Gitiles
Code Review Sign In
gerrit-public.fairphone.software / platform / external / libxml2 / 5b16f588daddf6b3ef3f1e38bc4be9dbfb690fe3 / . / doc / xml.html
blob: 8b1132fb21beaa53d639d42da799b392bca59389 [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 Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]6 <meta name="GENERATOR" content="amaya V5.0">
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
24markup language.</p>
25
26<p>Libxml2 implements a number of existing standards related to markup
27languages:</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]28<ul>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]29 <li>the XML standard: <a
30 href="http://www.w3.org/TR/REC-xml">http://www.w3.org/TR/REC-xml</a></li>
31 <li>Namespaces in XML: <a
32 href="http://www.w3.org/TR/REC-xml-names/">http://www.w3.org/TR/REC-xml-names/</a></li>
33 <li>XML Base: <a
34 href="http://www.w3.org/TR/xmlbase/">http://www.w3.org/TR/xmlbase/</a></li>
35 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc2396.txt">RFC 2396</a>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]36 : Uniform Resource Identifiers <a
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]37 href="http://www.ietf.org/rfc/rfc2396.txt">http://www.ietf.org/rfc/rfc2396.txt</a></li>
38 <li>XML Path Language (XPath) 1.0: <a
39 href="http://www.w3.org/TR/xpath">http://www.w3.org/TR/xpath</a></li>
40 <li>HTML4 parser: <a
41 href="http://www.w3.org/TR/html401/">http://www.w3.org/TR/html401/</a></li>
42 <li>most of XML Pointer Language (XPointer) Version 1.0: <a
43 href="http://www.w3.org/TR/xptr">http://www.w3.org/TR/xptr</a></li>
44 <li>XML Inclusions (XInclude) Version 1.0: <a
45 href="http://www.w3.org/TR/xinclude/">http://www.w3.org/TR/xinclude/</a></li>
46 <li>[ISO-8859-1], <a
47 href="http://www.cis.ohio-state.edu/rfc/rfc2044.txt">rfc2044</a> [UTF-8]
48 and <a href="http://www.cis.ohio-state.edu/rfc/rfc2781.txt">rfc2781</a>
49 [UTF-16] core encodings</li>
50 <li>part of SGML Open Technical Resolution TR9401:1997</li>
51 <li>XML Catalogs Working Draft 06 August 2001: <a
52 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 Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]53</ul>
54
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]55<p>In most cases libxml tries to implement the specifications in a relatively
Daniel Veillard5b16f582002-02-20 11:38:46 +0000[diff] [blame^]56strict way. As of release 2.4.16, libxml2 passes all 1800+ tests from the
57OASIS XML Tests Suite.</p>
58
59<p>To some extent libxml2 provide some support for the following other
60specification but don't claim to implement them:</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]61<ul>
62 <li>Document Object Model (DOM) <a
63 href="http://www.w3.org/TR/DOM-Level-2-Core/">http://www.w3.org/TR/DOM-Level-2-Core/</a>
64 it doesn't implement the API itself, gdome2 does this in top of
65 libxml2</li>
66 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc959.txt">RFC 959</a>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]67 : libxml implements a basic FTP client code</li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]68 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc1945.txt">RFC 1945</a>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]69 : HTTP/1.0, again a basic HTTP client code</li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]70 <li>SAX: a minimal SAX implementation compatible with early expat
71 versions</li>
72 <li>DocBook SGML v4: libxml2 includes a hackish parser to transition to
73 XML</li>
74</ul>
75
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]76<p>Libxml2 is known to be very portable, should build and work without
77serious troubles on a variety of systems (Linux, Unix, Windows, CygWin,
78MacOs, MacOsX, RISC Os, OS/2, VMS, QNX, MVS, ...)</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]79
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]80<p>Separate documents:</p>
81<ul>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]82 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a>
83 providing an implementation of XSLT 1.0 and extensions on top of
84 libxml2</li>
85 <li><a href="http://www.cs.unibo.it/~casarini/gdome2/">the gdome2 page</a>
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]86 : a standard DOM2 implementation based on libxml2</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]87</ul>
88
89<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]90
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]91<p>This document describes libxml, the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]92href="http://www.w3.org/XML/">XML</a> C library developped for the <a
93href="http://www.gnome.org/">Gnome</a> project. <a
94href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
95structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]96
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]97<p>Here are some key points about libxml:</p>
98<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]99 <li>Libxml exports Push and Pull type parser interfaces for both XML and
100 HTML.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]101 <li>Libxml can do DTD validation at parse time, using a parsed document
102 instance, or with an arbitrary DTD.</li>
103 <li>Libxml now includes nearly complete <a
Daniel Veillard8c2ecaf2001-07-10 17:53:07 +0000[diff] [blame]104 href="http://www.w3.org/TR/xpath">XPath</a>, <a
105 href="http://www.w3.org/TR/xptr">XPointer</a> and <a
106 href="http://www.w3.org/TR/xinclude">XInclude</a> implementations.</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]107 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]108 sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]109 Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]110 <li>Basic support for HTTP and FTP client allowing aplications to fetch
111 remote resources</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]112 <li>The design is modular, most of the extensions can be compiled out.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]113 <li>The internal document repesentation is as close as possible to the <a
114 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
115 <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]116 like interface</a>; the interface is designed to be compatible with <a
117 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]118 <li>This library is released under the <a
119 href="http://www.opensource.org/licenses/mit-license.html">MIT
120 Licence</a> see the Copyright file in the distribution for the precise
121 wording.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]122</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]123
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]124<p>Warning: unless you are forced to because your application links with a
125Gnome library requiring it, <strong><span
126style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
127libxml2</p>
128
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]129<h2><a name="FAQ">FAQ</a></h2>
130
131<p>Table of Content:</p>
132<ul>
133 <li><a href="FAQ.html#Licence">Licence(s)</a></li>
134 <li><a href="FAQ.html#Installati">Installation</a></li>
135 <li><a href="FAQ.html#Compilatio">Compilation</a></li>
136 <li><a href="FAQ.html#Developer">Developer corner</a></li>
137</ul>
138
139<h3><a name="Licence">Licence</a>(s)</h3>
140<ol>
141 <li><em>Licensing Terms for libxml</em>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]142 <p>libxml is released under the <a
143 href="http://www.opensource.org/licenses/mit-license.html">MIT
144 Licence</a>, see the file Copyright in the distribution for the precise
145 wording</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]146 </li>
147 <li><em>Can I embed libxml in a proprietary application ?</em>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]148 <p>Yes. The MIT Licence allows you to also keep proprietary the changes
149 you made to libxml, but it would be graceful to provide back bugfixes and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]150 improvements as patches for possible incorporation in the main
151 development tree</p>
152 </li>
153</ol>
154
155<h3><a name="Installati">Installation</a></h3>
156<ol>
157 <li>Unless you are forced to because your application links with a Gnome
158 library requiring it, <strong><span style="background-color: #FF0000">Do
159 Not Use libxml1</span></strong>, use libxml2</li>
160 <li><em>Where can I get libxml</em>
161 ?
162 <p>The original distribution comes from <a
163 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a
164 href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">gnome.org</a></p>
165 <p>Most linux and Bsd distribution includes libxml, this is probably the
166 safer way for end-users</p>
167 <p>David Doolin provides precompiled Windows versions at <a
168 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
169 </li>
170 <li><em>I see libxml and libxml2 releases, which one should I install ?</em>
171 <ul>
172 <li>If you are not concerned by any existing backward compatibility
173 with existing application, install libxml2 only</li>
174 <li>If you are not doing development, you can safely install both.
175 usually the packages <a
176 href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a
177 href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
178 compatible (this is not the case for development packages)</li>
179 <li>If you are a developer and your system provides separate packaging
180 for shared libraries and the development components, it is possible
181 to install libxml and libxml2, and also <a
182 href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
183 and <a
184 href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
185 too for libxml2 &gt;= 2.3.0</li>
186 <li>If you are developing a new application, please develop against
187 libxml2(-devel)</li>
188 </ul>
189 </li>
190 <li><em>I can't install the libxml package it conflicts with libxml0</em>
191 <p>You probably have an old libxml0 package used to provide the shared
192 library for libxml.so.0, you can probably safely remove it. Anyway the
193 libxml packages provided on <a
194 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provides
195 libxml.so.0</p>
196 </li>
197 <li><em>I can't install the libxml(2) RPM package due to failed
198 dependancies</em>
199 <p>The most generic solution is to refetch the latest src.rpm , and
200 rebuild it locally with</p>
201 <p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code></p>
202 <p>if everything goes well it will generate two binary rpm (one providing
203 the shared libs and xmllint, and the other one, the -devel package
204 providing includes, static libraries and scripts needed to build
205 applications with libxml(2)) that you can install locally.</p>
206 </li>
207</ol>
208
209<h3><a name="Compilatio">Compilation</a></h3>
210<ol>
211 <li><em>What is the process to compile libxml ?</em>
212 <p>As most UNIX libraries libxml follows the "standard":</p>
213 <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p>
214 <p><code>cd libxml-xxxx</code></p>
215 <p><code>./configure --help</code></p>
216 <p>to see the options, then the compilation/installation proper</p>
217 <p><code>./configure [possible options]</code></p>
218 <p><code>make</code></p>
219 <p><code>make install</code></p>
220 <p>At that point you may have to rerun ldconfig or similar utility to
221 update your list of installed shared libs.</p>
222 </li>
223 <li><em>What other libraries are needed to compile/install libxml ?</em>
224 <p>Libxml does not requires any other library, the normal C ANSI API
225 should be sufficient (please report any violation to this rule you may
226 find).</p>
227 <p>However if found at configuration time libxml will detect and use the
228 following libs:</p>
229 <ul>
230 <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a>
231 : a highly portable and available widely compression library</li>
232 <li>iconv: a powerful character encoding conversion library. It's
233 included by default on recent glibc libraries, so it doesn't need to
234 be installed specifically on linux. It seems it's now <a
235 href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
236 of the official UNIX</a> specification. Here is one <a
237 href="http://clisp.cons.org/~haible/packages-libiconv.html">implementation
238 of the library</a> which source can be found <a
239 href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
240 </ul>
241 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]242 <li><em>make check fails on some platforms</em>
243 <p>Sometime the regression tests results don't completely match the value
244 produced by the parser, and the makefile uses diff to print the delta. On
245 some platforms the diff return breaks the compilation process, if the
Daniel Veillarde46182c2002-02-12 14:29:11 +0000[diff] [blame]246 diff is small this is probably not a serious problem.</p>
247 <p>Sometimes (especially on Solaris) make checks fails due to limitations
248 in make. Try using GNU-make instead.</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]249 </li>
250 <li><em>I use the CVS version and there is no configure script</em>
251 <p>The configure (and other Makefiles) are generated. Use the autogen.sh
252 script to regenerate the configure and Makefiles, like:</p>
253 <p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
254 </li>
255 <li><em>I have troubles when running make tests with gcc-3.0</em>
256 <p>It seems the initial release of gcc-3.0 has a problem with the
257 optimizer which miscompiles the URI module. Please use another
258 compiler</p>
259 </li>
260</ol>
261
262<h3><a name="Developer">Developer</a> corner</h3>
263<ol>
264 <li><em>xmlDocDump() generates output on one line</em>
265 <p>libxml will not <strong>invent</strong> spaces in the content of a
266 document since <strong>all spaces in the content of a document are
267 significant</strong>. If you build a tree from the API and want
268 indentation:</p>
269 <ol>
270 <li>the correct way is to generate those yourself too</li>
271 <li>the dangerous way is to ask libxml to add those blanks to your
272 content <strong>modifying the content of your document in the
273 process</strong>. The result may not be what you expect. There is
274 <strong>NO</strong> way to guarantee that such a modification won't
275 impact other part of the content of your document. See <a
