resolver and regexp
Daniel Veillard321be0c2002-10-08 21:26:42 +0000783 APIs</li>
Daniel Veillarde16b5742002-09-26 17:50:03 +0000784 <li>New logos from Marc Liyanage</li>
785 <li>Tutorial improvements: John Fleck, Christopher Harris</li>
786 <li>Makefile: Fixes for AMD x86_64 (Mandrake), DESTDIR (Christophe
787 Merlet)</li>
788 <li>removal of all stderr/perror use for error reporting</li>
789 <li>Better error reporting: XPath and DTD validation</li>
790 <li>update of the trio portability layer (Bjorn Reese)</li>
791</ul>
792
Daniel Veillard42766c02002-08-22 20:52:17 +0000793<p><strong>2.4.24: Aug 22 2002</strong></p>
794<ul>
795 <li>XPath fixes (William), xf:escape-uri() (Wesley Terpstra)</li>
796 <li>Python binding fixes: makefiles (William), generator, rpm build, x86-64
797 (fcrozat)</li>
798 <li>HTML &lt;style&gt; and boolean attributes serializer fixes</li>
799 <li>C14N improvements by Aleksey</li>
Daniel Veillarde1662542002-08-28 11:50:59 +0000800 <li>doc cleanups: Rick Jones</li>
Daniel Veillard42766c02002-08-22 20:52:17 +0000801 <li>Windows compiler makefile updates: Igor and Elizabeth Barham</li>
802 <li>XInclude: implementation of fallback and xml:base fixup added</li>
803</ul>
804
Daniel Veillard782afda2002-07-08 15:12:49 +0000805<h3>2.4.23: July 6 2002</h3>
806<ul>
807 <li>performances patches: Peter Jacobi</li>
808 <li>c14n fixes, testsuite and performances: Aleksey Sanin</li>
809 <li>added xmlDocFormatDump: Chema Celorio</li>
810 <li>new tutorial: John Fleck</li>
811 <li>new hash functions and performances: Sander Vesik, portability fix from
812 Peter Jacobi</li>
813 <li>a number of bug fixes: XPath (William Brack, Richard Jinks), XML and
814 HTML parsers, ID lookup function</li>
815 <li>removal of all remaining sprintf: Aleksey Sanin</li>
816</ul>
817
Daniel Veillardc0801af2002-05-28 16:28:42 +0000818<h3>2.4.22: May 27 2002</h3>
819<ul>
820 <li>a number of bug fixes: configure scripts, base handling, parser, memory
821 usage, HTML parser, XPath, documentation (Christian Cornelssen),
Daniel Veillard21473672002-06-17 07:29:22 +0000822 indentation, URI parsing</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +0000823 <li>Optimizations for XMLSec, fixing and making public some of the network
824 protocol handlers (Aleksey)</li>
825 <li>performance patch from Gary Pennington</li>
826 <li>Charles Bozeman provided date and time support for XML Schemas
827 datatypes</li>
828</ul>
829
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000830<h3>2.4.21: Apr 29 2002</h3>
831
832<p>This release is both a bug fix release and also contains the early XML
833Schemas <a href="http://www.w3.org/TR/xmlschema-1/">structures</a> and <a
834href="http://www.w3.org/TR/xmlschema-2/">datatypes</a> code, beware, all
835interfaces are likely to change, there is huge holes, it is clearly a work in
836progress and don't even think of putting this code in a production system,
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000837it's actually not compiled in by default. The real fixes are:</p>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000838<ul>
839 <li>a couple of bugs or limitations introduced in 2.4.20</li>
840 <li>patches for Borland C++ and MSC by Igor</li>
841 <li>some fixes on XPath strings and conformance patches by Richard
842 Jinks</li>
843 <li>patch from Aleksey for the ExcC14N specification</li>
844 <li>OSF/1 bug fix by Bjorn</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000845</ul>
846
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000847<h3>2.4.20: Apr 15 2002</h3>
848<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000849 <li>bug fixes: file descriptor leak, XPath, HTML output, DTD validation</li>
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000850 <li>XPath conformance testing by Richard Jinks</li>
851 <li>Portability fixes: Solaris, MPE/iX, Windows, OSF/1, python bindings,
852 libxml.m4</li>
853</ul>
854
Daniel Veillard19274092002-03-25 16:48:03 +0000855<h3>2.4.19: Mar 25 2002</h3>
856<ul>
857 <li>bug fixes: half a dozen XPath bugs, Validation, ISO-Latin to UTF8
858 encoder</li>
859 <li>portability fixes in the HTTP code</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000860 <li>memory allocation checks using valgrind, and profiling tests</li>
Daniel Veillard19274092002-03-25 16:48:03 +0000861 <li>revamp of the Windows build and Makefiles</li>
862</ul>
863
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000864<h3>2.4.18: Mar 18 2002</h3>
865<ul>
866 <li>bug fixes: tree, SAX, canonicalization, validation, portability,
Daniel Veillard63d83142002-05-20 06:51:05 +0000867 XPath</li>
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000868 <li>removed the --with-buffer option it was becoming unmaintainable</li>
869 <li>serious cleanup of the Python makefiles</li>
870 <li>speedup patch to XPath very effective for DocBook stylesheets</li>
871 <li>Fixes for Windows build, cleanup of the documentation</li>
872</ul>
873
Daniel Veillardaf43f632002-03-08 15:05:20 +0000874<h3>2.4.17: Mar 8 2002</h3>
875<ul>
876 <li>a lot of bug fixes, including "namespace nodes have no parents in
877 XPath"</li>
878 <li>fixed/improved the Python wrappers, added more examples and more
879 regression tests, XPath extension functions can now return node-sets</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000880 <li>added the XML Canonicalization support from Aleksey Sanin</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000881</ul>
882
Daniel Veillard5f4b5992002-02-20 10:22:49 +0000883<h3>2.4.16: Feb 20 2002</h3>
884<ul>
885 <li>a lot of bug fixes, most of them were triggered by the XML Testsuite
886 from OASIS and W3C. Compliance has been significantly improved.</li>
887 <li>a couple of portability fixes too.</li>
888</ul>
889
Daniel Veillard397ff112002-02-11 18:27:20 +0000890<h3>2.4.15: Feb 11 2002</h3>
891<ul>
892 <li>Fixed the Makefiles, especially the python module ones</li>
893 <li>A few bug fixes and cleanup</li>
894 <li>Includes cleanup</li>
895</ul>
896
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000897<h3>2.4.14: Feb 8 2002</h3>
898<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +0000899 <li>Change of License to the <a
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000900 href="http://www.opensource.org/licenses/mit-license.html">MIT
Daniel Veillard63d83142002-05-20 06:51:05 +0000901 License</a> basically for integration in XFree86 codebase, and removing
902 confusion around the previous dual-licensing</li>
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000903 <li>added Python bindings, beta software but should already be quite
904 complete</li>
905 <li>a large number of fixes and cleanups, especially for all tree
906 manipulations</li>
907 <li>cleanup of the headers, generation of a reference API definition in
908 XML</li>
909</ul>
910
911<h3>2.4.13: Jan 14 2002</h3>
Daniel Veillard744683d2002-01-14 17:30:20 +0000912<ul>
913 <li>update of the documentation: John Fleck and Charlie Bozeman</li>
914 <li>cleanup of timing code from Justin Fletcher</li>
915 <li>fixes for Windows and initial thread support on Win32: Igor and Serguei
916 Narojnyi</li>
917 <li>Cygwin patch from Robert Collins</li>
918 <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
919</ul>
920
Daniel Veillardef90ba72001-12-07 14:24:22 +0000921<h3>2.4.12: Dec 7 2001</h3>
922<ul>
923 <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
924 XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
925 (robert)</li>
926 <li>Eric Lavigne contributed project files for MacOS</li>
927 <li>some makefiles cleanups</li>
928</ul>
929
Daniel Veillarda4871052001-11-26 13:19:48 +0000930<h3>2.4.11: Nov 26 2001</h3>
931<ul>
932 <li>fixed a couple of errors in the includes, fixed a few bugs, some code
933 cleanups</li>
934 <li>xmllint man pages improvement by Heiko Rupp</li>
935 <li>updated VMS build instructions from John A Fotheringham</li>
936 <li>Windows Makefiles updates from Igor</li>
937</ul>
938
Daniel Veillard43d3f612001-11-10 11:57:23 +0000939<h3>2.4.10: Nov 10 2001</h3>
940<ul>
941 <li>URI escaping fix (Joel Young)</li>
942 <li>added xmlGetNodePath() (for paths or XPointers generation)</li>
943 <li>Fixes namespace handling problems when using DTD and validation</li>
944 <li>improvements on xmllint: Morus Walter patches for --format and
945 --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
946 <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
947 <li>fixes to the HTML parser</li>
948</ul>
949
950<h3>2.4.9: Nov 6 2001</h3>
951<ul>
952 <li>fixes more catalog bugs</li>
953 <li>avoid a compilation problem, improve xmlGetLineNo()</li>
954</ul>
955
Daniel Veillarded421aa2001-11-04 21:22:45 +0000956<h3>2.4.8: Nov 4 2001</h3>
957<ul>
958 <li>fixed SGML catalogs broken in previous release, updated xmlcatalog
959 tool</li>
960 <li>fixed a compile errors and some includes troubles.</li>
961</ul>
962
Daniel Veillard52dcab32001-10-30 12:51:17 +0000963<h3>2.4.7: Oct 30 2001</h3>
964<ul>
965 <li>exported some debugging interfaces</li>
966 <li>serious rewrite of the catalog code</li>
967 <li>integrated Gary Pennington thread safety patch, added configure option
968 and regression tests</li>
969 <li>removed an HTML parser bug</li>
970 <li>fixed a couple of potentially serious validation bugs</li>
971 <li>integrated the SGML DocBook support in xmllint</li>
972 <li>changed the nanoftp anonymous login passwd</li>
973 <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
974 <li>general bug fixes</li>
975 <li>updated xmllint man page by John Fleck</li>
976 <li>some VMS and Windows updates</li>
977</ul>
978
Daniel Veillard60087f32001-10-10 09:45:09 +0000979<h3>2.4.6: Oct 10 2001</h3>
980<ul>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000981 <li>added an updated man pages by John Fleck</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000982 <li>portability and configure fixes</li>
983 <li>an infinite loop on the HTML parser was removed (William)</li>
984 <li>Windows makefile patches from Igor</li>
Daniel Veillard63d83142002-05-20 06:51:05 +0000985 <li>fixed half a dozen bugs reported for libxml or libxslt</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000986 <li>updated xmlcatalog to be able to modify SGML super catalogs</li>
987</ul>
988
Daniel Veillarddadd0872001-09-15 09:21:44 +0000989<h3>2.4.5: Sep 14 2001</h3>
990<ul>
991 <li>Remove a few annoying bugs in 2.4.4</li>
992 <li>forces the HTML serializer to output decimal charrefs since some
993 version of Netscape can't handle hexadecimal ones</li>
994</ul>
995
996<h3>1.8.16: Sep 14 2001</h3>
997<ul>
998 <li>maintenance release of the old libxml1 branch, couple of bug and
999 portability fixes</li>
1000</ul>
1001
Daniel Veillard04382ae2001-09-12 18:51:30 +00001002<h3>2.4.4: Sep 12 2001</h3>
1003<ul>
1004 <li>added --convert to xmlcatalog, bug fixes and cleanups of XML
1005 Catalog</li>
1006 <li>a few bug fixes and some portability changes</li>
1007 <li>some documentation cleanups</li>
1008</ul>
1009
Daniel Veillard39936902001-08-24 00:49:01 +00001010<h3>2.4.3: Aug 23 2001</h3>
1011<ul>
1012 <li>XML Catalog support see the doc</li>
1013 <li>New NaN/Infinity floating point code</li>
1014 <li>A few bug fixes</li>
1015</ul>
1016
1017<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001018<ul>
1019 <li>adds xmlLineNumbersDefault() to control line number generation</li>
1020 <li>lot of bug fixes</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001021 <li>the Microsoft MSC projects files should now be up to date</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001022 <li>inheritance of namespaces from DTD defaulted attributes</li>
1023 <li>fixes a serious potential security bug</li>
1024 <li>added a --format option to xmllint</li>
1025</ul>
1026
1027<h3>2.4.1: July 24 2001</h3>
1028<ul>
1029 <li>possibility to keep line numbers in the tree</li>
1030 <li>some computation NaN fixes</li>
1031 <li>extension of the XPath API</li>
1032 <li>cleanup for alpha and ia64 targets</li>
1033 <li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard09ab7e12001-07-10 15:49:44 +00001034</ul>
1035
1036<h3>2.4.0: July 10 2001</h3>
1037<ul>
1038 <li>Fixed a few bugs in XPath, validation, and tree handling.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001039 <li>Fixed XML Base implementation, added a couple of examples to the
Daniel Veillard09ab7e12001-07-10 15:49:44 +00001040 regression tests</li>
1041 <li>A bit of cleanup</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +00001042</ul>
1043
Daniel Veillard5b43fde2001-07-05 23:31:40 +00001044<h3>2.3.14: July 5 2001</h3>
1045<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +00001046 <li>fixed some entities problems and reduce memory requirement when
1047 substituting them</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +00001048 <li>lots of improvements in the XPath queries interpreter can be
Daniel Veillard63d83142002-05-20 06:51:05 +00001049 substantially faster</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +00001050 <li>Makefiles and configure cleanups</li>
1051 <li>Fixes to XPath variable eval, and compare on empty node set</li>
1052 <li>HTML tag closing bug fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001053 <li>Fixed an URI reference computation problem when validating</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +00001054</ul>
1055
Daniel Veillard2adbb512001-06-28 16:20:36 +00001056<h3>2.3.13: June 28 2001</h3>
1057<ul>
1058 <li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
1059 <li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
1060</ul>
1061
1062<h3>1.8.14: June 28 2001</h3>
1063<ul>
1064 <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
1065 <li>Small Makefile fix</li>
1066</ul>
1067
Daniel Veillard11648102001-06-26 16:08:24 +00001068<h3>2.3.12: June 26 2001</h3>
1069<ul>
1070 <li>lots of cleanup</li>
1071 <li>a couple of validation fix</li>
1072 <li>fixed line number counting</li>
1073 <li>fixed serious problems in the XInclude processing</li>
1074 <li>added support for UTF8 BOM at beginning of entities</li>
1075 <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
1076 miscompile uri.c (William), Thomas Leitner provided a fix for the
1077 optimizer on Tru64</li>
1078 <li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
1079 compilation on Windows MSC</li>
1080 <li>update of libxml-doc.el (Felix Natter)</li>
1081 <li>fixed 2 bugs in URI normalization code</li>
1082</ul>
1083
Daniel Veillarde3c81b52001-06-17 14:50:34 +00001084<h3>2.3.11: June 17 2001</h3>
1085<ul>
1086 <li>updates to trio, Makefiles and configure should fix some portability
1087 problems (alpha)</li>
1088 <li>fixed some HTML serialization problems (pre, script, and block/inline
1089 handling), added encoding aware APIs, cleanup of this code</li>
1090 <li>added xmlHasNsProp()</li>
1091 <li>implemented a specific PI for encoding support in the DocBook SGML
1092 parser</li>
1093 <li>some XPath fixes (-Infinity, / as a function parameter and namespaces
1094 node selection)</li>
1095 <li>fixed a performance problem and an error in the validation code</li>
1096 <li>fixed XInclude routine to implement the recursive behaviour</li>
1097 <li>fixed xmlFreeNode problem when libxml is included statically twice</li>
1098 <li>added --version to xmllint for bug reports</li>
1099</ul>
1100
Daniel Veillard2e4f1882001-06-01 10:11:57 +00001101<h3>2.3.10: June 1 2001</h3>
1102<ul>
1103 <li>fixed the SGML catalog support</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001104 <li>a number of reported bugs got fixed, in XPath, iconv detection,
1105 XInclude processing</li>
Daniel Veillard2e4f1882001-06-01 10:11:57 +00001106 <li>XPath string function should now handle unicode correctly</li>
1107</ul>
1108
Daniel Veillard4623acd2001-05-19 15:13:15 +00001109<h3>2.3.9: May 19 2001</h3>
1110
1111<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
1112<ul>
1113 <li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001114 <li>some serious speed optimization again</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +00001115 <li>some documentation cleanups</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001116 <li>trying to get better linking on Solaris (-R)</li>
Daniel Veillard4623acd2001-05-19 15:13:15 +00001117 <li>XPath API cleanup from Thomas Broyer</li>
1118 <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
1119 xmlValidGetValidElements()</li>
1120 <li>Added an INSTALL file</li>
1121 <li>Attribute removal added to API: #54433</li>
1122 <li>added a basic support for SGML catalogs</li>
1123 <li>fixed xmlKeepBlanksDefault(0) API</li>
1124 <li>bugfix in xmlNodeGetLang()</li>
1125 <li>fixed a small configure portability problem</li>
1126 <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
1127</ul>
1128
Daniel Veillarda265af72001-05-14 11:13:58 +00001129<h3>1.8.13: May 14 2001</h3>
1130<ul>
1131 <li>bugfixes release of the old libxml1 branch used by Gnome</li>
1132</ul>
1133
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +00001134<h3>2.3.8: May 3 2001</h3>
1135<ul>
1136 <li>Integrated an SGML DocBook parser for the Gnome project</li>
1137 <li>Fixed a few things in the HTML parser</li>
1138 <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
1139 point portability issue</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001140 <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
1141 DOM+validation using the XML REC as input and a 700MHz celeron).</li>
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +00001142 <li>incorporated more Windows cleanup</li>
1143 <li>added xmlSaveFormatFile()</li>
1144 <li>fixed problems in copying nodes with entities references (gdome)</li>
1145 <li>removed some troubles surrounding the new validation module</li>
1146</ul>
1147
Daniel Veillarda41123c2001-04-22 19:31:20 +00001148<h3>2.3.7: April 22 2001</h3>
1149<ul>
1150 <li>lots of small bug fixes, corrected XPointer</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001151 <li>Non deterministic content model validation support</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +00001152 <li>added xmlDocCopyNode for gdome2</li>
1153 <li>revamped the way the HTML parser handles end of tags</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001154 <li>XPath: corrections of namespaces support and number formatting</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +00001155 <li>Windows: Igor Zlatkovic patches for MSC compilation</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001156 <li>HTML output fixes from P C Chow and William M. Brack</li>
Daniel Veillarda41123c2001-04-22 19:31:20 +00001157 <li>Improved validation speed sensible for DocBook</li>
1158 <li>fixed a big bug with ID declared in external parsed entities</li>
1159 <li>portability fixes, update of Trio from Bjorn Reese</li>
1160</ul>
1161
Daniel Veillardafc73112001-04-11 11:51:41 +00001162<h3>2.3.6: April 8 2001</h3>
1163<ul>
1164 <li>Code cleanup using extreme gcc compiler warning options, found and
1165 cleared half a dozen potential problem</li>
1166 <li>the Eazel team found an XML parser bug</li>
1167 <li>cleaned up the user of some of the string formatting function. used the
1168 trio library code to provide the one needed when the platform is missing
1169 them</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001170 <li>xpath: removed a memory leak and fixed the predicate evaluation
1171 problem, extended the testsuite and cleaned up the result. XPointer seems
1172 broken ...</li>
Daniel Veillardafc73112001-04-11 11:51:41 +00001173</ul>
1174
Daniel Veillard56a4cb82001-03-24 17:00:36 +00001175<h3>2.3.5: Mar 23 2001</h3>
1176<ul>
1177 <li>Biggest change is separate parsing and evaluation of XPath expressions,
1178 there is some new APIs for this too</li>
1179 <li>included a number of bug fixes(XML push parser, 51876, notations,
1180 52299)</li>
1181 <li>Fixed some portability issues</li>
1182</ul>
1183
Daniel Veillarde356c282001-03-10 12:32:04 +00001184<h3>2.3.4: Mar 10 2001</h3>
1185<ul>
1186 <li>Fixed bugs #51860 and #51861</li>
1187 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
1188 size to be application tunable.</li>
1189 <li>Some cleanup in the validation code, still a bug left and this part
1190 should probably be rewritten to support ambiguous content model :-\</li>
1191 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
1192 parser</li>
1193 <li>Fixed another bug in xmlNodeGetContent()</li>
1194 <li>Bjorn fixed XPath node collection and Number formatting</li>
1195 <li>Fixed a loop reported in the HTML parsing</li>
1196 <li>blank space are reported even if the Dtd content model proves that they
Daniel Veillard63d83142002-05-20 06:51:05 +00001197 are formatting spaces, this is for XML conformance</li>
Daniel Veillarde356c282001-03-10 12:32:04 +00001198</ul>
1199
Daniel Veillardb402c072001-03-01 17:28:58 +00001200<h3>2.3.3: Mar 1 2001</h3>
1201<ul>
1202 <li>small change in XPath for XSLT</li>
1203 <li>documentation cleanups</li>
1204 <li>fix in validation by Gary Pennington</li>
1205 <li>serious parsing performances improvements</li>
1206</ul>
1207
Daniel Veillardec70e912001-02-26 20:10:45 +00001208<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +00001209<ul>
