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blob: 95f9c146543ad80d539e1b836da98707d364e903 [file] [log] [blame]
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
2 "http://www.w3.org/TR/html4/loose.dtd">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3<html>
4<head>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]5 <title>The XML C library for Gnome</title>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]6 <meta name="GENERATOR" content="amaya 5.1">
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]7 <meta http-equiv="Content-Type" content="text/html">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]8</head>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]9
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]10<body bgcolor="#ffffff">
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]11<h1 align="center">The XML C library for Gnome</h1>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]12
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]13<h1>Note: this is the flat content of the <a href="index.html">web
14site</a></h1>
15
Daniel Veillardc9484202001-10-24 12:35:52 +0000[diff] [blame]16<h1 style="text-align: center">libxml, a.k.a. gnome-xml</h1>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]17
18<p></p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]19
20<p>Libxml is the XML C library developped for the Gnome project. XML itself
21is a metalanguage to design markup languages, i.e. text language where
22semantic and structure are added to the content using extra "markup"
23information enclosed between angle bracket. HTML is the most well-known
Daniel Veillard1eb24242002-03-18 11:33:03 +0000[diff] [blame]24markup language. Though the library is written in C <a href="python.html">a
25variety of language binding</a> makes it available in other environments.</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]26
27<p>Libxml2 implements a number of existing standards related to markup
28languages:</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]29<ul>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]30 <li>the XML standard: <a
31 href="http://www.w3.org/TR/REC-xml">http://www.w3.org/TR/REC-xml</a></li>
32 <li>Namespaces in XML: <a
33 href="http://www.w3.org/TR/REC-xml-names/">http://www.w3.org/TR/REC-xml-names/</a></li>
34 <li>XML Base: <a
35 href="http://www.w3.org/TR/xmlbase/">http://www.w3.org/TR/xmlbase/</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]36 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc2396.txt">RFC 2396</a> :
37 Uniform Resource Identifiers <a
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]38 href="http://www.ietf.org/rfc/rfc2396.txt">http://www.ietf.org/rfc/rfc2396.txt</a></li>
39 <li>XML Path Language (XPath) 1.0: <a
40 href="http://www.w3.org/TR/xpath">http://www.w3.org/TR/xpath</a></li>
41 <li>HTML4 parser: <a
42 href="http://www.w3.org/TR/html401/">http://www.w3.org/TR/html401/</a></li>
43 <li>most of XML Pointer Language (XPointer) Version 1.0: <a
44 href="http://www.w3.org/TR/xptr">http://www.w3.org/TR/xptr</a></li>
45 <li>XML Inclusions (XInclude) Version 1.0: <a
46 href="http://www.w3.org/TR/xinclude/">http://www.w3.org/TR/xinclude/</a></li>
47 <li>[ISO-8859-1], <a
48 href="http://www.cis.ohio-state.edu/rfc/rfc2044.txt">rfc2044</a> [UTF-8]
49 and <a href="http://www.cis.ohio-state.edu/rfc/rfc2781.txt">rfc2781</a>
50 [UTF-16] core encodings</li>
51 <li>part of SGML Open Technical Resolution TR9401:1997</li>
52 <li>XML Catalogs Working Draft 06 August 2001: <a
53 href="http://www.oasis-open.org/committees/entity/spec-2001-08-06.html">http://www.oasis-open.org/committees/entity/spec-2001-08-06.html</a></li>
Daniel Veillard5c396542002-03-15 07:57:50 +0000[diff] [blame]54 <li>Canonical XML Version 1.0: <a
55 href="http://www.w3.org/TR/xml-c14n">http://www.w3.org/TR/xml-c14n</a>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]56 and the Exclusive XML Canonicalization CR draft <a
57 href="http://www.w3.org/TR/xml-exc-c14n">http://www.w3.org/TR/xml-exc-c14n</a></li>
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]58</ul>
59
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]60<p>In most cases libxml tries to implement the specifications in a relatively
Daniel Veillarda5393562002-02-20 11:40:49 +0000[diff] [blame]61strict way. As of release 2.4.16, libxml2 passes all 1800+ tests from the <a
62href="http://www.oasis-open.org/committees/xml-conformance/">OASIS XML Tests
63Suite</a>.</p>
Daniel Veillard5b16f582002-02-20 11:38:46 +0000[diff] [blame]64
65<p>To some extent libxml2 provide some support for the following other
66specification but don't claim to implement them:</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]67<ul>
68 <li>Document Object Model (DOM) <a
69 href="http://www.w3.org/TR/DOM-Level-2-Core/">http://www.w3.org/TR/DOM-Level-2-Core/</a>
70 it doesn't implement the API itself, gdome2 does this in top of
71 libxml2</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]72 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc959.txt">RFC 959</a> :
73 libxml implements a basic FTP client code</li>
74 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc1945.txt">RFC 1945</a> :
75 HTTP/1.0, again a basic HTTP client code</li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]76 <li>SAX: a minimal SAX implementation compatible with early expat
77 versions</li>
78 <li>DocBook SGML v4: libxml2 includes a hackish parser to transition to
79 XML</li>
80</ul>
81
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame^]82<p>XML Schemas is being worked on but it would be far too early to make any
83conformance statement about it at the moment.</p>
84
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]85<p>Libxml2 is known to be very portable, the library should build and work
86without serious troubles on a variety of systems (Linux, Unix, Windows,
87CygWin, MacOs, MacOsX, RISC Os, OS/2, VMS, QNX, MVS, ...)</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]88
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]89<p>Separate documents:</p>
90<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]91 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a> providing an
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]92 implementation of XSLT 1.0 and common extensions like EXSLT for
93 libxml2</li>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]94 <li><a href="http://www.cs.unibo.it/~casarini/gdome2/">the gdome2 page</a>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]95 : a standard DOM2 implementation for libxml2</li>
96 <li><a href="http://www.aleksey.com/xmlsec/">the XMLSec page</a>: an
97 implementation of <a href="http://www.w3.org/TR/xmldsig-core/">W3C XML
98 Digital Signature</a> for libxml2</li>
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame^]99 <li>also check the related links section below for more related and active
100 projects.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]101</ul>
102
103<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]104
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]105<p>This document describes libxml, the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]106href="http://www.w3.org/XML/">XML</a> C library developped for the <a
107href="http://www.gnome.org/">Gnome</a> project. <a
108href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
109structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]110
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]111<p>Here are some key points about libxml:</p>
112<ul>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]113 <li>Libxml exports Push (progressive) and Pull (blocking) type parser
114 interfaces for both XML and HTML.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]115 <li>Libxml can do DTD validation at parse time, using a parsed document
116 instance, or with an arbitrary DTD.</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]117 <li>Libxml includes complete <a
Daniel Veillard8c2ecaf2001-07-10 17:53:07 +0000[diff] [blame]118 href="http://www.w3.org/TR/xpath">XPath</a>, <a
119 href="http://www.w3.org/TR/xptr">XPointer</a> and <a
120 href="http://www.w3.org/TR/xinclude">XInclude</a> implementations.</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]121 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]122 sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]123 Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]124 <li>Basic support for HTTP and FTP client allowing aplications to fetch
125 remote resources</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]126 <li>The design is modular, most of the extensions can be compiled out.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]127 <li>The internal document repesentation is as close as possible to the <a
128 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
129 <li>Libxml also has a <a href="http://www.megginson.com/SAX/index.html">SAX
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]130 like interface</a>; the interface is designed to be compatible with <a
131 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]132 <li>This library is released under the <a
133 href="http://www.opensource.org/licenses/mit-license.html">MIT
134 Licence</a> see the Copyright file in the distribution for the precise
135 wording.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]136</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]137
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]138<p>Warning: unless you are forced to because your application links with a
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]139Gnome-1.X library requiring it, <strong><span
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]140style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
141libxml2</p>
142
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]143<h2><a name="FAQ">FAQ</a></h2>
144
145<p>Table of Content:</p>
146<ul>
147 <li><a href="FAQ.html#Licence">Licence(s)</a></li>
148 <li><a href="FAQ.html#Installati">Installation</a></li>
149 <li><a href="FAQ.html#Compilatio">Compilation</a></li>
150 <li><a href="FAQ.html#Developer">Developer corner</a></li>
151</ul>
152
153<h3><a name="Licence">Licence</a>(s)</h3>
154<ol>
155 <li><em>Licensing Terms for libxml</em>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]156 <p>libxml is released under the <a
157 href="http://www.opensource.org/licenses/mit-license.html">MIT
158 Licence</a>, see the file Copyright in the distribution for the precise
159 wording</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]160 </li>
161 <li><em>Can I embed libxml in a proprietary application ?</em>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]162 <p>Yes. The MIT Licence allows you to also keep proprietary the changes
163 you made to libxml, but it would be graceful to provide back bugfixes and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]164 improvements as patches for possible incorporation in the main
165 development tree</p>
166 </li>
167</ol>
168
169<h3><a name="Installati">Installation</a></h3>
170<ol>
171 <li>Unless you are forced to because your application links with a Gnome
172 library requiring it, <strong><span style="background-color: #FF0000">Do
173 Not Use libxml1</span></strong>, use libxml2</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]174 <li><em>Where can I get libxml</em> ?
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]175 <p>The original distribution comes from <a
176 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a
177 href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">gnome.org</a></p>
178 <p>Most linux and Bsd distribution includes libxml, this is probably the
179 safer way for end-users</p>
180 <p>David Doolin provides precompiled Windows versions at <a
181 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
182 </li>
183 <li><em>I see libxml and libxml2 releases, which one should I install ?</em>
184 <ul>
185 <li>If you are not concerned by any existing backward compatibility
186 with existing application, install libxml2 only</li>
187 <li>If you are not doing development, you can safely install both.
188 usually the packages <a
189 href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a
190 href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
191 compatible (this is not the case for development packages)</li>
192 <li>If you are a developer and your system provides separate packaging
193 for shared libraries and the development components, it is possible
194 to install libxml and libxml2, and also <a
195 href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
196 and <a
197 href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
198 too for libxml2 &gt;= 2.3.0</li>
199 <li>If you are developing a new application, please develop against
200 libxml2(-devel)</li>
201 </ul>
202 </li>
203 <li><em>I can't install the libxml package it conflicts with libxml0</em>
204 <p>You probably have an old libxml0 package used to provide the shared
205 library for libxml.so.0, you can probably safely remove it. Anyway the
206 libxml packages provided on <a
207 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provides
208 libxml.so.0</p>
209 </li>
210 <li><em>I can't install the libxml(2) RPM package due to failed
211 dependancies</em>
212 <p>The most generic solution is to refetch the latest src.rpm , and
213 rebuild it locally with</p>
214 <p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code></p>
215 <p>if everything goes well it will generate two binary rpm (one providing
216 the shared libs and xmllint, and the other one, the -devel package
217 providing includes, static libraries and scripts needed to build
218 applications with libxml(2)) that you can install locally.</p>
219 </li>
220</ol>
221
222<h3><a name="Compilatio">Compilation</a></h3>
223<ol>
224 <li><em>What is the process to compile libxml ?</em>
225 <p>As most UNIX libraries libxml follows the "standard":</p>
226 <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p>
227 <p><code>cd libxml-xxxx</code></p>
228 <p><code>./configure --help</code></p>
229 <p>to see the options, then the compilation/installation proper</p>
230 <p><code>./configure [possible options]</code></p>
231 <p><code>make</code></p>
232 <p><code>make install</code></p>
233 <p>At that point you may have to rerun ldconfig or similar utility to
234 update your list of installed shared libs.</p>
235 </li>
236 <li><em>What other libraries are needed to compile/install libxml ?</em>
237 <p>Libxml does not requires any other library, the normal C ANSI API
238 should be sufficient (please report any violation to this rule you may
239 find).</p>
240 <p>However if found at configuration time libxml will detect and use the
241 following libs:</p>
242 <ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]243 <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a> : a
244 highly portable and available widely compression library</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]245 <li>iconv: a powerful character encoding conversion library. It's
246 included by default on recent glibc libraries, so it doesn't need to
247 be installed specifically on linux. It seems it's now <a
248 href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
249 of the official UNIX</a> specification. Here is one <a
250 href="http://clisp.cons.org/~haible/packages-libiconv.html">implementation
251 of the library</a> which source can be found <a
252 href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
253 </ul>
254 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]255 <li><em>make check fails on some platforms</em>
256 <p>Sometime the regression tests results don't completely match the value
257 produced by the parser, and the makefile uses diff to print the delta. On
258 some platforms the diff return breaks the compilation process, if the
Daniel Veillarde46182c2002-02-12 14:29:11 +0000[diff] [blame]259 diff is small this is probably not a serious problem.</p>
260 <p>Sometimes (especially on Solaris) make checks fails due to limitations
261 in make. Try using GNU-make instead.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]262 </li>
263 <li><em>I use the CVS version and there is no configure script</em>
264 <p>The configure (and other Makefiles) are generated. Use the autogen.sh
265 script to regenerate the configure and Makefiles, like:</p>
266 <p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
267 </li>
268 <li><em>I have troubles when running make tests with gcc-3.0</em>
269 <p>It seems the initial release of gcc-3.0 has a problem with the
270 optimizer which miscompiles the URI module. Please use another
271 compiler</p>
272 </li>
273</ol>
274
275<h3><a name="Developer">Developer</a> corner</h3>
276<ol>
277 <li><em>xmlDocDump() generates output on one line</em>
278 <p>libxml will not <strong>invent</strong> spaces in the content of a
279 document since <strong>all spaces in the content of a document are
280 significant</strong>. If you build a tree from the API and want
281 indentation:</p>
282 <ol>
283 <li>the correct way is to generate those yourself too</li>
284 <li>the dangerous way is to ask libxml to add those blanks to your
285 content <strong>modifying the content of your document in the
286 process</strong>. The result may not be what you expect. There is
287 <strong>NO</strong> way to guarantee that such a modification won't
288 impact other part of the content of your document. See <a
289 href="http://xmlsoft.org/html/libxml-parser.html#XMLKEEPBLANKSDEFAULT">xmlKeepBlanksDefault
290 ()</a> and <a
291 href="http://xmlsoft.org/html/libxml-tree.html#XMLSAVEFORMATFILE">xmlSaveFormatFile
292 ()</a></li>
293 </ol>
294 </li>
295 <li>Extra nodes in the document:
296 <p><em>For a XML file as below:</em></p>
297 <pre>&lt;?xml version="1.0"?&gt;
298&lt;PLAN xmlns="http://www.argus.ca/autotest/1.0/"&gt;
299&lt;NODE CommFlag="0"/&gt;
300&lt;NODE CommFlag="1"/&gt;
301&lt;/PLAN&gt;</pre>
302 <p><em>after parsing it with the function
303 pxmlDoc=xmlParseFile(...);</em></p>
304 <p><em>I want to the get the content of the first node (node with the
305 CommFlag="0")</em></p>
306 <p><em>so I did it as following;</em></p>
307 <pre>xmlNodePtr pode;
308pnode=pxmlDoc-&gt;children-&gt;children;</pre>
309 <p><em>but it does not work. If I change it to</em></p>
310 <pre>pnode=pxmlDoc-&gt;children-&gt;children-&gt;next;</pre>
311 <p><em>then it works. Can someone explain it to me.</em></p>
312 <p></p>
313 <p>In XML all characters in the content of the document are significant
314 <strong>including blanks and formatting line breaks</strong>.</p>
315 <p>The extra nodes you are wondering about are just that, text nodes with
316 the formatting spaces wich are part of the document but that people tend
317 to forget. There is a function <a
318 href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
319 ()</a> to remove those at parse time, but that's an heuristic, and its
320 use should be limited to case where you are sure there is no
321 mixed-content in the document.</p>
322 </li>
323 <li><em>I get compilation errors of existing code like when accessing
324 <strong>root</strong> or <strong>childs fields</strong> of nodes</em>
325 <p>You are compiling code developed for libxml version 1 and using a
326 libxml2 development environment. Either switch back to libxml v1 devel or
327 even better fix the code to compile with libxml2 (or both) by <a
328 href="upgrade.html">following the instructions</a>.</p>
329 </li>
330 <li><em>I get compilation errors about non existing
331 <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
332 fields</em>
333 <p>The source code you are using has been <a
334 href="upgrade.html">upgraded</a> to be able to compile with both libxml
335 and libxml2, but you need to install a more recent version:
336 libxml(-devel) &gt;= 1.8.8 or libxml2(-devel) &gt;= 2.1.0</p>
337 </li>
338 <li><em>XPath implementation looks seriously broken</em>
339 <p>XPath implementation prior to 2.3.0 was really incomplete, upgrade to
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]340 a recent version, there is no known bug in the current version.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]341 </li>
342 <li><em>The example provided in the web page does not compile</em>
343 <p>It's hard to maintain the documentation in sync with the code
344 &lt;grin/&gt; ...</p>
345 <p>Check the previous points 1/ and 2/ raised before, and send
346 patches.</p>
347 </li>
348 <li><em>Where can I get more examples and informations than in the web
349 page</em>
350 <p>Ideally a libxml book would be nice. I have no such plan ... But you
351 can:</p>
352 <ul>
353 <li>check more deeply the <a href="html/libxml-lib.html">existing
354 generated doc</a></li>
355 <li>looks for examples of use for libxml function using the Gnome code
356 for example the following will query the full Gnome CVs base for the
357 use of the <strong>xmlAddChild()</strong> function:
358 <p><a
359 href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p>
360 <p>This may be slow, a large hardware donation to the gnome project
361 could cure this :-)</p>
362 </li>
363 <li><a
364 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gnome-xml">Browse
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]365 the libxml source</a> , I try to write code as clean and documented
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]366 as possible, so looking at it may be helpful. Especially the code of
367 xmllint.c and of the various testXXX.c tests programs should provide
368 good example on how to do things with the library.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]369 </ul>
370 </li>
371 <li>What about C++ ?