276 href="http://xmlsoft.org/html/libxml-parser.html#XMLKEEPBLANKSDEFAULT">xmlKeepBlanksDefault
277 ()</a> and <a
278 href="http://xmlsoft.org/html/libxml-tree.html#XMLSAVEFORMATFILE">xmlSaveFormatFile
279 ()</a></li>
280 </ol>
281 </li>
282 <li>Extra nodes in the document:
283 <p><em>For a XML file as below:</em></p>
284 <pre>&lt;?xml version="1.0"?&gt;
285&lt;PLAN xmlns="http://www.argus.ca/autotest/1.0/"&gt;
286&lt;NODE CommFlag="0"/&gt;
287&lt;NODE CommFlag="1"/&gt;
288&lt;/PLAN&gt;</pre>
289 <p><em>after parsing it with the function
290 pxmlDoc=xmlParseFile(...);</em></p>
291 <p><em>I want to the get the content of the first node (node with the
292 CommFlag="0")</em></p>
293 <p><em>so I did it as following;</em></p>
294 <pre>xmlNodePtr pode;
295pnode=pxmlDoc-&gt;children-&gt;children;</pre>
296 <p><em>but it does not work. If I change it to</em></p>
297 <pre>pnode=pxmlDoc-&gt;children-&gt;children-&gt;next;</pre>
298 <p><em>then it works. Can someone explain it to me.</em></p>
299 <p></p>
300 <p>In XML all characters in the content of the document are significant
301 <strong>including blanks and formatting line breaks</strong>.</p>
302 <p>The extra nodes you are wondering about are just that, text nodes with
303 the formatting spaces wich are part of the document but that people tend
304 to forget. There is a function <a
305 href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
306 ()</a> to remove those at parse time, but that's an heuristic, and its
307 use should be limited to case where you are sure there is no
308 mixed-content in the document.</p>
309 </li>
310 <li><em>I get compilation errors of existing code like when accessing
311 <strong>root</strong> or <strong>childs fields</strong> of nodes</em>
312 <p>You are compiling code developed for libxml version 1 and using a
313 libxml2 development environment. Either switch back to libxml v1 devel or
314 even better fix the code to compile with libxml2 (or both) by <a
315 href="upgrade.html">following the instructions</a>.</p>
316 </li>
317 <li><em>I get compilation errors about non existing
318 <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
319 fields</em>
320 <p>The source code you are using has been <a
321 href="upgrade.html">upgraded</a> to be able to compile with both libxml
322 and libxml2, but you need to install a more recent version:
323 libxml(-devel) &gt;= 1.8.8 or libxml2(-devel) &gt;= 2.1.0</p>
324 </li>
325 <li><em>XPath implementation looks seriously broken</em>
326 <p>XPath implementation prior to 2.3.0 was really incomplete, upgrade to
327 a recent version, the implementation and debug of libxslt generated fixes
328 for most obvious problems.</p>
329 </li>
330 <li><em>The example provided in the web page does not compile</em>
331 <p>It's hard to maintain the documentation in sync with the code
332 &lt;grin/&gt; ...</p>
333 <p>Check the previous points 1/ and 2/ raised before, and send
334 patches.</p>
335 </li>
336 <li><em>Where can I get more examples and informations than in the web
337 page</em>
338 <p>Ideally a libxml book would be nice. I have no such plan ... But you
339 can:</p>
340 <ul>
341 <li>check more deeply the <a href="html/libxml-lib.html">existing
342 generated doc</a></li>
343 <li>looks for examples of use for libxml function using the Gnome code
344 for example the following will query the full Gnome CVs base for the
345 use of the <strong>xmlAddChild()</strong> function:
346 <p><a
347 href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p>
348 <p>This may be slow, a large hardware donation to the gnome project
349 could cure this :-)</p>
350 </li>
351 <li><a
352 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gnome-xml">Browse
353 the libxml source</a>
354 , I try to write code as clean and documented as possible, so
355 looking at it may be helpful</li>
356 </ul>
357 </li>
358 <li>What about C++ ?
359 <p>libxml is written in pure C in order to allow easy reuse on a number
360 of platforms, including embedded systems. I don't intend to convert to
361 C++.</p>
362 <p>There is however a C++ wrapper provided by Ari Johnson
363 &lt;ari@btigate.com&gt; which may fullfill your needs:</p>
364 <p>Website: <a
365 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
366 <p>Download: <a
367 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
368 </li>
369 <li>How to validate a document a posteriori ?
370 <p>It is possible to validate documents which had not been validated at
371 initial parsing time or documents who have been built from scratch using
372 the API. Use the <a
373 href="http://xmlsoft.org/html/libxml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a>
374 function. It is also possible to simply add a Dtd to an existing
375 document:</p>
376 <pre>xmlDocPtr doc; /* your existing document */
377 xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
378 dtd-&gt;name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */
379
380 doc-&gt;intSubset = dtd;
381 if (doc-&gt;children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
382 else xmlAddPrevSibling(doc-&gt;children, (xmlNodePtr)dtd);
383 </pre>
384 </li>
385 <li>etc ...</li>
386</ol>
387
388<p></p>
389
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]390<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]391
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]392<p>There are some on-line resources about using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]393<ol>
Daniel Veillard365e13b2000-07-02 07:56:37 +0000[diff] [blame]394 <li>Check the <a href="FAQ.html">FAQ</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]395 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]396 documentation</a> automatically extracted from code comments (using <a
397 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
398 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]399 <li>Look at the documentation about <a href="encoding.html">libxml
400 internationalization support</a></li>
Daniel Veillardbc66f852002-01-14 09:49:20 +0000[diff] [blame]401 <li>This page provides a global overview and <a href="example.html">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]402 examples</a> on how to use libxml.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]403 <li><a href="mailto:james@daa.com.au">James Henstridge</a>
404 wrote <a
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]405 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
406 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]407 <li>George Lebl wrote <a
408 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]409 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]410 <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO
411 file</a></li>
412 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>. If you are
413 starting a new project using libxml you should really use the 2.x
414 version.</li>
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]415 <li>And don't forget to look at the <a
416 href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]417</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]418
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]419<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]420
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]421<p>Well, bugs or missing features are always possible, and I will make a
422point of fixing them in a timely fashion. The best way to report a bug is to
423use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome
424bug tracking database</a> (make sure to use the "libxml" module name). I look
425at 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]426still open. Be sure to specify that the bug is for the package libxml.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]427
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]428<p>There is also a mailing-list <a
Daniel Veillard3197f162001-04-04 00:40:08 +0000[diff] [blame]429href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
430href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]431href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
432please visit the <a
433href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
434follow the instructions. <strong>Do not send code, I won't debug it</strong>
435(but patches are really appreciated!).</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]436
Daniel Veillard008186f2001-09-13 14:24:44 +0000[diff] [blame]437<p>Check the following <strong><span style="color: #FF0000">before
438posting</span></strong>:</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]439<ul>
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]440 <li>read the <a href="FAQ.html">FAQ</a></li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]441 <li>make sure you are <a href="ftp://xmlsoft.org/">using a recent
442 version</a>, and that the problem still shows up in those</li>
443 <li>check the <a href="http://mail.gnome.org/archives/xml/">list
444 archives</a> to see if the problem was reported already, in this case
Daniel Veillarde7ead2d2001-08-22 23:44:09 +0000[diff] [blame]445 there is probably a fix available, similary check the <a
446 href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">registered
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]447 open bugs</a></li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]448 <li>make sure you can reproduce the bug with xmllint or one of the test
449 programs found in source in the distribution</li>
450 <li>Please send the command showing the error as well as the input (as an
451 attachement)</li>
452</ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]453
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]454<p>Then send the bug with associated informations to reproduce it to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]455href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillard008186f2001-09-13 14:24:44 +0000[diff] [blame]456related I will approve it.. Please do not send me mail directly, it makes
457things really harder to track and in some cases I'm not the best person to
458answer a given question, ask the list instead.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]459
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]460<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]461probably be processed faster.</p>
462
463<p>If you're looking for help, a quick look at <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]464href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]465provide the answer, I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]466questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]467documentantion</a> is not as polished as I would like (i need to learn more
468about Docbook), but it's a good starting point.</p>
469
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]470<h2><a name="help">How to help</a></h2>
471
472<p>You can help the project in various ways, the best thing to do first is to
473subscribe to the mailing-list as explained before, check the <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]474href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
475href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]476database:</a>:</p>
477<ol>
478 <li>provide patches when you find problems</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]479 <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]480 be integrated in all cases but help pinpointing portability problems
481 and</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]482 <li>provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]483 as HTML diffs).</li>
484 <li>provide new documentations pieces (translations, examples, etc ...)</li>
485 <li>Check the TODO file and try to close one of the items</li>
486 <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]487 provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me
488 </a>before to avoid synchronization problems and check that the suggested
489 fix will fit in nicely :-)</li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]490</ol>
491
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]492<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]493
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]494<p>The latest versions of libxml can be found on <a
Daniel Veillard20c8cf22001-06-26 22:47:36 +0000[diff] [blame]495href="ftp://xmlsoft.org/">xmlsoft.org</a> (<a
496href="ftp://speakeasy.rpmfind.net/pub/libxml/">Seattle</a>, <a
497href="ftp://fr.rpmfind.net/pub/libxml/">France</a>) or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]498href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]499as a <a href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">source
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]500archive</a> or <a
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]501href="ftp://ftp.gnome.org/pub/GNOME/stable/redhat/i386/libxml/">RPM
502packages</a>. (NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]503href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
504href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]505packages installed to compile applications using libxml.) <a
506href="mailto:izlatkovic@daenet.de">Igor Zlatkovic</a> is now the maintainer
507of the Windows port, <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]508href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]509provides binaries</a>. <a href="mailto:Gary.Pennington@sun.com">Gary
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]510Pennington</a> provides <a href="http://garypennington.net/libxml2/">Solaris
511binaries</a>.</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]512
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]513<p><a name="Snapshot">Snapshot:</a></p>
514<ul>
515 <li>Code from the W3C cvs base libxml <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]516 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]517 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]518 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]519</ul>
520
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]521<p><a name="Contribs">Contributions:</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]522
523<p>I do accept external contributions, especially if compiling on another
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]524platform, get in touch with me to upload the package, wrappers for various