1210 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
1211 <li>fixed a Dtd parsing bug</li>
1212 <li>fixed a bug in xmlNodeGetContent</li>
1213 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
1214</ul>
1215
Daniel Veillardec70e912001-02-26 20:10:45 +00001216<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +00001217<ul>
1218 <li>some XPath and HTML bug fixes for XSLT</li>
1219 <li>small extension of the hash table interfaces for DOM gdome2
1220 implementation</li>
1221 <li>A few bug fixes</li>
1222</ul>
1223
Daniel Veillardec70e912001-02-26 20:10:45 +00001224<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 +00001225<ul>
1226 <li>Lots of XPath bug fixes</li>
1227 <li>Add a mode with Dtd lookup but without validation error reporting for
1228 XSLT</li>
1229 <li>Add support for text node without escaping (XSLT)</li>
1230 <li>bug fixes for xmlCheckFilename</li>
1231 <li>validation code bug fixes from Gary Pennington</li>
1232 <li>Patch from Paul D. Smith correcting URI path normalization</li>
1233 <li>Patch to allow simultaneous install of libxml-devel and
1234 libxml2-devel</li>
1235 <li>the example Makefile is now fixed</li>
1236 <li>added HTML to the RPM packages</li>
1237 <li>tree copying bugfixes</li>
1238 <li>updates to Windows makefiles</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001239 <li>optimization patch from Bjorn Reese</li>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +00001240</ul>
1241
Daniel Veillardec70e912001-02-26 20:10:45 +00001242<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +00001243<ul>
1244 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
1245 <li>added htmlHandleOmittedElem()</li>
1246 <li>Applied Bjorn Reese's IPV6 first patch</li>
1247 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +00001248 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +00001249</ul>
1250
Daniel Veillard2ddd23d2000-11-25 10:42:19 +00001251<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +00001252<ul>
1253 <li>Fix the Windows problems of 2.2.8</li>
1254 <li>integrate OpenVMS patches</li>
1255 <li>better handling of some nasty HTML input</li>
1256 <li>Improved the XPointer implementation</li>
1257 <li>integrate a number of provided patches</li>
1258</ul>
1259
Daniel Veillard2ddd23d2000-11-25 10:42:19 +00001260<h3>2.2.9: Nov 25 2000</h3>
1261<ul>
1262 <li>erroneous release :-(</li>
1263</ul>
1264
Daniel Veillard28929b22000-11-13 18:22:49 +00001265<h3>2.2.8: Nov 13 2000</h3>
1266<ul>
1267 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
1268 support</li>
1269 <li>Patch in conditional section handling</li>
1270 <li>updated MS compiler project</li>
1271 <li>fixed some XPath problems</li>
1272 <li>added an URI escaping function</li>
1273 <li>some other bug fixes</li>
1274</ul>
1275
1276<h3>2.2.7: Oct 31 2000</h3>
1277<ul>
1278 <li>added message redirection</li>
1279 <li>XPath improvements (thanks TOM !)</li>
1280 <li>xmlIOParseDTD() added</li>
1281 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
1282 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
1283</ul>
1284
Daniel Veillard29a11cc2000-10-25 13:32:39 +00001285<h3>2.2.6: Oct 25 2000:</h3>
1286<ul>
1287 <li>Added an hash table module, migrated a number of internal structure to
1288 those</li>
1289 <li>Fixed a posteriori validation problems</li>
1290 <li>HTTP module cleanups</li>
1291 <li>HTML parser improvements (tag errors, script/style handling, attribute
1292 normalization)</li>
1293 <li>coalescing of adjacent text nodes</li>
1294 <li>couple of XPath bug fixes, exported the internal API</li>
1295</ul>
1296
Daniel Veillardab8500d2000-10-15 21:06:19 +00001297<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +00001298<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +00001299 <li>XPointer implementation and testsuite</li>
1300 <li>Lot of XPath fixes, added variable and functions registration, more
1301 tests</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001302 <li>Portability fixes, lots of enhancements toward an easy Windows build
1303 and release</li>
Daniel Veillard189446d2000-10-13 10:23:06 +00001304 <li>Late validation fixes</li>
1305 <li>Integrated a lot of contributed patches</li>
1306 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +00001307 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +00001308</ul>
1309
1310<h3>2.2.4: Oct 1 2000:</h3>
1311<ul>
1312 <li>main XPath problem fixed</li>
1313 <li>Integrated portability patches for Windows</li>
1314 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +00001315</ul>
1316
Daniel Veillardd5f97f82000-09-17 16:38:14 +00001317<h3>2.2.3: Sep 17 2000</h3>
1318<ul>
1319 <li>bug fixes</li>
1320 <li>cleanup of entity handling code</li>
1321 <li>overall review of all loops in the parsers, all sprintf usage has been
1322 checked too</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001323 <li>Far better handling of larges Dtd. Validating against DocBook XML Dtd
Daniel Veillardd5f97f82000-09-17 16:38:14 +00001324 works smoothly now.</li>
1325</ul>
1326
1327<h3>1.8.10: Sep 6 2000</h3>
1328<ul>
1329 <li>bug fix release for some Gnome projects</li>
1330</ul>
1331
1332<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +00001333<ul>
1334 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +00001335 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +00001336</ul>
1337
Daniel Veillardd5f97f82000-09-17 16:38:14 +00001338<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +00001339<ul>
1340 <li>a purely bug fixes release</li>
1341 <li>fixed an encoding support problem when parsing from a memory block</li>
1342 <li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001343 <li>removed a bug in the function allowing to override the memory
1344 allocation routines</li>
Daniel Veillarda2679fa2000-07-22 02:38:15 +00001345</ul>
1346
Daniel Veillardd5f97f82000-09-17 16:38:14 +00001347<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +00001348<ul>
1349 <li>applied a lot of portability fixes</li>
1350 <li>better encoding support/cleanup and saving (content is now always
1351 encoded in UTF-8)</li>
1352 <li>the HTML parser now correctly handles encodings</li>
1353 <li>added xmlHasProp()</li>
1354 <li>fixed a serious problem with &amp;#38;</li>
1355 <li>propagated the fix to FTP client</li>
1356 <li>cleanup, bugfixes, etc ...</li>
1357 <li>Added a page about <a href="encoding.html">libxml Internationalization
1358 support</a></li>
1359</ul>
1360
Daniel Veillard60979bd2000-07-10 12:17:33 +00001361<h3>1.8.9: July 9 2000</h3>
1362<ul>
1363 <li>fixed the spec the RPMs should be better</li>
1364 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
1365 rpmfind users problem</li>
1366</ul>
1367
Daniel Veillard6388e172000-07-03 16:07:19 +00001368<h3>2.1.1: July 1 2000</h3>
1369<ul>
1370 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
1371 <li>improvements on the HTML parser</li>
1372</ul>
1373
Daniel Veillard3f6f7f62000-06-30 17:58:25 +00001374<h3>2.1.0 and 1.8.8: June 29 2000</h3>
1375<ul>
Daniel Veillardc0801af2002-05-28 16:28:42 +00001376 <li>1.8.8 is mostly a commodity package for upgrading to libxml2 according
1377 to <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
Daniel Veillard3f6f7f62000-06-30 17:58:25 +00001378 about &amp;#38; charref parsing</li>
1379 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
1380 also contains numerous fixes and enhancements:
1381 <ul>
1382 <li>added xmlStopParser() to stop parsing</li>
1383 <li>improved a lot parsing speed when there is large CDATA blocs</li>
1384 <li>includes XPath patches provided by Picdar Technology</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001385 <li>tried to fix as much as possible DTD validation and namespace
Daniel Veillard3f6f7f62000-06-30 17:58:25 +00001386 related problems</li>
1387 <li>output to a given encoding has been added/tested</li>
1388 <li>lot of various fixes</li>
1389 </ul>
1390 </li>
1391</ul>
1392
Daniel Veillarde0aed302000-04-16 08:52:20 +00001393<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +00001394<ul>
1395 <li>First public release of libxml2. If you are using libxml, it's a good
Daniel Veillard63d83142002-05-20 06:51:05 +00001396 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initially
1397 scheduled for Apr 3 the release occurred only on Apr 12 due to massive
Daniel Veillarde0aed302000-04-16 08:52:20 +00001398 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +00001399 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +00001400 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +00001401 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +00001402 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +00001403 <pre>#include "xxx.h"</pre>
1404 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +00001405 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
1406 <li>the memory allocation routines used by libxml can now be overloaded
1407 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +00001408 <li>The previously CVS only tool tester has been renamed
1409 <strong>xmllint</strong> and is now installed as part of the libxml2
1410 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +00001411 <li>The I/O interface has been revamped. There is now ways to plug in
1412 specific I/O modules, either at the URI scheme detection level using
1413 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
1414 parser context using xmlCreateIOParserCtxt()</li>
1415 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
1416 number of the libxml module in use</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001417 <li>a number of optional features of libxml can now be excluded at
1418 configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +00001419</ul>
1420
1421<h3>2.0.0beta: Mar 14 2000</h3>
1422<ul>
1423 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +00001424 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
1425 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
1426 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +00001427 <li>This version is now the head in the Gnome CVS base, the old one is
1428 available under the tag LIB_XML_1_X</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +00001429 <li>This includes a very large set of changes. From a programmatic point
1430 of view applications should not have to be modified too much, check the
1431 <a href="upgrade.html">upgrade page</a></li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +00001432 <li>Some interfaces may changes (especially a bit about encoding).</li>
1433 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +00001434 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +00001435 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
1436 handled now</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001437 <li>Better handling of entities, especially well-formedness checking
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001438 and proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +00001439 <li>DTD conditional sections</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001440 <li>Validation now correctly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +00001441 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
Daniel Veillard63d83142002-05-20 06:51:05 +00001442 structures to accommodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +00001443 </ul>
1444 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +00001445 <li>Serious progress were made toward compliance, <a
1446 href="conf/result.html">here are the result of the test</a> against the
Daniel Veillard63d83142002-05-20 06:51:05 +00001447 OASIS testsuite (except the Japanese tests since I don't support that
Daniel Veillardedfb29b2000-03-14 19:59:05 +00001448 encoding yet). This URL is rebuilt every couple of hours using the CVS
1449 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +00001450</ul>
1451
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00001452<h3>1.8.7: Mar 6 2000</h3>
1453<ul>
1454 <li>This is a bug fix release:</li>
1455 <li>It is possible to disable the ignorable blanks heuristic used by
1456 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001457 that for adherence to XML spec, this behaviour will be disabled by
1458 default in 2.x . The same function will allow to keep compatibility for
1459 old code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +00001460 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
1461 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00001462 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
1463 compilation on some platforms has been fixed</li>
1464 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
1465 URIs</li>
1466</ul>
1467
Daniel Veillarde41f2b72000-01-30 20:00:07 +00001468<h3>1.8.6: Jan 31 2000</h3>
1469<ul>
1470 <li>added a nanoFTP transport module, debugged until the new version of <a
1471 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
1472 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +00001473</ul>
1474
1475<h3>1.8.5: Jan 21 2000</h3>
1476<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +00001477 <li>adding APIs to parse a well balanced chunk of XML (production <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001478 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
1479 XML spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +00001480 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +00001481 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
1482 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +00001483 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
1484 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +00001485</ul>
1486
1487<h3>1.8.4: Jan 13 2000</h3>
1488<ul>
1489 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
1490 <li>all exit() call should have been removed from libxml</li>
1491 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
1492 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +00001493</ul>
1494
1495<h3>1.8.3: Jan 5 2000</h3>
1496<ul>
1497 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00001498 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001499 <li>lots of bug fixes and improvement added over XMas holidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +00001500 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +00001501 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
1502 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +00001503 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +00001504 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +00001505 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +00001506</ul>
1507
1508<h3>1.8.2: Dec 21 1999</h3>
1509<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +00001510 <li>I got another problem with includes and C++, I hope this issue is fixed
1511 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +00001512 <li>Added a few tree modification functions: xmlReplaceNode,
1513 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
1514 xmlDocSetRootElement</li>
1515 <li>Tried to improve the HTML output with help from <a
1516 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +00001517</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +00001518
Daniel Veillarde4e51311999-12-18 15:32:46 +00001519<h3>1.8.1: Dec 18 1999</h3>
1520<ul>
1521 <li>various patches to avoid troubles when using libxml with C++ compilers
1522 the "namespace" keyword and C escaping in include files</li>
1523 <li>a problem in one of the core macros IS_CHAR was corrected</li>
1524 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
1525 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +00001526 <li>fixed a posteriori validation (validation after parsing, or by using a
1527 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +00001528 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +00001529</ul>
1530
1531<h3>1.8.0: Dec 12 1999</h3>
1532<ul>
1533 <li>cleanup, especially memory wise</li>
1534 <li>the parser should be more reliable, especially the HTML one, it should
1535 not crash, whatever the input !</li>
1536 <li>Integrated various patches, especially a speedup improvement for large
1537 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
1538 configure with --with-buffers to enable them.</li>
1539 <li>attribute normalization, oops should have been added long ago !</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001540 <li>attributes defaulted from DTDs should be available, xmlSetProp() now
1541 does entities escaping by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +00001542</ul>
Daniel Veillard35008381999-10-25 13:15:52 +00001543
1544<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00001545<ul>
Daniel Veillard35008381999-10-25 13:15:52 +00001546 <li>Lots of HTML improvement</li>
1547 <li>Fixed some errors when saving both XML and HTML</li>
1548 <li>More examples, the regression tests should now look clean</li>
1549 <li>Fixed a bug with contiguous charref</li>
1550</ul>
1551
1552<h3>1.7.3: Sep 29 1999</h3>
1553<ul>
1554 <li>portability problems fixed</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00001555 <li>snprintf was used unconditionally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +00001556 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00001557</ul>
1558
1559<h3>1.7.1: Sep 24 1999</h3>
1560<ul>
1561 <li>The basic type for strings manipulated by libxml has been renamed in
1562 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001563 is that CHAR was conflicting with a predefined type on Windows. However
1564 on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00001565 <strong>#define </strong>.</li>
1566 <li>Changed another error : the use of a structure field called errno, and
1567 leading to troubles on platforms where it's a macro</li>
1568</ul>
1569
Daniel Veillard63d83142002-05-20 06:51:05 +00001570<h3>1.7.0: Sep 23 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00001571<ul>
1572 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +00001573 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00001574 <li>Added an errno to report errors by another mean than a simple printf
1575 like callback</li>
1576 <li>Finished ID/IDREF support and checking when validation</li>
1577 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +00001578 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00001579 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
1580 implementation</li>
1581 <li>Added an HTML parser front-end</li>
1582</ul>
1583
1584<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00001585
Daniel Veillard402e8c82000-02-29 22:57:47 +00001586<p><a href="http://www.w3.org/TR/REC-xml">XML is a standard</a> for
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00001587markup-based structured documents. Here is <a name="example">an example XML
1588document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +00001589<pre>&lt;?xml version="1.0"?&gt;
1590&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
1591 &lt;head&gt;
1592 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
1593 &lt;/head&gt;
1594 &lt;chapter&gt;
1595 &lt;title&gt;The Linux adventure&lt;/title&gt;
1596 &lt;p&gt;bla bla bla ...&lt;/p&gt;
1597 &lt;image href="linus.gif"/&gt;
1598 &lt;p&gt;...&lt;/p&gt;
1599 &lt;/chapter&gt;
1600&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +00001601
Daniel Veillard0b28e882002-07-24 23:47:05 +00001602<p>The first line specifies that it is an XML document and gives useful
Daniel Veillard42766c02002-08-22 20:52:17 +00001603information about its encoding. Then the rest of the document is a text
1604format whose structure is specified by tags between brackets. <strong>Each
1605tag opened has to be closed</strong>. XML is pedantic about this. However, if
1606a tag is empty (no content), a single tag can serve as both the opening and
1607closing tag if it ends with <code>/&gt;</code> rather than with
1608<code>&gt;</code>. Note that, for example, the image tag has no content (just
1609an attribute) and is closed by ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +00001610
Daniel Veillard42766c02002-08-22 20:52:17 +00001611<p>XML can be applied successfully to a wide range of tasks, ranging from
1612long term structured document maintenance (where it follows the steps of
1613SGML) to simple data encoding mechanisms like configuration file formatting
1614(glade), spreadsheets (gnumeric), or even shorter lived documents such as
1615WebDAV where it is used to encode remote calls between a client and a
1616server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00001617
Daniel Veillard82687162001-01-22 15:32:01 +00001618<h2><a name="XSLT">XSLT</a></h2>
1619
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +00001620<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
1621
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001622<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
1623language for transforming XML documents into other XML documents (or
1624HTML/textual output).</p>
Daniel Veillard82687162001-01-22 15:32:01 +00001625
Daniel Veillard42766c02002-08-22 20:52:17 +00001626<p>A separate library called libxslt is being developed on top of libxml2.