372 <p>libxml is written in pure C in order to allow easy reuse on a number
373 of platforms, including embedded systems. I don't intend to convert to
374 C++.</p>
375 <p>There is however a C++ wrapper provided by Ari Johnson
376 &lt;ari@btigate.com&gt; which may fullfill your needs:</p>
377 <p>Website: <a
378 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
379 <p>Download: <a
380 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
381 </li>
382 <li>How to validate a document a posteriori ?
383 <p>It is possible to validate documents which had not been validated at
384 initial parsing time or documents who have been built from scratch using
385 the API. Use the <a
386 href="http://xmlsoft.org/html/libxml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a>
387 function. It is also possible to simply add a Dtd to an existing
388 document:</p>
389 <pre>xmlDocPtr doc; /* your existing document */
390 xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
391 dtd-&gt;name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */
392
393 doc-&gt;intSubset = dtd;
394 if (doc-&gt;children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
395 else xmlAddPrevSibling(doc-&gt;children, (xmlNodePtr)dtd);
396 </pre>
397 </li>
398 <li>etc ...</li>
399</ol>
400
401<p></p>
402
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]403<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]404
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]405<p>There are some on-line resources about using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]406<ol>
Daniel Veillard365e13b2000-07-02 07:56:37 +0000[diff] [blame]407 <li>Check the <a href="FAQ.html">FAQ</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]408 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]409 documentation</a> automatically extracted from code comments (using <a
410 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
411 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]412 <li>Look at the documentation about <a href="encoding.html">libxml
413 internationalization support</a></li>
Daniel Veillardbc66f852002-01-14 09:49:20 +0000[diff] [blame]414 <li>This page provides a global overview and <a href="example.html">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]415 examples</a> on how to use libxml.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]416 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]417 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
418 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]419 <li>George Lebl wrote <a
420 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]421 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]422 <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO
423 file</a></li>
424 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>. If you are
425 starting a new project using libxml you should really use the 2.x
426 version.</li>
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]427 <li>And don't forget to look at the <a
428 href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]429</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]430
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]431<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]432
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]433<p>Well, bugs or missing features are always possible, and I will make a
434point of fixing them in a timely fashion. The best way to report a bug is to
435use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome
436bug tracking database</a> (make sure to use the "libxml" module name). I look
437at reports there regularly and it's good to have a reminder when a bug is
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]438still open. Be sure to specify that the bug is for the package libxml.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]439
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]440<p>There is also a mailing-list <a
Daniel Veillard3197f162001-04-04 00:40:08 +0000[diff] [blame]441href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
442href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]443href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
444please visit the <a
445href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
446follow the instructions. <strong>Do not send code, I won't debug it</strong>
447(but patches are really appreciated!).</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]448
Daniel Veillard008186f2001-09-13 14:24:44 +0000[diff] [blame]449<p>Check the following <strong><span style="color: #FF0000">before
450posting</span></strong>:</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]451<ul>
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]452 <li>read the <a href="FAQ.html">FAQ</a></li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]453 <li>make sure you are <a href="ftp://xmlsoft.org/">using a recent
454 version</a>, and that the problem still shows up in those</li>
455 <li>check the <a href="http://mail.gnome.org/archives/xml/">list
456 archives</a> to see if the problem was reported already, in this case
Daniel Veillarde7ead2d2001-08-22 23:44:09 +0000[diff] [blame]457 there is probably a fix available, similary check the <a
458 href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">registered
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]459 open bugs</a></li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]460 <li>make sure you can reproduce the bug with xmllint or one of the test
461 programs found in source in the distribution</li>
462 <li>Please send the command showing the error as well as the input (as an
463 attachement)</li>
464</ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]465
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]466<p>Then send the bug with associated informations to reproduce it to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]467href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillard008186f2001-09-13 14:24:44 +0000[diff] [blame]468related I will approve it.. Please do not send me mail directly, it makes
469things really harder to track and in some cases I'm not the best person to
470answer a given question, ask the list instead.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]471
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]472<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]473probably be processed faster.</p>
474
475<p>If you're looking for help, a quick look at <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]476href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]477provide the answer, I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]478questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]479documentantion</a> is not as polished as I would like (i need to learn more
480about Docbook), but it's a good starting point.</p>
481
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]482<h2><a name="help">How to help</a></h2>
483
484<p>You can help the project in various ways, the best thing to do first is to
485subscribe to the mailing-list as explained before, check the <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]486href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
487href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]488database:</a>:</p>
489<ol>
490 <li>provide patches when you find problems</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]491 <li>provide the diffs when you port libxml to a new platform. They may not
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]492 be integrated in all cases but help pinpointing portability problems
493 and</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]494 <li>provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]495 as HTML diffs).</li>
496 <li>provide new documentations pieces (translations, examples, etc ...)</li>
497 <li>Check the TODO file and try to close one of the items</li>
498 <li>take one of the points raised in the archive or the bug database and
Daniel Veillarde7ead2d2001-08-22 23:44:09 +0000[diff] [blame]499 provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me
500 </a>before to avoid synchronization problems and check that the suggested
501 fix will fit in nicely :-)</li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]502</ol>
503
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]504<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]505
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]506<p>The latest versions of libxml can be found on <a
Daniel Veillard20c8cf22001-06-26 22:47:36 +0000[diff] [blame]507href="ftp://xmlsoft.org/">xmlsoft.org</a> (<a
508href="ftp://speakeasy.rpmfind.net/pub/libxml/">Seattle</a>, <a
509href="ftp://fr.rpmfind.net/pub/libxml/">France</a>) or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]510href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]511as a <a href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">source
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]512archive</a> or <a
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]513href="ftp://ftp.gnome.org/pub/GNOME/stable/redhat/i386/libxml/">RPM
Daniel Veillard0bfbb422002-04-26 09:21:45 +0000[diff] [blame]514packages</a>, Antonin Sprinzl also provide <a
515href="ftp://gd.tuwien.ac.at/pub/libxml/">a mirror in Austria</a>. (NOTE that
516you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]517href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
518href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]519packages installed to compile applications using libxml.) <a
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]520href="mailto:igor@stud.fh-frankfurt.de">Igor Zlatkovic</a> is now the
521maintainer of the Windows port, <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]522href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]523provides binaries</a>. <a href="mailto:Gary.Pennington@sun.com">Gary
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]524Pennington</a> provides <a href="http://garypennington.net/libxml2/">Solaris
525binaries</a>.</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]526
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]527<p><a name="Snapshot">Snapshot:</a></p>
528<ul>
529 <li>Code from the W3C cvs base libxml <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]530 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]531 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]532 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]533</ul>
534
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]535<p><a name="Contribs">Contributions:</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]536
537<p>I do accept external contributions, especially if compiling on another
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]538platform, get in touch with me to upload the package, wrappers for various
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]539languages have been provided, and can be found in the <a
540href="contribs.html">contrib section</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]541
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]542<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]543<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]544 <li><p>The <a
545 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gnome-xml">Gnome
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]546 CVS base</a>. Check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]547 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a>
548 page; the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]549 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]550 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]551</ul>
552
553<h2><a name="News">News</a></h2>
554
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]555<h3>CVS only : check the <a
556href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]557for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]558
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame^]559<p>Items not finished and worked on, get in touch with the list if you want
560to test those</p>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]561<ul>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]562 <li>Finishing up <a href="http://www.w3.org/TR/xmlschema-1/">XML
563 Schemas</a> and <a href="http://www.w3.org/TR/xinclude">XInclude</a></li>
564</ul>
565
566<h3>2.4.21: Apr 29 2002</h3>
567
568<p>This release is both a bug fix release and also contains the early XML
569Schemas <a href="http://www.w3.org/TR/xmlschema-1/">structures</a> and <a
570href="http://www.w3.org/TR/xmlschema-2/">datatypes</a> code, beware, all
571interfaces are likely to change, there is huge holes, it is clearly a work in
572progress and don't even think of putting this code in a production system,
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame^]573it's actually not compiled in by default. The real fixes are:</p>
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]574<ul>
575 <li>a couple of bugs or limitations introduced in 2.4.20</li>
576 <li>patches for Borland C++ and MSC by Igor</li>
577 <li>some fixes on XPath strings and conformance patches by Richard
578 Jinks</li>
579 <li>patch from Aleksey for the ExcC14N specification</li>
580 <li>OSF/1 bug fix by Bjorn</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]581</ul>
582
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]583<h3>2.4.20: Apr 15 2002</h3>
584<ul>
585 <li>bug fixes: file descriptor leak, XPath, HTML ouput, DTD validation</li>
586 <li>XPath conformance testing by Richard Jinks</li>
587 <li>Portability fixes: Solaris, MPE/iX, Windows, OSF/1, python bindings,
588 libxml.m4</li>
589</ul>
590
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]591<h3>2.4.19: Mar 25 2002</h3>
592<ul>
593 <li>bug fixes: half a dozen XPath bugs, Validation, ISO-Latin to UTF8
594 encoder</li>
595 <li>portability fixes in the HTTP code</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]596 <li>memory allocation checks using valgrind, and profiling tests</li>
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]597 <li>revamp of the Windows build and Makefiles</li>
598</ul>
599
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]600<h3>2.4.18: Mar 18 2002</h3>
601<ul>
602 <li>bug fixes: tree, SAX, canonicalization, validation, portability,
603 xpath</li>
604 <li>removed the --with-buffer option it was becoming unmaintainable</li>
605 <li>serious cleanup of the Python makefiles</li>
606 <li>speedup patch to XPath very effective for DocBook stylesheets</li>
607 <li>Fixes for Windows build, cleanup of the documentation</li>
608</ul>
609
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]610<h3>2.4.17: Mar 8 2002</h3>
611<ul>
612 <li>a lot of bug fixes, including "namespace nodes have no parents in
613 XPath"</li>
614 <li>fixed/improved the Python wrappers, added more examples and more
615 regression tests, XPath extension functions can now return node-sets</li>
616 <li>added the XML Canonalization support from Aleksey Sanin</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]617</ul>
618
Daniel Veillard5f4b5992002-02-20 10:22:49 +0000[diff] [blame]619<h3>2.4.16: Feb 20 2002</h3>
620<ul>
621 <li>a lot of bug fixes, most of them were triggered by the XML Testsuite
622 from OASIS and W3C. Compliance has been significantly improved.</li>
623 <li>a couple of portability fixes too.</li>
624</ul>
625
Daniel Veillard397ff112002-02-11 18:27:20 +0000[diff] [blame]626<h3>2.4.15: Feb 11 2002</h3>
627<ul>
628 <li>Fixed the Makefiles, especially the python module ones</li>
629 <li>A few bug fixes and cleanup</li>
630 <li>Includes cleanup</li>
631</ul>
632
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]633<h3>2.4.14: Feb 8 2002</h3>
634<ul>
635 <li>Change of Licence to the <a
636 href="http://www.opensource.org/licenses/mit-license.html">MIT
637 Licence</a> basisally for integration in XFree86 codebase, and removing
638 confusion around the previous dual-licencing</li>
639 <li>added Python bindings, beta software but should already be quite
640 complete</li>
641 <li>a large number of fixes and cleanups, especially for all tree
642 manipulations</li>
643 <li>cleanup of the headers, generation of a reference API definition in
644 XML</li>
645</ul>
646
647<h3>2.4.13: Jan 14 2002</h3>
Daniel Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame]648<ul>
649 <li>update of the documentation: John Fleck and Charlie Bozeman</li>
650 <li>cleanup of timing code from Justin Fletcher</li>
651 <li>fixes for Windows and initial thread support on Win32: Igor and Serguei
652 Narojnyi</li>
653 <li>Cygwin patch from Robert Collins</li>
654 <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
655</ul>
656
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]657<h3>2.4.12: Dec 7 2001</h3>
658<ul>
659 <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
660 XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
661 (robert)</li>
662 <li>Eric Lavigne contributed project files for MacOS</li>
663 <li>some makefiles cleanups</li>
664</ul>
665
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]666<h3>2.4.11: Nov 26 2001</h3>
667<ul>
668 <li>fixed a couple of errors in the includes, fixed a few bugs, some code
669 cleanups</li>
670 <li>xmllint man pages improvement by Heiko Rupp</li>
671 <li>updated VMS build instructions from John A Fotheringham</li>
672 <li>Windows Makefiles updates from Igor</li>
673</ul>
674
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]675<h3>2.4.10: Nov 10 2001</h3>
676<ul>
677 <li>URI escaping fix (Joel Young)</li>
678 <li>added xmlGetNodePath() (for paths or XPointers generation)</li>
679 <li>Fixes namespace handling problems when using DTD and validation</li>
680 <li>improvements on xmllint: Morus Walter patches for --format and
681 --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
682 <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
683 <li>fixes to the HTML parser</li>
684</ul>
685
686<h3>2.4.9: Nov 6 2001</h3>
687<ul>
688 <li>fixes more catalog bugs</li>
689 <li>avoid a compilation problem, improve xmlGetLineNo()</li>
690</ul>
691
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]692<h3>2.4.8: Nov 4 2001</h3>
693<ul>
694 <li>fixed SGML catalogs broken in previous release, updated xmlcatalog
695 tool</li>
696 <li>fixed a compile errors and some includes troubles.</li>
697</ul>
698
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]699<h3>2.4.7: Oct 30 2001</h3>
700<ul>
701 <li>exported some debugging interfaces</li>
702 <li>serious rewrite of the catalog code</li>
703 <li>integrated Gary Pennington thread safety patch, added configure option
704 and regression tests</li>
705 <li>removed an HTML parser bug</li>
706 <li>fixed a couple of potentially serious validation bugs</li>
707 <li>integrated the SGML DocBook support in xmllint</li>
708 <li>changed the nanoftp anonymous login passwd</li>
709 <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
710 <li>general bug fixes</li>
711 <li>updated xmllint man page by John Fleck</li>
712 <li>some VMS and Windows updates</li>
713</ul>
714
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]715<h3>2.4.6: Oct 10 2001</h3>
716<ul>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]717 <li>added an updated man pages by John Fleck</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]718 <li>portability and configure fixes</li>
719 <li>an infinite loop on the HTML parser was removed (William)</li>
720 <li>Windows makefile patches from Igor</li>
721 <li>fixed half a dozen bugs reported fof libxml or libxslt</li>
722 <li>updated xmlcatalog to be able to modify SGML super catalogs</li>
723</ul>
724
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]725<h3>2.4.5: Sep 14 2001</h3>
726<ul>
727 <li>Remove a few annoying bugs in 2.4.4</li>
728 <li>forces the HTML serializer to output decimal charrefs since some
729 version of Netscape can't handle hexadecimal ones</li>
730</ul>
731
732<h3>1.8.16: Sep 14 2001</h3>
733<ul>
734 <li>maintenance release of the old libxml1 branch, couple of bug and
735 portability fixes</li>
736</ul>
737
Daniel Veillard04382ae2001-09-12 18:51:30 +0000[diff] [blame]738<h3>2.4.4: Sep 12 2001</h3>
739<ul>
740 <li>added --convert to xmlcatalog, bug fixes and cleanups of XML
741 Catalog</li>
742 <li>a few bug fixes and some portability changes</li>
743 <li>some documentation cleanups</li>
744</ul>
745
Daniel Veillard39936902001-08-24 00:49:01 +0000[diff] [blame]746<h3>2.4.3: Aug 23 2001</h3>
747<ul>
748 <li>XML Catalog support see the doc</li>
749 <li>New NaN/Infinity floating point code</li>
750 <li>A few bug fixes</li>
751</ul>
752
753<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]754<ul>
755 <li>adds xmlLineNumbersDefault() to control line number generation</li>
756 <li>lot of bug fixes</li>
757 <li>the Microsoft MSC projects files shuld now be up to date</li>
758 <li>inheritance of namespaces from DTD defaulted attributes</li>
759 <li>fixes a serious potential security bug</li>
760 <li>added a --format option to xmllint</li>
761</ul>
762
763<h3>2.4.1: July 24 2001</h3>
764<ul>
765 <li>possibility to keep line numbers in the tree</li>
766 <li>some computation NaN fixes</li>
767 <li>extension of the XPath API</li>
768 <li>cleanup for alpha and ia64 targets</li>
769 <li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]770</ul>
771
772<h3>2.4.0: July 10 2001</h3>
773<ul>
774 <li>Fixed a few bugs in XPath, validation, and tree handling.</li>
775 <li>Fixed XML Base implementation, added a coupel of examples to the
776 regression tests</li>
777 <li>A bit of cleanup</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]778</ul>
779
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]780<h3>2.3.14: July 5 2001</h3>
781<ul>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]782 <li>fixed some entities problems and reduce mem requirement when
783 substituing them</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]784 <li>lots of improvements in the XPath queries interpreter can be
785 substancially faster</li>
786 <li>Makefiles and configure cleanups</li>
787 <li>Fixes to XPath variable eval, and compare on empty node set</li>
788 <li>HTML tag closing bug fixed</li>
789 <li>Fixed an URI reference computating problem when validating</li>
790</ul>
791
Daniel Veillard2adbb512001-06-28 16:20:36 +0000[diff] [blame]792<h3>2.3.13: June 28 2001</h3>
793<ul>
794 <li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
795 <li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
796</ul>
797
798<h3>1.8.14: June 28 2001</h3>
799<ul>
800 <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
801 <li>Small Makefile fix</li>
802</ul>
803
Daniel Veillard11648102001-06-26 16:08:24 +0000[diff] [blame]804<h3>2.3.12: June 26 2001</h3>
805<ul>
806 <li>lots of cleanup</li>
807 <li>a couple of validation fix</li>
808 <li>fixed line number counting</li>
809 <li>fixed serious problems in the XInclude processing</li>
810 <li>added support for UTF8 BOM at beginning of entities</li>
811 <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
812 miscompile uri.c (William), Thomas Leitner provided a fix for the
813 optimizer on Tru64</li>
814 <li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