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]525languages have been provided, and can be found in the <a
526href="contribs.html">contrib section</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]527
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]528<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]529<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]530 <li><p>The <a
531 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]532 CVS base</a>. Check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]533 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a>
534 page; the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]535 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]536 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]537</ul>
538
539<h2><a name="News">News</a></h2>
540
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]541<h3>CVS only : check the <a
542href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]543for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]544
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]545<p>Items floating around but not actively worked on, get in touch with me if
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]546you want to test those</p>
547<ul>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]548 <li>Implementing <a href="http://xmlsoft.org/XSLT">XSLT</a>, this is done
549 as a separate C library on top of libxml called libxslt</li>
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]550 <li>Finishing up <a href="http://www.w3.org/TR/xptr">XPointer</a> and <a
551 href="http://www.w3.org/TR/xinclude">XInclude</a></li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]552 <li>(seeems working but delayed from release) parsing/import of Docbook
553 SGML docs</li>
554</ul>
555
Daniel Veillard5f4b5992002-02-20 10:22:49 +0000[diff] [blame]556<h3>2.4.16: Feb 20 2002</h3>
557<ul>
558 <li>a lot of bug fixes, most of them were triggered by the XML Testsuite
559 from OASIS and W3C. Compliance has been significantly improved.</li>
560 <li>a couple of portability fixes too.</li>
561</ul>
562
Daniel Veillard397ff112002-02-11 18:27:20 +0000[diff] [blame]563<h3>2.4.15: Feb 11 2002</h3>
564<ul>
565 <li>Fixed the Makefiles, especially the python module ones</li>
566 <li>A few bug fixes and cleanup</li>
567 <li>Includes cleanup</li>
568</ul>
569
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]570<h3>2.4.14: Feb 8 2002</h3>
571<ul>
572 <li>Change of Licence to the <a
573 href="http://www.opensource.org/licenses/mit-license.html">MIT
574 Licence</a> basisally for integration in XFree86 codebase, and removing
575 confusion around the previous dual-licencing</li>
576 <li>added Python bindings, beta software but should already be quite
577 complete</li>
578 <li>a large number of fixes and cleanups, especially for all tree
579 manipulations</li>
580 <li>cleanup of the headers, generation of a reference API definition in
581 XML</li>
582</ul>
583
584<h3>2.4.13: Jan 14 2002</h3>
Daniel Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame]585<ul>
586 <li>update of the documentation: John Fleck and Charlie Bozeman</li>
587 <li>cleanup of timing code from Justin Fletcher</li>
588 <li>fixes for Windows and initial thread support on Win32: Igor and Serguei
589 Narojnyi</li>
590 <li>Cygwin patch from Robert Collins</li>
591 <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
592</ul>
593
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]594<h3>2.4.12: Dec 7 2001</h3>
595<ul>
596 <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
597 XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
598 (robert)</li>
599 <li>Eric Lavigne contributed project files for MacOS</li>
600 <li>some makefiles cleanups</li>
601</ul>
602
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]603<h3>2.4.11: Nov 26 2001</h3>
604<ul>
605 <li>fixed a couple of errors in the includes, fixed a few bugs, some code
606 cleanups</li>
607 <li>xmllint man pages improvement by Heiko Rupp</li>
608 <li>updated VMS build instructions from John A Fotheringham</li>
609 <li>Windows Makefiles updates from Igor</li>
610</ul>
611
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]612<h3>2.4.10: Nov 10 2001</h3>
613<ul>
614 <li>URI escaping fix (Joel Young)</li>
615 <li>added xmlGetNodePath() (for paths or XPointers generation)</li>
616 <li>Fixes namespace handling problems when using DTD and validation</li>
617 <li>improvements on xmllint: Morus Walter patches for --format and
618 --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
619 <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
620 <li>fixes to the HTML parser</li>
621</ul>
622
623<h3>2.4.9: Nov 6 2001</h3>
624<ul>
625 <li>fixes more catalog bugs</li>
626 <li>avoid a compilation problem, improve xmlGetLineNo()</li>
627</ul>
628
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]629<h3>2.4.8: Nov 4 2001</h3>
630<ul>
631 <li>fixed SGML catalogs broken in previous release, updated xmlcatalog
632 tool</li>
633 <li>fixed a compile errors and some includes troubles.</li>
634</ul>
635
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]636<h3>2.4.7: Oct 30 2001</h3>
637<ul>
638 <li>exported some debugging interfaces</li>
639 <li>serious rewrite of the catalog code</li>
640 <li>integrated Gary Pennington thread safety patch, added configure option
641 and regression tests</li>
642 <li>removed an HTML parser bug</li>
643 <li>fixed a couple of potentially serious validation bugs</li>
644 <li>integrated the SGML DocBook support in xmllint</li>
645 <li>changed the nanoftp anonymous login passwd</li>
646 <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
647 <li>general bug fixes</li>
648 <li>updated xmllint man page by John Fleck</li>
649 <li>some VMS and Windows updates</li>
650</ul>
651
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]652<h3>2.4.6: Oct 10 2001</h3>
653<ul>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]654 <li>added an updated man pages by John Fleck</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]655 <li>portability and configure fixes</li>
656 <li>an infinite loop on the HTML parser was removed (William)</li>
657 <li>Windows makefile patches from Igor</li>
658 <li>fixed half a dozen bugs reported fof libxml or libxslt</li>
659 <li>updated xmlcatalog to be able to modify SGML super catalogs</li>
660</ul>
661
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]662<h3>2.4.5: Sep 14 2001</h3>
663<ul>
664 <li>Remove a few annoying bugs in 2.4.4</li>
665 <li>forces the HTML serializer to output decimal charrefs since some
666 version of Netscape can't handle hexadecimal ones</li>
667</ul>
668
669<h3>1.8.16: Sep 14 2001</h3>
670<ul>
671 <li>maintenance release of the old libxml1 branch, couple of bug and
672 portability fixes</li>
673</ul>
674
Daniel Veillard04382ae2001-09-12 18:51:30 +0000[diff] [blame]675<h3>2.4.4: Sep 12 2001</h3>
676<ul>
677 <li>added --convert to xmlcatalog, bug fixes and cleanups of XML
678 Catalog</li>
679 <li>a few bug fixes and some portability changes</li>
680 <li>some documentation cleanups</li>
681</ul>
682
Daniel Veillard39936902001-08-24 00:49:01 +0000[diff] [blame]683<h3>2.4.3: Aug 23 2001</h3>
684<ul>
685 <li>XML Catalog support see the doc</li>
686 <li>New NaN/Infinity floating point code</li>
687 <li>A few bug fixes</li>
688</ul>
689
690<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]691<ul>
692 <li>adds xmlLineNumbersDefault() to control line number generation</li>
693 <li>lot of bug fixes</li>
694 <li>the Microsoft MSC projects files shuld now be up to date</li>
695 <li>inheritance of namespaces from DTD defaulted attributes</li>
696 <li>fixes a serious potential security bug</li>
697 <li>added a --format option to xmllint</li>
698</ul>
699
700<h3>2.4.1: July 24 2001</h3>
701<ul>
702 <li>possibility to keep line numbers in the tree</li>
703 <li>some computation NaN fixes</li>
704 <li>extension of the XPath API</li>
705 <li>cleanup for alpha and ia64 targets</li>
706 <li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]707</ul>
708
709<h3>2.4.0: July 10 2001</h3>
710<ul>
711 <li>Fixed a few bugs in XPath, validation, and tree handling.</li>
712 <li>Fixed XML Base implementation, added a coupel of examples to the
713 regression tests</li>
714 <li>A bit of cleanup</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]715</ul>
716
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]717<h3>2.3.14: July 5 2001</h3>
718<ul>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]719 <li>fixed some entities problems and reduce mem requirement when
720 substituing them</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]721 <li>lots of improvements in the XPath queries interpreter can be
722 substancially faster</li>
723 <li>Makefiles and configure cleanups</li>
724 <li>Fixes to XPath variable eval, and compare on empty node set</li>
725 <li>HTML tag closing bug fixed</li>
726 <li>Fixed an URI reference computating problem when validating</li>
727</ul>
728
Daniel Veillard2adbb512001-06-28 16:20:36 +0000[diff] [blame]729<h3>2.3.13: June 28 2001</h3>
730<ul>
731 <li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
732 <li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
733</ul>
734
735<h3>1.8.14: June 28 2001</h3>
736<ul>
737 <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
738 <li>Small Makefile fix</li>
739</ul>
740
Daniel Veillard11648102001-06-26 16:08:24 +0000[diff] [blame]741<h3>2.3.12: June 26 2001</h3>
742<ul>
743 <li>lots of cleanup</li>
744 <li>a couple of validation fix</li>
745 <li>fixed line number counting</li>
746 <li>fixed serious problems in the XInclude processing</li>
747 <li>added support for UTF8 BOM at beginning of entities</li>
748 <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
749 miscompile uri.c (William), Thomas Leitner provided a fix for the
750 optimizer on Tru64</li>
751 <li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
752 compilation on Windows MSC</li>
753 <li>update of libxml-doc.el (Felix Natter)</li>
754 <li>fixed 2 bugs in URI normalization code</li>
755</ul>
756
Daniel Veillarde3c81b52001-06-17 14:50:34 +0000[diff] [blame]757<h3>2.3.11: June 17 2001</h3>
758<ul>
759 <li>updates to trio, Makefiles and configure should fix some portability
760 problems (alpha)</li>
761 <li>fixed some HTML serialization problems (pre, script, and block/inline
762 handling), added encoding aware APIs, cleanup of this code</li>
763 <li>added xmlHasNsProp()</li>
764 <li>implemented a specific PI for encoding support in the DocBook SGML
765 parser</li>
766 <li>some XPath fixes (-Infinity, / as a function parameter and namespaces
767 node selection)</li>
768 <li>fixed a performance problem and an error in the validation code</li>
769 <li>fixed XInclude routine to implement the recursive behaviour</li>
770 <li>fixed xmlFreeNode problem when libxml is included statically twice</li>
771 <li>added --version to xmllint for bug reports</li>
772</ul>
773
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]774<h3>2.3.10: June 1 2001</h3>
775<ul>
776 <li>fixed the SGML catalog support</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]777 <li>a number of reported bugs got fixed, in XPath, iconv detection,
778 XInclude processing</li>
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]779 <li>XPath string function should now handle unicode correctly</li>
780</ul>
781
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]782<h3>2.3.9: May 19 2001</h3>
783
784<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
785<ul>
786 <li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
787 <li>some serious speed optimisation again</li>
788 <li>some documentation cleanups</li>
789 <li>trying to get better linking on solaris (-R)</li>
790 <li>XPath API cleanup from Thomas Broyer</li>
791 <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
792 xmlValidGetValidElements()</li>
793 <li>Added an INSTALL file</li>
794 <li>Attribute removal added to API: #54433</li>
795 <li>added a basic support for SGML catalogs</li>
796 <li>fixed xmlKeepBlanksDefault(0) API</li>
797 <li>bugfix in xmlNodeGetLang()</li>
798 <li>fixed a small configure portability problem</li>
799 <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
800</ul>
801
Daniel Veillarda265af72001-05-14 11:13:58 +0000[diff] [blame]802<h3>1.8.13: May 14 2001</h3>
803<ul>
804 <li>bugfixes release of the old libxml1 branch used by Gnome</li>
805</ul>
806
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]807<h3>2.3.8: May 3 2001</h3>
808<ul>
809 <li>Integrated an SGML DocBook parser for the Gnome project</li>
810 <li>Fixed a few things in the HTML parser</li>
811 <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
812 point portability issue</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]813 <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
814 DOM+validation using the XML REC as input and a 700MHz celeron).</li>
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]815 <li>incorporated more Windows cleanup</li>
816 <li>added xmlSaveFormatFile()</li>
817 <li>fixed problems in copying nodes with entities references (gdome)</li>
818 <li>removed some troubles surrounding the new validation module</li>
819</ul>
820
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]821<h3>2.3.7: April 22 2001</h3>
822<ul>
823 <li>lots of small bug fixes, corrected XPointer</li>
824 <li>Non determinist content model validation support</li>
825 <li>added xmlDocCopyNode for gdome2</li>
826 <li>revamped the way the HTML parser handles end of tags</li>
827 <li>XPath: corrctions of namespacessupport and number formatting</li>
828 <li>Windows: Igor Zlatkovic patches for MSC compilation</li>
829 <li>HTML ouput fixes from P C Chow and William M. Brack</li>
830 <li>Improved validation speed sensible for DocBook</li>
831 <li>fixed a big bug with ID declared in external parsed entities</li>
832 <li>portability fixes, update of Trio from Bjorn Reese</li>
833</ul>
834
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]835<h3>2.3.6: April 8 2001</h3>
836<ul>
837 <li>Code cleanup using extreme gcc compiler warning options, found and
838 cleared half a dozen potential problem</li>
839 <li>the Eazel team found an XML parser bug</li>
840 <li>cleaned up the user of some of the string formatting function. used the
841 trio library code to provide the one needed when the platform is missing
842 them</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]843 <li>xpath: removed a memory leak and fixed the predicate evaluation