1627This module "libxslt" too can be found in the Gnome CVS base.</p>
Daniel Veillard82687162001-01-22 15:32:01 +00001628
Daniel Veillard383b1472001-01-23 11:39:52 +00001629<p>You can check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00001630href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
1631supported and the progresses on the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001632href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog"
Daniel Veillard0b28e882002-07-24 23:47:05 +00001633name="Changelog">Changelog</a>.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001634
1635<h2><a name="Python">Python and bindings</a></h2>
1636
Daniel Veillard42766c02002-08-22 20:52:17 +00001637<p>There are a number of language bindings and wrappers available for
1638libxml2, the list below is not exhaustive. Please contact the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001639href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a>
1640(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in
1641order to get updates to this list or to discuss the specific topic of libxml2
1642or libxslt wrappers or bindings:</p>
1643<ul>
Daniel Veillardc14401e2002-11-20 14:28:17 +00001644 <li><a href="http://libxmlplusplus.sourceforge.net/">Libxml++</a> seems the
1645 most up-to-date C++ bindings for libxml2, check the <a
1646 href="http://libxmlplusplus.sourceforge.net/reference/html/hierarchy.html">documentation</a>
1647 and the <a
1648 href="http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/libxmlplusplus/libxml%2b%2b/examples/">examples</a>.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001649 <li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper
Daniel Veillard0b28e882002-07-24 23:47:05 +00001650 based on the gdome2 bindings</a> maintained by Tobias Peters.</li>
Daniel Veillard9b6fd302002-05-13 12:06:47 +00001651 <li>and a third C++ wrapper by Peter Jones &lt;pjones@pmade.org&gt;
1652 <p>Website: <a
1653 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
1654 </li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001655 <li><a
1656 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +00001657 Sergeant</a> developed <a
1658 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +00001659 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
Daniel Veillard0b28e882002-07-24 23:47:05 +00001660 application server</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +00001661 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides an
Daniel Veillardaf43f632002-03-08 15:05:20 +00001662 earlier version of the libxml/libxslt <a
Daniel Veillard0b28e882002-07-24 23:47:05 +00001663 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li>
Daniel Veillard21473672002-06-17 07:29:22 +00001664 <li>Gopal.V and Peter Minten develop <a
1665 href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of
Daniel Veillard0b28e882002-07-24 23:47:05 +00001666 C# libxml2 bindings.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001667 <li>Petr Kozelka provides <a
1668 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
Daniel Veillard0b28e882002-07-24 23:47:05 +00001669 libxml2</a> with Kylix, Delphi and other Pascal compilers.</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +00001670 <li>Uwe Fechner also provides <a
1671 href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2
Daniel Veillard0b28e882002-07-24 23:47:05 +00001672 implementation for Kylix2/D5/D6 from Borland.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001673 <li>Wai-Sun "Squidster" Chia provides <a
1674 href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and
1675 libxml2 bindings are also available in Ruby through the <a
1676 href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module
1677 maintained by Tobias Peters.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +00001678 <li>Steve Ball and contributors maintains <a
1679 href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for
Daniel Veillard0b28e882002-07-24 23:47:05 +00001680 Tcl</a>.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +00001681 <li>There is support for libxml2 in the DOM module of PHP.</li>
Daniel Veillard41b01a82003-02-27 11:09:06 +00001682 <li><a href="http://savannah.gnu.org/projects/classpathx/">LibxmlJ</a> is
Daniel Veillard806cada2003-03-19 21:58:59 +00001683 an effort to create a 100% JAXP-compatible Java wrapper for libxml2 and
1684 libxslt as part of GNU ClasspathX project.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001685</ul>
1686
Daniel Veillardc0801af2002-05-28 16:28:42 +00001687<p>The distribution includes a set of Python bindings, which are guaranteed
1688to be maintained as part of the library in the future, though the Python
Daniel Veillard41b01a82003-02-27 11:09:06 +00001689interface have not yet reached the completeness of the C API.</p>
Daniel Veillard7b4b2f92003-01-06 13:11:20 +00001690
Daniel Veillard27907c72002-12-16 16:05:58 +00001691<p><a href="mailto:stephane.bidoul@softwareag.com">Stéphane Bidoul</a>
Daniel Veillard7b4b2f92003-01-06 13:11:20 +00001692maintains <a href="http://users.skynet.be/sbi/libxml-python/">a Windows port
1693of the Python bindings</a>.</p>
Daniel Veillardaf43f632002-03-08 15:05:20 +00001694
Daniel Veillard7ef0fcb2002-12-14 10:38:55 +00001695<p>Note to people interested in building bindings, the API is formalized as
1696<a href="libxml2-api.xml">an XML API description file</a> which allows to
1697automate a large part of the Python bindings, this includes function
Daniel Veillard7b4b2f92003-01-06 13:11:20 +00001698descriptions, enums, structures, typedefs, etc... The Python script used to
1699build the bindings is python/generator.py in the source distribution.</p>
Daniel Veillard7ef0fcb2002-12-14 10:38:55 +00001700
Daniel Veillardaf43f632002-03-08 15:05:20 +00001701<p>To install the Python bindings there are 2 options:</p>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +00001702<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +00001703 <li>If you use an RPM based distribution, simply install the <a
1704 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python
1705 RPM</a> (and if needed the <a
1706 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python
1707 RPM</a>).</li>
1708 <li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python
1709 module distribution</a> corresponding to your installed version of
1710 libxml2 and libxslt. Note that to install it you will need both libxml2
1711 and libxslt installed and run "python setup.py build install" in the
1712 module tree.</li>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +00001713</ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +00001714
1715<p>The distribution includes a set of examples and regression tests for the
1716python bindings in the <code>python/tests</code> directory. Here are some
Daniel Veillard0b28e882002-07-24 23:47:05 +00001717excerpts from those tests:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001718
1719<h3>tst.py:</h3>
1720
1721<p>This is a basic test of the file interface and DOM navigation:</p>
1722<pre>import libxml2
1723
1724doc = libxml2.parseFile("tst.xml")
1725if doc.name != "tst.xml":
1726 print "doc.name failed"
1727 sys.exit(1)
1728root = doc.children
1729if root.name != "doc":
1730 print "root.name failed"
1731 sys.exit(1)
1732child = root.children
1733if child.name != "foo":
1734 print "child.name failed"
1735 sys.exit(1)
1736doc.freeDoc()</pre>
1737
Daniel Veillard0b28e882002-07-24 23:47:05 +00001738<p>The Python module is called libxml2; parseFile is the equivalent of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001739xmlParseFile (most of the bindings are automatically generated, and the xml
1740prefix is removed and the casing convention are kept). All node seen at the
Daniel Veillard63d83142002-05-20 06:51:05 +00001741binding level share the same subset of accessors:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001742<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +00001743 <li><code>name</code> : returns the node name</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +00001744 <li><code>type</code> : returns a string indicating the node type</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +00001745 <li><code>content</code> : returns the content of the node, it is based on
1746 xmlNodeGetContent() and hence is recursive.</li>
1747 <li><code>parent</code> , <code>children</code>, <code>last</code>,
1748 <code>next</code>, <code>prev</code>, <code>doc</code>,
1749 <code>properties</code>: pointing to the associated element in the tree,
1750 those may return None in case no such link exists.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001751</ul>
1752
Daniel Veillard63d83142002-05-20 06:51:05 +00001753<p>Also note the need to explicitly deallocate documents with freeDoc() .
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001754Reference counting for libxml2 trees would need quite a lot of work to
1755function properly, and rather than risk memory leaks if not implemented
1756correctly it sounds safer to have an explicit function to free a tree. The
1757wrapper python objects like doc, root or child are them automatically garbage
1758collected.</p>
1759
1760<h3>validate.py:</h3>
1761
1762<p>This test check the validation interfaces and redirection of error
1763messages:</p>
1764<pre>import libxml2
1765
Daniel Veillard63d83142002-05-20 06:51:05 +00001766#deactivate error messages from the validation
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001767def noerr(ctx, str):
1768 pass
1769
1770libxml2.registerErrorHandler(noerr, None)
1771
1772ctxt = libxml2.createFileParserCtxt("invalid.xml")
1773ctxt.validate(1)
1774ctxt.parseDocument()
1775doc = ctxt.doc()
1776valid = ctxt.isValid()
1777doc.freeDoc()
1778if valid != 0:
Daniel Veillard63d83142002-05-20 06:51:05 +00001779 print "validity check failed"</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001780
1781<p>The first thing to notice is the call to registerErrorHandler(), it
1782defines a new error handler global to the library. It is used to avoid seeing
1783the error messages when trying to validate the invalid document.</p>
1784
1785<p>The main interest of that test is the creation of a parser context with
1786createFileParserCtxt() and how the behaviour can be changed before calling
Daniel Veillard63d83142002-05-20 06:51:05 +00001787parseDocument() . Similarly the informations resulting from the parsing phase
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001788are also available using context methods.</p>
1789
1790<p>Contexts like nodes are defined as class and the libxml2 wrappers maps the
1791C function interfaces in terms of objects method as much as possible. The
1792best to get a complete view of what methods are supported is to look at the
1793libxml2.py module containing all the wrappers.</p>
1794
1795<h3>push.py:</h3>
1796
1797<p>This test show how to activate the push parser interface:</p>
1798<pre>import libxml2
1799
1800ctxt = libxml2.createPushParser(None, "&lt;foo", 4, "test.xml")
1801ctxt.parseChunk("/&gt;", 2, 1)
1802doc = ctxt.doc()
1803
1804doc.freeDoc()</pre>
1805
Daniel Veillard63d83142002-05-20 06:51:05 +00001806<p>The context is created with a special call based on the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001807xmlCreatePushParser() from the C library. The first argument is an optional
Daniel Veillard63d83142002-05-20 06:51:05 +00001808SAX callback object, then the initial set of data, the length and the name of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001809the resource in case URI-References need to be computed by the parser.</p>
1810
1811<p>Then the data are pushed using the parseChunk() method, the last call
Daniel Veillard63d83142002-05-20 06:51:05 +00001812setting the third argument terminate to 1.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001813
1814<h3>pushSAX.py:</h3>
1815
1816<p>this test show the use of the event based parsing interfaces. In this case
1817the parser does not build a document, but provides callback information as
1818the parser makes progresses analyzing the data being provided:</p>
1819<pre>import libxml2
1820log = ""
1821
1822class callback:
1823 def startDocument(self):
1824 global log
1825 log = log + "startDocument:"
1826
1827 def endDocument(self):
1828 global log
1829 log = log + "endDocument:"
1830
1831 def startElement(self, tag, attrs):
1832 global log
1833 log = log + "startElement %s %s:" % (tag, attrs)
1834
1835 def endElement(self, tag):
1836 global log
1837 log = log + "endElement %s:" % (tag)
1838
1839 def characters(self, data):
1840 global log
1841 log = log + "characters: %s:" % (data)
1842
1843 def warning(self, msg):
1844 global log
1845 log = log + "warning: %s:" % (msg)
1846
1847 def error(self, msg):
1848 global log
1849 log = log + "error: %s:" % (msg)
1850
1851 def fatalError(self, msg):
1852 global log
1853 log = log + "fatalError: %s:" % (msg)
1854
1855handler = callback()
1856
1857ctxt = libxml2.createPushParser(handler, "&lt;foo", 4, "test.xml")
1858chunk = " url='tst'&gt;b"
1859ctxt.parseChunk(chunk, len(chunk), 0)
1860chunk = "ar&lt;/foo&gt;"
1861ctxt.parseChunk(chunk, len(chunk), 1)
1862
Daniel Veillardfcbfa2d2002-02-21 17:54:27 +00001863reference = "startDocument:startElement foo {'url': 'tst'}:" + \
1864 "characters: bar:endElement foo:endDocument:"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001865if log != reference:
1866 print "Error got: %s" % log
Daniel Veillard63d83142002-05-20 06:51:05 +00001867 print "Expected: %s" % reference</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001868
1869<p>The key object in that test is the handler, it provides a number of entry
1870points which can be called by the parser as it makes progresses to indicate
1871the information set obtained. The full set of callback is larger than what
1872the callback class in that specific example implements (see the SAX
1873definition for a complete list). The wrapper will only call those supplied by
1874the object when activated. The startElement receives the names of the element
Daniel Veillard63d83142002-05-20 06:51:05 +00001875and a dictionary containing the attributes carried by this element.</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001876
1877<p>Also note that the reference string generated from the callback shows a
1878single character call even though the string "bar" is passed to the parser
1879from 2 different call to parseChunk()</p>
1880
1881<h3>xpath.py:</h3>
1882
Daniel Veillard63d83142002-05-20 06:51:05 +00001883<p>This is a basic test of XPath wrappers support</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001884<pre>import libxml2
1885
1886doc = libxml2.parseFile("tst.xml")
1887ctxt = doc.xpathNewContext()
1888res = ctxt.xpathEval("//*")
1889if len(res) != 2:
1890 print "xpath query: wrong node set size"
1891 sys.exit(1)
1892if res[0].name != "doc" or res[1].name != "foo":
1893 print "xpath query: wrong node set value"
1894 sys.exit(1)
1895doc.freeDoc()
1896ctxt.xpathFreeContext()</pre>
1897
1898<p>This test parses a file, then create an XPath context to evaluate XPath
1899expression on it. The xpathEval() method execute an XPath query and returns
1900the result mapped in a Python way. String and numbers are natively converted,
1901and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like
Daniel Veillard63d83142002-05-20 06:51:05 +00001902the document, the XPath context need to be freed explicitly, also not that
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001903the result of the XPath query may point back to the document tree and hence
1904the document must be freed after the result of the query is used.</p>
1905
1906<h3>xpathext.py:</h3>
1907
1908<p>This test shows how to extend the XPath engine with functions written in
1909python:</p>
1910<pre>import libxml2
1911
1912def foo(ctx, x):
1913 return x + 1
1914
1915doc = libxml2.parseFile("tst.xml")
1916ctxt = doc.xpathNewContext()
1917libxml2.registerXPathFunction(ctxt._o, "foo", None, foo)
1918res = ctxt.xpathEval("foo(1)")
1919if res != 2:
1920 print "xpath extension failure"
1921doc.freeDoc()
1922ctxt.xpathFreeContext()</pre>
1923
1924<p>Note how the extension function is registered with the context (but that
Daniel Veillard63d83142002-05-20 06:51:05 +00001925part is not yet finalized, this may change slightly in the future).</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001926
1927<h3>tstxpath.py:</h3>
1928
Daniel Veillard63d83142002-05-20 06:51:05 +00001929<p>This test is similar to the previous one but shows how the extension
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001930function can access the XPath evaluation context:</p>
1931<pre>def foo(ctx, x):
1932 global called
1933
1934 #
1935 # test that access to the XPath evaluation contexts
1936 #
1937 pctxt = libxml2.xpathParserContext(_obj=ctx)
1938 ctxt = pctxt.context()
1939 called = ctxt.function()
1940 return x + 1</pre>
1941
1942<p>All the interfaces around the XPath parser(or rather evaluation) context
1943are not finalized, but it should be sufficient to do contextual work at the
1944evaluation point.</p>
1945
1946<h3>Memory debugging:</h3>
1947
1948<p>last but not least, all tests starts with the following prologue:</p>
1949<pre>#memory debug specific
Daniel Veillardaf43f632002-03-08 15:05:20 +00001950libxml2.debugMemory(1)</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001951
1952<p>and ends with the following epilogue:</p>
1953<pre>#memory debug specific
1954libxml2.cleanupParser()
1955if libxml2.debugMemory(1) == 0:
1956 print "OK"
1957else:
1958 print "Memory leak %d bytes" % (libxml2.debugMemory(1))
1959 libxml2.dumpMemory()</pre>
1960
1961<p>Those activate the memory debugging interface of libxml2 where all
Daniel Veillard63d83142002-05-20 06:51:05 +00001962allocated block in the library are tracked. The prologue then cleans up the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +00001963library state and checks that all allocated memory has been freed. If not it
1964calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p>
Daniel Veillard82687162001-01-22 15:32:01 +00001965
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00001966<h2><a name="architecture">libxml architecture</a></h2>
Daniel Veillard4540be42000-08-19 16:40:28 +00001967
Daniel Veillardec70e912001-02-26 20:10:45 +00001968<p>Libxml is made of multiple components; some of them are optional, and most
1969of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +00001970<ul>
1971 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +00001972 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +00001973 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +00001974 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +00001975 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +00001976 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +00001977 <li>a SAX tree module to build an in-memory DOM representation</li>
1978 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +00001979 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +00001980 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +00001981 (optional)</li>
1982 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +00001983</ul>
1984
1985<p>Graphically this gives the following:</p>
1986
1987<p><img src="libxml.gif" alt="a graphical view of the various"></p>
1988
1989<p></p>
1990
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00001991<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +00001992
1993<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +00001994returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00001995<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +00001996as the file name, the document type, and a <strong>children</strong> pointer
1997which is the root of the document (or more exactly the first child under the
1998root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +00001999chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +00002000relationship. An xmlNode can also carry properties (a chain of xmlAttr
2001structures). An attribute may have a value which is a list of TEXT or
2002ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00002003
Daniel Veillard88f00ae2000-03-02 00:15:55 +00002004<p>Here is an example (erroneous with respect to the XML spec since there
2005should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00002006
2007<p><img src="structure.gif" alt=" structure.gif "></p>
2008
2009<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +00002010called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00002011prints them back as parsed. This is useful for detecting errors both in XML
2012code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +00002013which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00002014result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +00002015<pre>DOCUMENT
2016version=1.0
2017standalone=true
2018 ELEMENT EXAMPLE
2019 ATTRIBUTE prop1
2020 TEXT
2021 content=gnome is great
2022 ATTRIBUTE prop2
2023 ENTITY_REF
2024 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +00002025 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +00002026 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +00002027 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +00002028 TEXT
2029 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +00002030 ELEMENT chapter
2031 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +00002032 TEXT
2033 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +00002034 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +00002035 TEXT
2036 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +00002037 ELEMENT image
2038 ATTRIBUTE href
2039 TEXT
2040 content=linus.gif