815 compilation on Windows MSC</li>
816 <li>update of libxml-doc.el (Felix Natter)</li>
817 <li>fixed 2 bugs in URI normalization code</li>
818</ul>
819
Daniel Veillarde3c81b52001-06-17 14:50:34 +0000[diff] [blame]820<h3>2.3.11: June 17 2001</h3>
821<ul>
822 <li>updates to trio, Makefiles and configure should fix some portability
823 problems (alpha)</li>
824 <li>fixed some HTML serialization problems (pre, script, and block/inline
825 handling), added encoding aware APIs, cleanup of this code</li>
826 <li>added xmlHasNsProp()</li>
827 <li>implemented a specific PI for encoding support in the DocBook SGML
828 parser</li>
829 <li>some XPath fixes (-Infinity, / as a function parameter and namespaces
830 node selection)</li>
831 <li>fixed a performance problem and an error in the validation code</li>
832 <li>fixed XInclude routine to implement the recursive behaviour</li>
833 <li>fixed xmlFreeNode problem when libxml is included statically twice</li>
834 <li>added --version to xmllint for bug reports</li>
835</ul>
836
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]837<h3>2.3.10: June 1 2001</h3>
838<ul>
839 <li>fixed the SGML catalog support</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]840 <li>a number of reported bugs got fixed, in XPath, iconv detection,
841 XInclude processing</li>
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]842 <li>XPath string function should now handle unicode correctly</li>
843</ul>
844
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]845<h3>2.3.9: May 19 2001</h3>
846
847<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
848<ul>
849 <li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
850 <li>some serious speed optimisation again</li>
851 <li>some documentation cleanups</li>
852 <li>trying to get better linking on solaris (-R)</li>
853 <li>XPath API cleanup from Thomas Broyer</li>
854 <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
855 xmlValidGetValidElements()</li>
856 <li>Added an INSTALL file</li>
857 <li>Attribute removal added to API: #54433</li>
858 <li>added a basic support for SGML catalogs</li>
859 <li>fixed xmlKeepBlanksDefault(0) API</li>
860 <li>bugfix in xmlNodeGetLang()</li>
861 <li>fixed a small configure portability problem</li>
862 <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
863</ul>
864
Daniel Veillarda265af72001-05-14 11:13:58 +0000[diff] [blame]865<h3>1.8.13: May 14 2001</h3>
866<ul>
867 <li>bugfixes release of the old libxml1 branch used by Gnome</li>
868</ul>
869
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]870<h3>2.3.8: May 3 2001</h3>
871<ul>
872 <li>Integrated an SGML DocBook parser for the Gnome project</li>
873 <li>Fixed a few things in the HTML parser</li>
874 <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
875 point portability issue</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]876 <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
877 DOM+validation using the XML REC as input and a 700MHz celeron).</li>
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]878 <li>incorporated more Windows cleanup</li>
879 <li>added xmlSaveFormatFile()</li>
880 <li>fixed problems in copying nodes with entities references (gdome)</li>
881 <li>removed some troubles surrounding the new validation module</li>
882</ul>
883
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]884<h3>2.3.7: April 22 2001</h3>
885<ul>
886 <li>lots of small bug fixes, corrected XPointer</li>
887 <li>Non determinist content model validation support</li>
888 <li>added xmlDocCopyNode for gdome2</li>
889 <li>revamped the way the HTML parser handles end of tags</li>
890 <li>XPath: corrctions of namespacessupport and number formatting</li>
891 <li>Windows: Igor Zlatkovic patches for MSC compilation</li>
892 <li>HTML ouput fixes from P C Chow and William M. Brack</li>
893 <li>Improved validation speed sensible for DocBook</li>
894 <li>fixed a big bug with ID declared in external parsed entities</li>
895 <li>portability fixes, update of Trio from Bjorn Reese</li>
896</ul>
897
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]898<h3>2.3.6: April 8 2001</h3>
899<ul>
900 <li>Code cleanup using extreme gcc compiler warning options, found and
901 cleared half a dozen potential problem</li>
902 <li>the Eazel team found an XML parser bug</li>
903 <li>cleaned up the user of some of the string formatting function. used the
904 trio library code to provide the one needed when the platform is missing
905 them</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]906 <li>xpath: removed a memory leak and fixed the predicate evaluation
907 problem, extended the testsuite and cleaned up the result. XPointer seems
908 broken ...</li>
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]909</ul>
910
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame]911<h3>2.3.5: Mar 23 2001</h3>
912<ul>
913 <li>Biggest change is separate parsing and evaluation of XPath expressions,
914 there is some new APIs for this too</li>
915 <li>included a number of bug fixes(XML push parser, 51876, notations,
916 52299)</li>
917 <li>Fixed some portability issues</li>
918</ul>
919
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]920<h3>2.3.4: Mar 10 2001</h3>
921<ul>
922 <li>Fixed bugs #51860 and #51861</li>
923 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
924 size to be application tunable.</li>
925 <li>Some cleanup in the validation code, still a bug left and this part
926 should probably be rewritten to support ambiguous content model :-\</li>
927 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
928 parser</li>
929 <li>Fixed another bug in xmlNodeGetContent()</li>
930 <li>Bjorn fixed XPath node collection and Number formatting</li>
931 <li>Fixed a loop reported in the HTML parsing</li>
932 <li>blank space are reported even if the Dtd content model proves that they
933 are formatting spaces, this is for XmL conformance</li>
934</ul>
935
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]936<h3>2.3.3: Mar 1 2001</h3>
937<ul>
938 <li>small change in XPath for XSLT</li>
939 <li>documentation cleanups</li>
940 <li>fix in validation by Gary Pennington</li>
941 <li>serious parsing performances improvements</li>
942</ul>
943
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]944<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]945<ul>
946 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
947 <li>fixed a Dtd parsing bug</li>
948 <li>fixed a bug in xmlNodeGetContent</li>
949 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
950</ul>
951
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]952<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]953<ul>
954 <li>some XPath and HTML bug fixes for XSLT</li>
955 <li>small extension of the hash table interfaces for DOM gdome2
956 implementation</li>
957 <li>A few bug fixes</li>
958</ul>
959
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]960<h3>2.3.0: Feb 8 2001 (2.2.12 was on 25 Jan but I didn't kept track)</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]961<ul>
962 <li>Lots of XPath bug fixes</li>
963 <li>Add a mode with Dtd lookup but without validation error reporting for
964 XSLT</li>
965 <li>Add support for text node without escaping (XSLT)</li>
966 <li>bug fixes for xmlCheckFilename</li>
967 <li>validation code bug fixes from Gary Pennington</li>
968 <li>Patch from Paul D. Smith correcting URI path normalization</li>
969 <li>Patch to allow simultaneous install of libxml-devel and
970 libxml2-devel</li>
971 <li>the example Makefile is now fixed</li>
972 <li>added HTML to the RPM packages</li>
973 <li>tree copying bugfixes</li>
974 <li>updates to Windows makefiles</li>
975 <li>optimisation patch from Bjorn Reese</li>
976</ul>
977
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]978<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]979<ul>
980 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
981 <li>added htmlHandleOmittedElem()</li>
982 <li>Applied Bjorn Reese's IPV6 first patch</li>
983 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]984 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]985</ul>
986
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]987<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]988<ul>
989 <li>Fix the Windows problems of 2.2.8</li>
990 <li>integrate OpenVMS patches</li>
991 <li>better handling of some nasty HTML input</li>
992 <li>Improved the XPointer implementation</li>
993 <li>integrate a number of provided patches</li>
994</ul>
995
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]996<h3>2.2.9: Nov 25 2000</h3>
997<ul>
998 <li>erroneous release :-(</li>
999</ul>
1000
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]1001<h3>2.2.8: Nov 13 2000</h3>
1002<ul>
1003 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
1004 support</li>
1005 <li>Patch in conditional section handling</li>
1006 <li>updated MS compiler project</li>
1007 <li>fixed some XPath problems</li>
1008 <li>added an URI escaping function</li>
1009 <li>some other bug fixes</li>
1010</ul>
1011
1012<h3>2.2.7: Oct 31 2000</h3>
1013<ul>
1014 <li>added message redirection</li>
1015 <li>XPath improvements (thanks TOM !)</li>
1016 <li>xmlIOParseDTD() added</li>
1017 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
1018 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
1019</ul>
1020
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]1021<h3>2.2.6: Oct 25 2000:</h3>
1022<ul>
1023 <li>Added an hash table module, migrated a number of internal structure to
1024 those</li>
1025 <li>Fixed a posteriori validation problems</li>
1026 <li>HTTP module cleanups</li>
1027 <li>HTML parser improvements (tag errors, script/style handling, attribute
1028 normalization)</li>
1029 <li>coalescing of adjacent text nodes</li>
1030 <li>couple of XPath bug fixes, exported the internal API</li>
1031</ul>
1032
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1033<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1034<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1035 <li>XPointer implementation and testsuite</li>
1036 <li>Lot of XPath fixes, added variable and functions registration, more
1037 tests</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1038 <li>Portability fixes, lots of enhancements toward an easy Windows build
1039 and release</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1040 <li>Late validation fixes</li>
1041 <li>Integrated a lot of contributed patches</li>
1042 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]1043 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]1044</ul>
1045
1046<h3>2.2.4: Oct 1 2000:</h3>
1047<ul>
1048 <li>main XPath problem fixed</li>
1049 <li>Integrated portability patches for Windows</li>
1050 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1051</ul>
1052
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1053<h3>2.2.3: Sep 17 2000</h3>
1054<ul>
1055 <li>bug fixes</li>
1056 <li>cleanup of entity handling code</li>
1057 <li>overall review of all loops in the parsers, all sprintf usage has been
1058 checked too</li>
1059 <li>Far better handling of larges Dtd. Validating against Docbook XML Dtd
1060 works smoothly now.</li>
1061</ul>
1062
1063<h3>1.8.10: Sep 6 2000</h3>
1064<ul>
1065 <li>bug fix release for some Gnome projects</li>
1066</ul>
1067
1068<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1069<ul>
1070 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]1071 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1072</ul>
1073
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1074<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1075<ul>
1076 <li>a purely bug fixes release</li>
1077 <li>fixed an encoding support problem when parsing from a memory block</li>
1078 <li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1079 <li>removed a bug in the function allowing to override the memory
1080 allocation routines</li>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1081</ul>
1082
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1083<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]1084<ul>
1085 <li>applied a lot of portability fixes</li>
1086 <li>better encoding support/cleanup and saving (content is now always
1087 encoded in UTF-8)</li>
1088 <li>the HTML parser now correctly handles encodings</li>
1089 <li>added xmlHasProp()</li>
1090 <li>fixed a serious problem with &amp;#38;</li>
1091 <li>propagated the fix to FTP client</li>
1092 <li>cleanup, bugfixes, etc ...</li>
1093 <li>Added a page about <a href="encoding.html">libxml Internationalization
1094 support</a></li>
1095</ul>
1096
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1097<h3>1.8.9: July 9 2000</h3>
1098<ul>
1099 <li>fixed the spec the RPMs should be better</li>
1100 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
1101 rpmfind users problem</li>
1102</ul>
1103
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]1104<h3>2.1.1: July 1 2000</h3>
1105<ul>
1106 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
1107 <li>improvements on the HTML parser</li>
1108</ul>
1109
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1110<h3>2.1.0 and 1.8.8: June 29 2000</h3>
1111<ul>
1112 <li>1.8.8 is mostly a comodity package for upgrading to libxml2 accoding to
1113 <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
1114 about &amp;#38; charref parsing</li>
1115 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
1116 also contains numerous fixes and enhancements:
1117 <ul>
1118 <li>added xmlStopParser() to stop parsing</li>
1119 <li>improved a lot parsing speed when there is large CDATA blocs</li>
1120 <li>includes XPath patches provided by Picdar Technology</li>
1121 <li>tried to fix as much as possible DtD validation and namespace
1122 related problems</li>
1123 <li>output to a given encoding has been added/tested</li>
1124 <li>lot of various fixes</li>
1125 </ul>
1126 </li>
1127</ul>
1128
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1129<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1130<ul>
1131 <li>First public release of libxml2. If you are using libxml, it's a good
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1132 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initally
1133 scheduled for Apr 3 the relase occured only on Apr 12 due to massive
1134 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1135 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1136 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1137 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1138 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1139 <pre>#include "xxx.h"</pre>
1140 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]1141 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
1142 <li>the memory allocation routines used by libxml can now be overloaded
1143 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1144 <li>The previously CVS only tool tester has been renamed
1145 <strong>xmllint</strong> and is now installed as part of the libxml2
1146 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1147 <li>The I/O interface has been revamped. There is now ways to plug in
1148 specific I/O modules, either at the URI scheme detection level using
1149 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
1150 parser context using xmlCreateIOParserCtxt()</li>
1151 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
1152 number of the libxml module in use</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1153 <li>a number of optional features of libxml can now be excluded at
1154 configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1155</ul>
1156
1157<h3>2.0.0beta: Mar 14 2000</h3>
1158<ul>
1159 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1160 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
1161 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
1162 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1163 <li>This version is now the head in the Gnome CVS base, the old one is
1164 available under the tag LIB_XML_1_X</li>
1165 <li>This includes a very large set of changes. Froma programmatic point of
1166 view applications should not have to be modified too much, check the <a
1167 href="upgrade.html">upgrade page</a></li>
1168 <li>Some interfaces may changes (especially a bit about encoding).</li>
1169 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1170 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1171 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
1172 handled now</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1173 <li>Better handling of entities, especially well formedness checking
1174 and proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1175 <li>DTD conditional sections</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1176 <li>Validation now correcly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1177 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
1178 structures to accomodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1179 </ul>
1180 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1181 <li>Serious progress were made toward compliance, <a
1182 href="conf/result.html">here are the result of the test</a> against the
1183 OASIS testsuite (except the japanese tests since I don't support that
1184 encoding yet). This URL is rebuilt every couple of hours using the CVS
1185 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1186</ul>
1187
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1188<h3>1.8.7: Mar 6 2000</h3>
1189<ul>
1190 <li>This is a bug fix release:</li>
1191 <li>It is possible to disable the ignorable blanks heuristic used by
1192 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1193 that for adherence to XML spec, this behaviour will be disabled by
1194 default in 2.x . The same function will allow to keep compatibility for
1195 old code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1196 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
1197 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1198 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
1199 compilation on some platforms has been fixed</li>
1200 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
1201 URIs</li>
1202</ul>
1203
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1204<h3>1.8.6: Jan 31 2000</h3>
1205<ul>
1206 <li>added a nanoFTP transport module, debugged until the new version of <a
1207 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
1208 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]1209</ul>
1210
1211<h3>1.8.5: Jan 21 2000</h3>
1212<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1213 <li>adding APIs to parse a well balanced chunk of XML (production <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1214 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
1215 XML spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1216 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1217 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
1218 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1219 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
1220 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1221</ul>
1222
1223<h3>1.8.4: Jan 13 2000</h3>
1224<ul>
1225 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
1226 <li>all exit() call should have been removed from libxml</li>
1227 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
1228 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1229</ul>
1230
1231<h3>1.8.3: Jan 5 2000</h3>
1232<ul>
1233 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1234 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillarddbfd6411999-12-28 16:35:14 +0000[diff] [blame]1235 <li>lots of bug fixes and improvement added over XMas hollidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1236 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1237 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
1238 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1239 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1240 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1241 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1242</ul>
1243
1244<h3>1.8.2: Dec 21 1999</h3>
1245<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1246 <li>I got another problem with includes and C++, I hope this issue is fixed
1247 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1248 <li>Added a few tree modification functions: xmlReplaceNode,
1249 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
1250 xmlDocSetRootElement</li>
1251 <li>Tried to improve the HTML output with help from <a
1252 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1253</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1254
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1255<h3>1.8.1: Dec 18 1999</h3>
1256<ul>
1257 <li>various patches to avoid troubles when using libxml with C++ compilers
1258 the "namespace" keyword and C escaping in include files</li>
1259 <li>a problem in one of the core macros IS_CHAR was corrected</li>
1260 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
1261 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]1262 <li>fixed a posteriori validation (validation after parsing, or by using a
1263 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1264 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]1265</ul>
1266
1267<h3>1.8.0: Dec 12 1999</h3>
1268<ul>
1269 <li>cleanup, especially memory wise</li>
1270 <li>the parser should be more reliable, especially the HTML one, it should
1271 not crash, whatever the input !</li>
1272 <li>Integrated various patches, especially a speedup improvement for large
1273 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
1274 configure with --with-buffers to enable them.</li>
1275 <li>attribute normalization, oops should have been added long ago !</li>
1276 <li>attributes defaulted from Dtds should be available, xmlSetProp() now
1277 does entities escapting by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1278</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1279
1280<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1281<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1282 <li>Lots of HTML improvement</li>
1283 <li>Fixed some errors when saving both XML and HTML</li>
1284 <li>More examples, the regression tests should now look clean</li>
1285 <li>Fixed a bug with contiguous charref</li>
1286</ul>
1287
1288<h3>1.7.3: Sep 29 1999</h3>
1289<ul>
1290 <li>portability problems fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1291 <li>snprintf was used unconditionnally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1292 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1293</ul>
1294
1295<h3>1.7.1: Sep 24 1999</h3>
1296<ul>
1297 <li>The basic type for strings manipulated by libxml has been renamed in
1298 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1299 is that CHAR was conflicting with a predefined type on Windows. However
1300 on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1301 <strong>#define </strong>.</li>
1302 <li>Changed another error : the use of a structure field called errno, and
1303 leading to troubles on platforms where it's a macro</li>
1304</ul>
1305
1306<h3>1.7.0: sep 23 1999</h3>
1307<ul>