844 problem, extended the testsuite and cleaned up the result. XPointer seems
845 broken ...</li>
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]846</ul>
847
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame]848<h3>2.3.5: Mar 23 2001</h3>
849<ul>
850 <li>Biggest change is separate parsing and evaluation of XPath expressions,
851 there is some new APIs for this too</li>
852 <li>included a number of bug fixes(XML push parser, 51876, notations,
853 52299)</li>
854 <li>Fixed some portability issues</li>
855</ul>
856
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]857<h3>2.3.4: Mar 10 2001</h3>
858<ul>
859 <li>Fixed bugs #51860 and #51861</li>
860 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
861 size to be application tunable.</li>
862 <li>Some cleanup in the validation code, still a bug left and this part
863 should probably be rewritten to support ambiguous content model :-\</li>
864 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
865 parser</li>
866 <li>Fixed another bug in xmlNodeGetContent()</li>
867 <li>Bjorn fixed XPath node collection and Number formatting</li>
868 <li>Fixed a loop reported in the HTML parsing</li>
869 <li>blank space are reported even if the Dtd content model proves that they
870 are formatting spaces, this is for XmL conformance</li>
871</ul>
872
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]873<h3>2.3.3: Mar 1 2001</h3>
874<ul>
875 <li>small change in XPath for XSLT</li>
876 <li>documentation cleanups</li>
877 <li>fix in validation by Gary Pennington</li>
878 <li>serious parsing performances improvements</li>
879</ul>
880
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]881<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]882<ul>
883 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
884 <li>fixed a Dtd parsing bug</li>
885 <li>fixed a bug in xmlNodeGetContent</li>
886 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
887</ul>
888
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]889<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]890<ul>
891 <li>some XPath and HTML bug fixes for XSLT</li>
892 <li>small extension of the hash table interfaces for DOM gdome2
893 implementation</li>
894 <li>A few bug fixes</li>
895</ul>
896
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]897<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]898<ul>
899 <li>Lots of XPath bug fixes</li>
900 <li>Add a mode with Dtd lookup but without validation error reporting for
901 XSLT</li>
902 <li>Add support for text node without escaping (XSLT)</li>
903 <li>bug fixes for xmlCheckFilename</li>
904 <li>validation code bug fixes from Gary Pennington</li>
905 <li>Patch from Paul D. Smith correcting URI path normalization</li>
906 <li>Patch to allow simultaneous install of libxml-devel and
907 libxml2-devel</li>
908 <li>the example Makefile is now fixed</li>
909 <li>added HTML to the RPM packages</li>
910 <li>tree copying bugfixes</li>
911 <li>updates to Windows makefiles</li>
912 <li>optimisation patch from Bjorn Reese</li>
913</ul>
914
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]915<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]916<ul>
917 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
918 <li>added htmlHandleOmittedElem()</li>
919 <li>Applied Bjorn Reese's IPV6 first patch</li>
920 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]921 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]922</ul>
923
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]924<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]925<ul>
926 <li>Fix the Windows problems of 2.2.8</li>
927 <li>integrate OpenVMS patches</li>
928 <li>better handling of some nasty HTML input</li>
929 <li>Improved the XPointer implementation</li>
930 <li>integrate a number of provided patches</li>
931</ul>
932
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]933<h3>2.2.9: Nov 25 2000</h3>
934<ul>
935 <li>erroneous release :-(</li>
936</ul>
937
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]938<h3>2.2.8: Nov 13 2000</h3>
939<ul>
940 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
941 support</li>
942 <li>Patch in conditional section handling</li>
943 <li>updated MS compiler project</li>
944 <li>fixed some XPath problems</li>
945 <li>added an URI escaping function</li>
946 <li>some other bug fixes</li>
947</ul>
948
949<h3>2.2.7: Oct 31 2000</h3>
950<ul>
951 <li>added message redirection</li>
952 <li>XPath improvements (thanks TOM !)</li>
953 <li>xmlIOParseDTD() added</li>
954 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
955 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
956</ul>
957
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]958<h3>2.2.6: Oct 25 2000:</h3>
959<ul>
960 <li>Added an hash table module, migrated a number of internal structure to
961 those</li>
962 <li>Fixed a posteriori validation problems</li>
963 <li>HTTP module cleanups</li>
964 <li>HTML parser improvements (tag errors, script/style handling, attribute
965 normalization)</li>
966 <li>coalescing of adjacent text nodes</li>
967 <li>couple of XPath bug fixes, exported the internal API</li>
968</ul>
969
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]970<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]971<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]972 <li>XPointer implementation and testsuite</li>
973 <li>Lot of XPath fixes, added variable and functions registration, more
974 tests</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]975 <li>Portability fixes, lots of enhancements toward an easy Windows build
976 and release</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]977 <li>Late validation fixes</li>
978 <li>Integrated a lot of contributed patches</li>
979 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]980 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]981</ul>
982
983<h3>2.2.4: Oct 1 2000:</h3>
984<ul>
985 <li>main XPath problem fixed</li>
986 <li>Integrated portability patches for Windows</li>
987 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]988</ul>
989
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]990<h3>2.2.3: Sep 17 2000</h3>
991<ul>
992 <li>bug fixes</li>
993 <li>cleanup of entity handling code</li>
994 <li>overall review of all loops in the parsers, all sprintf usage has been
995 checked too</li>
996 <li>Far better handling of larges Dtd. Validating against Docbook XML Dtd
997 works smoothly now.</li>
998</ul>
999
1000<h3>1.8.10: Sep 6 2000</h3>
1001<ul>
1002 <li>bug fix release for some Gnome projects</li>
1003</ul>
1004
1005<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1006<ul>
1007 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]1008 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]1009</ul>
1010
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1011<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1012<ul>
1013 <li>a purely bug fixes release</li>
1014 <li>fixed an encoding support problem when parsing from a memory block</li>
1015 <li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1016 <li>removed a bug in the function allowing to override the memory
1017 allocation routines</li>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]1018</ul>
1019
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]1020<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]1021<ul>
1022 <li>applied a lot of portability fixes</li>
1023 <li>better encoding support/cleanup and saving (content is now always
1024 encoded in UTF-8)</li>
1025 <li>the HTML parser now correctly handles encodings</li>
1026 <li>added xmlHasProp()</li>
1027 <li>fixed a serious problem with &amp;#38;</li>
1028 <li>propagated the fix to FTP client</li>
1029 <li>cleanup, bugfixes, etc ...</li>
1030 <li>Added a page about <a href="encoding.html">libxml Internationalization
1031 support</a></li>
1032</ul>
1033
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1034<h3>1.8.9: July 9 2000</h3>
1035<ul>
1036 <li>fixed the spec the RPMs should be better</li>
1037 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
1038 rpmfind users problem</li>
1039</ul>
1040
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]1041<h3>2.1.1: July 1 2000</h3>
1042<ul>
1043 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
1044 <li>improvements on the HTML parser</li>
1045</ul>
1046
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1047<h3>2.1.0 and 1.8.8: June 29 2000</h3>
1048<ul>
1049 <li>1.8.8 is mostly a comodity package for upgrading to libxml2 accoding to
1050 <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
1051 about &amp;#38; charref parsing</li>
1052 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
1053 also contains numerous fixes and enhancements:
1054 <ul>
1055 <li>added xmlStopParser() to stop parsing</li>
1056 <li>improved a lot parsing speed when there is large CDATA blocs</li>
1057 <li>includes XPath patches provided by Picdar Technology</li>
1058 <li>tried to fix as much as possible DtD validation and namespace
1059 related problems</li>
1060 <li>output to a given encoding has been added/tested</li>
1061 <li>lot of various fixes</li>
1062 </ul>
1063 </li>
1064</ul>
1065
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1066<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1067<ul>
1068 <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]1069 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initally
1070 scheduled for Apr 3 the relase occured only on Apr 12 due to massive
1071 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1072 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1073 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1074 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1075 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1076 <pre>#include "xxx.h"</pre>
1077 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]1078 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
1079 <li>the memory allocation routines used by libxml can now be overloaded
1080 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1081 <li>The previously CVS only tool tester has been renamed
1082 <strong>xmllint</strong> and is now installed as part of the libxml2
1083 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1084 <li>The I/O interface has been revamped. There is now ways to plug in
1085 specific I/O modules, either at the URI scheme detection level using
1086 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
1087 parser context using xmlCreateIOParserCtxt()</li>
1088 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
1089 number of the libxml module in use</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1090 <li>a number of optional features of libxml can now be excluded at
1091 configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1092</ul>
1093
1094<h3>2.0.0beta: Mar 14 2000</h3>
1095<ul>
1096 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1097 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
1098 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
1099 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1100 <li>This version is now the head in the Gnome CVS base, the old one is
1101 available under the tag LIB_XML_1_X</li>
1102 <li>This includes a very large set of changes. Froma programmatic point of
1103 view applications should not have to be modified too much, check the <a
1104 href="upgrade.html">upgrade page</a></li>
1105 <li>Some interfaces may changes (especially a bit about encoding).</li>
1106 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1107 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1108 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
1109 handled now</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1110 <li>Better handling of entities, especially well formedness checking
1111 and proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1112 <li>DTD conditional sections</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1113 <li>Validation now correcly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1114 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
1115 structures to accomodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1116 </ul>
1117 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1118 <li>Serious progress were made toward compliance, <a
1119 href="conf/result.html">here are the result of the test</a> against the
1120 OASIS testsuite (except the japanese tests since I don't support that
1121 encoding yet). This URL is rebuilt every couple of hours using the CVS
1122 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1123</ul>
1124
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1125<h3>1.8.7: Mar 6 2000</h3>
1126<ul>
1127 <li>This is a bug fix release:</li>
1128 <li>It is possible to disable the ignorable blanks heuristic used by
1129 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1130 that for adherence to XML spec, this behaviour will be disabled by
1131 default in 2.x . The same function will allow to keep compatibility for
1132 old code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1133 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
1134 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1135 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
1136 compilation on some platforms has been fixed</li>
1137 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
1138 URIs</li>
1139</ul>
1140
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1141<h3>1.8.6: Jan 31 2000</h3>
1142<ul>
1143 <li>added a nanoFTP transport module, debugged until the new version of <a
1144 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
1145 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]1146</ul>
1147
1148<h3>1.8.5: Jan 21 2000</h3>
1149<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1150 <li>adding APIs to parse a well balanced chunk of XML (production <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1151 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
1152 XML spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1153 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1154 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
1155 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1156 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
1157 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1158</ul>
1159
1160<h3>1.8.4: Jan 13 2000</h3>
1161<ul>