2041 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +00002042 TEXT
2043 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +00002044
Daniel Veillard88f00ae2000-03-02 00:15:55 +00002045<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +00002046
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00002047<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00002048
Daniel Veillard402e8c82000-02-29 22:57:47 +00002049<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +00002050memory. In that case (and if you don't expect to save back the XML document
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00002051loaded using libxml), it's better to use the SAX interface of libxml. SAX is
2052a <strong>callback-based interface</strong> to the parser. Before parsing,
2053the application layer registers a customized set of callbacks which are
2054called by the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00002055
Daniel Veillard88f00ae2000-03-02 00:15:55 +00002056<p>To get more detailed step-by-step guidance on using the SAX interface of
Daniel Veillard4540be42000-08-19 16:40:28 +00002057libxml, see the <a
2058href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
2059documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +00002060Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00002061
2062<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
2063program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +00002064binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +00002065distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +00002066testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00002067<pre>SAX.setDocumentLocator()
2068SAX.startDocument()
2069SAX.getEntity(amp)
2070SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
2071SAX.characters( , 3)
2072SAX.startElement(head)
2073SAX.characters( , 4)
2074SAX.startElement(title)
2075SAX.characters(Welcome to Gnome, 16)
2076SAX.endElement(title)
2077SAX.characters( , 3)
2078SAX.endElement(head)
2079SAX.characters( , 3)
2080SAX.startElement(chapter)
2081SAX.characters( , 4)
2082SAX.startElement(title)
2083SAX.characters(The Linux adventure, 19)
2084SAX.endElement(title)
2085SAX.characters( , 4)
2086SAX.startElement(p)
2087SAX.characters(bla bla bla ..., 15)
2088SAX.endElement(p)
2089SAX.characters( , 4)
2090SAX.startElement(image, href='linus.gif')
2091SAX.endElement(image)
2092SAX.characters( , 4)
2093SAX.startElement(p)
2094SAX.characters(..., 3)
2095SAX.endElement(p)
2096SAX.characters( , 3)
2097SAX.endElement(chapter)
2098SAX.characters( , 1)
2099SAX.endElement(EXAMPLE)
2100SAX.endDocument()</pre>
2101
Daniel Veillardec70e912001-02-26 20:10:45 +00002102<p>Most of the other interfaces of libxml are based on the DOM tree-building
2103facility, so nearly everything up to the end of this document presupposes the
2104use of the standard DOM tree build. Note that the DOM tree itself is built by
2105a set of registered default callbacks, without internal specific
2106interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00002107
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002108<h2><a name="Validation">Validation &amp; DTDs</a></h2>
2109
2110<p>Table of Content:</p>
2111<ol>
2112 <li><a href="#General5">General overview</a></li>
2113 <li><a href="#definition">The definition</a></li>
2114 <li><a href="#Simple">Simple rules</a>
2115 <ol>
Daniel Veillard9c466822001-10-25 12:03:39 +00002116 <li><a href="#reference">How to reference a DTD from a document</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002117 <li><a href="#Declaring">Declaring elements</a></li>
2118 <li><a href="#Declaring1">Declaring attributes</a></li>
2119 </ol>
2120 </li>
2121 <li><a href="#Some">Some examples</a></li>
2122 <li><a href="#validate">How to validate</a></li>
2123 <li><a href="#Other">Other resources</a></li>
2124</ol>
2125
2126<h3><a name="General5">General overview</a></h3>
2127
2128<p>Well what is validation and what is a DTD ?</p>
2129
2130<p>DTD is the acronym for Document Type Definition. This is a description of
Daniel Veillard63d83142002-05-20 06:51:05 +00002131the content for a family of XML files. This is part of the XML 1.0
Daniel Veillard0b28e882002-07-24 23:47:05 +00002132specification, and allows one to describe and verify that a given document
2133instance conforms to the set of rules detailing its structure and content.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002134
2135<p>Validation is the process of checking a document against a DTD (more
2136generally against a set of construction rules).</p>
2137
2138<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard0b28e882002-07-24 23:47:05 +00002139of the XML life cycle. Briefly a DTD defines all the possible elements to be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002140found within your document, what is the formal shape of your document tree
Daniel Veillard0b28e882002-07-24 23:47:05 +00002141(by defining the allowed content of an element; either text, a regular
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002142expression for the allowed list of children, or mixed content i.e. both text
Daniel Veillard42766c02002-08-22 20:52:17 +00002143and children). The DTD also defines the valid attributes for all elements and
2144the types of those attributes.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002145
2146<h3><a name="definition1">The definition</a></h3>
2147
2148<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
2149href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
2150Rev1</a>):</p>
2151<ul>
2152 <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
2153 elements</a></li>
2154 <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
2155 attributes</a></li>
2156</ul>
2157
2158<p>(unfortunately) all this is inherited from the SGML world, the syntax is
2159ancient...</p>
2160
2161<h3><a name="Simple1">Simple rules</a></h3>
2162
Daniel Veillard42766c02002-08-22 20:52:17 +00002163<p>Writing DTDs can be done in many ways. The rules to build them if you need
2164something permanent or something which can evolve over time can be radically
2165different. Really complex DTDs like DocBook ones are flexible but quite
2166harder to design. I will just focus on DTDs for a formats with a fixed simple
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002167structure. It is just a set of basic rules, and definitely not exhaustive nor
Daniel Veillard63d83142002-05-20 06:51:05 +00002168usable for complex DTD design.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002169
2170<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
2171
2172<p>Assuming the top element of the document is <code>spec</code> and the dtd
2173is placed in the file <code>mydtd</code> in the subdirectory
2174<code>dtds</code> of the directory from where the document were loaded:</p>
2175
2176<p><code>&lt;!DOCTYPE spec SYSTEM "dtds/mydtd"&gt;</code></p>
2177
2178<p>Notes:</p>
2179<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +00002180 <li>The system string is actually an URI-Reference (as defined in <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002181 href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396</a>) so you can use a
Daniel Veillard0b28e882002-07-24 23:47:05 +00002182 full URL string indicating the location of your DTD on the Web. This is a
2183 really good thing to do if you want others to validate your document.</li>
2184 <li>It is also possible to associate a <code>PUBLIC</code> identifier (a
Daniel Veillard63d83142002-05-20 06:51:05 +00002185 magic string) so that the DTD is looked up in catalogs on the client side
Daniel Veillard0b28e882002-07-24 23:47:05 +00002186 without having to locate it on the web.</li>
2187 <li>A DTD contains a set of element and attribute declarations, but they
Daniel Veillard63d83142002-05-20 06:51:05 +00002188 don't define what the root of the document should be. This is explicitly
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002189 told to the parser/validator as the first element of the
2190 <code>DOCTYPE</code> declaration.</li>
2191</ul>
2192
2193<h4><a name="Declaring2">Declaring elements</a>:</h4>
2194
2195<p>The following declares an element <code>spec</code>:</p>
2196
2197<p><code>&lt;!ELEMENT spec (front, body, back?)&gt;</code></p>
2198
Daniel Veillard0b28e882002-07-24 23:47:05 +00002199<p>It also expresses that the spec element contains one <code>front</code>,
Daniel Veillardc0801af2002-05-28 16:28:42 +00002200one <code>body</code> and one optional <code>back</code> children elements in
2201this order. The declaration of one element of the structure and its content
2202are done in a single declaration. Similarly the following declares
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002203<code>div1</code> elements:</p>
2204
Daniel Veillard51737272002-01-23 23:10:38 +00002205<p><code>&lt;!ELEMENT div1 (head, (p | list | note)*, div2?)&gt;</code></p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002206
Daniel Veillard0b28e882002-07-24 23:47:05 +00002207<p>which means div1 contains one <code>head</code> then a series of optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002208<code>p</code>, <code>list</code>s and <code>note</code>s and then an
2209optional <code>div2</code>. And last but not least an element can contain
2210text:</p>
2211
2212<p><code>&lt;!ELEMENT b (#PCDATA)&gt;</code></p>
2213
2214<p><code>b</code> contains text or being of mixed content (text and elements
2215in no particular order):</p>
2216
2217<p><code>&lt;!ELEMENT p (#PCDATA|a|ul|b|i|em)*&gt;</code></p>
2218
2219<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
2220<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
2221order.</p>
2222
2223<h4><a name="Declaring1">Declaring attributes</a>:</h4>
2224
Daniel Veillard0b28e882002-07-24 23:47:05 +00002225<p>Again the attributes declaration includes their content definition:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002226
2227<p><code>&lt;!ATTLIST termdef name CDATA #IMPLIED&gt;</code></p>
2228
2229<p>means that the element <code>termdef</code> can have a <code>name</code>
Daniel Veillard63d83142002-05-20 06:51:05 +00002230attribute containing text (<code>CDATA</code>) and which is optional
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002231(<code>#IMPLIED</code>). The attribute value can also be defined within a
2232set:</p>
2233
2234<p><code>&lt;!ATTLIST list type (bullets|ordered|glossary)
2235"ordered"&gt;</code></p>
2236
2237<p>means <code>list</code> element have a <code>type</code> attribute with 3
2238allowed values "bullets", "ordered" or "glossary" and which default to
Daniel Veillard63d83142002-05-20 06:51:05 +00002239"ordered" if the attribute is not explicitly specified.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002240
2241<p>The content type of an attribute can be text (<code>CDATA</code>),
2242anchor/reference/references
2243(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
2244(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
2245(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
2246<code>chapter</code> element can have an optional <code>id</code> attribute
2247of type <code>ID</code>, usable for reference from attribute of type
2248IDREF:</p>
2249
2250<p><code>&lt;!ATTLIST chapter id ID #IMPLIED&gt;</code></p>
2251
2252<p>The last value of an attribute definition can be <code>#REQUIRED
2253</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
2254meaning that it is optional, or the default value (possibly prefixed by
2255<code>#FIXED</code> if it is the only allowed).</p>
2256
2257<p>Notes:</p>
2258<ul>
Daniel Veillard0b28e882002-07-24 23:47:05 +00002259 <li>Usually the attributes pertaining to a given element are declared in a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002260 single expression, but it is just a convention adopted by a lot of DTD
2261 writers:
2262 <pre>&lt;!ATTLIST termdef
2263 id ID #REQUIRED
2264 name CDATA #IMPLIED&gt;</pre>
2265 <p>The previous construct defines both <code>id</code> and
Daniel Veillard0b28e882002-07-24 23:47:05 +00002266 <code>name</code> attributes for the element <code>termdef</code>.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002267 </li>
2268</ul>
2269
2270<h3><a name="Some1">Some examples</a></h3>
2271
2272<p>The directory <code>test/valid/dtds/</code> in the libxml distribution
Daniel Veillard42766c02002-08-22 20:52:17 +00002273contains some complex DTD examples. The example in the file
2274<code>test/valid/dia.xml</code> shows an XML file where the simple DTD is
2275directly included within the document.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002276
2277<h3><a name="validate1">How to validate</a></h3>
2278
Daniel Veillard0b28e882002-07-24 23:47:05 +00002279<p>The simplest way is to use the xmllint program included with libxml. The
2280<code>--valid</code> option turns-on validation of the files given as input.
2281For example the following validates a copy of the first revision of the XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +000022821.0 specification:</p>
2283
2284<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
2285
Daniel Veillard0b28e882002-07-24 23:47:05 +00002286<p>the -- noout is used to disable output of the resulting tree.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002287
Daniel Veillard42766c02002-08-22 20:52:17 +00002288<p>The <code>--dtdvalid dtd</code> allows validation of the document(s)
2289against a given DTD.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002290
2291<p>Libxml exports an API to handle DTDs and validation, check the <a
2292href="http://xmlsoft.org/html/libxml-valid.html">associated
2293description</a>.</p>
2294
2295<h3><a name="Other1">Other resources</a></h3>
2296
2297<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
2298will just list one for now, others pointers welcome:</p>
2299<ul>
2300 <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
2301</ul>
2302
2303<p>I suggest looking at the examples found under test/valid/dtd and any of
2304the large number of books available on XML. The dia example in test/valid
2305should be both simple and complete enough to allow you to build your own.</p>
2306
2307<p></p>
2308
2309<h2><a name="Memory">Memory Management</a></h2>
2310
2311<p>Table of Content:</p>
2312<ol>
2313 <li><a href="#General3">General overview</a></li>
Daniel Veillard9c466822001-10-25 12:03:39 +00002314 <li><a href="#setting">Setting libxml set of memory routines</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002315 <li><a href="#cleanup">Cleaning up after parsing</a></li>
2316 <li><a href="#Debugging">Debugging routines</a></li>
2317 <li><a href="#General4">General memory requirements</a></li>
2318</ol>
2319
2320<h3><a name="General3">General overview</a></h3>
2321
2322<p>The module <code><a
2323href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
2324provides the interfaces to the libxml memory system:</p>
2325<ul>
2326 <li>libxml does not use the libc memory allocator directly but xmlFree(),
2327 xmlMalloc() and xmlRealloc()</li>
2328 <li>those routines can be reallocated to a specific set of routine, by
2329 default the libc ones i.e. free(), malloc() and realloc()</li>
2330 <li>the xmlmemory.c module includes a set of debugging routine</li>
2331</ul>
2332
2333<h3><a name="setting">Setting libxml set of memory routines</a></h3>
2334
2335<p>It is sometimes useful to not use the default memory allocator, either for
2336debugging, analysis or to implement a specific behaviour on memory management
2337(like on embedded systems). Two function calls are available to do so:</p>
2338<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +00002339 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet
2340 ()</a> which return the current set of functions in use by the parser</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002341 <li><a
2342 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +00002343 which allow to set up a new set of memory allocation functions</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002344</ul>
2345
2346<p>Of course a call to xmlMemSetup() should probably be done before calling
2347any other libxml routines (unless you are sure your allocations routines are
2348compatibles).</p>
2349
2350<h3><a name="cleanup">Cleaning up after parsing</a></h3>
2351
2352<p>Libxml is not stateless, there is a few set of memory structures needing
Daniel Veillard63d83142002-05-20 06:51:05 +00002353allocation before the parser is fully functional (some encoding structures
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002354for example). This also mean that once parsing is finished there is a tiny
2355amount of memory (a few hundred bytes) which can be recollected if you don't
2356reuse the parser immediately:</p>
2357<ul>
2358 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
Daniel Veillardaf43f632002-03-08 15:05:20 +00002359 ()</a> is a centralized routine to free the parsing states. Note that it
2360 won't deallocate any produced tree if any (use the xmlFreeDoc() and
2361 related routines for this).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002362 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
Daniel Veillardaf43f632002-03-08 15:05:20 +00002363 ()</a> is the dual routine allowing to preallocate the parsing state
2364 which can be useful for example to avoid initialization reentrancy
2365 problems when using libxml in multithreaded applications</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002366</ul>
2367
2368<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
2369at the next invocation of parser routines, but be careful of the consequences
2370in multithreaded applications.</p>
2371
2372<h3><a name="Debugging">Debugging routines</a></h3>
2373
2374<p>When configured using --with-mem-debug flag (off by default), libxml uses
Daniel Veillard63d83142002-05-20 06:51:05 +00002375a set of memory allocation debugging routines keeping track of all allocated
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002376blocks and the location in the code where the routine was called. A couple of
2377other debugging routines allow to dump the memory allocated infos to a file
2378or call a specific routine when a given block number is allocated:</p>
2379<ul>
2380 <li><a
2381 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +00002382 <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002383 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
2384 and <a
2385 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
2386 are the memory debugging replacement allocation routines</li>
2387 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
Daniel Veillardaf43f632002-03-08 15:05:20 +00002388 ()</a> dumps all the informations about the allocated memory block lefts
2389 in the <code>.memdump</code> file</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002390</ul>
2391
Daniel Veillard63d83142002-05-20 06:51:05 +00002392<p>When developing libxml memory debug is enabled, the tests programs call
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002393xmlMemoryDump () and the "make test" regression tests will check for any
2394memory leak during the full regression test sequence, this helps a lot
2395ensuring that libxml does not leak memory and bullet proof memory
2396allocations use (some libc implementations are known to be far too permissive
2397resulting in major portability problems!).</p>
2398
2399<p>If the .memdump reports a leak, it displays the allocation function and
2400also tries to give some informations about the content and structure of the
2401allocated blocks left. This is sufficient in most cases to find the culprit,
Daniel Veillard63d83142002-05-20 06:51:05 +00002402but not always. Assuming the allocation problem is reproducible, it is
2403possible to find more easily:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002404<ol>
2405 <li>write down the block number xxxx not allocated</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00002406 <li>export the environment variable XML_MEM_BREAKPOINT=xxxx , the easiest
Daniel Veillard75794822002-04-11 16:24:32 +00002407 when using GDB is to simply give the command
2408 <p><code>set environment XML_MEM_BREAKPOINT xxxx</code></p>
2409 <p>before running the program.</p>
2410 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002411 <li>run the program under a debugger and set a breakpoint on
2412 xmlMallocBreakpoint() a specific function called when this precise block
2413 is allocated</li>
2414 <li>when the breakpoint is reached you can then do a fine analysis of the
2415 allocation an step to see the condition resulting in the missing
2416 deallocation.</li>
2417</ol>
2418
2419<p>I used to use a commercial tool to debug libxml memory problems but after
2420noticing that it was not detecting memory leaks that simple mechanism was
Daniel Veillard75794822002-04-11 16:24:32 +00002421used and proved extremely efficient until now. Lately I have also used <a
2422href="http://developer.kde.org/~sewardj/">valgrind</a> with quite some
2423success, it is tied to the i386 architecture since it works by emulating the
2424processor and instruction set, it is slow but extremely efficient, i.e. it
2425spot memory usage errors in a very precise way.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002426
2427<h3><a name="General4">General memory requirements</a></h3>
2428
2429<p>How much libxml memory require ? It's hard to tell in average it depends
2430of a number of things:</p>
2431<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +00002432 <li>the parser itself should work in a fixed amount of memory, except for
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002433 information maintained about the stacks of names and entities locations.