1308 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1309 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1310 <li>Added an errno to report errors by another mean than a simple printf
1311 like callback</li>
1312 <li>Finished ID/IDREF support and checking when validation</li>
1313 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1314 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1315 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
1316 implementation</li>
1317 <li>Added an HTML parser front-end</li>
1318</ul>
1319
1320<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1321
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1322<p><a href="http://www.w3.org/TR/REC-xml">XML is a standard</a> for
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1323markup-based structured documents. Here is <a name="example">an example XML
1324document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1325<pre>&lt;?xml version="1.0"?&gt;
1326&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
1327 &lt;head&gt;
1328 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
1329 &lt;/head&gt;
1330 &lt;chapter&gt;
1331 &lt;title&gt;The Linux adventure&lt;/title&gt;
1332 &lt;p&gt;bla bla bla ...&lt;/p&gt;
1333 &lt;image href="linus.gif"/&gt;
1334 &lt;p&gt;...&lt;/p&gt;
1335 &lt;/chapter&gt;
1336&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1337
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1338<p>The first line specifies that it's an XML document and gives useful
1339information about its encoding. Then the document is a text format whose
1340structure is specified by tags between brackets. <strong>Each tag opened has
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1341to be closed</strong>. XML is pedantic about this. However, if a tag is empty
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1342(no content), a single tag can serve as both the opening and closing tag if
1343it ends with <code>/&gt;</code> rather than with <code>&gt;</code>. Note
1344that, for example, the image tag has no content (just an attribute) and is
1345closed by ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1346
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1347<p>XML can be applied sucessfully to a wide range of uses, from long term
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1348structured document maintenance (where it follows the steps of SGML) to
1349simple data encoding mechanisms like configuration file formatting (glade),
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1350spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where
1351it is used to encode remote calls between a client and a server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1352
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1353<h2><a name="XSLT">XSLT</a></h2>
1354
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1355<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
1356
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1357<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
1358language for transforming XML documents into other XML documents (or
1359HTML/textual output).</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1360
1361<p>A separate library called libxslt is being built on top of libxml2. This
1362module "libxslt" can be found in the Gnome CVS base too.</p>
1363
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]1364<p>You can check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1365href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
1366supported and the progresses on the <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1367href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog"
1368name="Changelog">Changelog</a></p>
1369
1370<h2><a name="Python">Python and bindings</a></h2>
1371
1372<p>There is a number of language bindings and wrappers available for libxml2,
1373the list below is not exhaustive. Please contact the <a
1374href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a>
1375(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in
1376order to get updates to this list or to discuss the specific topic of libxml2
1377or libxslt wrappers or bindings:</p>
1378<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1379 <li><a href="mailto:ari@lusis.org">Ari Johnson</a> provides a C++ wrapper
1380 for libxml:<br>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1381 Website: <a
1382 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a><br>
1383 Download: <a
1384 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></li>
1385 <li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper
1386 based on the gdome2 </a>bindings maintained by Tobias Peters.</li>
1387 <li><a
1388 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1389 Sergeant</a> developped <a
1390 href="http://axkit.org/download/">XML::LibXSLT</a>, a perl wrapper for
1391 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
1392 application server</a></li>
1393 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides and
1394 earlier version of the libxml/libxslt <a
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1395 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li>
1396 <li>Petr Kozelka provides <a
1397 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
1398 libxml2</a> with Kylix, Delphi and other Pascal compilers</li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]1399 <li>Uwe Fechner also provides <a
1400 href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]1401 implementation for Kylix2/D5/D6 from Borland</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1402 <li>Wai-Sun "Squidster" Chia provides <a
1403 href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and
1404 libxml2 bindings are also available in Ruby through the <a
1405 href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module
1406 maintained by Tobias Peters.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1407 <li>Steve Ball and contributors maintains <a
1408 href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for
1409 Tcl</a></li>
1410 <li>There is support for libxml2 in the DOM module of PHP.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1411</ul>
1412
1413<p>The distribution includes a set of Python bindings, which are garanteed to
1414be maintained as part of the library in the future, though the Python
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1415interface have not yet reached the maturity of the C API.</p>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1416
1417<p>To install the Python bindings there are 2 options:</p>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1418<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1419 <li>If you use an RPM based distribution, simply install the <a
1420 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python
1421 RPM</a> (and if needed the <a
1422 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python
1423 RPM</a>).</li>
1424 <li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python
1425 module distribution</a> corresponding to your installed version of
1426 libxml2 and libxslt. Note that to install it you will need both libxml2
1427 and libxslt installed and run "python setup.py build install" in the
1428 module tree.</li>
Daniel Veillard0b79dfe2002-02-23 13:02:31 +0000[diff] [blame]1429</ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1430
1431<p>The distribution includes a set of examples and regression tests for the
1432python bindings in the <code>python/tests</code> directory. Here are some
1433excepts from those tests:</p>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1434
1435<h3>tst.py:</h3>
1436
1437<p>This is a basic test of the file interface and DOM navigation:</p>
1438<pre>import libxml2
1439
1440doc = libxml2.parseFile("tst.xml")
1441if doc.name != "tst.xml":
1442 print "doc.name failed"
1443 sys.exit(1)
1444root = doc.children
1445if root.name != "doc":
1446 print "root.name failed"
1447 sys.exit(1)
1448child = root.children
1449if child.name != "foo":
1450 print "child.name failed"
1451 sys.exit(1)
1452doc.freeDoc()</pre>
1453
1454<p>The Python module is called libxml2, parseFile is the equivalent of
1455xmlParseFile (most of the bindings are automatically generated, and the xml
1456prefix is removed and the casing convention are kept). All node seen at the
1457binding level share the same subset of accesors:</p>
1458<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1459 <li><code>name</code> : returns the node name</li>
1460 <li><code>type</code> : returns a string indicating the node
1461 typ<code>e</code></li>
1462 <li><code>content</code> : returns the content of the node, it is based on
1463 xmlNodeGetContent() and hence is recursive.</li>
1464 <li><code>parent</code> , <code>children</code>, <code>last</code>,
1465 <code>next</code>, <code>prev</code>, <code>doc</code>,
1466 <code>properties</code>: pointing to the associated element in the tree,
1467 those may return None in case no such link exists.</li>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1468</ul>
1469
1470<p>Also note the need to explicitely deallocate documents with freeDoc() .
1471Reference counting for libxml2 trees would need quite a lot of work to
1472function properly, and rather than risk memory leaks if not implemented
1473correctly it sounds safer to have an explicit function to free a tree. The
1474wrapper python objects like doc, root or child are them automatically garbage
1475collected.</p>
1476
1477<h3>validate.py:</h3>
1478
1479<p>This test check the validation interfaces and redirection of error
1480messages:</p>
1481<pre>import libxml2
1482
1483#desactivate error messages from the validation
1484def noerr(ctx, str):
1485 pass
1486
1487libxml2.registerErrorHandler(noerr, None)
1488
1489ctxt = libxml2.createFileParserCtxt("invalid.xml")
1490ctxt.validate(1)
1491ctxt.parseDocument()
1492doc = ctxt.doc()
1493valid = ctxt.isValid()
1494doc.freeDoc()
1495if valid != 0:
1496 print "validity chec failed"</pre>
1497
1498<p>The first thing to notice is the call to registerErrorHandler(), it
1499defines a new error handler global to the library. It is used to avoid seeing
1500the error messages when trying to validate the invalid document.</p>
1501
1502<p>The main interest of that test is the creation of a parser context with
1503createFileParserCtxt() and how the behaviour can be changed before calling
1504parseDocument() . Similary the informations resulting from the parsing phase
1505are also available using context methods.</p>
1506
1507<p>Contexts like nodes are defined as class and the libxml2 wrappers maps the
1508C function interfaces in terms of objects method as much as possible. The
1509best to get a complete view of what methods are supported is to look at the
1510libxml2.py module containing all the wrappers.</p>
1511
1512<h3>push.py:</h3>
1513
1514<p>This test show how to activate the push parser interface:</p>
1515<pre>import libxml2
1516
1517ctxt = libxml2.createPushParser(None, "&lt;foo", 4, "test.xml")
1518ctxt.parseChunk("/&gt;", 2, 1)
1519doc = ctxt.doc()
1520
1521doc.freeDoc()</pre>
1522
1523<p>The context is created with a speciall call based on the
1524xmlCreatePushParser() from the C library. The first argument is an optional
1525SAX callback object, then the initial set of data, the lenght and the name of
1526the resource in case URI-References need to be computed by the parser.</p>
1527
1528<p>Then the data are pushed using the parseChunk() method, the last call
1529setting the thrird argument terminate to 1.</p>
1530
1531<h3>pushSAX.py:</h3>
1532
1533<p>this test show the use of the event based parsing interfaces. In this case
1534the parser does not build a document, but provides callback information as
1535the parser makes progresses analyzing the data being provided:</p>
1536<pre>import libxml2
1537log = ""
1538
1539class callback:
1540 def startDocument(self):
1541 global log
1542 log = log + "startDocument:"
1543
1544 def endDocument(self):
1545 global log
1546 log = log + "endDocument:"
1547
1548 def startElement(self, tag, attrs):
1549 global log
1550 log = log + "startElement %s %s:" % (tag, attrs)
1551
1552 def endElement(self, tag):
1553 global log
1554 log = log + "endElement %s:" % (tag)
1555
1556 def characters(self, data):
1557 global log
1558 log = log + "characters: %s:" % (data)
1559
1560 def warning(self, msg):
1561 global log
1562 log = log + "warning: %s:" % (msg)
1563
1564 def error(self, msg):
1565 global log
1566 log = log + "error: %s:" % (msg)
1567
1568 def fatalError(self, msg):
1569 global log
1570 log = log + "fatalError: %s:" % (msg)
1571
1572handler = callback()
1573
1574ctxt = libxml2.createPushParser(handler, "&lt;foo", 4, "test.xml")
1575chunk = " url='tst'&gt;b"
1576ctxt.parseChunk(chunk, len(chunk), 0)
1577chunk = "ar&lt;/foo&gt;"
1578ctxt.parseChunk(chunk, len(chunk), 1)
1579
Daniel Veillardfcbfa2d2002-02-21 17:54:27 +0000[diff] [blame]1580reference = "startDocument:startElement foo {'url': 'tst'}:" + \
1581 "characters: bar:endElement foo:endDocument:"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1582if log != reference:
1583 print "Error got: %s" % log
1584 print "Exprected: %s" % reference</pre>
1585
1586<p>The key object in that test is the handler, it provides a number of entry
1587points which can be called by the parser as it makes progresses to indicate
1588the information set obtained. The full set of callback is larger than what
1589the callback class in that specific example implements (see the SAX
1590definition for a complete list). The wrapper will only call those supplied by
1591the object when activated. The startElement receives the names of the element
1592and a dictionnary containing the attributes carried by this element.</p>
1593
1594<p>Also note that the reference string generated from the callback shows a
1595single character call even though the string "bar" is passed to the parser
1596from 2 different call to parseChunk()</p>
1597
1598<h3>xpath.py:</h3>
1599
1600<p>This is a basic test of XPath warppers support</p>
1601<pre>import libxml2
1602
1603doc = libxml2.parseFile("tst.xml")
1604ctxt = doc.xpathNewContext()
1605res = ctxt.xpathEval("//*")
1606if len(res) != 2:
1607 print "xpath query: wrong node set size"
1608 sys.exit(1)
1609if res[0].name != "doc" or res[1].name != "foo":
1610 print "xpath query: wrong node set value"
1611 sys.exit(1)
1612doc.freeDoc()
1613ctxt.xpathFreeContext()</pre>
1614
1615<p>This test parses a file, then create an XPath context to evaluate XPath
1616expression on it. The xpathEval() method execute an XPath query and returns
1617the result mapped in a Python way. String and numbers are natively converted,
1618and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like
1619the document, the XPath context need to be freed explicitely, also not that
1620the result of the XPath query may point back to the document tree and hence
1621the document must be freed after the result of the query is used.</p>
1622
1623<h3>xpathext.py:</h3>
1624
1625<p>This test shows how to extend the XPath engine with functions written in
1626python:</p>
1627<pre>import libxml2
1628
1629def foo(ctx, x):
1630 return x + 1
1631
1632doc = libxml2.parseFile("tst.xml")
1633ctxt = doc.xpathNewContext()
1634libxml2.registerXPathFunction(ctxt._o, "foo", None, foo)
1635res = ctxt.xpathEval("foo(1)")
1636if res != 2:
1637 print "xpath extension failure"
1638doc.freeDoc()
1639ctxt.xpathFreeContext()</pre>
1640
1641<p>Note how the extension function is registered with the context (but that
1642part is not yet finalized, ths may change slightly in the future).</p>
1643
1644<h3>tstxpath.py:</h3>
1645
1646<p>This test is similar to the previousone but shows how the extension
1647function can access the XPath evaluation context:</p>
1648<pre>def foo(ctx, x):
1649 global called
1650
1651 #
1652 # test that access to the XPath evaluation contexts
1653 #
1654 pctxt = libxml2.xpathParserContext(_obj=ctx)
1655 ctxt = pctxt.context()
1656 called = ctxt.function()
1657 return x + 1</pre>
1658
1659<p>All the interfaces around the XPath parser(or rather evaluation) context
1660are not finalized, but it should be sufficient to do contextual work at the
1661evaluation point.</p>
1662
1663<h3>Memory debugging:</h3>
1664
1665<p>last but not least, all tests starts with the following prologue:</p>
1666<pre>#memory debug specific
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]1667libxml2.debugMemory(1)</pre>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]1668
1669<p>and ends with the following epilogue:</p>
1670<pre>#memory debug specific
1671libxml2.cleanupParser()
1672if libxml2.debugMemory(1) == 0:
1673 print "OK"
1674else:
1675 print "Memory leak %d bytes" % (libxml2.debugMemory(1))
1676 libxml2.dumpMemory()</pre>
1677
1678<p>Those activate the memory debugging interface of libxml2 where all
1679alloacted block in the library are tracked. The prologue then cleans up the
1680library state and checks that all allocated memory has been freed. If not it
1681calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1682
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1683<h2><a name="architecture">libxml architecture</a></h2>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1684
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1685<p>Libxml is made of multiple components; some of them are optional, and most
1686of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1687<ul>
1688 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1689 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1690 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1691 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1692 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1693 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1694 <li>a SAX tree module to build an in-memory DOM representation</li>
1695 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1696 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1697 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1698 (optional)</li>
1699 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1700</ul>
1701
1702<p>Graphically this gives the following:</p>
1703
1704<p><img src="libxml.gif" alt="a graphical view of the various"></p>
1705
1706<p></p>
1707
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1708<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1709
1710<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1711returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1712<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1713as the file name, the document type, and a <strong>children</strong> pointer
1714which is the root of the document (or more exactly the first child under the
1715root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1716chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1717relationship. An xmlNode can also carry properties (a chain of xmlAttr
1718structures). An attribute may have a value which is a list of TEXT or
1719ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1720
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1721<p>Here is an example (erroneous with respect to the XML spec since there
1722should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1723
1724<p><img src="structure.gif" alt=" structure.gif "></p>
1725
1726<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1727called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1728prints them back as parsed. This is useful for detecting errors both in XML
1729code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1730which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1731result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1732<pre>DOCUMENT
1733version=1.0
1734standalone=true
1735 ELEMENT EXAMPLE
1736 ATTRIBUTE prop1
1737 TEXT
1738 content=gnome is great
1739 ATTRIBUTE prop2
1740 ENTITY_REF
1741 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1742 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1743 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1744 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1745 TEXT
1746 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1747 ELEMENT chapter
1748 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1749 TEXT
1750 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1751 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1752 TEXT
1753 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1754 ELEMENT image
1755 ATTRIBUTE href
1756 TEXT
1757 content=linus.gif
1758 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1759 TEXT
1760 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1761
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1762<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1763
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1764<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1765
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1766<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1767memory. In that case (and if you don't expect to save back the XML document
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1768loaded using libxml), it's better to use the SAX interface of libxml. SAX is
1769a <strong>callback-based interface</strong> to the parser. Before parsing,
1770the application layer registers a customized set of callbacks which are
1771called by the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1772
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1773<p>To get more detailed step-by-step guidance on using the SAX interface of
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1774libxml, see the <a
1775href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
1776documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1777Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1778
1779<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
1780program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1781binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1782distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1783testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1784<pre>SAX.setDocumentLocator()
1785SAX.startDocument()
1786SAX.getEntity(amp)
1787SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
1788SAX.characters( , 3)
1789SAX.startElement(head)
1790SAX.characters( , 4)
1791SAX.startElement(title)
1792SAX.characters(Welcome to Gnome, 16)
1793SAX.endElement(title)
1794SAX.characters( , 3)
1795SAX.endElement(head)
1796SAX.characters( , 3)
1797SAX.startElement(chapter)
1798SAX.characters( , 4)
1799SAX.startElement(title)
1800SAX.characters(The Linux adventure, 19)
1801SAX.endElement(title)
1802SAX.characters( , 4)
1803SAX.startElement(p)
1804SAX.characters(bla bla bla ..., 15)
1805SAX.endElement(p)
1806SAX.characters( , 4)
1807SAX.startElement(image, href='linus.gif')
1808SAX.endElement(image)
1809SAX.characters( , 4)
1810SAX.startElement(p)
1811SAX.characters(..., 3)
1812SAX.endElement(p)
1813SAX.characters( , 3)
1814SAX.endElement(chapter)
1815SAX.characters( , 1)
1816SAX.endElement(EXAMPLE)
1817SAX.endDocument()</pre>
1818
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1819<p>Most of the other interfaces of libxml are based on the DOM tree-building