1162 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
1163 <li>all exit() call should have been removed from libxml</li>
1164 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
1165 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1166</ul>
1167
1168<h3>1.8.3: Jan 5 2000</h3>
1169<ul>
1170 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1171 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillarddbfd6411999-12-28 16:35:14 +0000[diff] [blame]1172 <li>lots of bug fixes and improvement added over XMas hollidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1173 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1174 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
1175 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1176 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1177 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1178 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1179</ul>
1180
1181<h3>1.8.2: Dec 21 1999</h3>
1182<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1183 <li>I got another problem with includes and C++, I hope this issue is fixed
1184 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1185 <li>Added a few tree modification functions: xmlReplaceNode,
1186 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
1187 xmlDocSetRootElement</li>
1188 <li>Tried to improve the HTML output with help from <a
1189 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1190</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1191
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1192<h3>1.8.1: Dec 18 1999</h3>
1193<ul>
1194 <li>various patches to avoid troubles when using libxml with C++ compilers
1195 the "namespace" keyword and C escaping in include files</li>
1196 <li>a problem in one of the core macros IS_CHAR was corrected</li>
1197 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
1198 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]1199 <li>fixed a posteriori validation (validation after parsing, or by using a
1200 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1201 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]1202</ul>
1203
1204<h3>1.8.0: Dec 12 1999</h3>
1205<ul>
1206 <li>cleanup, especially memory wise</li>
1207 <li>the parser should be more reliable, especially the HTML one, it should
1208 not crash, whatever the input !</li>
1209 <li>Integrated various patches, especially a speedup improvement for large
1210 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
1211 configure with --with-buffers to enable them.</li>
1212 <li>attribute normalization, oops should have been added long ago !</li>
1213 <li>attributes defaulted from Dtds should be available, xmlSetProp() now
1214 does entities escapting by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1215</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1216
1217<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1218<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1219 <li>Lots of HTML improvement</li>
1220 <li>Fixed some errors when saving both XML and HTML</li>
1221 <li>More examples, the regression tests should now look clean</li>
1222 <li>Fixed a bug with contiguous charref</li>
1223</ul>
1224
1225<h3>1.7.3: Sep 29 1999</h3>
1226<ul>
1227 <li>portability problems fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1228 <li>snprintf was used unconditionnally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1229 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1230</ul>
1231
1232<h3>1.7.1: Sep 24 1999</h3>
1233<ul>
1234 <li>The basic type for strings manipulated by libxml has been renamed in
1235 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1236 is that CHAR was conflicting with a predefined type on Windows. However
1237 on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1238 <strong>#define </strong>.</li>
1239 <li>Changed another error : the use of a structure field called errno, and
1240 leading to troubles on platforms where it's a macro</li>
1241</ul>
1242
1243<h3>1.7.0: sep 23 1999</h3>
1244<ul>
1245 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1246 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1247 <li>Added an errno to report errors by another mean than a simple printf
1248 like callback</li>
1249 <li>Finished ID/IDREF support and checking when validation</li>
1250 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1251 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1252 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
1253 implementation</li>
1254 <li>Added an HTML parser front-end</li>
1255</ul>
1256
1257<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1258
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1259<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]1260markup-based structured documents. Here is <a name="example">an example XML
1261document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1262<pre>&lt;?xml version="1.0"?&gt;
1263&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
1264 &lt;head&gt;
1265 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
1266 &lt;/head&gt;
1267 &lt;chapter&gt;
1268 &lt;title&gt;The Linux adventure&lt;/title&gt;
1269 &lt;p&gt;bla bla bla ...&lt;/p&gt;
1270 &lt;image href="linus.gif"/&gt;
1271 &lt;p&gt;...&lt;/p&gt;
1272 &lt;/chapter&gt;
1273&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1274
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1275<p>The first line specifies that it's an XML document and gives useful
1276information about its encoding. Then the document is a text format whose
1277structure is specified by tags between brackets. <strong>Each tag opened has
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1278to be closed</strong>. XML is pedantic about this. However, if a tag is empty
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1279(no content), a single tag can serve as both the opening and closing tag if
1280it ends with <code>/&gt;</code> rather than with <code>&gt;</code>. Note
1281that, for example, the image tag has no content (just an attribute) and is
1282closed by ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1283
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1284<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]1285structured document maintenance (where it follows the steps of SGML) to
1286simple data encoding mechanisms like configuration file formatting (glade),
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1287spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where
1288it is used to encode remote calls between a client and a server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1289
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1290<h2><a name="XSLT">XSLT</a></h2>
1291
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1292<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
1293
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1294<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
1295language for transforming XML documents into other XML documents (or
1296HTML/textual output).</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1297
1298<p>A separate library called libxslt is being built on top of libxml2. This
1299module "libxslt" can be found in the Gnome CVS base too.</p>
1300
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]1301<p>You can check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1302href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
1303supported and the progresses on the <a
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1304href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog">Changelog</a></p>
1305
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1306<h2><a name="architecture">libxml architecture</a></h2>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1307
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1308<p>Libxml is made of multiple components; some of them are optional, and most
1309of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1310<ul>
1311 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1312 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1313 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1314 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1315 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1316 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1317 <li>a SAX tree module to build an in-memory DOM representation</li>
1318 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1319 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1320 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1321 (optional)</li>
1322 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1323</ul>
1324
1325<p>Graphically this gives the following:</p>
1326
1327<p><img src="libxml.gif" alt="a graphical view of the various"></p>
1328
1329<p></p>
1330
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1331<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1332
1333<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1334returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1335<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1336as the file name, the document type, and a <strong>children</strong> pointer
1337which is the root of the document (or more exactly the first child under the
1338root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1339chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1340relationship. An xmlNode can also carry properties (a chain of xmlAttr
1341structures). An attribute may have a value which is a list of TEXT or
1342ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1343
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1344<p>Here is an example (erroneous with respect to the XML spec since there
1345should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1346
1347<p><img src="structure.gif" alt=" structure.gif "></p>
1348
1349<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1350called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1351prints them back as parsed. This is useful for detecting errors both in XML
1352code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1353which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1354result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1355<pre>DOCUMENT
1356version=1.0
1357standalone=true
1358 ELEMENT EXAMPLE
1359 ATTRIBUTE prop1
1360 TEXT
1361 content=gnome is great
1362 ATTRIBUTE prop2
1363 ENTITY_REF
1364 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1365 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1366 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1367 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1368 TEXT
1369 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1370 ELEMENT chapter
1371 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1372 TEXT
1373 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1374 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1375 TEXT
1376 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1377 ELEMENT image
1378 ATTRIBUTE href
1379 TEXT
1380 content=linus.gif
1381 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1382 TEXT
1383 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1384
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1385<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1386
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1387<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1388
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1389<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1390memory. 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]1391loaded using libxml), it's better to use the SAX interface of libxml. SAX is
1392a <strong>callback-based interface</strong> to the parser. Before parsing,
1393the application layer registers a customized set of callbacks which are
1394called by the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1395
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1396<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]1397libxml, see the <a
1398href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
1399documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1400Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1401
1402<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
1403program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1404binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1405distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1406testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1407<pre>SAX.setDocumentLocator()
1408SAX.startDocument()
1409SAX.getEntity(amp)
1410SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
1411SAX.characters( , 3)
1412SAX.startElement(head)
1413SAX.characters( , 4)
1414SAX.startElement(title)
1415SAX.characters(Welcome to Gnome, 16)
1416SAX.endElement(title)
1417SAX.characters( , 3)
1418SAX.endElement(head)
1419SAX.characters( , 3)
1420SAX.startElement(chapter)
1421SAX.characters( , 4)
1422SAX.startElement(title)
1423SAX.characters(The Linux adventure, 19)
1424SAX.endElement(title)
1425SAX.characters( , 4)
1426SAX.startElement(p)
1427SAX.characters(bla bla bla ..., 15)
1428SAX.endElement(p)
1429SAX.characters( , 4)
1430SAX.startElement(image, href='linus.gif')
1431SAX.endElement(image)
1432SAX.characters( , 4)
1433SAX.startElement(p)
1434SAX.characters(..., 3)
1435SAX.endElement(p)
1436SAX.characters( , 3)
1437SAX.endElement(chapter)
1438SAX.characters( , 1)
1439SAX.endElement(EXAMPLE)
1440SAX.endDocument()</pre>
1441
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1442<p>Most of the other interfaces of libxml are based on the DOM tree-building
1443facility, so nearly everything up to the end of this document presupposes the
1444use of the standard DOM tree build. Note that the DOM tree itself is built by
1445a set of registered default callbacks, without internal specific
1446interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1447
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1448<h2><a name="Validation">Validation &amp; DTDs</a></h2>
1449
1450<p>Table of Content:</p>
1451<ol>
1452 <li><a href="#General5">General overview</a></li>
1453 <li><a href="#definition">The definition</a></li>
1454 <li><a href="#Simple">Simple rules</a>
1455 <ol>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]1456 <li><a href="#reference">How to reference a DTD from a document</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1457 <li><a href="#Declaring">Declaring elements</a></li>