2434 The I/O and encoding handlers will probably account for a few KBytes.
2435 This is true for both the XML and HTML parser (though the HTML parser
2436 need more state).</li>
2437 <li>If you are generating the DOM tree then memory requirements will grow
Daniel Veillard63d83142002-05-20 06:51:05 +00002438 nearly linear with the size of the data. In general for a balanced
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002439 textual document the internal memory requirement is about 4 times the
Daniel Veillard63d83142002-05-20 06:51:05 +00002440 size of the UTF8 serialization of this document (example the XML-1.0
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002441 recommendation is a bit more of 150KBytes and takes 650KBytes of main
2442 memory when parsed). Validation will add a amount of memory required for
2443 maintaining the external Dtd state which should be linear with the
2444 complexity of the content model defined by the Dtd</li>
2445 <li>If you don't care about the advanced features of libxml like
2446 validation, DOM, XPath or XPointer, but really need to work fixed memory
2447 requirements, then the SAX interface should be used.</li>
2448</ul>
2449
2450<p></p>
2451
2452<h2><a name="Encodings">Encodings support</a></h2>
2453
2454<p>Table of Content:</p>
2455<ol>
2456 <li><a href="encoding.html#What">What does internationalization support
2457 mean ?</a></li>
2458 <li><a href="encoding.html#internal">The internal encoding, how and
2459 why</a></li>
2460 <li><a href="encoding.html#implemente">How is it implemented ?</a></li>
2461 <li><a href="encoding.html#Default">Default supported encodings</a></li>
2462 <li><a href="encoding.html#extend">How to extend the existing
2463 support</a></li>
2464</ol>
2465
2466<h3><a name="What">What does internationalization support mean ?</a></h3>
2467
Daniel Veillard238836e2003-04-07 22:57:29 +00002468<p>If you are not really familiar with Internationalization (usual shorcut is
2469I18N) , Unicode, characters and glyphs, I suggest you read a <a
2470href="http://www.tbray.org/ongoing/When/200x/2003/04/06/Unicode">presentation</a>
2471by Tim Bray on Unicode and why you should care about it.</p>
2472
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002473<p>XML was designed from the start to allow the support of any character set
2474by using Unicode. Any conformant XML parser has to support the UTF-8 and
2475UTF-16 default encodings which can both express the full unicode ranges. UTF8
Daniel Veillard63d83142002-05-20 06:51:05 +00002476is a variable length encoding whose greatest points are to reuse the same
2477encoding for ASCII and to save space for Western encodings, but it is a bit
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002478more complex to handle in practice. UTF-16 use 2 bytes per characters (and
2479sometimes combines two pairs), it makes implementation easier, but looks a
2480bit overkill for Western languages encoding. Moreover the XML specification
2481allows document to be encoded in other encodings at the condition that they
Daniel Veillard63d83142002-05-20 06:51:05 +00002482are clearly labeled as such. For example the following is a wellformed XML
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002483document encoded in ISO-8859 1 and using accentuated letter that we French
2484likes for both markup and content:</p>
2485<pre>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2486&lt;très&gt;là&lt;/très&gt;</pre>
2487
Daniel Veillard63d83142002-05-20 06:51:05 +00002488<p>Having internationalization support in libxml means the following:</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002489<ul>
2490 <li>the document is properly parsed</li>
2491 <li>informations about it's encoding are saved</li>
2492 <li>it can be modified</li>
2493 <li>it can be saved in its original encoding</li>
2494 <li>it can also be saved in another encoding supported by libxml (for
2495 example straight UTF8 or even an ASCII form)</li>
2496</ul>
2497
2498<p>Another very important point is that the whole libxml API, with the
2499exception of a few routines to read with a specific encoding or save to a
2500specific encoding, is completely agnostic about the original encoding of the
2501document.</p>
2502
Daniel Veillard63d83142002-05-20 06:51:05 +00002503<p>It should be noted too that the HTML parser embedded in libxml now obey
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002504the same rules too, the following document will be (as of 2.2.2) handled in
2505an internationalized fashion by libxml too:</p>
2506<pre>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
2507 "http://www.w3.org/TR/REC-html40/loose.dtd"&gt;
2508&lt;html lang="fr"&gt;
2509&lt;head&gt;
2510 &lt;META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&gt;
2511&lt;/head&gt;
2512&lt;body&gt;
2513&lt;p&gt;W3C crée des standards pour le Web.&lt;/body&gt;
2514&lt;/html&gt;</pre>
2515
2516<h3><a name="internal">The internal encoding, how and why</a></h3>
2517
2518<p>One of the core decision was to force all documents to be converted to a
2519default internal encoding, and that encoding to be UTF-8, here are the
2520rationale for those choices:</p>
2521<ul>
2522 <li>keeping the native encoding in the internal form would force the libxml
2523 users (or the code associated) to be fully aware of the encoding of the
2524 original document, for examples when adding a text node to a document,
2525 the content would have to be provided in the document encoding, i.e. the
2526 client code would have to check it before hand, make sure it's conformant
2527 to the encoding, etc ... Very hard in practice, though in some specific
2528 cases this may make sense.</li>
2529 <li>the second decision was which encoding. From the XML spec only UTF8 and
2530 UTF16 really makes sense as being the two only encodings for which there
Daniel Veillard63d83142002-05-20 06:51:05 +00002531 is mandatory support. UCS-4 (32 bits fixed size encoding) could be
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002532 considered an intelligent choice too since it's a direct Unicode mapping
2533 support. I selected UTF-8 on the basis of efficiency and compatibility
2534 with surrounding software:
2535 <ul>
2536 <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
2537 more costly to import and export CPU wise) is also far more compact
2538 than UTF-16 (and UCS-4) for a majority of the documents I see it used
2539 for right now (RPM RDF catalogs, advogato data, various configuration
2540 file formats, etc.) and the key point for today's computer
2541 architecture is efficient uses of caches. If one nearly double the
2542 memory requirement to store the same amount of data, this will trash
2543 caches (main memory/external caches/internal caches) and my take is
2544 that this harms the system far more than the CPU requirements needed
2545 for the conversion to UTF-8</li>
2546 <li>Most of libxml version 1 users were using it with straight ASCII
2547 most of the time, doing the conversion with an internal encoding
2548 requiring all their code to be rewritten was a serious show-stopper
2549 for using UTF-16 or UCS-4.</li>
2550 <li>UTF-8 is being used as the de-facto internal encoding standard for
2551 related code like the <a href="http://www.pango.org/">pango</a>
2552 upcoming Gnome text widget, and a lot of Unix code (yep another place
2553 where Unix programmer base takes a different approach from Microsoft
2554 - they are using UTF-16)</li>
2555 </ul>
2556 </li>
2557</ul>
2558
2559<p>What does this mean in practice for the libxml user:</p>
2560<ul>
2561 <li>xmlChar, the libxml data type is a byte, those bytes must be assembled
2562 as UTF-8 valid strings. The proper way to terminate an xmlChar * string
2563 is simply to append 0 byte, as usual.</li>
2564 <li>One just need to make sure that when using chars outside the ASCII set,
2565 the values has been properly converted to UTF-8</li>
2566</ul>
2567
2568<h3><a name="implemente">How is it implemented ?</a></h3>
2569
2570<p>Let's describe how all this works within libxml, basically the I18N
2571(internationalization) support get triggered only during I/O operation, i.e.
2572when reading a document or saving one. Let's look first at the reading
2573sequence:</p>
2574<ol>
2575 <li>when a document is processed, we usually don't know the encoding, a
2576 simple heuristic allows to detect UTF-18 and UCS-4 from whose where the
2577 ASCII range (0-0x7F) maps with ASCII</li>
2578 <li>the xml declaration if available is parsed, including the encoding
2579 declaration. At that point, if the autodetected encoding is different
2580 from the one declared a call to xmlSwitchEncoding() is issued.</li>
2581 <li>If there is no encoding declaration, then the input has to be in either
2582 UTF-8 or UTF-16, if it is not then at some point when processing the
2583 input, the converter/checker of UTF-8 form will raise an encoding error.
2584 You may end-up with a garbled document, or no document at all ! Example:
2585 <pre>~/XML -&gt; ./xmllint err.xml
2586err.xml:1: error: Input is not proper UTF-8, indicate encoding !
2587&lt;très&gt;là&lt;/très&gt;
2588 ^
2589err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
2590&lt;très&gt;là&lt;/très&gt;
2591 ^</pre>
2592 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +00002593 <li>xmlSwitchEncoding() does an encoding name lookup, canonicalize it, and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002594 then search the default registered encoding converters for that encoding.
2595 If it's not within the default set and iconv() support has been compiled
2596 it, it will ask iconv for such an encoder. If this fails then the parser
2597 will report an error and stops processing:
2598 <pre>~/XML -&gt; ./xmllint err2.xml
2599err2.xml:1: error: Unsupported encoding UnsupportedEnc
2600&lt;?xml version="1.0" encoding="UnsupportedEnc"?&gt;
2601 ^</pre>
2602 </li>
Daniel Veillard46c5c1d2002-05-20 07:15:54 +00002603 <li>From that point the encoder processes progressively the input (it is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002604 plugged as a front-end to the I/O module) for that entity. It captures
2605 and convert on-the-fly the document to be parsed to UTF-8. The parser
2606 itself just does UTF-8 checking of this input and process it
2607 transparently. The only difference is that the encoding information has
2608 been added to the parsing context (more precisely to the input
2609 corresponding to this entity).</li>
2610 <li>The result (when using DOM) is an internal form completely in UTF-8
2611 with just an encoding information on the document node.</li>
2612</ol>
2613
Daniel Veillard63d83142002-05-20 06:51:05 +00002614<p>Ok then what happens when saving the document (assuming you
2615collected/built an xmlDoc DOM like structure) ? It depends on the function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002616called, xmlSaveFile() will just try to save in the original encoding, while
2617xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
2618encoding:</p>
2619<ol>
2620 <li>if no encoding is given, libxml will look for an encoding value
2621 associated to the document and if it exists will try to save to that
2622 encoding,
2623 <p>otherwise everything is written in the internal form, i.e. UTF-8</p>
2624 </li>
2625 <li>so if an encoding was specified, either at the API level or on the
Daniel Veillard63d83142002-05-20 06:51:05 +00002626 document, libxml will again canonicalize the encoding name, lookup for a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002627 converter in the registered set or through iconv. If not found the
2628 function will return an error code</li>
2629 <li>the converter is placed before the I/O buffer layer, as another kind of
2630 buffer, then libxml will simply push the UTF-8 serialization to through
2631 that buffer, which will then progressively be converted and pushed onto
2632 the I/O layer.</li>
2633 <li>It is possible that the converter code fails on some input, for example
Daniel Veillard63d83142002-05-20 06:51:05 +00002634 trying to push an UTF-8 encoded Chinese character through the UTF-8 to
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002635 ISO-8859-1 converter won't work. Since the encoders are progressive they
2636 will just report the error and the number of bytes converted, at that
2637 point libxml will decode the offending character, remove it from the
2638 buffer and replace it with the associated charRef encoding &amp;#123; and
Daniel Veillard63d83142002-05-20 06:51:05 +00002639 resume the conversion. This guarantees that any document will be saved
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002640 without losses (except for markup names where this is not legal, this is
Daniel Veillard63d83142002-05-20 06:51:05 +00002641 a problem in the current version, in practice avoid using non-ascii
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002642 characters for tags or attributes names @@). A special "ascii" encoding
2643 name is used to save documents to a pure ascii form can be used when
2644 portability is really crucial</li>
2645</ol>
2646
2647<p>Here is a few examples based on the same test document:</p>
2648<pre>~/XML -&gt; ./xmllint isolat1
2649&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2650&lt;très&gt;là&lt;/très&gt;
2651~/XML -&gt; ./xmllint --encode UTF-8 isolat1
2652&lt;?xml version="1.0" encoding="UTF-8"?&gt;
2653&lt;très&gt;là  &lt;/très&gt;
2654~/XML -&gt; </pre>
2655
2656<p>The same processing is applied (and reuse most of the code) for HTML I18N
2657processing. Looking up and modifying the content encoding is a bit more
2658difficult since it is located in a &lt;meta&gt; tag under the &lt;head&gt;,
2659so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
2660been provided. The parser also attempts to switch encoding on the fly when
2661detecting such a tag on input. Except for that the processing is the same
2662(and again reuses the same code).</p>
2663
2664<h3><a name="Default">Default supported encodings</a></h3>
2665
2666<p>libxml has a set of default converters for the following encodings
2667(located in encoding.c):</p>
2668<ol>
2669 <li>UTF-8 is supported by default (null handlers)</li>
2670 <li>UTF-16, both little and big endian</li>
2671 <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
2672 <li>ASCII, useful mostly for saving</li>
2673 <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
2674 predefined entities like &amp;copy; for the Copyright sign.</li>
2675</ol>
2676
Daniel Veillardc0801af2002-05-28 16:28:42 +00002677<p>More over when compiled on an Unix platform with iconv support the full
2678set of encodings supported by iconv can be instantly be used by libxml. On a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002679linux machine with glibc-2.1 the list of supported encodings and aliases fill
26803 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
2681various Japanese ones.</p>
2682
2683<h4>Encoding aliases</h4>
2684
2685<p>From 2.2.3, libxml has support to register encoding names aliases. The
2686goal is to be able to parse document whose encoding is supported but where
2687the name differs (for example from the default set of names accepted by
2688iconv). The following functions allow to register and handle new aliases for
2689existing encodings. Once registered libxml will automatically lookup the
2690aliases when handling a document:</p>
2691<ul>
2692 <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li>
2693 <li>int xmlDelEncodingAlias(const char *alias);</li>
2694 <li>const char * xmlGetEncodingAlias(const char *alias);</li>
2695 <li>void xmlCleanupEncodingAliases(void);</li>
2696</ul>
2697
2698<h3><a name="extend">How to extend the existing support</a></h3>
2699
2700<p>Well adding support for new encoding, or overriding one of the encoders
2701(assuming it is buggy) should not be hard, just write an input and output
2702conversion routines to/from UTF-8, and register them using
2703xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
2704called automatically if the parser(s) encounter such an encoding name
2705(register it uppercase, this will help). The description of the encoders,
2706their arguments and expected return values are described in the encoding.h
2707header.</p>
2708
2709<p>A quick note on the topic of subverting the parser to use a different
2710internal encoding than UTF-8, in some case people will absolutely want to
2711keep the internal encoding different, I think it's still possible (but the
2712encoding must be compliant with ASCII on the same subrange) though I didn't
2713tried it. The key is to override the default conversion routines (by
2714registering null encoders/decoders for your charsets), and bypass the UTF-8
2715checking of the parser by setting the parser context charset
2716(ctxt-&gt;charset) to something different than XML_CHAR_ENCODING_UTF8, but
Daniel Veillard63d83142002-05-20 06:51:05 +00002717there is no guarantee that this will work. You may also have some troubles
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002718saving back.</p>
2719
2720<p>Basically proper I18N support is important, this requires at least
2721libxml-2.0.0, but a lot of features and corrections are really available only
2722starting 2.2.</p>
2723
2724<h2><a name="IO">I/O Interfaces</a></h2>
2725
2726<p>Table of Content:</p>
2727<ol>
2728 <li><a href="#General1">General overview</a></li>
2729 <li><a href="#basic">The basic buffer type</a></li>
2730 <li><a href="#Input">Input I/O handlers</a></li>
2731 <li><a href="#Output">Output I/O handlers</a></li>
2732 <li><a href="#entities">The entities loader</a></li>
2733 <li><a href="#Example2">Example of customized I/O</a></li>
2734</ol>
2735
2736<h3><a name="General1">General overview</a></h3>
2737
2738<p>The module <code><a
2739href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
2740the interfaces to the libxml I/O system. This consists of 4 main parts:</p>
2741<ul>
2742 <li>Entities loader, this is a routine which tries to fetch the entities
2743 (files) based on their PUBLIC and SYSTEM identifiers. The default loader
2744 don't look at the public identifier since libxml do not maintain a
2745 catalog. You can redefine you own entity loader by using
2746 <code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard9c466822001-10-25 12:03:39 +00002747 <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
2748 example</a>.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002749 <li>Input I/O buffers which are a commodity structure used by the parser(s)
2750 input layer to handle fetching the informations to feed the parser. This
2751 provides buffering and is also a placeholder where the encoding
Daniel Veillard63d83142002-05-20 06:51:05 +00002752 converters to UTF8 are piggy-backed.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002753 <li>Output I/O buffers are similar to the Input ones and fulfill similar
2754 task but when generating a serialization from a tree.</li>
2755 <li>A mechanism to register sets of I/O callbacks and associate them with
2756 specific naming schemes like the protocol part of the URIs.