1820facility, so nearly everything up to the end of this document presupposes the
1821use of the standard DOM tree build. Note that the DOM tree itself is built by
1822a set of registered default callbacks, without internal specific
1823interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1824
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1825<h2><a name="Validation">Validation &amp; DTDs</a></h2>
1826
1827<p>Table of Content:</p>
1828<ol>
1829 <li><a href="#General5">General overview</a></li>
1830 <li><a href="#definition">The definition</a></li>
1831 <li><a href="#Simple">Simple rules</a>
1832 <ol>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]1833 <li><a href="#reference">How to reference a DTD from a document</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1834 <li><a href="#Declaring">Declaring elements</a></li>
1835 <li><a href="#Declaring1">Declaring attributes</a></li>
1836 </ol>
1837 </li>
1838 <li><a href="#Some">Some examples</a></li>
1839 <li><a href="#validate">How to validate</a></li>
1840 <li><a href="#Other">Other resources</a></li>
1841</ol>
1842
1843<h3><a name="General5">General overview</a></h3>
1844
1845<p>Well what is validation and what is a DTD ?</p>
1846
1847<p>DTD is the acronym for Document Type Definition. This is a description of
1848the content for a familly of XML files. This is part of the XML 1.0
1849specification, and alows to describe and check that a given document instance
1850conforms to a set of rules detailing its structure and content.</p>
1851
1852<p>Validation is the process of checking a document against a DTD (more
1853generally against a set of construction rules).</p>
1854
1855<p>The validation process and building DTDs are the two most difficult parts
1856of the XML life cycle. Briefly a DTD defines all the possibles element to be
1857found within your document, what is the formal shape of your document tree
1858(by defining the allowed content of an element, either text, a regular
1859expression for the allowed list of children, or mixed content i.e. both text
1860and children). The DTD also defines the allowed attributes for all elements
1861and the types of the attributes.</p>
1862
1863<h3><a name="definition1">The definition</a></h3>
1864
1865<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
1866href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
1867Rev1</a>):</p>
1868<ul>
1869 <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
1870 elements</a></li>
1871 <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
1872 attributes</a></li>
1873</ul>
1874
1875<p>(unfortunately) all this is inherited from the SGML world, the syntax is
1876ancient...</p>
1877
1878<h3><a name="Simple1">Simple rules</a></h3>
1879
1880<p>Writing DTD can be done in multiple ways, the rules to build them if you
1881need something fixed or something which can evolve over time can be radically
1882different. Really complex DTD like Docbook ones are flexible but quite harder
1883to design. I will just focuse on DTDs for a formats with a fixed simple
1884structure. It is just a set of basic rules, and definitely not exhaustive nor
1885useable for complex DTD design.</p>
1886
1887<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
1888
1889<p>Assuming the top element of the document is <code>spec</code> and the dtd
1890is placed in the file <code>mydtd</code> in the subdirectory
1891<code>dtds</code> of the directory from where the document were loaded:</p>
1892
1893<p><code>&lt;!DOCTYPE spec SYSTEM "dtds/mydtd"&gt;</code></p>
1894
1895<p>Notes:</p>
1896<ul>
1897 <li>the system string is actually an URI-Reference (as defined in <a
1898 href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396</a>) so you can use a
1899 full URL string indicating the location of your DTD on the Web, this is a
1900 really good thing to do if you want others to validate your document</li>
1901 <li>it is also possible to associate a <code>PUBLIC</code> identifier (a
1902 magic string) so that the DTd is looked up in catalogs on the client side
1903 without having to locate it on the web</li>
1904 <li>a dtd contains a set of elements and attributes declarations, but they
1905 don't define what the root of the document should be. This is explicitely
1906 told to the parser/validator as the first element of the
1907 <code>DOCTYPE</code> declaration.</li>
1908</ul>
1909
1910<h4><a name="Declaring2">Declaring elements</a>:</h4>
1911
1912<p>The following declares an element <code>spec</code>:</p>
1913
1914<p><code>&lt;!ELEMENT spec (front, body, back?)&gt;</code></p>
1915
1916<p>it also expresses that the spec element contains one <code>front</code>,
1917one <code>body</code> and one optionnal <code>back</code> children elements
1918in this order. The declaration of one element of the structure and its
1919content are done in a single declaration. Similary the following declares
1920<code>div1</code> elements:</p>
1921
Daniel Veillard51737272002-01-23 23:10:38 +0000[diff] [blame]1922<p><code>&lt;!ELEMENT div1 (head, (p | list | note)*, div2?)&gt;</code></p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1923
1924<p>means div1 contains one <code>head</code> then a series of optional
1925<code>p</code>, <code>list</code>s and <code>note</code>s and then an
1926optional <code>div2</code>. And last but not least an element can contain
1927text:</p>
1928
1929<p><code>&lt;!ELEMENT b (#PCDATA)&gt;</code></p>
1930
1931<p><code>b</code> contains text or being of mixed content (text and elements
1932in no particular order):</p>
1933
1934<p><code>&lt;!ELEMENT p (#PCDATA|a|ul|b|i|em)*&gt;</code></p>
1935
1936<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
1937<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
1938order.</p>
1939
1940<h4><a name="Declaring1">Declaring attributes</a>:</h4>
1941
1942<p>again the attributes declaration includes their content definition:</p>
1943
1944<p><code>&lt;!ATTLIST termdef name CDATA #IMPLIED&gt;</code></p>
1945
1946<p>means that the element <code>termdef</code> can have a <code>name</code>
1947attribute containing text (<code>CDATA</code>) and which is optionnal
1948(<code>#IMPLIED</code>). The attribute value can also be defined within a
1949set:</p>
1950
1951<p><code>&lt;!ATTLIST list type (bullets|ordered|glossary)
1952"ordered"&gt;</code></p>
1953
1954<p>means <code>list</code> element have a <code>type</code> attribute with 3
1955allowed values "bullets", "ordered" or "glossary" and which default to
1956"ordered" if the attribute is not explicitely specified.</p>
1957
1958<p>The content type of an attribute can be text (<code>CDATA</code>),
1959anchor/reference/references
1960(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
1961(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
1962(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
1963<code>chapter</code> element can have an optional <code>id</code> attribute
1964of type <code>ID</code>, usable for reference from attribute of type
1965IDREF:</p>
1966
1967<p><code>&lt;!ATTLIST chapter id ID #IMPLIED&gt;</code></p>
1968
1969<p>The last value of an attribute definition can be <code>#REQUIRED
1970</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
1971meaning that it is optional, or the default value (possibly prefixed by
1972<code>#FIXED</code> if it is the only allowed).</p>
1973
1974<p>Notes:</p>
1975<ul>
1976 <li>usually the attributes pertaining to a given element are declared in a
1977 single expression, but it is just a convention adopted by a lot of DTD
1978 writers:
1979 <pre>&lt;!ATTLIST termdef
1980 id ID #REQUIRED
1981 name CDATA #IMPLIED&gt;</pre>
1982 <p>The previous construct defines both <code>id</code> and
1983 <code>name</code> attributes for the element <code>termdef</code></p>
1984 </li>
1985</ul>
1986
1987<h3><a name="Some1">Some examples</a></h3>
1988
1989<p>The directory <code>test/valid/dtds/</code> in the libxml distribution
1990contains some complex DTD examples. The <code>test/valid/dia.xml</code>
1991example shows an XML file where the simple DTD is directly included within
1992the document.</p>
1993
1994<h3><a name="validate1">How to validate</a></h3>
1995
1996<p>The simplest is to use the xmllint program comming with libxml. The
1997<code>--valid</code> option turn on validation of the files given as input,
1998for example the following validates a copy of the first revision of the XML
19991.0 specification:</p>
2000
2001<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
2002
2003<p>the -- noout is used to not output the resulting tree.</p>
2004
2005<p>The <code>--dtdvalid dtd</code> allows to validate the document(s) against
2006a given DTD.</p>
2007
2008<p>Libxml exports an API to handle DTDs and validation, check the <a
2009href="http://xmlsoft.org/html/libxml-valid.html">associated
2010description</a>.</p>
2011
2012<h3><a name="Other1">Other resources</a></h3>
2013
2014<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
2015will just list one for now, others pointers welcome:</p>
2016<ul>
2017 <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
2018</ul>
2019
2020<p>I suggest looking at the examples found under test/valid/dtd and any of
2021the large number of books available on XML. The dia example in test/valid
2022should be both simple and complete enough to allow you to build your own.</p>
2023
2024<p></p>
2025
2026<h2><a name="Memory">Memory Management</a></h2>
2027
2028<p>Table of Content:</p>
2029<ol>
2030 <li><a href="#General3">General overview</a></li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2031 <li><a href="#setting">Setting libxml set of memory routines</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2032 <li><a href="#cleanup">Cleaning up after parsing</a></li>
2033 <li><a href="#Debugging">Debugging routines</a></li>
2034 <li><a href="#General4">General memory requirements</a></li>
2035</ol>
2036
2037<h3><a name="General3">General overview</a></h3>
2038
2039<p>The module <code><a
2040href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
2041provides the interfaces to the libxml memory system:</p>
2042<ul>
2043 <li>libxml does not use the libc memory allocator directly but xmlFree(),
2044 xmlMalloc() and xmlRealloc()</li>
2045 <li>those routines can be reallocated to a specific set of routine, by
2046 default the libc ones i.e. free(), malloc() and realloc()</li>
2047 <li>the xmlmemory.c module includes a set of debugging routine</li>
2048</ul>
2049
2050<h3><a name="setting">Setting libxml set of memory routines</a></h3>
2051
2052<p>It is sometimes useful to not use the default memory allocator, either for
2053debugging, analysis or to implement a specific behaviour on memory management
2054(like on embedded systems). Two function calls are available to do so:</p>
2055<ul>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2056 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet
2057 ()</a> which return the current set of functions in use by the parser</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2058 <li><a
2059 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2060 which allow to set up a new set of memory allocation functions</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2061</ul>
2062
2063<p>Of course a call to xmlMemSetup() should probably be done before calling
2064any other libxml routines (unless you are sure your allocations routines are
2065compatibles).</p>
2066
2067<h3><a name="cleanup">Cleaning up after parsing</a></h3>
2068
2069<p>Libxml is not stateless, there is a few set of memory structures needing
2070allocation before the parser is fully functionnal (some encoding structures
2071for example). This also mean that once parsing is finished there is a tiny
2072amount of memory (a few hundred bytes) which can be recollected if you don't
2073reuse the parser immediately:</p>
2074<ul>
2075 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2076 ()</a> is a centralized routine to free the parsing states. Note that it
2077 won't deallocate any produced tree if any (use the xmlFreeDoc() and
2078 related routines for this).</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2079 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2080 ()</a> is the dual routine allowing to preallocate the parsing state
2081 which can be useful for example to avoid initialization reentrancy
2082 problems when using libxml in multithreaded applications</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2083</ul>
2084
2085<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
2086at the next invocation of parser routines, but be careful of the consequences
2087in multithreaded applications.</p>
2088
2089<h3><a name="Debugging">Debugging routines</a></h3>
2090
2091<p>When configured using --with-mem-debug flag (off by default), libxml uses
2092a set of memory allocation debugging routineskeeping track of all allocated
2093blocks and the location in the code where the routine was called. A couple of
2094other debugging routines allow to dump the memory allocated infos to a file
2095or call a specific routine when a given block number is allocated:</p>
2096<ul>
2097 <li><a
2098 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2099 <a
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2100 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
2101 and <a
2102 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
2103 are the memory debugging replacement allocation routines</li>
2104 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2105 ()</a> dumps all the informations about the allocated memory block lefts
2106 in the <code>.memdump</code> file</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2107</ul>
2108
2109<p>When developping libxml memory debug is enabled, the tests programs call
2110xmlMemoryDump () and the "make test" regression tests will check for any
2111memory leak during the full regression test sequence, this helps a lot
2112ensuring that libxml does not leak memory and bullet proof memory
2113allocations use (some libc implementations are known to be far too permissive
2114resulting in major portability problems!).</p>
2115
2116<p>If the .memdump reports a leak, it displays the allocation function and
2117also tries to give some informations about the content and structure of the
2118allocated blocks left. This is sufficient in most cases to find the culprit,
2119but not always. Assuming the allocation problem is reproductible, it is
2120possible to find more easilly:</p>
2121<ol>
2122 <li>write down the block number xxxx not allocated</li>
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2123 <li>export the environement variable XML_MEM_BREAKPOINT=xxxx , the easiest
2124 when using GDB is to simply give the command
2125 <p><code>set environment XML_MEM_BREAKPOINT xxxx</code></p>
2126 <p>before running the program.</p>
2127 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2128 <li>run the program under a debugger and set a breakpoint on
2129 xmlMallocBreakpoint() a specific function called when this precise block
2130 is allocated</li>
2131 <li>when the breakpoint is reached you can then do a fine analysis of the
2132 allocation an step to see the condition resulting in the missing
2133 deallocation.</li>
2134</ol>
2135
2136<p>I used to use a commercial tool to debug libxml memory problems but after
2137noticing that it was not detecting memory leaks that simple mechanism was
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2138used and proved extremely efficient until now. Lately I have also used <a
2139href="http://developer.kde.org/~sewardj/">valgrind</a> with quite some
2140success, it is tied to the i386 architecture since it works by emulating the
2141processor and instruction set, it is slow but extremely efficient, i.e. it
2142spot memory usage errors in a very precise way.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2143
2144<h3><a name="General4">General memory requirements</a></h3>
2145
2146<p>How much libxml memory require ? It's hard to tell in average it depends
2147of a number of things:</p>
2148<ul>
2149 <li>the parser itself should work in a fixed amout of memory, except for
2150 information maintained about the stacks of names and entities locations.
2151 The I/O and encoding handlers will probably account for a few KBytes.
2152 This is true for both the XML and HTML parser (though the HTML parser
2153 need more state).</li>
2154 <li>If you are generating the DOM tree then memory requirements will grow
2155 nearly lineary with the size of the data. In general for a balanced
2156 textual document the internal memory requirement is about 4 times the
2157 size of the UTF8 serialization of this document (exmple the XML-1.0
2158 recommendation is a bit more of 150KBytes and takes 650KBytes of main
2159 memory when parsed). Validation will add a amount of memory required for
2160 maintaining the external Dtd state which should be linear with the
2161 complexity of the content model defined by the Dtd</li>
2162 <li>If you don't care about the advanced features of libxml like
2163 validation, DOM, XPath or XPointer, but really need to work fixed memory
2164 requirements, then the SAX interface should be used.</li>
2165</ul>
2166
2167<p></p>
2168
2169<h2><a name="Encodings">Encodings support</a></h2>
2170
2171<p>Table of Content:</p>
2172<ol>
2173 <li><a href="encoding.html#What">What does internationalization support
2174 mean ?</a></li>
2175 <li><a href="encoding.html#internal">The internal encoding, how and
2176 why</a></li>
2177 <li><a href="encoding.html#implemente">How is it implemented ?</a></li>
2178 <li><a href="encoding.html#Default">Default supported encodings</a></li>
2179 <li><a href="encoding.html#extend">How to extend the existing
2180 support</a></li>
2181</ol>
2182
2183<h3><a name="What">What does internationalization support mean ?</a></h3>
2184
2185<p>XML was designed from the start to allow the support of any character set
2186by using Unicode. Any conformant XML parser has to support the UTF-8 and
2187UTF-16 default encodings which can both express the full unicode ranges. UTF8
2188is a variable length encoding whose greatest point are to resuse the same
2189emcoding for ASCII and to save space for Western encodings, but it is a bit
2190more complex to handle in practice. UTF-16 use 2 bytes per characters (and
2191sometimes combines two pairs), it makes implementation easier, but looks a
2192bit overkill for Western languages encoding. Moreover the XML specification
2193allows document to be encoded in other encodings at the condition that they
2194are clearly labelled as such. For example the following is a wellformed XML
2195document encoded in ISO-8859 1 and using accentuated letter that we French
2196likes for both markup and content:</p>
2197<pre>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2198&lt;très&gt;là&lt;/très&gt;</pre>
2199
2200<p>Having internationalization support in libxml means the foolowing:</p>
2201<ul>
2202 <li>the document is properly parsed</li>
2203 <li>informations about it's encoding are saved</li>
2204 <li>it can be modified</li>
2205 <li>it can be saved in its original encoding</li>
2206 <li>it can also be saved in another encoding supported by libxml (for
2207 example straight UTF8 or even an ASCII form)</li>
2208</ul>
2209
2210<p>Another very important point is that the whole libxml API, with the
2211exception of a few routines to read with a specific encoding or save to a
2212specific encoding, is completely agnostic about the original encoding of the
2213document.</p>
2214
2215<p>It should be noted too that the HTML parser embedded in libxml now obbey
2216the same rules too, the following document will be (as of 2.2.2) handled in
2217an internationalized fashion by libxml too:</p>
2218<pre>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
2219 "http://www.w3.org/TR/REC-html40/loose.dtd"&gt;
2220&lt;html lang="fr"&gt;
2221&lt;head&gt;
2222 &lt;META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&gt;
2223&lt;/head&gt;
2224&lt;body&gt;
2225&lt;p&gt;W3C crée des standards pour le Web.&lt;/body&gt;
2226&lt;/html&gt;</pre>
2227
2228<h3><a name="internal">The internal encoding, how and why</a></h3>
2229
2230<p>One of the core decision was to force all documents to be converted to a
2231default internal encoding, and that encoding to be UTF-8, here are the
2232rationale for those choices:</p>
2233<ul>
2234 <li>keeping the native encoding in the internal form would force the libxml
2235 users (or the code associated) to be fully aware of the encoding of the
2236 original document, for examples when adding a text node to a document,
2237 the content would have to be provided in the document encoding, i.e. the
2238 client code would have to check it before hand, make sure it's conformant
2239 to the encoding, etc ... Very hard in practice, though in some specific
2240 cases this may make sense.</li>
2241 <li>the second decision was which encoding. From the XML spec only UTF8 and
2242 UTF16 really makes sense as being the two only encodings for which there
2243 is amndatory support. UCS-4 (32 bits fixed size encoding) could be
2244 considered an intelligent choice too since it's a direct Unicode mapping
2245 support. I selected UTF-8 on the basis of efficiency and compatibility
2246 with surrounding software:
2247 <ul>
2248 <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
2249 more costly to import and export CPU wise) is also far more compact
2250 than UTF-16 (and UCS-4) for a majority of the documents I see it used
2251 for right now (RPM RDF catalogs, advogato data, various configuration
2252 file formats, etc.) and the key point for today's computer
2253 architecture is efficient uses of caches. If one nearly double the
2254 memory requirement to store the same amount of data, this will trash
2255 caches (main memory/external caches/internal caches) and my take is
2256 that this harms the system far more than the CPU requirements needed
2257 for the conversion to UTF-8</li>
2258 <li>Most of libxml version 1 users were using it with straight ASCII
2259 most of the time, doing the conversion with an internal encoding
2260 requiring all their code to be rewritten was a serious show-stopper
2261 for using UTF-16 or UCS-4.</li>
2262 <li>UTF-8 is being used as the de-facto internal encoding standard for
2263 related code like the <a href="http://www.pango.org/">pango</a>
2264 upcoming Gnome text widget, and a lot of Unix code (yep another place
2265 where Unix programmer base takes a different approach from Microsoft
2266 - they are using UTF-16)</li>
2267 </ul>
2268 </li>
2269</ul>
2270
2271<p>What does this mean in practice for the libxml user:</p>
2272<ul>
2273 <li>xmlChar, the libxml data type is a byte, those bytes must be assembled
2274 as UTF-8 valid strings. The proper way to terminate an xmlChar * string
2275 is simply to append 0 byte, as usual.</li>
2276 <li>One just need to make sure that when using chars outside the ASCII set,
2277 the values has been properly converted to UTF-8</li>
2278</ul>
2279
2280<h3><a name="implemente">How is it implemented ?</a></h3>
2281
2282<p>Let's describe how all this works within libxml, basically the I18N
2283(internationalization) support get triggered only during I/O operation, i.e.