1458 <li><a href="#Declaring1">Declaring attributes</a></li>
1459 </ol>
1460 </li>
1461 <li><a href="#Some">Some examples</a></li>
1462 <li><a href="#validate">How to validate</a></li>
1463 <li><a href="#Other">Other resources</a></li>
1464</ol>
1465
1466<h3><a name="General5">General overview</a></h3>
1467
1468<p>Well what is validation and what is a DTD ?</p>
1469
1470<p>DTD is the acronym for Document Type Definition. This is a description of
1471the content for a familly of XML files. This is part of the XML 1.0
1472specification, and alows to describe and check that a given document instance
1473conforms to a set of rules detailing its structure and content.</p>
1474
1475<p>Validation is the process of checking a document against a DTD (more
1476generally against a set of construction rules).</p>
1477
1478<p>The validation process and building DTDs are the two most difficult parts
1479of the XML life cycle. Briefly a DTD defines all the possibles element to be
1480found within your document, what is the formal shape of your document tree
1481(by defining the allowed content of an element, either text, a regular
1482expression for the allowed list of children, or mixed content i.e. both text
1483and children). The DTD also defines the allowed attributes for all elements
1484and the types of the attributes.</p>
1485
1486<h3><a name="definition1">The definition</a></h3>
1487
1488<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
1489href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
1490Rev1</a>):</p>
1491<ul>
1492 <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
1493 elements</a></li>
1494 <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
1495 attributes</a></li>
1496</ul>
1497
1498<p>(unfortunately) all this is inherited from the SGML world, the syntax is
1499ancient...</p>
1500
1501<h3><a name="Simple1">Simple rules</a></h3>
1502
1503<p>Writing DTD can be done in multiple ways, the rules to build them if you
1504need something fixed or something which can evolve over time can be radically
1505different. Really complex DTD like Docbook ones are flexible but quite harder
1506to design. I will just focuse on DTDs for a formats with a fixed simple
1507structure. It is just a set of basic rules, and definitely not exhaustive nor
1508useable for complex DTD design.</p>
1509
1510<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
1511
1512<p>Assuming the top element of the document is <code>spec</code> and the dtd
1513is placed in the file <code>mydtd</code> in the subdirectory
1514<code>dtds</code> of the directory from where the document were loaded:</p>
1515
1516<p><code>&lt;!DOCTYPE spec SYSTEM "dtds/mydtd"&gt;</code></p>
1517
1518<p>Notes:</p>
1519<ul>
1520 <li>the system string is actually an URI-Reference (as defined in <a
1521 href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396</a>) so you can use a
1522 full URL string indicating the location of your DTD on the Web, this is a
1523 really good thing to do if you want others to validate your document</li>
1524 <li>it is also possible to associate a <code>PUBLIC</code> identifier (a
1525 magic string) so that the DTd is looked up in catalogs on the client side
1526 without having to locate it on the web</li>
1527 <li>a dtd contains a set of elements and attributes declarations, but they
1528 don't define what the root of the document should be. This is explicitely
1529 told to the parser/validator as the first element of the
1530 <code>DOCTYPE</code> declaration.</li>
1531</ul>
1532
1533<h4><a name="Declaring2">Declaring elements</a>:</h4>
1534
1535<p>The following declares an element <code>spec</code>:</p>
1536
1537<p><code>&lt;!ELEMENT spec (front, body, back?)&gt;</code></p>
1538
1539<p>it also expresses that the spec element contains one <code>front</code>,
1540one <code>body</code> and one optionnal <code>back</code> children elements
1541in this order. The declaration of one element of the structure and its
1542content are done in a single declaration. Similary the following declares
1543<code>div1</code> elements:</p>
1544
Daniel Veillard51737272002-01-23 23:10:38 +0000[diff] [blame]1545<p><code>&lt;!ELEMENT div1 (head, (p | list | note)*, div2?)&gt;</code></p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1546
1547<p>means div1 contains one <code>head</code> then a series of optional
1548<code>p</code>, <code>list</code>s and <code>note</code>s and then an
1549optional <code>div2</code>. And last but not least an element can contain
1550text:</p>
1551
1552<p><code>&lt;!ELEMENT b (#PCDATA)&gt;</code></p>
1553
1554<p><code>b</code> contains text or being of mixed content (text and elements
1555in no particular order):</p>
1556
1557<p><code>&lt;!ELEMENT p (#PCDATA|a|ul|b|i|em)*&gt;</code></p>
1558
1559<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
1560<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
1561order.</p>
1562
1563<h4><a name="Declaring1">Declaring attributes</a>:</h4>
1564
1565<p>again the attributes declaration includes their content definition:</p>
1566
1567<p><code>&lt;!ATTLIST termdef name CDATA #IMPLIED&gt;</code></p>
1568
1569<p>means that the element <code>termdef</code> can have a <code>name</code>
1570attribute containing text (<code>CDATA</code>) and which is optionnal
1571(<code>#IMPLIED</code>). The attribute value can also be defined within a
1572set:</p>
1573
1574<p><code>&lt;!ATTLIST list type (bullets|ordered|glossary)
1575"ordered"&gt;</code></p>
1576
1577<p>means <code>list</code> element have a <code>type</code> attribute with 3
1578allowed values "bullets", "ordered" or "glossary" and which default to
1579"ordered" if the attribute is not explicitely specified.</p>
1580
1581<p>The content type of an attribute can be text (<code>CDATA</code>),
1582anchor/reference/references
1583(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
1584(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
1585(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
1586<code>chapter</code> element can have an optional <code>id</code> attribute
1587of type <code>ID</code>, usable for reference from attribute of type
1588IDREF:</p>
1589
1590<p><code>&lt;!ATTLIST chapter id ID #IMPLIED&gt;</code></p>
1591
1592<p>The last value of an attribute definition can be <code>#REQUIRED
1593</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
1594meaning that it is optional, or the default value (possibly prefixed by
1595<code>#FIXED</code> if it is the only allowed).</p>
1596
1597<p>Notes:</p>
1598<ul>
1599 <li>usually the attributes pertaining to a given element are declared in a
1600 single expression, but it is just a convention adopted by a lot of DTD
1601 writers:
1602 <pre>&lt;!ATTLIST termdef
1603 id ID #REQUIRED
1604 name CDATA #IMPLIED&gt;</pre>
1605 <p>The previous construct defines both <code>id</code> and
1606 <code>name</code> attributes for the element <code>termdef</code></p>
1607 </li>
1608</ul>
1609
1610<h3><a name="Some1">Some examples</a></h3>
1611
1612<p>The directory <code>test/valid/dtds/</code> in the libxml distribution
1613contains some complex DTD examples. The <code>test/valid/dia.xml</code>
1614example shows an XML file where the simple DTD is directly included within
1615the document.</p>
1616
1617<h3><a name="validate1">How to validate</a></h3>
1618
1619<p>The simplest is to use the xmllint program comming with libxml. The
1620<code>--valid</code> option turn on validation of the files given as input,
1621for example the following validates a copy of the first revision of the XML
16221.0 specification:</p>
1623
1624<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
1625
1626<p>the -- noout is used to not output the resulting tree.</p>
1627
1628<p>The <code>--dtdvalid dtd</code> allows to validate the document(s) against
1629a given DTD.</p>
1630
1631<p>Libxml exports an API to handle DTDs and validation, check the <a
1632href="http://xmlsoft.org/html/libxml-valid.html">associated
1633description</a>.</p>
1634
1635<h3><a name="Other1">Other resources</a></h3>
1636
1637<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
1638will just list one for now, others pointers welcome:</p>
1639<ul>
1640 <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
1641</ul>
1642
1643<p>I suggest looking at the examples found under test/valid/dtd and any of
1644the large number of books available on XML. The dia example in test/valid
1645should be both simple and complete enough to allow you to build your own.</p>
1646
1647<p></p>
1648
1649<h2><a name="Memory">Memory Management</a></h2>
1650
1651<p>Table of Content:</p>
1652<ol>
1653 <li><a href="#General3">General overview</a></li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]1654 <li><a href="#setting">Setting libxml set of memory routines</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1655 <li><a href="#cleanup">Cleaning up after parsing</a></li>
1656 <li><a href="#Debugging">Debugging routines</a></li>
1657 <li><a href="#General4">General memory requirements</a></li>
1658</ol>
1659
1660<h3><a name="General3">General overview</a></h3>
1661
1662<p>The module <code><a
1663href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
1664provides the interfaces to the libxml memory system:</p>
1665<ul>
1666 <li>libxml does not use the libc memory allocator directly but xmlFree(),
1667 xmlMalloc() and xmlRealloc()</li>
1668 <li>those routines can be reallocated to a specific set of routine, by
1669 default the libc ones i.e. free(), malloc() and realloc()</li>
1670 <li>the xmlmemory.c module includes a set of debugging routine</li>
1671</ul>
1672
1673<h3><a name="setting">Setting libxml set of memory routines</a></h3>
1674
1675<p>It is sometimes useful to not use the default memory allocator, either for
1676debugging, analysis or to implement a specific behaviour on memory management
1677(like on embedded systems). Two function calls are available to do so:</p>
1678<ul>
1679 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet ()</a>
1680 which return the current set of functions in use by the parser</li>
1681 <li><a
1682 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
1683 which allow to set up a new set of memory allocation functions</li>
1684</ul>
1685
1686<p>Of course a call to xmlMemSetup() should probably be done before calling
1687any other libxml routines (unless you are sure your allocations routines are
1688compatibles).</p>
1689
1690<h3><a name="cleanup">Cleaning up after parsing</a></h3>
1691
1692<p>Libxml is not stateless, there is a few set of memory structures needing
1693allocation before the parser is fully functionnal (some encoding structures
1694for example). This also mean that once parsing is finished there is a tiny
1695amount of memory (a few hundred bytes) which can be recollected if you don't
1696reuse the parser immediately:</p>
1697<ul>
1698 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
1699 ()</a>
1700 is a centralized routine to free the parsing states. Note that it won't
1701 deallocate any produced tree if any (use the xmlFreeDoc() and related
1702 routines for this).</li>
1703 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
1704 ()</a>
1705 is the dual routine allowing to preallocate the parsing state which can
1706 be useful for example to avoid initialization reentrancy problems when
1707 using libxml in multithreaded applications</li>
1708</ul>
1709
1710<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
1711at the next invocation of parser routines, but be careful of the consequences
1712in multithreaded applications.</p>
1713
1714<h3><a name="Debugging">Debugging routines</a></h3>
1715
1716<p>When configured using --with-mem-debug flag (off by default), libxml uses
1717a set of memory allocation debugging routineskeeping track of all allocated
1718blocks and the location in the code where the routine was called. A couple of
1719other debugging routines allow to dump the memory allocated infos to a file
1720or call a specific routine when a given block number is allocated:</p>
1721<ul>
1722 <li><a
1723 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
1724 <a
1725 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
1726 and <a
1727 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
1728 are the memory debugging replacement allocation routines</li>
1729 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
1730 ()</a>
1731 dumps all the informations about the allocated memory block lefts in the
1732 <code>.memdump</code> file</li>
1733</ul>
1734
1735<p>When developping libxml memory debug is enabled, the tests programs call
1736xmlMemoryDump () and the "make test" regression tests will check for any
1737memory leak during the full regression test sequence, this helps a lot
1738ensuring that libxml does not leak memory and bullet proof memory
1739allocations use (some libc implementations are known to be far too permissive
1740resulting in major portability problems!).</p>
1741
1742<p>If the .memdump reports a leak, it displays the allocation function and
1743also tries to give some informations about the content and structure of the
1744allocated blocks left. This is sufficient in most cases to find the culprit,
1745but not always. Assuming the allocation problem is reproductible, it is
1746possible to find more easilly:</p>
1747<ol>
1748 <li>write down the block number xxxx not allocated</li>
1749 <li>export the environement variable XML_MEM_BREAKPOINT=xxxx</li>
1750 <li>run the program under a debugger and set a breakpoint on
1751 xmlMallocBreakpoint() a specific function called when this precise block
1752 is allocated</li>
1753 <li>when the breakpoint is reached you can then do a fine analysis of the
1754 allocation an step to see the condition resulting in the missing
1755 deallocation.</li>
1756</ol>
1757
1758<p>I used to use a commercial tool to debug libxml memory problems but after
1759noticing that it was not detecting memory leaks that simple mechanism was
1760used and proved extremely efficient until now.</p>
1761
1762<h3><a name="General4">General memory requirements</a></h3>
1763
1764<p>How much libxml memory require ? It's hard to tell in average it depends
1765of a number of things:</p>
1766<ul>
1767 <li>the parser itself should work in a fixed amout of memory, except for
1768 information maintained about the stacks of names and entities locations.