2757 <p>This affect the default I/O operations and allows to use specific I/O
2758 handlers for certain names.</p>
2759 </li>
2760</ul>
2761
2762<p>The general mechanism used when loading http://rpmfind.net/xml.html for
2763example in the HTML parser is the following:</p>
2764<ol>
2765 <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
2766 the parsing context and the URI string.</li>
2767 <li>the URI string is checked against the existing registered handlers
2768 using their match() callback function, if the HTTP module was compiled
2769 in, it is registered and its match() function will succeeds</li>
2770 <li>the open() function of the handler is called and if successful will
2771 return an I/O Input buffer</li>
2772 <li>the parser will the start reading from this buffer and progressively
2773 fetch information from the resource, calling the read() function of the
2774 handler until the resource is exhausted</li>
2775 <li>if an encoding change is detected it will be installed on the input
2776 buffer, providing buffering and efficient use of the conversion
2777 routines</li>
2778 <li>once the parser has finished, the close() function of the handler is
Daniel Veillard63d83142002-05-20 06:51:05 +00002779 called once and the Input buffer and associated resources are
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002780 deallocated.</li>
2781</ol>
2782
2783<p>The user defined callbacks are checked first to allow overriding of the
2784default libxml I/O routines.</p>
2785
2786<h3><a name="basic">The basic buffer type</a></h3>
2787
2788<p>All the buffer manipulation handling is done using the
2789<code>xmlBuffer</code> type define in <code><a
2790href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
2791resizable memory buffer. The buffer allocation strategy can be selected to be
2792either best-fit or use an exponential doubling one (CPU vs. memory use
Daniel Veillard63d83142002-05-20 06:51:05 +00002793trade-off). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002794<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
2795system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
2796of functions allows to manipulate buffers with names starting with the
2797<code>xmlBuffer...</code> prefix.</p>
2798
2799<h3><a name="Input">Input I/O handlers</a></h3>
2800
2801<p>An Input I/O handler is a simple structure
2802<code>xmlParserInputBuffer</code> containing a context associated to the
2803resource (file descriptor, or pointer to a protocol handler), the read() and
2804close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
2805encoding handler are also present to support charset conversion when
2806needed.</p>
2807
2808<h3><a name="Output">Output I/O handlers</a></h3>
2809
2810<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
2811Input one except the callbacks are write() and close().</p>
2812
2813<h3><a name="entities">The entities loader</a></h3>
2814
2815<p>The entity loader resolves requests for new entities and create inputs for
2816the parser. Creating an input from a filename or an URI string is done
2817through the xmlNewInputFromFile() routine. The default entity loader do not
2818handle the PUBLIC identifier associated with an entity (if any). So it just
2819calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
2820XML).</p>
2821
2822<p>If you want to hook up a catalog mechanism then you simply need to
2823override the default entity loader, here is an example:</p>
2824<pre>#include &lt;libxml/xmlIO.h&gt;
2825
2826xmlExternalEntityLoader defaultLoader = NULL;
2827
2828xmlParserInputPtr
2829xmlMyExternalEntityLoader(const char *URL, const char *ID,
2830 xmlParserCtxtPtr ctxt) {
2831 xmlParserInputPtr ret;
2832 const char *fileID = NULL;
2833 /* lookup for the fileID depending on ID */
2834
2835 ret = xmlNewInputFromFile(ctxt, fileID);
2836 if (ret != NULL)
2837 return(ret);
2838 if (defaultLoader != NULL)
2839 ret = defaultLoader(URL, ID, ctxt);
2840 return(ret);
2841}
2842
2843int main(..) {
2844 ...
2845
2846 /*
2847 * Install our own entity loader
2848 */
2849 defaultLoader = xmlGetExternalEntityLoader();
2850 xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
2851
2852 ...
2853}</pre>
2854
2855<h3><a name="Example2">Example of customized I/O</a></h3>
2856
2857<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
2858real use case</a>, xmlDocDump() closes the FILE * passed by the application
2859and this was a problem. The <a
2860href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
2861new output handler with the closing call deactivated:</p>
2862<ol>
Daniel Veillardc0801af2002-05-28 16:28:42 +00002863 <li>First define a new I/O output allocator where the output don't close
2864 the file:
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002865 <pre>xmlOutputBufferPtr
2866xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
2867    xmlOutputBufferPtr ret;
2868    
2869    if (xmlOutputCallbackInitialized == 0)
2870        xmlRegisterDefaultOutputCallbacks();
2871
2872    if (file == NULL) return(NULL);
2873    ret = xmlAllocOutputBuffer(encoder);
2874    if (ret != NULL) {
2875        ret-&gt;context = file;
2876        ret-&gt;writecallback = xmlFileWrite;
2877        ret-&gt;closecallback = NULL; /* No close callback */
2878    }
2879    return(ret); <br>
Daniel Veillard1eb24242002-03-18 11:33:03 +00002880
Daniel Veillard34ce8be2002-03-18 19:37:11 +00002881
2882
Daniel Veillard19274092002-03-25 16:48:03 +00002883
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +00002884
Daniel Veillard75794822002-04-11 16:24:32 +00002885
Daniel Veillarda7084cd2002-04-15 17:12:47 +00002886
Daniel Veillard0bfbb422002-04-26 09:21:45 +00002887
Daniel Veillard93d3a472002-04-26 14:04:55 +00002888
Daniel Veillardcf27f7c2002-04-30 07:12:39 +00002889
Daniel Veillarde6d8e202002-05-02 06:11:10 +00002890
Daniel Veillard9b6fd302002-05-13 12:06:47 +00002891
Daniel Veillardc0801af2002-05-28 16:28:42 +00002892
Daniel Veillard21473672002-06-17 07:29:22 +00002893
Daniel Veillard782afda2002-07-08 15:12:49 +00002894
Daniel Veillard42766c02002-08-22 20:52:17 +00002895
Daniel Veillarde1662542002-08-28 11:50:59 +00002896
Daniel Veillarde16b5742002-09-26 17:50:03 +00002897
Daniel Veillard321be0c2002-10-08 21:26:42 +00002898
Daniel Veillard48267432002-10-18 11:21:38 +00002899
Daniel Veillarddad3f682002-11-17 16:47:27 +00002900
Daniel Veillardc14401e2002-11-20 14:28:17 +00002901
Daniel Veillardf9c4cad2002-11-22 15:57:07 +00002902
Daniel Veillard9b4bb4d2002-12-11 19:28:47 +00002903
Daniel Veillardc1eed322002-12-12 11:01:32 +00002904
Daniel Veillard7ef0fcb2002-12-14 10:38:55 +00002905
Daniel Veillard7b4b2f92003-01-06 13:11:20 +00002906
2907
Daniel Veillarde2830f12003-01-08 17:47:49 +00002908
Daniel Veillard98d071d2003-01-10 09:22:44 +00002909
2910
Daniel Veillard831e8fd2003-01-25 11:45:34 +00002911
Daniel Veillard72fef162003-02-05 14:31:19 +00002912
Daniel Veillard1d788d22003-02-10 16:21:58 +00002913
Daniel Veillard17bed982003-02-24 20:11:43 +00002914
Daniel Veillard806cada2003-03-19 21:58:59 +00002915
2916
Daniel Veillardd8da01c2003-03-24 15:58:23 +00002917
Daniel Veillardc2d4a932003-04-01 11:13:05 +00002918
Daniel Veillard238836e2003-04-07 22:57:29 +00002919
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002920} </pre>
2921 </li>
2922 <li>And then use it to save the document:
2923 <pre>FILE *f;
2924xmlOutputBufferPtr output;
2925xmlDocPtr doc;
2926int res;
2927
2928f = ...
2929doc = ....
2930
2931output = xmlOutputBufferCreateOwn(f, NULL);
2932res = xmlSaveFileTo(output, doc, NULL);
2933 </pre>
2934 </li>
2935</ol>
2936
2937<h2><a name="Catalog">Catalog support</a></h2>
2938
2939<p>Table of Content:</p>
2940<ol>
2941 <li><a href="General2">General overview</a></li>
2942 <li><a href="#definition">The definition</a></li>
2943 <li><a href="#Simple">Using catalogs</a></li>
2944 <li><a href="#Some">Some examples</a></li>
2945 <li><a href="#reference">How to tune catalog usage</a></li>
2946 <li><a href="#validate">How to debug catalog processing</a></li>
2947 <li><a href="#Declaring">How to create and maintain catalogs</a></li>
2948 <li><a href="#implemento">The implementor corner quick review of the
2949 API</a></li>
2950 <li><a href="#Other">Other resources</a></li>
2951</ol>
2952
2953<h3><a name="General2">General overview</a></h3>
2954
2955<p>What is a catalog? Basically it's a lookup mechanism used when an entity
2956(a file or a remote resource) references another entity. The catalog lookup
2957is inserted between the moment the reference is recognized by the software
2958(XML parser, stylesheet processing, or even images referenced for inclusion
2959in a rendering) and the time where loading that resource is actually
2960started.</p>
2961
2962<p>It is basically used for 3 things:</p>
2963<ul>
2964 <li>mapping from "logical" names, the public identifiers and a more
2965 concrete name usable for download (and URI). For example it can associate
2966 the logical name
2967 <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
2968 <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
2969 downloaded</p>
2970 <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
2971 </li>
2972 <li>remapping from a given URL to another one, like an HTTP indirection
2973 saying that
2974 <p>"http://www.oasis-open.org/committes/tr.xsl"</p>
2975 <p>should really be looked at</p>
2976 <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
2977 </li>
2978 <li>providing a local cache mechanism allowing to load the entities
2979 associated to public identifiers or remote resources, this is a really
2980 important feature for any significant deployment of XML or SGML since it
2981 allows to avoid the aleas and delays associated to fetching remote
2982 resources.</li>
2983</ul>
2984
2985<h3><a name="definition">The definitions</a></h3>
2986
2987<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
2988<ul>
2989 <li>the older SGML catalogs, the official spec is SGML Open Technical
2990 Resolution TR9401:1997, but is better understood by reading <a
2991 href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
2992 James Clark. This is relatively old and not the preferred mode of
2993 operation of libxml.</li>
2994 <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
Daniel Veillardaf43f632002-03-08 15:05:20 +00002995 Catalogs</a> is far more flexible, more recent, uses an XML syntax and
2996 should scale quite better. This is the default option of libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00002997</ul>
2998
2999<p></p>
3000
3001<h3><a name="Simple">Using catalog</a></h3>
3002
3003<p>In a normal environment libxml will by default check the presence of a
3004catalog in /etc/xml/catalog, and assuming it has been correctly populated,
3005the processing is completely transparent to the document user. To take a
3006concrete example, suppose you are authoring a DocBook document, this one
3007starts with the following DOCTYPE definition:</p>
3008<pre>&lt;?xml version='1.0'?&gt;
3009&lt;!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
3010 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"&gt;</pre>
3011
3012<p>When validating the document with libxml, the catalog will be
3013automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
3014DocBk XML V3.1.4//EN" and the system identifier
3015"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
3016been installed on your system and the catalogs actually point to them, libxml
3017will fetch them from the local disk.</p>
3018
3019<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
3020DOCTYPE example it's a really old version, but is fine as an example.</p>
3021
3022<p>Libxml will check the catalog each time that it is requested to load an
3023entity, this includes DTD, external parsed entities, stylesheets, etc ... If
3024your system is correctly configured all the authoring phase and processing
3025should use only local files, even if your document stays portable because it
3026uses the canonical public and system ID, referencing the remote document.</p>
3027
3028<h3><a name="Some">Some examples:</a></h3>
3029
3030<p>Here is a couple of fragments from XML Catalogs used in libxml early
3031regression tests in <code>test/catalogs</code> :</p>
3032<pre>&lt;?xml version="1.0"?&gt;
3033&lt;!DOCTYPE catalog PUBLIC
3034 "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
3035 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
3036&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
3037 &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
3038 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
3039...</pre>
3040
3041<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
3042written in XML, there is a specific namespace for catalog elements
3043"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
3044catalog is a <code>public</code> mapping it allows to associate a Public
3045Identifier with an URI.</p>
3046<pre>...
3047 &lt;rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
3048 rewritePrefix="file:///usr/share/xml/docbook/"/&gt;
3049...</pre>
3050
3051<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
3052any URI starting with a given prefix should be looked at another URI
3053constructed by replacing the prefix with an new one. In effect this acts like
3054a cache system for a full area of the Web. In practice it is extremely useful
3055with a file prefix if you have installed a copy of those resources on your
3056local system.</p>
3057<pre>...
3058&lt;delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
3059 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3060&lt;delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
3061 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3062&lt;delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
3063 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3064&lt;delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
3065 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3066&lt;delegateURI uriStartString="http://www.oasis-open.org/docbook/"
3067 catalog="file:///usr/share/xml/docbook.xml"/&gt;
3068...</pre>
3069
3070<p>Delegation is the core features which allows to build a tree of catalogs,
3071easier to maintain than a single catalog, based on Public Identifier, System
3072Identifier or URI prefixes it instructs the catalog software to look up
3073entries in another resource. This feature allow to build hierarchies of
3074catalogs, the set of entries presented should be sufficient to redirect the
3075resolution of all DocBook references to the specific catalog in
3076<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
3077references for DocBook 4.2.1 to a specific catalog installed at the same time
3078as the DocBook resources on the local machine.</p>
3079
3080<h3><a name="reference">How to tune catalog usage:</a></h3>
3081
3082<p>The user can change the default catalog behaviour by redirecting queries
3083to its own set of catalogs, this can be done by setting the
3084<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
3085empty one should deactivate loading the default <code>/etc/xml/catalog</code>
3086default catalog</p>
3087
3088<h3><a name="validate">How to debug catalog processing:</a></h3>
3089
3090<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
3091make libxml output debugging informations for each catalog operations, for
3092example:</p>
3093<pre>orchis:~/XML -&gt; xmllint --memory --noout test/ent2
3094warning: failed to load external entity "title.xml"
3095orchis:~/XML -&gt; export XML_DEBUG_CATALOG=
3096orchis:~/XML -&gt; xmllint --memory --noout test/ent2
3097Failed to parse catalog /etc/xml/catalog
3098Failed to parse catalog /etc/xml/catalog
3099warning: failed to load external entity "title.xml"
3100Catalogs cleanup
3101orchis:~/XML -&gt; </pre>
3102
3103<p>The test/ent2 references an entity, running the parser from memory makes
3104the base URI unavailable and the the "title.xml" entity cannot be loaded.