2284when reading a document or saving one. Let's look first at the reading
2285sequence:</p>
2286<ol>
2287 <li>when a document is processed, we usually don't know the encoding, a
2288 simple heuristic allows to detect UTF-18 and UCS-4 from whose where the
2289 ASCII range (0-0x7F) maps with ASCII</li>
2290 <li>the xml declaration if available is parsed, including the encoding
2291 declaration. At that point, if the autodetected encoding is different
2292 from the one declared a call to xmlSwitchEncoding() is issued.</li>
2293 <li>If there is no encoding declaration, then the input has to be in either
2294 UTF-8 or UTF-16, if it is not then at some point when processing the
2295 input, the converter/checker of UTF-8 form will raise an encoding error.
2296 You may end-up with a garbled document, or no document at all ! Example:
2297 <pre>~/XML -&gt; ./xmllint err.xml
2298err.xml:1: error: Input is not proper UTF-8, indicate encoding !
2299&lt;très&gt;là&lt;/très&gt;
2300 ^
2301err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
2302&lt;très&gt;là&lt;/très&gt;
2303 ^</pre>
2304 </li>
2305 <li>xmlSwitchEncoding() does an encoding name lookup, canonalize it, and
2306 then search the default registered encoding converters for that encoding.
2307 If it's not within the default set and iconv() support has been compiled
2308 it, it will ask iconv for such an encoder. If this fails then the parser
2309 will report an error and stops processing:
2310 <pre>~/XML -&gt; ./xmllint err2.xml
2311err2.xml:1: error: Unsupported encoding UnsupportedEnc
2312&lt;?xml version="1.0" encoding="UnsupportedEnc"?&gt;
2313 ^</pre>
2314 </li>
2315 <li>From that point the encoder process progressingly the input (it is
2316 plugged as a front-end to the I/O module) for that entity. It captures
2317 and convert on-the-fly the document to be parsed to UTF-8. The parser
2318 itself just does UTF-8 checking of this input and process it
2319 transparently. The only difference is that the encoding information has
2320 been added to the parsing context (more precisely to the input
2321 corresponding to this entity).</li>
2322 <li>The result (when using DOM) is an internal form completely in UTF-8
2323 with just an encoding information on the document node.</li>
2324</ol>
2325
2326<p>Ok then what's happen when saving the document (assuming you
2327colllected/built an xmlDoc DOM like structure) ? It depends on the function
2328called, xmlSaveFile() will just try to save in the original encoding, while
2329xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
2330encoding:</p>
2331<ol>
2332 <li>if no encoding is given, libxml will look for an encoding value
2333 associated to the document and if it exists will try to save to that
2334 encoding,
2335 <p>otherwise everything is written in the internal form, i.e. UTF-8</p>
2336 </li>
2337 <li>so if an encoding was specified, either at the API level or on the
2338 document, libxml will again canonalize the encoding name, lookup for a
2339 converter in the registered set or through iconv. If not found the
2340 function will return an error code</li>
2341 <li>the converter is placed before the I/O buffer layer, as another kind of
2342 buffer, then libxml will simply push the UTF-8 serialization to through
2343 that buffer, which will then progressively be converted and pushed onto
2344 the I/O layer.</li>
2345 <li>It is possible that the converter code fails on some input, for example
2346 trying to push an UTF-8 encoded chinese character through the UTF-8 to
2347 ISO-8859-1 converter won't work. Since the encoders are progressive they
2348 will just report the error and the number of bytes converted, at that
2349 point libxml will decode the offending character, remove it from the
2350 buffer and replace it with the associated charRef encoding &amp;#123; and
2351 resume the convertion. This guarante that any document will be saved
2352 without losses (except for markup names where this is not legal, this is
2353 a problem in the current version, in pactice avoid using non-ascci
2354 characters for tags or attributes names @@). A special "ascii" encoding
2355 name is used to save documents to a pure ascii form can be used when
2356 portability is really crucial</li>
2357</ol>
2358
2359<p>Here is a few examples based on the same test document:</p>
2360<pre>~/XML -&gt; ./xmllint isolat1
2361&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
2362&lt;très&gt;là&lt;/très&gt;
2363~/XML -&gt; ./xmllint --encode UTF-8 isolat1
2364&lt;?xml version="1.0" encoding="UTF-8"?&gt;
2365&lt;très&gt;là  &lt;/très&gt;
2366~/XML -&gt; </pre>
2367
2368<p>The same processing is applied (and reuse most of the code) for HTML I18N
2369processing. Looking up and modifying the content encoding is a bit more
2370difficult since it is located in a &lt;meta&gt; tag under the &lt;head&gt;,
2371so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
2372been provided. The parser also attempts to switch encoding on the fly when
2373detecting such a tag on input. Except for that the processing is the same
2374(and again reuses the same code).</p>
2375
2376<h3><a name="Default">Default supported encodings</a></h3>
2377
2378<p>libxml has a set of default converters for the following encodings
2379(located in encoding.c):</p>
2380<ol>
2381 <li>UTF-8 is supported by default (null handlers)</li>
2382 <li>UTF-16, both little and big endian</li>
2383 <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
2384 <li>ASCII, useful mostly for saving</li>
2385 <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
2386 predefined entities like &amp;copy; for the Copyright sign.</li>
2387</ol>
2388
2389<p>More over when compiled on an Unix platfor with iconv support the full set
2390of encodings supported by iconv can be instantly be used by libxml. On a
2391linux machine with glibc-2.1 the list of supported encodings and aliases fill
23923 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
2393various Japanese ones.</p>
2394
2395<h4>Encoding aliases</h4>
2396
2397<p>From 2.2.3, libxml has support to register encoding names aliases. The
2398goal is to be able to parse document whose encoding is supported but where
2399the name differs (for example from the default set of names accepted by
2400iconv). The following functions allow to register and handle new aliases for
2401existing encodings. Once registered libxml will automatically lookup the
2402aliases when handling a document:</p>
2403<ul>
2404 <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li>
2405 <li>int xmlDelEncodingAlias(const char *alias);</li>
2406 <li>const char * xmlGetEncodingAlias(const char *alias);</li>
2407 <li>void xmlCleanupEncodingAliases(void);</li>
2408</ul>
2409
2410<h3><a name="extend">How to extend the existing support</a></h3>
2411
2412<p>Well adding support for new encoding, or overriding one of the encoders
2413(assuming it is buggy) should not be hard, just write an input and output
2414conversion routines to/from UTF-8, and register them using
2415xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
2416called automatically if the parser(s) encounter such an encoding name
2417(register it uppercase, this will help). The description of the encoders,
2418their arguments and expected return values are described in the encoding.h
2419header.</p>
2420
2421<p>A quick note on the topic of subverting the parser to use a different
2422internal encoding than UTF-8, in some case people will absolutely want to
2423keep the internal encoding different, I think it's still possible (but the
2424encoding must be compliant with ASCII on the same subrange) though I didn't
2425tried it. The key is to override the default conversion routines (by
2426registering null encoders/decoders for your charsets), and bypass the UTF-8
2427checking of the parser by setting the parser context charset
2428(ctxt-&gt;charset) to something different than XML_CHAR_ENCODING_UTF8, but
2429there is no guarantee taht this will work. You may also have some troubles
2430saving back.</p>
2431
2432<p>Basically proper I18N support is important, this requires at least
2433libxml-2.0.0, but a lot of features and corrections are really available only
2434starting 2.2.</p>
2435
2436<h2><a name="IO">I/O Interfaces</a></h2>
2437
2438<p>Table of Content:</p>
2439<ol>
2440 <li><a href="#General1">General overview</a></li>
2441 <li><a href="#basic">The basic buffer type</a></li>
2442 <li><a href="#Input">Input I/O handlers</a></li>
2443 <li><a href="#Output">Output I/O handlers</a></li>
2444 <li><a href="#entities">The entities loader</a></li>
2445 <li><a href="#Example2">Example of customized I/O</a></li>
2446</ol>
2447
2448<h3><a name="General1">General overview</a></h3>
2449
2450<p>The module <code><a
2451href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
2452the interfaces to the libxml I/O system. This consists of 4 main parts:</p>
2453<ul>
2454 <li>Entities loader, this is a routine which tries to fetch the entities
2455 (files) based on their PUBLIC and SYSTEM identifiers. The default loader
2456 don't look at the public identifier since libxml do not maintain a
2457 catalog. You can redefine you own entity loader by using
2458 <code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2459 <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
2460 example</a>.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2461 <li>Input I/O buffers which are a commodity structure used by the parser(s)
2462 input layer to handle fetching the informations to feed the parser. This
2463 provides buffering and is also a placeholder where the encoding
2464 convertors to UTF8 are piggy-backed.</li>
2465 <li>Output I/O buffers are similar to the Input ones and fulfill similar
2466 task but when generating a serialization from a tree.</li>
2467 <li>A mechanism to register sets of I/O callbacks and associate them with
2468 specific naming schemes like the protocol part of the URIs.
2469 <p>This affect the default I/O operations and allows to use specific I/O
2470 handlers for certain names.</p>
2471 </li>
2472</ul>
2473
2474<p>The general mechanism used when loading http://rpmfind.net/xml.html for
2475example in the HTML parser is the following:</p>
2476<ol>
2477 <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
2478 the parsing context and the URI string.</li>
2479 <li>the URI string is checked against the existing registered handlers
2480 using their match() callback function, if the HTTP module was compiled
2481 in, it is registered and its match() function will succeeds</li>
2482 <li>the open() function of the handler is called and if successful will
2483 return an I/O Input buffer</li>
2484 <li>the parser will the start reading from this buffer and progressively
2485 fetch information from the resource, calling the read() function of the
2486 handler until the resource is exhausted</li>
2487 <li>if an encoding change is detected it will be installed on the input
2488 buffer, providing buffering and efficient use of the conversion
2489 routines</li>
2490 <li>once the parser has finished, the close() function of the handler is
2491 called once and the Input buffer and associed resources are
2492 deallocated.</li>
2493</ol>
2494
2495<p>The user defined callbacks are checked first to allow overriding of the
2496default libxml I/O routines.</p>
2497
2498<h3><a name="basic">The basic buffer type</a></h3>
2499
2500<p>All the buffer manipulation handling is done using the
2501<code>xmlBuffer</code> type define in <code><a
2502href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
2503resizable memory buffer. The buffer allocation strategy can be selected to be
2504either best-fit or use an exponential doubling one (CPU vs. memory use
2505tradeoff). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
2506<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
2507system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
2508of functions allows to manipulate buffers with names starting with the
2509<code>xmlBuffer...</code> prefix.</p>
2510
2511<h3><a name="Input">Input I/O handlers</a></h3>
2512
2513<p>An Input I/O handler is a simple structure
2514<code>xmlParserInputBuffer</code> containing a context associated to the
2515resource (file descriptor, or pointer to a protocol handler), the read() and
2516close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
2517encoding handler are also present to support charset conversion when
2518needed.</p>
2519
2520<h3><a name="Output">Output I/O handlers</a></h3>
2521
2522<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
2523Input one except the callbacks are write() and close().</p>
2524
2525<h3><a name="entities">The entities loader</a></h3>
2526
2527<p>The entity loader resolves requests for new entities and create inputs for
2528the parser. Creating an input from a filename or an URI string is done
2529through the xmlNewInputFromFile() routine. The default entity loader do not
2530handle the PUBLIC identifier associated with an entity (if any). So it just
2531calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
2532XML).</p>
2533
2534<p>If you want to hook up a catalog mechanism then you simply need to
2535override the default entity loader, here is an example:</p>
2536<pre>#include &lt;libxml/xmlIO.h&gt;
2537
2538xmlExternalEntityLoader defaultLoader = NULL;
2539
2540xmlParserInputPtr
2541xmlMyExternalEntityLoader(const char *URL, const char *ID,
2542 xmlParserCtxtPtr ctxt) {
2543 xmlParserInputPtr ret;
2544 const char *fileID = NULL;
2545 /* lookup for the fileID depending on ID */
2546
2547 ret = xmlNewInputFromFile(ctxt, fileID);
2548 if (ret != NULL)
2549 return(ret);
2550 if (defaultLoader != NULL)
2551 ret = defaultLoader(URL, ID, ctxt);
2552 return(ret);
2553}
2554
2555int main(..) {
2556 ...
2557
2558 /*
2559 * Install our own entity loader
2560 */
2561 defaultLoader = xmlGetExternalEntityLoader();
2562 xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
2563
2564 ...
2565}</pre>
2566
2567<h3><a name="Example2">Example of customized I/O</a></h3>
2568
2569<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
2570real use case</a>, xmlDocDump() closes the FILE * passed by the application
2571and this was a problem. The <a
2572href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
2573new output handler with the closing call deactivated:</p>
2574<ol>
2575 <li>First define a new I/O ouput allocator where the output don't close the
2576 file:
2577 <pre>xmlOutputBufferPtr
2578xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
2579    xmlOutputBufferPtr ret;
2580    
2581    if (xmlOutputCallbackInitialized == 0)
2582        xmlRegisterDefaultOutputCallbacks();
2583
2584    if (file == NULL) return(NULL);
2585    ret = xmlAllocOutputBuffer(encoder);
2586    if (ret != NULL) {
2587        ret-&gt;context = file;
2588        ret-&gt;writecallback = xmlFileWrite;
2589        ret-&gt;closecallback = NULL; /* No close callback */
2590    }
2591    return(ret); <br>
Daniel Veillard1eb24242002-03-18 11:33:03 +0000[diff] [blame]2592
Daniel Veillard34ce8be2002-03-18 19:37:11 +0000[diff] [blame]2593
2594
Daniel Veillard19274092002-03-25 16:48:03 +0000[diff] [blame]2595
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]2596
Daniel Veillard75794822002-04-11 16:24:32 +0000[diff] [blame]2597
Daniel Veillarda7084cd2002-04-15 17:12:47 +0000[diff] [blame]2598
Daniel Veillard0bfbb422002-04-26 09:21:45 +0000[diff] [blame]2599
Daniel Veillard93d3a472002-04-26 14:04:55 +0000[diff] [blame]2600
Daniel Veillardcf27f7c2002-04-30 07:12:39 +0000[diff] [blame]2601
Daniel Veillarde6d8e202002-05-02 06:11:10 +0000[diff] [blame^]2602
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2603} </pre>
2604 </li>
2605 <li>And then use it to save the document:
2606 <pre>FILE *f;
2607xmlOutputBufferPtr output;
2608xmlDocPtr doc;
2609int res;
2610
2611f = ...
2612doc = ....