1769 The I/O and encoding handlers will probably account for a few KBytes.
1770 This is true for both the XML and HTML parser (though the HTML parser
1771 need more state).</li>
1772 <li>If you are generating the DOM tree then memory requirements will grow
1773 nearly lineary with the size of the data. In general for a balanced
1774 textual document the internal memory requirement is about 4 times the
1775 size of the UTF8 serialization of this document (exmple the XML-1.0
1776 recommendation is a bit more of 150KBytes and takes 650KBytes of main
1777 memory when parsed). Validation will add a amount of memory required for
1778 maintaining the external Dtd state which should be linear with the
1779 complexity of the content model defined by the Dtd</li>
1780 <li>If you don't care about the advanced features of libxml like
1781 validation, DOM, XPath or XPointer, but really need to work fixed memory
1782 requirements, then the SAX interface should be used.</li>
1783</ul>
1784
1785<p></p>
1786
1787<h2><a name="Encodings">Encodings support</a></h2>
1788
1789<p>Table of Content:</p>
1790<ol>
1791 <li><a href="encoding.html#What">What does internationalization support
1792 mean ?</a></li>
1793 <li><a href="encoding.html#internal">The internal encoding, how and
1794 why</a></li>
1795 <li><a href="encoding.html#implemente">How is it implemented ?</a></li>
1796 <li><a href="encoding.html#Default">Default supported encodings</a></li>
1797 <li><a href="encoding.html#extend">How to extend the existing
1798 support</a></li>
1799</ol>
1800
1801<h3><a name="What">What does internationalization support mean ?</a></h3>
1802
1803<p>XML was designed from the start to allow the support of any character set
1804by using Unicode. Any conformant XML parser has to support the UTF-8 and
1805UTF-16 default encodings which can both express the full unicode ranges. UTF8
1806is a variable length encoding whose greatest point are to resuse the same
1807emcoding for ASCII and to save space for Western encodings, but it is a bit
1808more complex to handle in practice. UTF-16 use 2 bytes per characters (and
1809sometimes combines two pairs), it makes implementation easier, but looks a
1810bit overkill for Western languages encoding. Moreover the XML specification
1811allows document to be encoded in other encodings at the condition that they
1812are clearly labelled as such. For example the following is a wellformed XML
1813document encoded in ISO-8859 1 and using accentuated letter that we French
1814likes for both markup and content:</p>
1815<pre>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
1816&lt;très&gt;là&lt;/très&gt;</pre>
1817
1818<p>Having internationalization support in libxml means the foolowing:</p>
1819<ul>
1820 <li>the document is properly parsed</li>
1821 <li>informations about it's encoding are saved</li>
1822 <li>it can be modified</li>
1823 <li>it can be saved in its original encoding</li>
1824 <li>it can also be saved in another encoding supported by libxml (for
1825 example straight UTF8 or even an ASCII form)</li>
1826</ul>
1827
1828<p>Another very important point is that the whole libxml API, with the
1829exception of a few routines to read with a specific encoding or save to a
1830specific encoding, is completely agnostic about the original encoding of the
1831document.</p>
1832
1833<p>It should be noted too that the HTML parser embedded in libxml now obbey
1834the same rules too, the following document will be (as of 2.2.2) handled in
1835an internationalized fashion by libxml too:</p>
1836<pre>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
1837 "http://www.w3.org/TR/REC-html40/loose.dtd"&gt;
1838&lt;html lang="fr"&gt;
1839&lt;head&gt;
1840 &lt;META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&gt;
1841&lt;/head&gt;
1842&lt;body&gt;
1843&lt;p&gt;W3C crée des standards pour le Web.&lt;/body&gt;
1844&lt;/html&gt;</pre>
1845
1846<h3><a name="internal">The internal encoding, how and why</a></h3>
1847
1848<p>One of the core decision was to force all documents to be converted to a
1849default internal encoding, and that encoding to be UTF-8, here are the
1850rationale for those choices:</p>
1851<ul>
1852 <li>keeping the native encoding in the internal form would force the libxml
1853 users (or the code associated) to be fully aware of the encoding of the
1854 original document, for examples when adding a text node to a document,
1855 the content would have to be provided in the document encoding, i.e. the
1856 client code would have to check it before hand, make sure it's conformant
1857 to the encoding, etc ... Very hard in practice, though in some specific
1858 cases this may make sense.</li>
1859 <li>the second decision was which encoding. From the XML spec only UTF8 and
1860 UTF16 really makes sense as being the two only encodings for which there
1861 is amndatory support. UCS-4 (32 bits fixed size encoding) could be
1862 considered an intelligent choice too since it's a direct Unicode mapping
1863 support. I selected UTF-8 on the basis of efficiency and compatibility
1864 with surrounding software:
1865 <ul>
1866 <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
1867 more costly to import and export CPU wise) is also far more compact
1868 than UTF-16 (and UCS-4) for a majority of the documents I see it used
1869 for right now (RPM RDF catalogs, advogato data, various configuration
1870 file formats, etc.) and the key point for today's computer
1871 architecture is efficient uses of caches. If one nearly double the
1872 memory requirement to store the same amount of data, this will trash
1873 caches (main memory/external caches/internal caches) and my take is
1874 that this harms the system far more than the CPU requirements needed
1875 for the conversion to UTF-8</li>
1876 <li>Most of libxml version 1 users were using it with straight ASCII
1877 most of the time, doing the conversion with an internal encoding
1878 requiring all their code to be rewritten was a serious show-stopper
1879 for using UTF-16 or UCS-4.</li>
1880 <li>UTF-8 is being used as the de-facto internal encoding standard for
1881 related code like the <a href="http://www.pango.org/">pango</a>
1882 upcoming Gnome text widget, and a lot of Unix code (yep another place
1883 where Unix programmer base takes a different approach from Microsoft
1884 - they are using UTF-16)</li>
1885 </ul>
1886 </li>
1887</ul>
1888
1889<p>What does this mean in practice for the libxml user:</p>
1890<ul>
1891 <li>xmlChar, the libxml data type is a byte, those bytes must be assembled
1892 as UTF-8 valid strings. The proper way to terminate an xmlChar * string
1893 is simply to append 0 byte, as usual.</li>
1894 <li>One just need to make sure that when using chars outside the ASCII set,
1895 the values has been properly converted to UTF-8</li>
1896</ul>
1897
1898<h3><a name="implemente">How is it implemented ?</a></h3>
1899
1900<p>Let's describe how all this works within libxml, basically the I18N
1901(internationalization) support get triggered only during I/O operation, i.e.
1902when reading a document or saving one. Let's look first at the reading
1903sequence:</p>
1904<ol>
1905 <li>when a document is processed, we usually don't know the encoding, a
1906 simple heuristic allows to detect UTF-18 and UCS-4 from whose where the
1907 ASCII range (0-0x7F) maps with ASCII</li>
1908 <li>the xml declaration if available is parsed, including the encoding
1909 declaration. At that point, if the autodetected encoding is different
1910 from the one declared a call to xmlSwitchEncoding() is issued.</li>
1911 <li>If there is no encoding declaration, then the input has to be in either
1912 UTF-8 or UTF-16, if it is not then at some point when processing the
1913 input, the converter/checker of UTF-8 form will raise an encoding error.
1914 You may end-up with a garbled document, or no document at all ! Example:
1915 <pre>~/XML -&gt; ./xmllint err.xml
1916err.xml:1: error: Input is not proper UTF-8, indicate encoding !
1917&lt;très&gt;là&lt;/très&gt;
1918 ^
1919err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
1920&lt;très&gt;là&lt;/très&gt;
1921 ^</pre>
1922 </li>
1923 <li>xmlSwitchEncoding() does an encoding name lookup, canonalize it, and
1924 then search the default registered encoding converters for that encoding.