3105Setting up the debug environment variable allows to detect that an attempt is
3106made to load the <code>/etc/xml/catalog</code> but since it's not present the
3107resolution fails.</p>
3108
3109<p>But the most advanced way to debug XML catalog processing is to use the
3110<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
3111catalogs and make resolution queries to see what is going on. This is also
3112used for the regression tests:</p>
3113<pre>orchis:~/XML -&gt; ./xmlcatalog test/catalogs/docbook.xml \
3114 "-//OASIS//DTD DocBook XML V4.1.2//EN"
3115http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
3116orchis:~/XML -&gt; </pre>
3117
3118<p>For debugging what is going on, adding one -v flags increase the verbosity
3119level to indicate the processing done (adding a second flag also indicate
3120what elements are recognized at parsing):</p>
3121<pre>orchis:~/XML -&gt; ./xmlcatalog -v test/catalogs/docbook.xml \
3122 "-//OASIS//DTD DocBook XML V4.1.2//EN"
3123Parsing catalog test/catalogs/docbook.xml's content
3124Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
3125http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
3126Catalogs cleanup
3127orchis:~/XML -&gt; </pre>
3128
3129<p>A shell interface is also available to debug and process multiple queries
3130(and for regression tests):</p>
3131<pre>orchis:~/XML -&gt; ./xmlcatalog -shell test/catalogs/docbook.xml \
3132 "-//OASIS//DTD DocBook XML V4.1.2//EN"
3133&gt; help
3134Commands available:
3135public PublicID: make a PUBLIC identifier lookup
3136system SystemID: make a SYSTEM identifier lookup
3137resolve PublicID SystemID: do a full resolver lookup
3138add 'type' 'orig' 'replace' : add an entry
3139del 'values' : remove values
3140dump: print the current catalog state
3141debug: increase the verbosity level
3142quiet: decrease the verbosity level
3143exit: quit the shell
3144&gt; public "-//OASIS//DTD DocBook XML V4.1.2//EN"
3145http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
3146&gt; quit
3147orchis:~/XML -&gt; </pre>
3148
3149<p>This should be sufficient for most debugging purpose, this was actually
3150used heavily to debug the XML Catalog implementation itself.</p>
3151
3152<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
3153
3154<p>Basically XML Catalogs are XML files, you can either use XML tools to
3155manage them or use <strong>xmlcatalog</strong> for this. The basic step is
3156to create a catalog the -create option provide this facility:</p>
3157<pre>orchis:~/XML -&gt; ./xmlcatalog --create tst.xml
3158&lt;?xml version="1.0"?&gt;
3159&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
3160 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
3161&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
3162orchis:~/XML -&gt; </pre>
3163
3164<p>By default xmlcatalog does not overwrite the original catalog and save the
3165result on the standard output, this can be overridden using the -noout
3166option. The <code>-add</code> command allows to add entries in the
3167catalog:</p>
3168<pre>orchis:~/XML -&gt; ./xmlcatalog --noout --create --add "public" \
3169 "-//OASIS//DTD DocBook XML V4.1.2//EN" \
3170 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
3171orchis:~/XML -&gt; cat tst.xml
3172&lt;?xml version="1.0"?&gt;
3173&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
3174 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
3175&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
3176&lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
3177 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
3178&lt;/catalog&gt;
3179orchis:~/XML -&gt; </pre>
3180
3181<p>The <code>-add</code> option will always take 3 parameters even if some of
3182the XML Catalog constructs (like nextCatalog) will have only a single
3183argument, just pass a third empty string, it will be ignored.</p>
3184
3185<p>Similarly the <code>-del</code> option remove matching entries from the
3186catalog:</p>
3187<pre>orchis:~/XML -&gt; ./xmlcatalog --del \
3188 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
3189&lt;?xml version="1.0"?&gt;
3190&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
3191 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
3192&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
3193orchis:~/XML -&gt; </pre>
3194
3195<p>The catalog is now empty. Note that the matching of <code>-del</code> is
3196exact and would have worked in a similar fashion with the Public ID
3197string.</p>
3198
3199<p>This is rudimentary but should be sufficient to manage a not too complex
3200catalog tree of resources.</p>
3201
3202<h3><a name="implemento">The implementor corner quick review of the
3203API:</a></h3>
3204
3205<p>First, and like for every other module of libxml, there is an
3206automatically generated <a href="html/libxml-catalog.html">API page for
3207catalog support</a>.</p>
3208
3209<p>The header for the catalog interfaces should be included as:</p>
3210<pre>#include &lt;libxml/catalog.h&gt;</pre>
3211
3212<p>The API is voluntarily kept very simple. First it is not obvious that
3213applications really need access to it since it is the default behaviour of
3214libxml (Note: it is possible to completely override libxml default catalog by
3215using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
3216plug an application specific resolver).</p>
3217
3218<p>Basically libxml support 2 catalog lists:</p>
3219<ul>
3220 <li>the default one, global shared by all the application</li>
3221 <li>a per-document catalog, this one is built if the document uses the
3222 <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
3223 associated to the parser context and destroyed when the parsing context
3224 is destroyed.</li>
3225</ul>
3226
3227<p>the document one will be used first if it exists.</p>
3228
3229<h4>Initialization routines:</h4>
3230
3231<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
3232used at startup to initialize the catalog, if the catalog should be
3233initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
3234should be called before xmlInitializeCatalog() which would otherwise do a
3235default initialization first.</p>
3236
3237<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
3238own catalog list if needed.</p>
3239
3240<h4>Preferences setup:</h4>
3241
3242<p>The XML Catalog spec requires the possibility to select default
3243preferences between public and system delegation,
3244xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
3245xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
3246be forbidden, allowed for global catalog, for document catalog or both, the
3247default is to allow both.</p>
3248
3249<p>And of course xmlCatalogSetDebug() allows to generate debug messages
3250(through the xmlGenericError() mechanism).</p>
3251
3252<h4>Querying routines:</h4>
3253
3254<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
3255and xmlCatalogResolveURI() are relatively explicit if you read the XML
3256Catalog specification they correspond to section 7 algorithms, they should
3257also work if you have loaded an SGML catalog with a simplified semantic.</p>
3258
3259<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
3260operate on the document catalog list</p>
3261
3262<h4>Cleanup and Miscellaneous:</h4>
3263
3264<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
3265the per-document equivalent.</p>
3266
3267<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
3268first catalog in the global list, and xmlCatalogDump() allows to dump a
3269catalog state, those routines are primarily designed for xmlcatalog, I'm not
3270sure that exposing more complex interfaces (like navigation ones) would be
3271really useful.</p>
3272
3273<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
3274it's similar as xmlParseFile() except it bypass all catalog lookups, it's
3275provided because this functionality may be useful for client tools.</p>
3276
3277<h4>threaded environments:</h4>
3278
3279<p>Since the catalog tree is built progressively, some care has been taken to
3280try to avoid troubles in multithreaded environments. The code is now thread
3281safe assuming that the libxml library has been compiled with threads
3282support.</p>
3283
3284<p></p>
3285
3286<h3><a name="Other">Other resources</a></h3>
3287
3288<p>The XML Catalog specification is relatively recent so there isn't much
3289literature to point at:</p>
3290<ul>
Daniel Veillard63d83142002-05-20 06:51:05 +00003291 <li>You can find a good rant from Norm Walsh about <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003292 href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
3293 need for catalogs</a>, it provides a lot of context informations even if
Daniel Veillard93d3a472002-04-26 14:04:55 +00003294 I don't agree with everything presented. Norm also wrote a more recent
3295 article <a
3296 href="http://wwws.sun.com/software/xml/developers/resolver/article/">XML
3297 entities and URI resolvers</a> describing them.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003298 <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
3299 catalog proposal</a> from John Cowan</li>
3300 <li>The <a href="http://www.rddl.org/">Resource Directory Description
3301 Language</a> (RDDL) another catalog system but more oriented toward
3302 providing metadata for XML namespaces.</li>
3303 <li>the page from the OASIS Technical <a
3304 href="http://www.oasis-open.org/committees/entity/">Committee on Entity
3305 Resolution</a> who maintains XML Catalog, you will find pointers to the
3306 specification update, some background and pointers to others tools
3307 providing XML Catalog support</li>
Daniel Veillard35e937a2002-01-19 22:21:54 +00003308 <li>Here is a <a href="buildDocBookCatalog">shell script</a> to generate
3309 XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
3310 directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
3311 the resources found on the system. Otherwise it will just create
3312 ~/xmlcatalog and ~/dbkxmlcatalog and doing:
Daniel Veillardc575b992002-02-08 13:28:40 +00003313 <p><code>export XMLCATALOG=$HOME/xmlcatalog</code></p>
Daniel Veillard35e937a2002-01-19 22:21:54 +00003314 <p>should allow to process DocBook documentations without requiring
Daniel Veillard63d83142002-05-20 06:51:05 +00003315 network accesses for the DTD or stylesheets</p>
Daniel Veillard35e937a2002-01-19 22:21:54 +00003316 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003317 <li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a
Daniel Veillard35e937a2002-01-19 22:21:54 +00003318 small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
3319 to work fine for me too</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003320 <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
3321 manual page</a></li>
3322</ul>
3323
3324<p>If you have suggestions for corrections or additions, simply contact
3325me:</p>
3326
3327<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003328
3329<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003330using the XML library from the C language. It is not intended to be
3331extensive. I hope the automatically generated documents will provide the
3332completeness required, but as a separate set of documents. The interfaces of
3333the XML library are by principle low level, there is nearly zero abstraction.
3334Those interested in a higher level API should <a href="#DOM">look at
3335DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +00003336
Daniel Veillard9cb5ff42001-01-29 08:22:21 +00003337<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
3338separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003339interfaces</a>. Let's have a look at how the XML parser can be called:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +00003340
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003341<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003342
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003343<p>Usually, the first thing to do is to read an XML input. The parser accepts
3344documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +00003345defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +00003346<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003347 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003348 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003349 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +00003350</dl>
3351<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003352 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00003353 <dd><p>Parse an XML document contained in a (possibly compressed)
3354 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003355 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +00003356</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003357
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003358<p>The parser returns a pointer to the document structure (or NULL in case of
Daniel Veillard10c6a8f1998-10-28 01:00:12 +00003359failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003360
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003361<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +00003362
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003363<p>In order for the application to keep the control when the document is
3364being fetched (which is common for GUI based programs) libxml provides a push
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003365interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +00003366<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
3367 void *user_data,
3368 const char *chunk,
3369 int size,
3370 const char *filename);
3371int xmlParseChunk (xmlParserCtxtPtr ctxt,
3372 const char *chunk,
3373 int size,
3374 int terminate);</pre>
3375
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003376<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +00003377<pre> FILE *f;
3378
3379 f = fopen(filename, "r");
3380 if (f != NULL) {
3381 int res, size = 1024;
3382 char chars[1024];
3383 xmlParserCtxtPtr ctxt;
3384
3385 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +00003386 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +00003387 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
3388 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +00003389 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +00003390 xmlParseChunk(ctxt, chars, res, 0);
3391 }
3392 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +00003393 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +00003394 xmlFreeParserCtxt(ctxt);
3395 }
3396 }</pre>
3397
Daniel Veillardec70e912001-02-26 20:10:45 +00003398<p>The HTML parser embedded into libxml also has a push interface; the
3399functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +00003400
3401<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
3402
Daniel Veillardec70e912001-02-26 20:10:45 +00003403<p>The tree-building interface makes the parser memory-hungry, first loading
3404the document in memory and then building the tree itself. Reading a document
3405without building the tree is possible using the SAX interfaces (see SAX.h and
3406<a href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003407Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +00003408limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +00003409<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +00003410
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00003411<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003412
3413<p>The other way to get an XML tree in memory is by building it. Basically
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00003414there is a set of functions dedicated to building new elements. (These are
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003415also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of
3416code that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +00003417<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +00003418 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +00003419 xmlNodePtr tree, subtree;
3420
3421 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +00003422 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
3423 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
3424 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
3425 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +00003426 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +00003427 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +00003428 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
3429 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
3430 subtree = xmlNewChild(tree, NULL, "image", NULL);
3431 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003432
3433<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +00003434
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00003435<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003436
Daniel Veillard9cb5ff42001-01-29 08:22:21 +00003437<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003438code has access to the internal structure of all the elements of the tree.
3439The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +00003440<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003441<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +00003442example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +00003443<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003444
3445<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +00003446<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003447
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00003448<p>points to the text node containing the chapter title "The Linux
3449adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +00003450
Daniel Veillardb24054a1999-12-18 15:32:46 +00003451<p><strong>NOTE</strong>: XML allows <em>PI</em>s and <em>comments</em> to be
Daniel Veillard60979bd2000-07-10 12:17:33 +00003452present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +00003453to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +00003454<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +00003455
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00003456<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003457
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003458<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +00003459is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +00003460<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +00003461 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
3462 xmlChar *value);</code></dt>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003463 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
3464 The value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003465 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +00003466</dl>
3467<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +00003468 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +00003469 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +00003470 <dd><p>This function returns a pointer to new copy of the property
3471 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003472 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +00003473</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003474
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003475<p>Two functions are provided for reading and writing the text associated
3476with elements:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +00003477<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +00003478 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +00003479 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +00003480 <dd><p>This function takes an "external" string and converts it to one
3481 text node or possibly to a list of entity and text nodes. All
3482 non-predefined entity references like &amp;Gnome; will be stored
3483 internally as entity nodes, hence the result of the function may not be
3484 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003485 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +00003486</dl>
3487<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +00003488 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +00003489 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00003490 <dd><p>This function is the inverse of
3491 <code>xmlStringGetNodeList()</code>. It generates a new string
3492 containing the content of the text and entity nodes. Note the extra
3493 argument inLine. If this argument is set to 1, the function will expand
3494 entity references. For example, instead of returning the &amp;Gnome;
3495 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +00003496 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003497 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +00003498</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +00003499
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00003500<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003501
3502<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +00003503<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +00003504 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +00003505 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003506 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003507 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +00003508</dl>
3509<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003510 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003511 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003512 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +00003513</dl>
3514<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003515 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00003516 <dd><p>Saves the document to a file. In this case, the compression
3517 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003518 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +00003519</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +00003520
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00003521<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003522
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003523<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00003524accesses. The level of compression on saves can be turned on either globally
3525or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +00003526<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003527 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003528 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003529 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +00003530</dl>
3531<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003532 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003533 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003534 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +00003535</dl>
3536<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003537 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003538 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003539 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +00003540</dl>
3541<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003542 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003543 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003544 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +00003545</dl>
3546
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00003547<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003548
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003549<p>Entities in principle are similar to simple C macros. An entity defines an
3550abbreviation for a given string that you can reuse many times throughout the
3551content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00003552may occur frequently within a document, or to confine the change needed to a
3553document to a restricted area in the internal subset of the document (at the
3554beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +00003555<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +000035562 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +000035573 &lt;!ENTITY xml "Extensible Markup Language"&gt;
35584 ]&gt;
35595 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +000035606 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +000035617 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003562
3563<p>Line 3 declares the xml entity. Line 6 uses the xml entity, by prefixing
Daniel Veillard91e9d582001-02-26 07:31:12 +00003564its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard63d83142002-05-20 06:51:05 +00003565are 5 predefined entities in libxml allowing you to escape characters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003566predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003567<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +00003568for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003569<strong>&amp;quot;</strong> for the character '"', and
3570<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003571
3572<p>One of the problems related to entities is that you may want the parser to
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00003573substitute an entity's content so that you can see the replacement text in
3574your application. Or you may prefer to keep entity references as such in the
3575content to be able to save the document back without losing this usually
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003576precious information (if the user went through the pain of explicitly
3577defining entities, he may have a a rather negative attitude if you blindly
Daniel Veillard63d83142002-05-20 06:51:05 +00003578substitute them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +00003579href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003580function allows you to check and change the behaviour, which is to not
3581substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003582
3583<p>Here is the DOM tree built by libxml for the previous document in the
3584default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +00003585<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003586DOCUMENT
3587version=1.0
3588 ELEMENT EXAMPLE
3589 TEXT
3590 content=
3591 ENTITY_REF
3592 INTERNAL_GENERAL_ENTITY xml
3593 content=Extensible Markup Language
3594 TEXT
3595 content=</pre>
3596
3597<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +00003598<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003599DOCUMENT
3600version=1.0
3601 ELEMENT EXAMPLE
3602 TEXT
3603 content= Extensible Markup Language</pre>
3604
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003605<p>So, entities or no entities? Basically, it depends on your use case. I
3606suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003607entities in your XML document or data if you are not willing to handle the
3608entity references elements in the DOM tree.</p>
3609
Daniel Veillard91e9d582001-02-26 07:31:12 +00003610<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003611entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +00003612transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003613reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003614finding them in the input).</p>
3615
Daniel Veillard7b9c4b72000-08-25 16:26:50 +00003616<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +00003617on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard63d83142002-05-20 06:51:05 +00003618non-predefined entities in your documents, then the learning curve to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +00003619then using the SAX API may be long. If you plan to use complex documents, I
Daniel Veillard7b9c4b72000-08-25 16:26:50 +00003620strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +00003621deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +00003622
Daniel Veillard2f4dfc41999-09-24 14:03:48 +00003623<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003624
Daniel Veillardec303412000-03-24 13:41:54 +00003625<p>The libxml library implements <a
3626href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
Daniel Veillard63d83142002-05-20 06:51:05 +00003627recognizing namespace constructs in the input, and does namespace lookup
Daniel Veillardec303412000-03-24 13:41:54 +00003628automatically when building the DOM tree. A namespace declaration is
3629associated with an in-memory structure and all elements or attributes within
3630that namespace point to it. Hence testing the namespace is a simple and fast
3631equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003632
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00003633<p>I suggest that people using libxml use a namespace, and declare it in the
3634root element of their document as the default namespace. Then they don't need
3635to use the prefix in the content but we will have a basis for future semantic
Daniel Veillard91e9d582001-02-26 07:31:12 +00003636refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +00003637the size of the XML output significantly, but significantly increases its
3638value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +00003639<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
3640 &lt;elem1&gt;...&lt;/elem1&gt;
3641 &lt;elem2&gt;...&lt;/elem2&gt;
3642&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003643
Daniel Veillardec70e912001-02-26 20:10:45 +00003644<p>The namespace value has to be an absolute URL, but the URL doesn't have to
3645point to any existing resource on the Web. It will bind all the element and
Daniel Veillardc0801af2002-05-28 16:28:42 +00003646attributes with that URL. I suggest to use an URL within a domain you
3647control, and that the URL should contain some kind of version information if
3648possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a
3649good namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +00003650
3651<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +00003652version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003653and if the version information don't match something you know, warn the user
3654and be liberal in what you accept as the input. Also do *not* try to base
Daniel Veillard60979bd2000-07-10 12:17:33 +00003655namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +00003656same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +00003657associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +00003658just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +00003659<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +00003660prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003661
3662<p>@@Interfaces@@</p>
3663
3664<p>@@Examples@@</p>
3665
Daniel Veillard91e9d582001-02-26 07:31:12 +00003666<p>Usually people object to using namespaces together with validity checking.