2613
2614output = xmlOutputBufferCreateOwn(f, NULL);
2615res = xmlSaveFileTo(output, doc, NULL);
2616 </pre>
2617 </li>
2618</ol>
2619
2620<h2><a name="Catalog">Catalog support</a></h2>
2621
2622<p>Table of Content:</p>
2623<ol>
2624 <li><a href="General2">General overview</a></li>
2625 <li><a href="#definition">The definition</a></li>
2626 <li><a href="#Simple">Using catalogs</a></li>
2627 <li><a href="#Some">Some examples</a></li>
2628 <li><a href="#reference">How to tune catalog usage</a></li>
2629 <li><a href="#validate">How to debug catalog processing</a></li>
2630 <li><a href="#Declaring">How to create and maintain catalogs</a></li>
2631 <li><a href="#implemento">The implementor corner quick review of the
2632 API</a></li>
2633 <li><a href="#Other">Other resources</a></li>
2634</ol>
2635
2636<h3><a name="General2">General overview</a></h3>
2637
2638<p>What is a catalog? Basically it's a lookup mechanism used when an entity
2639(a file or a remote resource) references another entity. The catalog lookup
2640is inserted between the moment the reference is recognized by the software
2641(XML parser, stylesheet processing, or even images referenced for inclusion
2642in a rendering) and the time where loading that resource is actually
2643started.</p>
2644
2645<p>It is basically used for 3 things:</p>
2646<ul>
2647 <li>mapping from "logical" names, the public identifiers and a more
2648 concrete name usable for download (and URI). For example it can associate
2649 the logical name
2650 <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
2651 <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
2652 downloaded</p>
2653 <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
2654 </li>
2655 <li>remapping from a given URL to another one, like an HTTP indirection
2656 saying that
2657 <p>"http://www.oasis-open.org/committes/tr.xsl"</p>
2658 <p>should really be looked at</p>
2659 <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
2660 </li>
2661 <li>providing a local cache mechanism allowing to load the entities
2662 associated to public identifiers or remote resources, this is a really
2663 important feature for any significant deployment of XML or SGML since it
2664 allows to avoid the aleas and delays associated to fetching remote
2665 resources.</li>
2666</ul>
2667
2668<h3><a name="definition">The definitions</a></h3>
2669
2670<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
2671<ul>
2672 <li>the older SGML catalogs, the official spec is SGML Open Technical
2673 Resolution TR9401:1997, but is better understood by reading <a
2674 href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
2675 James Clark. This is relatively old and not the preferred mode of
2676 operation of libxml.</li>
2677 <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]2678 Catalogs</a> is far more flexible, more recent, uses an XML syntax and
2679 should scale quite better. This is the default option of libxml.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2680</ul>
2681
2682<p></p>
2683
2684<h3><a name="Simple">Using catalog</a></h3>
2685
2686<p>In a normal environment libxml will by default check the presence of a
2687catalog in /etc/xml/catalog, and assuming it has been correctly populated,
2688the processing is completely transparent to the document user. To take a
2689concrete example, suppose you are authoring a DocBook document, this one
2690starts with the following DOCTYPE definition:</p>
2691<pre>&lt;?xml version='1.0'?&gt;
2692&lt;!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
2693 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"&gt;</pre>
2694
2695<p>When validating the document with libxml, the catalog will be
2696automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
2697DocBk XML V3.1.4//EN" and the system identifier
2698"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
2699been installed on your system and the catalogs actually point to them, libxml
2700will fetch them from the local disk.</p>
2701
2702<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
2703DOCTYPE example it's a really old version, but is fine as an example.</p>
2704
2705<p>Libxml will check the catalog each time that it is requested to load an
2706entity, this includes DTD, external parsed entities, stylesheets, etc ... If
2707your system is correctly configured all the authoring phase and processing
2708should use only local files, even if your document stays portable because it
2709uses the canonical public and system ID, referencing the remote document.</p>
2710
2711<h3><a name="Some">Some examples:</a></h3>
2712
2713<p>Here is a couple of fragments from XML Catalogs used in libxml early
2714regression tests in <code>test/catalogs</code> :</p>
2715<pre>&lt;?xml version="1.0"?&gt;
2716&lt;!DOCTYPE catalog PUBLIC
2717 "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2718 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2719&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2720 &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2721 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2722...</pre>
2723
2724<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
2725written in XML, there is a specific namespace for catalog elements
2726"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
2727catalog is a <code>public</code> mapping it allows to associate a Public
2728Identifier with an URI.</p>
2729<pre>...
2730 &lt;rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2731 rewritePrefix="file:///usr/share/xml/docbook/"/&gt;
2732...</pre>
2733
2734<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
2735any URI starting with a given prefix should be looked at another URI
2736constructed by replacing the prefix with an new one. In effect this acts like
2737a cache system for a full area of the Web. In practice it is extremely useful
2738with a file prefix if you have installed a copy of those resources on your
2739local system.</p>
2740<pre>...
2741&lt;delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
2742 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2743&lt;delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
2744 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2745&lt;delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
2746 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2747&lt;delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2748 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2749&lt;delegateURI uriStartString="http://www.oasis-open.org/docbook/"
2750 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2751...</pre>
2752
2753<p>Delegation is the core features which allows to build a tree of catalogs,
2754easier to maintain than a single catalog, based on Public Identifier, System
2755Identifier or URI prefixes it instructs the catalog software to look up
2756entries in another resource. This feature allow to build hierarchies of
2757catalogs, the set of entries presented should be sufficient to redirect the
2758resolution of all DocBook references to the specific catalog in
2759<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
2760references for DocBook 4.2.1 to a specific catalog installed at the same time
2761as the DocBook resources on the local machine.</p>
2762
2763<h3><a name="reference">How to tune catalog usage:</a></h3>
2764
2765<p>The user can change the default catalog behaviour by redirecting queries
2766to its own set of catalogs, this can be done by setting the
2767<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
2768empty one should deactivate loading the default <code>/etc/xml/catalog</code>
2769default catalog</p>
2770
2771<h3><a name="validate">How to debug catalog processing:</a></h3>
2772
2773<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
2774make libxml output debugging informations for each catalog operations, for
2775example:</p>
2776<pre>orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2777warning: failed to load external entity "title.xml"
2778orchis:~/XML -&gt; export XML_DEBUG_CATALOG=
2779orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2780Failed to parse catalog /etc/xml/catalog
2781Failed to parse catalog /etc/xml/catalog
2782warning: failed to load external entity "title.xml"
2783Catalogs cleanup
2784orchis:~/XML -&gt; </pre>
2785
2786<p>The test/ent2 references an entity, running the parser from memory makes
2787the base URI unavailable and the the "title.xml" entity cannot be loaded.
2788Setting up the debug environment variable allows to detect that an attempt is
2789made to load the <code>/etc/xml/catalog</code> but since it's not present the
2790resolution fails.</p>
2791
2792<p>But the most advanced way to debug XML catalog processing is to use the
2793<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
2794catalogs and make resolution queries to see what is going on. This is also
2795used for the regression tests:</p>
2796<pre>orchis:~/XML -&gt; ./xmlcatalog test/catalogs/docbook.xml \
2797 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2798http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2799orchis:~/XML -&gt; </pre>
2800
2801<p>For debugging what is going on, adding one -v flags increase the verbosity
2802level to indicate the processing done (adding a second flag also indicate
2803what elements are recognized at parsing):</p>
2804<pre>orchis:~/XML -&gt; ./xmlcatalog -v test/catalogs/docbook.xml \
2805 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2806Parsing catalog test/catalogs/docbook.xml's content
2807Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
2808http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2809Catalogs cleanup
2810orchis:~/XML -&gt; </pre>
2811
2812<p>A shell interface is also available to debug and process multiple queries
2813(and for regression tests):</p>
2814<pre>orchis:~/XML -&gt; ./xmlcatalog -shell test/catalogs/docbook.xml \
2815 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2816&gt; help
2817Commands available:
2818public PublicID: make a PUBLIC identifier lookup
2819system SystemID: make a SYSTEM identifier lookup
2820resolve PublicID SystemID: do a full resolver lookup
2821add 'type' 'orig' 'replace' : add an entry
2822del 'values' : remove values
2823dump: print the current catalog state
2824debug: increase the verbosity level
2825quiet: decrease the verbosity level
2826exit: quit the shell
2827&gt; public "-//OASIS//DTD DocBook XML V4.1.2//EN"
2828http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2829&gt; quit
2830orchis:~/XML -&gt; </pre>
2831
2832<p>This should be sufficient for most debugging purpose, this was actually
2833used heavily to debug the XML Catalog implementation itself.</p>
2834
2835<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
2836
2837<p>Basically XML Catalogs are XML files, you can either use XML tools to
2838manage them or use <strong>xmlcatalog</strong> for this. The basic step is
2839to create a catalog the -create option provide this facility:</p>
2840<pre>orchis:~/XML -&gt; ./xmlcatalog --create tst.xml
2841&lt;?xml version="1.0"?&gt;
2842&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2843 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2844&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2845orchis:~/XML -&gt; </pre>
2846
2847<p>By default xmlcatalog does not overwrite the original catalog and save the
2848result on the standard output, this can be overridden using the -noout
2849option. The <code>-add</code> command allows to add entries in the
2850catalog:</p>
2851<pre>orchis:~/XML -&gt; ./xmlcatalog --noout --create --add "public" \
2852 "-//OASIS//DTD DocBook XML V4.1.2//EN" \
2853 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
2854orchis:~/XML -&gt; cat tst.xml
2855&lt;?xml version="1.0"?&gt;
2856&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
2857 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2858&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2859&lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2860 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2861&lt;/catalog&gt;
2862orchis:~/XML -&gt; </pre>
2863
2864<p>The <code>-add</code> option will always take 3 parameters even if some of
2865the XML Catalog constructs (like nextCatalog) will have only a single
2866argument, just pass a third empty string, it will be ignored.</p>
2867
2868<p>Similarly the <code>-del</code> option remove matching entries from the
2869catalog:</p>
2870<pre>orchis:~/XML -&gt; ./xmlcatalog --del \
2871 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
2872&lt;?xml version="1.0"?&gt;
2873&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2874 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2875&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2876orchis:~/XML -&gt; </pre>
2877
2878<p>The catalog is now empty. Note that the matching of <code>-del</code> is
2879exact and would have worked in a similar fashion with the Public ID
2880string.</p>
2881
2882<p>This is rudimentary but should be sufficient to manage a not too complex
2883catalog tree of resources.</p>
2884
2885<h3><a name="implemento">The implementor corner quick review of the
2886API:</a></h3>
2887
2888<p>First, and like for every other module of libxml, there is an
2889automatically generated <a href="html/libxml-catalog.html">API page for
2890catalog support</a>.</p>
2891
2892<p>The header for the catalog interfaces should be included as:</p>
2893<pre>#include &lt;libxml/catalog.h&gt;</pre>
2894
2895<p>The API is voluntarily kept very simple. First it is not obvious that
2896applications really need access to it since it is the default behaviour of
2897libxml (Note: it is possible to completely override libxml default catalog by
2898using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
2899plug an application specific resolver).</p>
2900
2901<p>Basically libxml support 2 catalog lists:</p>
2902<ul>
2903 <li>the default one, global shared by all the application</li>
2904 <li>a per-document catalog, this one is built if the document uses the
2905 <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
2906 associated to the parser context and destroyed when the parsing context
2907 is destroyed.</li>
2908</ul>
2909
2910<p>the document one will be used first if it exists.</p>
2911
2912<h4>Initialization routines:</h4>
2913
2914<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
2915used at startup to initialize the catalog, if the catalog should be
2916initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
2917should be called before xmlInitializeCatalog() which would otherwise do a
2918default initialization first.</p>
2919
2920<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
2921own catalog list if needed.</p>
2922
2923<h4>Preferences setup:</h4>
2924
2925<p>The XML Catalog spec requires the possibility to select default
2926preferences between public and system delegation,
2927xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
2928xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
2929be forbidden, allowed for global catalog, for document catalog or both, the
2930default is to allow both.</p>
2931
2932<p>And of course xmlCatalogSetDebug() allows to generate debug messages
2933(through the xmlGenericError() mechanism).</p>
2934
2935<h4>Querying routines:</h4>
2936
2937<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
2938and xmlCatalogResolveURI() are relatively explicit if you read the XML
2939Catalog specification they correspond to section 7 algorithms, they should
2940also work if you have loaded an SGML catalog with a simplified semantic.</p>
2941
2942<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
2943operate on the document catalog list</p>
2944
2945<h4>Cleanup and Miscellaneous:</h4>
2946
2947<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
2948the per-document equivalent.</p>
2949
2950<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
2951first catalog in the global list, and xmlCatalogDump() allows to dump a
2952catalog state, those routines are primarily designed for xmlcatalog, I'm not
2953sure that exposing more complex interfaces (like navigation ones) would be
2954really useful.</p>
2955
2956<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
2957it's similar as xmlParseFile() except it bypass all catalog lookups, it's
2958provided because this functionality may be useful for client tools.</p>
2959
2960<h4>threaded environments:</h4>
2961
2962<p>Since the catalog tree is built progressively, some care has been taken to
2963try to avoid troubles in multithreaded environments. The code is now thread
2964safe assuming that the libxml library has been compiled with threads
2965support.</p>
2966
2967<p></p>
2968
2969<h3><a name="Other">Other resources</a></h3>
2970
2971<p>The XML Catalog specification is relatively recent so there isn't much
2972literature to point at:</p>
2973<ul>
2974 <li>You can find an good rant from Norm Walsh about <a
2975 href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
2976 need for catalogs</a>, it provides a lot of context informations even if
Daniel Veillard93d3a472002-04-26 14:04:55 +0000[diff] [blame]2977 I don't agree with everything presented. Norm also wrote a more recent
2978 article <a
2979 href="http://wwws.sun.com/software/xml/developers/resolver/article/">XML
2980 entities and URI resolvers</a> describing them.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2981 <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
2982 catalog proposal</a> from John Cowan</li>
2983 <li>The <a href="http://www.rddl.org/">Resource Directory Description
2984 Language</a> (RDDL) another catalog system but more oriented toward
2985 providing metadata for XML namespaces.</li>
2986 <li>the page from the OASIS Technical <a
2987 href="http://www.oasis-open.org/committees/entity/">Committee on Entity
2988 Resolution</a> who maintains XML Catalog, you will find pointers to the
2989 specification update, some background and pointers to others tools
2990 providing XML Catalog support</li>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]2991 <li>Here is a <a href="buildDocBookCatalog">shell script</a> to generate
2992 XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
2993 directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
2994 the resources found on the system. Otherwise it will just create
2995 ~/xmlcatalog and ~/dbkxmlcatalog and doing:
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]2996 <p><code>export XMLCATALOG=$HOME/xmlcatalog</code></p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]2997 <p>should allow to process DocBook documentations without requiring
2998 network accesses for the DTd or stylesheets</p>
2999 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3000 <li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]3001 small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
3002 to work fine for me too</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3003 <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
3004 manual page</a></li>
3005</ul>
3006
3007<p>If you have suggestions for corrections or additions, simply contact
3008me:</p>
3009
3010<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3011
3012<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3013using the XML library from the C language. It is not intended to be
3014extensive. I hope the automatically generated documents will provide the
3015completeness required, but as a separate set of documents. The interfaces of
3016the XML library are by principle low level, there is nearly zero abstraction.
3017Those interested in a higher level API should <a href="#DOM">look at
3018DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3019
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3020<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
3021separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3022interfaces</a>. Let's have a look at how the XML parser can be called:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3023
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3024<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3025
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3026<p>Usually, the first thing to do is to read an XML input. The parser accepts
3027documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3028defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3029<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3030 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3031 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3032 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3033</dl>
3034<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3035 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3036 <dd><p>Parse an XML document contained in a (possibly compressed)
3037 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3038 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3039</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3040
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3041<p>The parser returns a pointer to the document structure (or NULL in case of
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3042failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3043
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3044<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3045
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3046<p>In order for the application to keep the control when the document is
3047being fetched (which is common for GUI based programs) libxml provides a push
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3048interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3049<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
3050 void *user_data,
3051 const char *chunk,
3052 int size,
3053 const char *filename);
3054int xmlParseChunk (xmlParserCtxtPtr ctxt,
3055 const char *chunk,
3056 int size,
3057 int terminate);</pre>
3058
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3059<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3060<pre> FILE *f;
3061
3062 f = fopen(filename, "r");
3063 if (f != NULL) {
3064 int res, size = 1024;
3065 char chars[1024];
3066 xmlParserCtxtPtr ctxt;
3067
3068 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3069 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3070 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
3071 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3072 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3073 xmlParseChunk(ctxt, chars, res, 0);
3074 }
3075 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3076 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3077 xmlFreeParserCtxt(ctxt);
3078 }
3079 }</pre>
3080
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3081<p>The HTML parser embedded into libxml also has a push interface; the
3082functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3083
3084<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
3085
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3086<p>The tree-building interface makes the parser memory-hungry, first loading
3087the document in memory and then building the tree itself. Reading a document
3088without building the tree is possible using the SAX interfaces (see SAX.h and
3089<a href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3090Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3091limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3092<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3093
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3094<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3095
3096<p>The other way to get an XML tree in memory is by building it. Basically
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3097there is a set of functions dedicated to building new elements. (These are
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3098also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of
3099code that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3100<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3101 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3102 xmlNodePtr tree, subtree;
3103
3104 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3105 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
3106 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
3107 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
3108 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3109 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3110 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3111 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
3112 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
3113 subtree = xmlNewChild(tree, NULL, "image", NULL);
3114 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3115
3116<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3117
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3118<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3119
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3120<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3121code has access to the internal structure of all the elements of the tree.