3667I will try to make sure that using namespaces won't break validity checking,
3668so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +00003669suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003670<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +00003671flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003672from multiple DTDs will certainly break current validation schemes. I will
3673try to provide ways to do this, but this may not be portable or
3674standardized.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003675
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003676<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003677
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003678<p>Incompatible changes:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003679
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003680<p>Version 2 of libxml is the first version introducing serious backward
3681incompatible changes. The main goals were:</p>
3682<ul>
3683 <li>a general cleanup. A number of mistakes inherited from the very early
3684 versions couldn't be changed due to compatibility constraints. Example
3685 the "childs" element in the nodes.</li>
3686 <li>Uniformization of the various nodes, at least for their header and link
3687 parts (doc, parent, children, prev, next), the goal is a simpler
3688 programming model and simplifying the task of the DOM implementors.</li>
3689 <li>better conformances to the XML specification, for example version 1.x
3690 had an heuristic to try to detect ignorable white spaces. As a result the
3691 SAX event generated were ignorableWhitespace() while the spec requires
3692 character() in that case. This also mean that a number of DOM node
3693 containing blank text may populate the DOM tree which were not present
3694 before.</li>
3695</ul>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003696
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003697<h3>How to fix libxml-1.x code:</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003698
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003699<p>So client code of libxml designed to run with version 1.x may have to be
3700changed to compile against version 2.x of libxml. Here is a list of changes
3701that I have collected, they may not be sufficient, so in case you find other
3702change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
3703mail</a>:</p>
3704<ol>
3705 <li>The package name have changed from libxml to libxml2, the library name
3706 is now -lxml2 . There is a new xml2-config script which should be used to
3707 select the right parameters libxml2</li>
3708 <li>Node <strong>childs</strong> field has been renamed
3709 <strong>children</strong> so s/childs/children/g should be applied
Daniel Veillard63d83142002-05-20 06:51:05 +00003710 (probability of having "childs" anywhere else is close to 0+</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003711 <li>The document don't have anymore a <strong>root</strong> element it has
3712 been replaced by <strong>children</strong> and usually you will get a
3713 list of element here. For example a Dtd element for the internal subset
3714 and it's declaration may be found in that list, as well as processing
3715 instructions or comments found before or after the document root element.
3716 Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
Daniel Veillard63d83142002-05-20 06:51:05 +00003717 a document. Alternatively if you are sure to not reference DTDs nor have
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003718 PIs or comments before or after the root element
3719 s/-&gt;root/-&gt;children/g will probably do it.</li>
3720 <li>The white space issue, this one is more complex, unless special case of
3721 validating parsing, the line breaks and spaces usually used for indenting
3722 and formatting the document content becomes significant. So they are
3723 reported by SAX and if your using the DOM tree, corresponding nodes are
3724 generated. Too approach can be taken:
3725 <ol>
3726 <li>lazy one, use the compatibility call
3727 <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
3728 relying on a special (and possibly broken) set of heuristics of
3729 libxml to detect ignorable blanks. Don't complain if it breaks or
3730 make your application not 100% clean w.r.t. to it's input.</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00003731 <li>the Right Way: change you code to accept possibly insignificant
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003732 blanks characters, or have your tree populated with weird blank text
Daniel Veillard63d83142002-05-20 06:51:05 +00003733 nodes. You can spot them using the commodity function
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003734 <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
3735 nodes.</li>
3736 </ol>
3737 <p>Note also that with the new default the output functions don't add any
3738 extra indentation when saving a tree in order to be able to round trip
3739 (read and save) without inflating the document with extra formatting
3740 chars.</p>
3741 </li>
3742 <li>The include path has changed to $prefix/libxml/ and the includes
3743 themselves uses this new prefix in includes instructions... If you are
3744 using (as expected) the
3745 <pre>xml2-config --cflags</pre>
3746 <p>output to generate you compile commands this will probably work out of
3747 the box</p>
3748 </li>
Daniel Veillard63d83142002-05-20 06:51:05 +00003749 <li>xmlDetectCharEncoding takes an extra argument indicating the length in
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003750 byte of the head of the document available for character detection.</li>
3751</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003752
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003753<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003754
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003755<p>Two new version of libxml (1.8.11) and libxml2 (2.3.4) have been released
Daniel Veillard63d83142002-05-20 06:51:05 +00003756to allow smooth upgrade of existing libxml v1code while retaining
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003757compatibility. They offers the following:</p>
3758<ol>
3759 <li>similar include naming, one should use
3760 <strong>#include&lt;libxml/...&gt;</strong> in both cases.</li>
3761 <li>similar identifiers defined via macros for the child and root fields:
3762 respectively <strong>xmlChildrenNode</strong> and
3763 <strong>xmlRootNode</strong></li>
3764 <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
3765 inserted once in the client code</li>
3766</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003767
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003768<p>So the roadmap to upgrade your existing libxml applications is the
3769following:</p>
3770<ol>
3771 <li>install the libxml-1.8.8 (and libxml-devel-1.8.8) packages</li>
Daniel Veillard63d83142002-05-20 06:51:05 +00003772 <li>find all occurrences where the xmlDoc <strong>root</strong> field is
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003773 used and change it to <strong>xmlRootNode</strong></li>
Daniel Veillardc0801af2002-05-28 16:28:42 +00003774 <li>similarly find all occurrences where the xmlNode
3775 <strong>childs</strong> field is used and change it to
3776 <strong>xmlChildrenNode</strong></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003777 <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
3778 <strong>main()</strong> or in the library init entry point</li>
3779 <li>Recompile, check compatibility, it should still work</li>
Daniel Veillardc0801af2002-05-28 16:28:42 +00003780 <li>Change your configure script to look first for xml2-config and fall
3781 back using xml-config . Use the --cflags and --libs output of the command
3782 as the Include and Linking parameters needed to use libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003783 <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
3784 libxml-devel-1.8.y can be kept simultaneously)</li>
3785 <li>remove your config.cache, relaunch your configuration mechanism, and
3786 recompile, if steps 2 and 3 were done right it should compile as-is</li>
3787 <li>Test that your application is still running correctly, if not this may
3788 be due to extra empty nodes due to formating spaces being kept in libxml2
3789 contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
3790 code before calling the parser (next to
3791 <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
3792</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003793
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003794<p>Following those steps should work. It worked for some of my own code.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003795
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00003796<p>Let me put some emphasis on the fact that there is far more changes from
3797libxml 1.x to 2.x than the ones you may have to patch for. The overall code
3798has been considerably cleaned up and the conformance to the XML specification
3799has been drastically improved too. Don't take those changes as an excuse to
3800not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003801
Daniel Veillard52dcab32001-10-30 12:51:17 +00003802<h2><a name="Thread">Thread safety</a></h2>
3803
Daniel Veillard63d83142002-05-20 06:51:05 +00003804<p>Starting with 2.4.7, libxml makes provisions to ensure that concurrent
Daniel Veillard52dcab32001-10-30 12:51:17 +00003805threads can safely work in parallel parsing different documents. There is
3806however a couple of things to do to ensure it:</p>
3807<ul>
3808 <li>configure the library accordingly using the --with-threads options</li>
3809 <li>call xmlInitParser() in the "main" thread before using any of the
3810 libxml API (except possibly selecting a different memory allocator)</li>
3811</ul>
3812
3813<p>Note that the thread safety cannot be ensured for multiple threads sharing
3814the same document, the locking must be done at the application level, libxml
3815exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
3816The parts of the library checked for thread safety are:</p>
3817<ul>
3818 <li>concurrent loading</li>
3819 <li>file access resolution</li>
3820 <li>catalog access</li>
3821 <li>catalog building</li>
3822 <li>entities lookup/accesses</li>
3823 <li>validation</li>
3824 <li>global variables per-thread override</li>
3825 <li>memory handling</li>
3826</ul>
3827
3828<p>XPath is supposed to be thread safe now, but this wasn't tested
3829seriously.</p>
3830
Daniel Veillard35008381999-10-25 13:15:52 +00003831<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003832
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003833<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
3834Object Model</em>; this is an API for accessing XML or HTML structured
3835documents. Native support for DOM in Gnome is on the way (module gnome-dom),
3836and will be based on gnome-xml. This will be a far cleaner interface to
3837manipulate XML files within Gnome since it won't expose the internal
3838structure.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +00003839
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003840<p>The current DOM implementation on top of libxml is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +00003841href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
3842is a full DOM interface, thanks to Paolo Casarini, check the <a
3843href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
3844informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00003845
Daniel Veillard35008381999-10-25 13:15:52 +00003846<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003847
3848<p>Here is a real size example, where the actual content of the application
3849data is not kept in the DOM tree but uses internal structures. It is based on
Daniel Veillard14fff061999-06-22 21:49:07 +00003850a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +00003851storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
3852base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +00003853<pre>&lt;?xml version="1.0"?&gt;
3854&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
3855 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +00003856
Daniel Veillard60979bd2000-07-10 12:17:33 +00003857 &lt;gjob:Job&gt;
3858 &lt;gjob:Project ID="3"/&gt;
3859 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
3860 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +00003861
Daniel Veillard60979bd2000-07-10 12:17:33 +00003862 &lt;gjob:Update&gt;
3863 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
3864 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
3865 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
3866 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +00003867
Daniel Veillard60979bd2000-07-10 12:17:33 +00003868 &lt;gjob:Developers&gt;
3869 &lt;gjob:Developer&gt;
3870 &lt;/gjob:Developer&gt;
3871 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +00003872
Daniel Veillard60979bd2000-07-10 12:17:33 +00003873 &lt;gjob:Contact&gt;
3874 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
3875 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
3876 &lt;gjob:Company&gt;
3877 &lt;/gjob:Company&gt;
3878 &lt;gjob:Organisation&gt;
3879 &lt;/gjob:Organisation&gt;
3880 &lt;gjob:Webpage&gt;
3881 &lt;/gjob:Webpage&gt;
3882 &lt;gjob:Snailmail&gt;
3883 &lt;/gjob:Snailmail&gt;
3884 &lt;gjob:Phone&gt;
3885 &lt;/gjob:Phone&gt;
3886 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +00003887
Daniel Veillard60979bd2000-07-10 12:17:33 +00003888 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +00003889 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +00003890 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +00003891
Daniel Veillard60979bd2000-07-10 12:17:33 +00003892 &lt;gjob:Skills&gt;
3893 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +00003894
Daniel Veillard60979bd2000-07-10 12:17:33 +00003895 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +00003896 A GNOME based system that will allow a superuser to configure
3897 compressed and uncompressed files and/or file systems to be backed
3898 up with a supported media in the system. This should be able to
3899 perform via find commands generating a list of files that are passed
3900 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
3901 or via operations performed on the filesystem itself. Email
3902 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +00003903 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +00003904
Daniel Veillard60979bd2000-07-10 12:17:33 +00003905 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +00003906
Daniel Veillard60979bd2000-07-10 12:17:33 +00003907 &lt;/gjob:Jobs&gt;
3908&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003909
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003910<p>While loading the XML file into an internal DOM tree is a matter of
Daniel Veillard63d83142002-05-20 06:51:05 +00003911calling only a couple of functions, browsing the tree to gather the data and
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003912generate the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003913
3914<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003915structure. For example, the ordering of the attributes is not significant,
3916the XML specification is clear about it. It's also usually a good idea not to
Daniel Veillardec70e912001-02-26 20:10:45 +00003917depend on the order of the children of a given node, unless it really makes
3918things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003919<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +00003920 * A person record
3921 */
3922typedef struct person {
3923 char *name;
3924 char *email;
3925 char *company;
3926 char *organisation;
3927 char *smail;
3928 char *webPage;
3929 char *phone;
3930} person, *personPtr;
3931
3932/*
3933 * And the code needed to parse it
3934 */
3935personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3936 personPtr ret = NULL;
3937
3938DEBUG("parsePerson\n");
3939 /*
3940 * allocate the struct
3941 */
3942 ret = (personPtr) malloc(sizeof(person));
3943 if (ret == NULL) {
3944 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +00003945 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +00003946 }
3947 memset(ret, 0, sizeof(person));
3948
3949 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +00003950 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +00003951 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +00003952 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
3953 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3954 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
3955 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3956 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +00003957 }
3958
3959 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +00003960}</pre>
3961
Daniel Veillard91e9d582001-02-26 07:31:12 +00003962<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +00003963<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +00003964 <li>Usually a recursive parsing style is the more convenient one: XML data
Daniel Veillard63d83142002-05-20 06:51:05 +00003965 is by nature subject to repetitive constructs and usually exhibits highly
3966 structured patterns.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00003967 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
3968 i.e. the pointer to the global XML document and the namespace reserved to
3969 the application. Document wide information are needed for example to
3970 decode entities and it's a good coding practice to define a namespace for
3971 your application set of data and test that the element and attributes
3972 you're analyzing actually pertains to your application space. This is
3973 done by a simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +00003974 <li>To retrieve text and attributes value, you can use the function
3975 <em>xmlNodeListGetString</em> to gather all the text and entity reference
3976 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +00003977</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +00003978
3979<p>Here is another piece of code used to parse another level of the
3980structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +00003981<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +00003982/*
Daniel Veillard14fff061999-06-22 21:49:07 +00003983 * a Description for a Job
3984 */
3985typedef struct job {
3986 char *projectID;
3987 char *application;
3988 char *category;
3989 personPtr contact;
3990 int nbDevelopers;
3991 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
3992} job, *jobPtr;
3993
3994/*
3995 * And the code needed to parse it
3996 */
3997jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3998 jobPtr ret = NULL;
3999
4000DEBUG("parseJob\n");
4001 /*
4002 * allocate the struct
4003 */
4004 ret = (jobPtr) malloc(sizeof(job));
4005 if (ret == NULL) {
4006 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +00004007 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +00004008 }
4009 memset(ret, 0, sizeof(job));
4010
4011 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +00004012 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +00004013 while (cur != NULL) {
4014
Daniel Veillard60979bd2000-07-10 12:17:33 +00004015 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
4016 ret-&gt;projectID = xmlGetProp(cur, "ID");
4017 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +00004018 fprintf(stderr, "Project has no ID\n");
4019 }
4020 }
Daniel Veillard60979bd2000-07-10 12:17:33 +00004021 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
4022 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
4023 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
4024 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
4025 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
4026 ret-&gt;contact = parsePerson(doc, ns, cur);
4027 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +00004028 }
4029
4030 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +00004031}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +00004032
Daniel Veillardec70e912001-02-26 20:10:45 +00004033<p>Once you are used to it, writing this kind of code is quite simple, but
Daniel Veillard63d83142002-05-20 06:51:05 +00004034boring. Ultimately, it could be possible to write stubbers taking either C
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +00004035data structure definitions, a set of XML examples or an XML DTD and produce
4036the code needed to import and export the content between C data and XML
4037storage. This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00004038
Daniel Veillard6f0adb52000-07-03 11:41:26 +00004039<p>Feel free to use <a href="example/gjobread.c">the code for the full C
4040parsing example</a> as a template, it is also available with Makefile in the
4041Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +00004042
Daniel Veillardc310d562000-06-23 18:32:15 +00004043<h2><a name="Contributi">Contributions</a></h2>
4044<ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +00004045 <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
4046 patches, Gary Pennington worked on the validation API, threading support
4047 and Solaris port.</li>
4048 <li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillard7b4b2f92003-01-06 13:11:20 +00004049 <li><a href="mailto:igor@zlatkovic.com">Igor Zlatkovic</a> is now the
4050 maintainer of the Windows port, <a
4051 href="http://www.zlatkovic.com/projects/libxml/index.html">he provides
4052 binaries</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +00004053 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
4054 <a href="http://garypennington.net/libxml2/">Solaris binaries</a></li>
Daniel Veillarde356c282001-03-10 12:32:04 +00004055 <li><a
4056 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +00004057 Sergeant</a> developed <a
4058 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +00004059 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
4060 application server</a></li>
4061 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> and <a
4062 href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillardca989762001-06-23 17:39:29 +00004063 href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
Daniel Veillard3f6f7f62000-06-30 17:58:25 +00004064 documentation</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +00004065 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
4066 href="http://xmlsoft.org/messages/0488.html">man pages</a></li>
Daniel Veillard5168dbf2001-07-07 00:18:23 +00004067 <li>there is a module for <a
4068 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
4069 in OpenNSD/AOLServer</a></li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +00004070 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provided the
4071 first version of libxml/libxslt <a
4072 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li>
Daniel Veillard1aadc442001-11-28 13:10:32 +00004073 <li>Petr Kozelka provides <a
4074 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
4075 libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +00004076 <li><a href="mailto:aleksey@aleksey.com">Aleksey Sanin</a> implemented the
4077 <a href="http://www.w3.org/Signature/">XML Canonicalization and XML
4078 Digital Signature</a> <a
4079 href="http://www.aleksey.com/xmlsec/">implementations for libxml2</a></li>
Daniel Veillard17bed982003-02-24 20:11:43 +00004080 <li><a href="mailto:Steve.Ball@zveno.com">Steve Ball</a>, <a
4081 href="http://www.zveno.com/">Zveno</a> and contributors maintain <a
4082 href="http://tclxml.sourceforge.net/">tcl bindings for libxml2 and
4083 libxslt</a>, as well as <a
4084 href="http://tclxml.sf.net/tkxmllint.html">tkxmllint</a> a GUI for
4085 xmllint and <a href="http://tclxml.sf.net/tkxsltproc.html">tkxsltproc</a>
4086 a GUI for xsltproc.</li>
Daniel Veillardc310d562000-06-23 18:32:15 +00004087</ul>
4088
Daniel Veillardc8eab3a1999-09-04 18:27:23 +00004089<p></p>
Daniel Veillardccb09631998-10-27 06:21:04 +00004090</body>
4091</html>