3122The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]3123<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3124<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]3125example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3126<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3127
3128<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3129<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3130
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3131<p>points to the text node containing the chapter title "The Linux
3132adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3133
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3134<p><strong>NOTE</strong>: XML allows <em>PI</em>s and <em>comments</em> to be
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3135present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3136to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]3137<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]3138
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3139<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3140
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3141<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3142is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3143<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3144 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
3145 xmlChar *value);</code></dt>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3146 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
3147 The value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3148 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3149</dl>
3150<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3151 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3152 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]3153 <dd><p>This function returns a pointer to new copy of the property
3154 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3155 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3156</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3157
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3158<p>Two functions are provided for reading and writing the text associated
3159with elements:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3160<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3161 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3162 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3163 <dd><p>This function takes an "external" string and converts it to one
3164 text node or possibly to a list of entity and text nodes. All
3165 non-predefined entity references like &amp;Gnome; will be stored
3166 internally as entity nodes, hence the result of the function may not be
3167 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3168 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3169</dl>
3170<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3171 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3172 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3173 <dd><p>This function is the inverse of
3174 <code>xmlStringGetNodeList()</code>. It generates a new string
3175 containing the content of the text and entity nodes. Note the extra
3176 argument inLine. If this argument is set to 1, the function will expand
3177 entity references. For example, instead of returning the &amp;Gnome;
3178 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3179 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3180 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3181</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3182
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3183<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3184
3185<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3186<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]3187 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3188 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3189 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3190 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3191</dl>
3192<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3193 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3194 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3195 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3196</dl>
3197<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3198 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3199 <dd><p>Saves the document to a file. In this case, the compression
3200 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3201 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3202</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]3203
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3204<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3205
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3206<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3207accesses. The level of compression on saves can be turned on either globally
3208or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3209<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3210 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3211 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3212 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3213</dl>
3214<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3215 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3216 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3217 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3218</dl>
3219<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3220 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3221 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3222 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3223</dl>
3224<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3225 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3226 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3227 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]3228</dl>
3229
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3230<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3231
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3232<p>Entities in principle are similar to simple C macros. An entity defines an
3233abbreviation for a given string that you can reuse many times throughout the
3234content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3235may occur frequently within a document, or to confine the change needed to a
3236document to a restricted area in the internal subset of the document (at the
3237beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3238<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]32392 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]32403 &lt;!ENTITY xml "Extensible Markup Language"&gt;
32414 ]&gt;
32425 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]32436 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]32447 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3245
3246<p>Line 3 declares the xml entity. Line 6 uses the xml entity, by prefixing
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3247its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3248are 5 predefined entities in libxml allowing you to escape charaters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3249predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3250<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3251for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3252<strong>&amp;quot;</strong> for the character '"', and
3253<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3254
3255<p>One of the problems related to entities is that you may want the parser to
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3256substitute an entity's content so that you can see the replacement text in
3257your application. Or you may prefer to keep entity references as such in the
3258content to be able to save the document back without losing this usually
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3259precious information (if the user went through the pain of explicitly
3260defining entities, he may have a a rather negative attitude if you blindly
3261susbtitute them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]3262href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3263function allows you to check and change the behaviour, which is to not
3264substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3265
3266<p>Here is the DOM tree built by libxml for the previous document in the
3267default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3268<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3269DOCUMENT
3270version=1.0
3271 ELEMENT EXAMPLE
3272 TEXT
3273 content=
3274 ENTITY_REF
3275 INTERNAL_GENERAL_ENTITY xml
3276 content=Extensible Markup Language
3277 TEXT
3278 content=</pre>
3279
3280<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3281<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3282DOCUMENT
3283version=1.0
3284 ELEMENT EXAMPLE
3285 TEXT
3286 content= Extensible Markup Language</pre>
3287
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3288<p>So, entities or no entities? Basically, it depends on your use case. I
3289suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3290entities in your XML document or data if you are not willing to handle the
3291entity references elements in the DOM tree.</p>
3292
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3293<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3294entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3295transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3296reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3297finding them in the input).</p>
3298
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3299<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3300on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3301non-predefined entities in your documents, then the learning cuvre to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3302then using the SAX API may be long. If you plan to use complex documents, I
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3303strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]3304deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]3305
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]3306<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3307
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3308<p>The libxml library implements <a
3309href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
3310recognizing namespace contructs in the input, and does namespace lookup
3311automatically when building the DOM tree. A namespace declaration is
3312associated with an in-memory structure and all elements or attributes within
3313that namespace point to it. Hence testing the namespace is a simple and fast
3314equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3315
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3316<p>I suggest that people using libxml use a namespace, and declare it in the
3317root element of their document as the default namespace. Then they don't need
3318to use the prefix in the content but we will have a basis for future semantic
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3319refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3320the size of the XML output significantly, but significantly increases its
3321value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3322<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
3323 &lt;elem1&gt;...&lt;/elem1&gt;
3324 &lt;elem2&gt;...&lt;/elem2&gt;
3325&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3326
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3327<p>The namespace value has to be an absolute URL, but the URL doesn't have to
3328point to any existing resource on the Web. It will bind all the element and
3329atributes with that URL. I suggest to use an URL within a domain you control,
3330and that the URL should contain some kind of version information if possible.
3331For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a good
3332namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3333
3334<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]3335version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3336and if the version information don't match something you know, warn the user
3337and be liberal in what you accept as the input. Also do *not* try to base
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3338namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3339same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3340associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3341just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]3342<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3343prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3344
3345<p>@@Interfaces@@</p>
3346
3347<p>@@Examples@@</p>
3348
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3349<p>Usually people object to using namespaces together with validity checking.
3350I will try to make sure that using namespaces won't break validity checking,
3351so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]3352suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3353<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3354flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3355from multiple DTDs will certainly break current validation schemes. I will
3356try to provide ways to do this, but this may not be portable or
3357standardized.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3358
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3359<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3360
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3361<p>Incompatible changes:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3362
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3363<p>Version 2 of libxml is the first version introducing serious backward
3364incompatible changes. The main goals were:</p>
3365<ul>
3366 <li>a general cleanup. A number of mistakes inherited from the very early
3367 versions couldn't be changed due to compatibility constraints. Example
3368 the "childs" element in the nodes.</li>
3369 <li>Uniformization of the various nodes, at least for their header and link
3370 parts (doc, parent, children, prev, next), the goal is a simpler
3371 programming model and simplifying the task of the DOM implementors.</li>
3372 <li>better conformances to the XML specification, for example version 1.x
3373 had an heuristic to try to detect ignorable white spaces. As a result the
3374 SAX event generated were ignorableWhitespace() while the spec requires
3375 character() in that case. This also mean that a number of DOM node
3376 containing blank text may populate the DOM tree which were not present
3377 before.</li>
3378</ul>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3379
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3380<h3>How to fix libxml-1.x code:</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3381
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3382<p>So client code of libxml designed to run with version 1.x may have to be
3383changed to compile against version 2.x of libxml. Here is a list of changes
3384that I have collected, they may not be sufficient, so in case you find other
3385change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
3386mail</a>:</p>
3387<ol>
3388 <li>The package name have changed from libxml to libxml2, the library name
3389 is now -lxml2 . There is a new xml2-config script which should be used to
3390 select the right parameters libxml2</li>
3391 <li>Node <strong>childs</strong> field has been renamed
3392 <strong>children</strong> so s/childs/children/g should be applied
3393 (probablility of having "childs" anywere else is close to 0+</li>
3394 <li>The document don't have anymore a <strong>root</strong> element it has
3395 been replaced by <strong>children</strong> and usually you will get a
3396 list of element here. For example a Dtd element for the internal subset
3397 and it's declaration may be found in that list, as well as processing
3398 instructions or comments found before or after the document root element.
3399 Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
3400 a document. Alternatively if you are sure to not reference Dtds nor have
3401 PIs or comments before or after the root element
3402 s/-&gt;root/-&gt;children/g will probably do it.</li>
3403 <li>The white space issue, this one is more complex, unless special case of
3404 validating parsing, the line breaks and spaces usually used for indenting
3405 and formatting the document content becomes significant. So they are
3406 reported by SAX and if your using the DOM tree, corresponding nodes are
3407 generated. Too approach can be taken:
3408 <ol>
3409 <li>lazy one, use the compatibility call
3410 <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
3411 relying on a special (and possibly broken) set of heuristics of
3412 libxml to detect ignorable blanks. Don't complain if it breaks or
3413 make your application not 100% clean w.r.t. to it's input.</li>
3414 <li>the Right Way: change you code to accept possibly unsignificant
3415 blanks characters, or have your tree populated with weird blank text
3416 nodes. You can spot them using the comodity function
3417 <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
3418 nodes.</li>
3419 </ol>
3420 <p>Note also that with the new default the output functions don't add any
3421 extra indentation when saving a tree in order to be able to round trip
3422 (read and save) without inflating the document with extra formatting
3423 chars.</p>
3424 </li>
3425 <li>The include path has changed to $prefix/libxml/ and the includes
3426 themselves uses this new prefix in includes instructions... If you are
3427 using (as expected) the
3428 <pre>xml2-config --cflags</pre>
3429 <p>output to generate you compile commands this will probably work out of
3430 the box</p>
3431 </li>
3432 <li>xmlDetectCharEncoding takes an extra argument indicating the lenght in
3433 byte of the head of the document available for character detection.</li>
3434</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3435
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3436<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3437
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3438<p>Two new version of libxml (1.8.11) and libxml2 (2.3.4) have been released
3439to allow smoth upgrade of existing libxml v1code while retaining
3440compatibility. They offers the following:</p>
3441<ol>
3442 <li>similar include naming, one should use
3443 <strong>#include&lt;libxml/...&gt;</strong> in both cases.</li>
3444 <li>similar identifiers defined via macros for the child and root fields:
3445 respectively <strong>xmlChildrenNode</strong> and
3446 <strong>xmlRootNode</strong></li>
3447 <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
3448 inserted once in the client code</li>
3449</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3450
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3451<p>So the roadmap to upgrade your existing libxml applications is the
3452following:</p>
3453<ol>
3454 <li>install the libxml-1.8.8 (and libxml-devel-1.8.8) packages</li>
3455 <li>find all occurences where the xmlDoc <strong>root</strong> field is
3456 used and change it to <strong>xmlRootNode</strong></li>
3457 <li>similary find all occurences where the xmlNode <strong>childs</strong>
3458 field is used and change it to <strong>xmlChildrenNode</strong></li>
3459 <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
3460 <strong>main()</strong> or in the library init entry point</li>
3461 <li>Recompile, check compatibility, it should still work</li>
3462 <li>Change your configure script to look first for xml2-config and fallback
3463 using xml-config . Use the --cflags and --libs ouptut of the command as
3464 the Include and Linking parameters needed to use libxml.</li>
3465 <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
3466 libxml-devel-1.8.y can be kept simultaneously)</li>
3467 <li>remove your config.cache, relaunch your configuration mechanism, and
3468 recompile, if steps 2 and 3 were done right it should compile as-is</li>
3469 <li>Test that your application is still running correctly, if not this may
3470 be due to extra empty nodes due to formating spaces being kept in libxml2
3471 contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
3472 code before calling the parser (next to
3473 <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
3474</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3475
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3476<p>Following those steps should work. It worked for some of my own code.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3477
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3478<p>Let me put some emphasis on the fact that there is far more changes from
3479libxml 1.x to 2.x than the ones you may have to patch for. The overall code
3480has been considerably cleaned up and the conformance to the XML specification
3481has been drastically improved too. Don't take those changes as an excuse to
3482not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3483
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3484<h2><a name="Thread">Thread safety</a></h2>
3485
3486<p>Starting with 2.4.7, libxml makes provisions to ensure that concurent
3487threads can safely work in parallel parsing different documents. There is
3488however a couple of things to do to ensure it:</p>
3489<ul>
3490 <li>configure the library accordingly using the --with-threads options</li>
3491 <li>call xmlInitParser() in the "main" thread before using any of the
3492 libxml API (except possibly selecting a different memory allocator)</li>
3493</ul>
3494
3495<p>Note that the thread safety cannot be ensured for multiple threads sharing
3496the same document, the locking must be done at the application level, libxml
3497exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
3498The parts of the library checked for thread safety are:</p>
3499<ul>
3500 <li>concurrent loading</li>
3501 <li>file access resolution</li>
3502 <li>catalog access</li>
3503 <li>catalog building</li>
3504 <li>entities lookup/accesses</li>
3505 <li>validation</li>
3506 <li>global variables per-thread override</li>
3507 <li>memory handling</li>
3508</ul>
3509
3510<p>XPath is supposed to be thread safe now, but this wasn't tested
3511seriously.</p>
3512
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3513<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3514
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3515<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
3516Object Model</em>; this is an API for accessing XML or HTML structured
3517documents. Native support for DOM in Gnome is on the way (module gnome-dom),
3518and will be based on gnome-xml. This will be a far cleaner interface to
3519manipulate XML files within Gnome since it won't expose the internal
3520structure.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3521
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3522<p>The current DOM implementation on top of libxml is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame]3523href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
3524is a full DOM interface, thanks to Paolo Casarini, check the <a
3525href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
3526informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3527
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3528<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3529
3530<p>Here is a real size example, where the actual content of the application
3531data is not kept in the DOM tree but uses internal structures. It is based on
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3532a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3533storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
3534base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3535<pre>&lt;?xml version="1.0"?&gt;
3536&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
3537 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3538
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3539 &lt;gjob:Job&gt;
3540 &lt;gjob:Project ID="3"/&gt;
3541 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
3542 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3543
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3544 &lt;gjob:Update&gt;
3545 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
3546 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
3547 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
3548 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3549
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3550 &lt;gjob:Developers&gt;
3551 &lt;gjob:Developer&gt;
3552 &lt;/gjob:Developer&gt;
3553 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3554
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3555 &lt;gjob:Contact&gt;
3556 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
3557 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
3558 &lt;gjob:Company&gt;
3559 &lt;/gjob:Company&gt;
3560 &lt;gjob:Organisation&gt;
3561 &lt;/gjob:Organisation&gt;
3562 &lt;gjob:Webpage&gt;
3563 &lt;/gjob:Webpage&gt;
3564 &lt;gjob:Snailmail&gt;
3565 &lt;/gjob:Snailmail&gt;
3566 &lt;gjob:Phone&gt;
3567 &lt;/gjob:Phone&gt;
3568 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3569
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3570 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3571 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3572 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3573
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3574 &lt;gjob:Skills&gt;
3575 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3576
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3577 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3578 A GNOME based system that will allow a superuser to configure
3579 compressed and uncompressed files and/or file systems to be backed
3580 up with a supported media in the system. This should be able to
3581 perform via find commands generating a list of files that are passed
3582 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
3583 or via operations performed on the filesystem itself. Email
3584 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3585 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3586
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3587 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3588
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3589 &lt;/gjob:Jobs&gt;
3590&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3591
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3592<p>While loading the XML file into an internal DOM tree is a matter of
3593calling only a couple of functions, browsing the tree to gather the ata and
3594generate the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3595
3596<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3597structure. For example, the ordering of the attributes is not significant,
3598the XML specification is clear about it. It's also usually a good idea not to
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3599depend on the order of the children of a given node, unless it really makes
3600things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3601<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3602 * A person record
3603 */
3604typedef struct person {
3605 char *name;
3606 char *email;
3607 char *company;
3608 char *organisation;
3609 char *smail;
3610 char *webPage;
3611 char *phone;
3612} person, *personPtr;
3613
3614/*
3615 * And the code needed to parse it
3616 */
3617personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3618 personPtr ret = NULL;
3619
3620DEBUG("parsePerson\n");
3621 /*
3622 * allocate the struct
3623 */
3624 ret = (personPtr) malloc(sizeof(person));
3625 if (ret == NULL) {
3626 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3627 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3628 }
3629 memset(ret, 0, sizeof(person));
3630
3631 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3632 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3633 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3634 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
3635 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3636 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
3637 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3638 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3639 }
3640
3641 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3642}</pre>
3643
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3644<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3645<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3646 <li>Usually a recursive parsing style is the more convenient one: XML data
3647 is by nature subject to repetitive constructs and usually exibits highly
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3648 stuctured patterns.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3649 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
3650 i.e. the pointer to the global XML document and the namespace reserved to
3651 the application. Document wide information are needed for example to
3652 decode entities and it's a good coding practice to define a namespace for
3653 your application set of data and test that the element and attributes
3654 you're analyzing actually pertains to your application space. This is
3655 done by a simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3656 <li>To retrieve text and attributes value, you can use the function
3657 <em>xmlNodeListGetString</em> to gather all the text and entity reference
3658 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3659</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3660
3661<p>Here is another piece of code used to parse another level of the
3662structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3663<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3664/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3665 * a Description for a Job
3666 */
3667typedef struct job {
3668 char *projectID;
3669 char *application;
3670 char *category;
3671 personPtr contact;
3672 int nbDevelopers;
3673 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
3674} job, *jobPtr;
3675
3676/*
3677 * And the code needed to parse it
3678 */
3679jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3680 jobPtr ret = NULL;
3681
3682DEBUG("parseJob\n");
3683 /*
3684 * allocate the struct
3685 */
3686 ret = (jobPtr) malloc(sizeof(job));
3687 if (ret == NULL) {
3688 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3689 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3690 }
3691 memset(ret, 0, sizeof(job));
3692
3693 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3694 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3695 while (cur != NULL) {
3696
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3697 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
3698 ret-&gt;projectID = xmlGetProp(cur, "ID");
3699 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3700 fprintf(stderr, "Project has no ID\n");
3701 }
3702 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3703 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
3704 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3705 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
3706 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3707 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
3708 ret-&gt;contact = parsePerson(doc, ns, cur);
3709 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3710 }
3711
3712 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3713}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3714
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3715<p>Once you are used to it, writing this kind of code is quite simple, but
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3716boring. Ultimately, it could be possble to write stubbers taking either C
3717data structure definitions, a set of XML examples or an XML DTD and produce
3718the code needed to import and export the content between C data and XML
3719storage. This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3720
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]3721<p>Feel free to use <a href="example/gjobread.c">the code for the full C
3722parsing example</a> as a template, it is also available with Makefile in the
3723Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3724
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3725<h2><a name="Contributi">Contributions</a></h2>
3726<ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3727 <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
3728 patches, Gary Pennington worked on the validation API, threading support
3729 and Solaris port.</li>
3730 <li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3731 <li><a href="mailto:ari@lusis.org">Ari Johnson</a> provides a C++ wrapper
3732 for libxml:<br>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]3733 Website: <a
3734 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a><br>
3735 Download: <a
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]3736 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></li>
Daniel Veillardb2fb8ed2002-04-01 09:33:12 +0000[diff] [blame]3737 <li><a href="mailto:igor@stud.fh-frankfurt.de">Igor Zlatkovic</a> is now
3738 the maintainer of the Windows port, <a
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]3739 href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
3740 provides binaries</a></li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3741 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
3742 <a href="http://garypennington.net/libxml2/">Solaris binaries</a></li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]3743 <li><a
3744 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3745 Sergeant</a> developped <a
3746 href="http://axkit.org/download/">XML::LibXSLT</a>, a perl wrapper for
3747 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
3748 application server</a></li>
3749 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> and <a
3750 href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillardca989762001-06-23 17:39:29 +0000[diff] [blame]3751 href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]3752 documentation</li>
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]3753 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
3754 href="http://xmlsoft.org/messages/0488.html">man pages</a></li>
Daniel Veillard5168dbf2001-07-07 00:18:23 +0000[diff] [blame]3755 <li>there is a module for <a
3756 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
3757 in OpenNSD/AOLServer</a></li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]3758 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provided the
3759 first version of libxml/libxslt <a
3760 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li>
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]3761 <li>Petr Kozelka provides <a
3762 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
3763 libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillard2d347fa2002-03-17 10:34:11 +0000[diff] [blame]3764 <li><a href="mailto:aleksey@aleksey.com">Aleksey Sanin</a> implemented the
3765 <a href="http://www.w3.org/Signature/">XML Canonicalization and XML
3766 Digital Signature</a> <a
3767 href="http://www.aleksey.com/xmlsec/">implementations for libxml2</a></li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3768</ul>
3769
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3770<p></p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3771</body>
3772</html>