1925 If it's not within the default set and iconv() support has been compiled
1926 it, it will ask iconv for such an encoder. If this fails then the parser
1927 will report an error and stops processing:
1928 <pre>~/XML -&gt; ./xmllint err2.xml
1929err2.xml:1: error: Unsupported encoding UnsupportedEnc
1930&lt;?xml version="1.0" encoding="UnsupportedEnc"?&gt;
1931 ^</pre>
1932 </li>
1933 <li>From that point the encoder process progressingly the input (it is
1934 plugged as a front-end to the I/O module) for that entity. It captures
1935 and convert on-the-fly the document to be parsed to UTF-8. The parser
1936 itself just does UTF-8 checking of this input and process it
1937 transparently. The only difference is that the encoding information has
1938 been added to the parsing context (more precisely to the input
1939 corresponding to this entity).</li>
1940 <li>The result (when using DOM) is an internal form completely in UTF-8
1941 with just an encoding information on the document node.</li>
1942</ol>
1943
1944<p>Ok then what's happen when saving the document (assuming you
1945colllected/built an xmlDoc DOM like structure) ? It depends on the function
1946called, xmlSaveFile() will just try to save in the original encoding, while
1947xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
1948encoding:</p>
1949<ol>
1950 <li>if no encoding is given, libxml will look for an encoding value
1951 associated to the document and if it exists will try to save to that
1952 encoding,
1953 <p>otherwise everything is written in the internal form, i.e. UTF-8</p>
1954 </li>
1955 <li>so if an encoding was specified, either at the API level or on the
1956 document, libxml will again canonalize the encoding name, lookup for a
1957 converter in the registered set or through iconv. If not found the
1958 function will return an error code</li>
1959 <li>the converter is placed before the I/O buffer layer, as another kind of
1960 buffer, then libxml will simply push the UTF-8 serialization to through
1961 that buffer, which will then progressively be converted and pushed onto
1962 the I/O layer.</li>
1963 <li>It is possible that the converter code fails on some input, for example
1964 trying to push an UTF-8 encoded chinese character through the UTF-8 to
1965 ISO-8859-1 converter won't work. Since the encoders are progressive they
1966 will just report the error and the number of bytes converted, at that
1967 point libxml will decode the offending character, remove it from the
1968 buffer and replace it with the associated charRef encoding &amp;#123; and
1969 resume the convertion. This guarante that any document will be saved
1970 without losses (except for markup names where this is not legal, this is
1971 a problem in the current version, in pactice avoid using non-ascci
1972 characters for tags or attributes names @@). A special "ascii" encoding
1973 name is used to save documents to a pure ascii form can be used when
1974 portability is really crucial</li>
1975</ol>
1976
1977<p>Here is a few examples based on the same test document:</p>
1978<pre>~/XML -&gt; ./xmllint isolat1
1979&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
1980&lt;très&gt;là&lt;/très&gt;
1981~/XML -&gt; ./xmllint --encode UTF-8 isolat1
1982&lt;?xml version="1.0" encoding="UTF-8"?&gt;
1983&lt;très&gt;là  &lt;/très&gt;
1984~/XML -&gt; </pre>
1985
1986<p>The same processing is applied (and reuse most of the code) for HTML I18N
1987processing. Looking up and modifying the content encoding is a bit more
1988difficult since it is located in a &lt;meta&gt; tag under the &lt;head&gt;,
1989so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
1990been provided. The parser also attempts to switch encoding on the fly when
1991detecting such a tag on input. Except for that the processing is the same
1992(and again reuses the same code).</p>
1993
1994<h3><a name="Default">Default supported encodings</a></h3>
1995
1996<p>libxml has a set of default converters for the following encodings
1997(located in encoding.c):</p>
1998<ol>
1999 <li>UTF-8 is supported by default (null handlers)</li>
2000 <li>UTF-16, both little and big endian</li>
2001 <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
2002 <li>ASCII, useful mostly for saving</li>
2003 <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
2004 predefined entities like &amp;copy; for the Copyright sign.</li>
2005</ol>
2006
2007<p>More over when compiled on an Unix platfor with iconv support the full set
2008of encodings supported by iconv can be instantly be used by libxml. On a
2009linux machine with glibc-2.1 the list of supported encodings and aliases fill
20103 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
2011various Japanese ones.</p>
2012
2013<h4>Encoding aliases</h4>
2014
2015<p>From 2.2.3, libxml has support to register encoding names aliases. The
2016goal is to be able to parse document whose encoding is supported but where
2017the name differs (for example from the default set of names accepted by
2018iconv). The following functions allow to register and handle new aliases for
2019existing encodings. Once registered libxml will automatically lookup the
2020aliases when handling a document:</p>
2021<ul>
2022 <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li>
2023 <li>int xmlDelEncodingAlias(const char *alias);</li>
2024 <li>const char * xmlGetEncodingAlias(const char *alias);</li>
2025 <li>void xmlCleanupEncodingAliases(void);</li>
2026</ul>
2027
2028<h3><a name="extend">How to extend the existing support</a></h3>
2029
2030<p>Well adding support for new encoding, or overriding one of the encoders
2031(assuming it is buggy) should not be hard, just write an input and output
2032conversion routines to/from UTF-8, and register them using
2033xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
2034called automatically if the parser(s) encounter such an encoding name
2035(register it uppercase, this will help). The description of the encoders,
2036their arguments and expected return values are described in the encoding.h
2037header.</p>
2038
2039<p>A quick note on the topic of subverting the parser to use a different
2040internal encoding than UTF-8, in some case people will absolutely want to
2041keep the internal encoding different, I think it's still possible (but the
2042encoding must be compliant with ASCII on the same subrange) though I didn't
2043tried it. The key is to override the default conversion routines (by
2044registering null encoders/decoders for your charsets), and bypass the UTF-8
2045checking of the parser by setting the parser context charset
2046(ctxt-&gt;charset) to something different than XML_CHAR_ENCODING_UTF8, but
2047there is no guarantee taht this will work. You may also have some troubles
2048saving back.</p>
2049
2050<p>Basically proper I18N support is important, this requires at least
2051libxml-2.0.0, but a lot of features and corrections are really available only
2052starting 2.2.</p>
2053
2054<h2><a name="IO">I/O Interfaces</a></h2>
2055
2056<p>Table of Content:</p>
2057<ol>
2058 <li><a href="#General1">General overview</a></li>
2059 <li><a href="#basic">The basic buffer type</a></li>
2060 <li><a href="#Input">Input I/O handlers</a></li>
2061 <li><a href="#Output">Output I/O handlers</a></li>
2062 <li><a href="#entities">The entities loader</a></li>
2063 <li><a href="#Example2">Example of customized I/O</a></li>
2064</ol>
2065
2066<h3><a name="General1">General overview</a></h3>
2067
2068<p>The module <code><a
2069href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
2070the interfaces to the libxml I/O system. This consists of 4 main parts:</p>
2071<ul>
2072 <li>Entities loader, this is a routine which tries to fetch the entities
2073 (files) based on their PUBLIC and SYSTEM identifiers. The default loader
2074 don't look at the public identifier since libxml do not maintain a
2075 catalog. You can redefine you own entity loader by using
2076 <code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2077 <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
2078 example</a>.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2079 <li>Input I/O buffers which are a commodity structure used by the parser(s)
2080 input layer to handle fetching the informations to feed the parser. This
2081 provides buffering and is also a placeholder where the encoding
2082 convertors to UTF8 are piggy-backed.</li>
2083 <li>Output I/O buffers are similar to the Input ones and fulfill similar
2084 task but when generating a serialization from a tree.</li>
2085 <li>A mechanism to register sets of I/O callbacks and associate them with
2086 specific naming schemes like the protocol part of the URIs.
2087 <p>This affect the default I/O operations and allows to use specific I/O
2088 handlers for certain names.</p>
2089 </li>
2090</ul>
2091
2092<p>The general mechanism used when loading http://rpmfind.net/xml.html for
2093example in the HTML parser is the following:</p>
2094<ol>
2095 <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
2096 the parsing context and the URI string.</li>
2097 <li>the URI string is checked against the existing registered handlers
2098 using their match() callback function, if the HTTP module was compiled
2099 in, it is registered and its match() function will succeeds</li>
2100 <li>the open() function of the handler is called and if successful will
2101 return an I/O Input buffer</li>
2102 <li>the parser will the start reading from this buffer and progressively
2103 fetch information from the resource, calling the read() function of the
2104 handler until the resource is exhausted</li>
2105 <li>if an encoding change is detected it will be installed on the input
2106 buffer, providing buffering and efficient use of the conversion
2107 routines</li>
2108 <li>once the parser has finished, the close() function of the handler is
2109 called once and the Input buffer and associed resources are
2110 deallocated.</li>
2111</ol>
2112
2113<p>The user defined callbacks are checked first to allow overriding of the
2114default libxml I/O routines.</p>
2115
2116<h3><a name="basic">The basic buffer type</a></h3>
2117
2118<p>All the buffer manipulation handling is done using the
2119<code>xmlBuffer</code> type define in <code><a
2120href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
2121resizable memory buffer. The buffer allocation strategy can be selected to be
2122either best-fit or use an exponential doubling one (CPU vs. memory use
2123tradeoff). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
2124<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
2125system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
2126of functions allows to manipulate buffers with names starting with the
2127<code>xmlBuffer...</code> prefix.</p>
2128
2129<h3><a name="Input">Input I/O handlers</a></h3>
2130
2131<p>An Input I/O handler is a simple structure
2132<code>xmlParserInputBuffer</code> containing a context associated to the
2133resource (file descriptor, or pointer to a protocol handler), the read() and
2134close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
2135encoding handler are also present to support charset conversion when
2136needed.</p>
2137
2138<h3><a name="Output">Output I/O handlers</a></h3>
2139
2140<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
2141Input one except the callbacks are write() and close().</p>
2142
2143<h3><a name="entities">The entities loader</a></h3>
2144
2145<p>The entity loader resolves requests for new entities and create inputs for
2146the parser. Creating an input from a filename or an URI string is done
2147through the xmlNewInputFromFile() routine. The default entity loader do not
2148handle the PUBLIC identifier associated with an entity (if any). So it just
2149calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
2150XML).</p>
2151
2152<p>If you want to hook up a catalog mechanism then you simply need to
2153override the default entity loader, here is an example:</p>
2154<pre>#include &lt;libxml/xmlIO.h&gt;
2155
2156xmlExternalEntityLoader defaultLoader = NULL;
2157
2158xmlParserInputPtr
2159xmlMyExternalEntityLoader(const char *URL, const char *ID,
2160 xmlParserCtxtPtr ctxt) {
2161 xmlParserInputPtr ret;
2162 const char *fileID = NULL;
2163 /* lookup for the fileID depending on ID */
2164
2165 ret = xmlNewInputFromFile(ctxt, fileID);
2166 if (ret != NULL)
2167 return(ret);
2168 if (defaultLoader != NULL)
2169 ret = defaultLoader(URL, ID, ctxt);
2170 return(ret);
2171}
2172
2173int main(..) {
2174 ...
2175
2176 /*
2177 * Install our own entity loader
2178 */
2179 defaultLoader = xmlGetExternalEntityLoader();
2180 xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
2181
2182 ...
2183}</pre>
2184
2185<h3><a name="Example2">Example of customized I/O</a></h3>
2186
2187<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
2188real use case</a>, xmlDocDump() closes the FILE * passed by the application
2189and this was a problem. The <a
2190href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
2191new output handler with the closing call deactivated:</p>
2192<ol>
2193 <li>First define a new I/O ouput allocator where the output don't close the
2194 file:
2195 <pre>xmlOutputBufferPtr
2196xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
2197    xmlOutputBufferPtr ret;
2198    
2199    if (xmlOutputCallbackInitialized == 0)
2200        xmlRegisterDefaultOutputCallbacks();
2201
2202    if (file == NULL) return(NULL);
2203    ret = xmlAllocOutputBuffer(encoder);
2204    if (ret != NULL) {
2205        ret-&gt;context = file;
2206        ret-&gt;writecallback = xmlFileWrite;
2207        ret-&gt;closecallback = NULL; /* No close callback */
2208    }
2209    return(ret); <br>
2210
2211
2212
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2213
2214
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]2215
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]2216
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]2217
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]2218
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]2219
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]2220
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]2221
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]2222
Daniel Veillard9ae4b7a2001-12-13 14:24:09 +0000[diff] [blame]2223
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]2224
Daniel Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame]2225
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]2226
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]2227
Daniel Veillardb6c1e2f2002-02-08 14:52:52 +0000[diff] [blame]2228
Daniel Veillard397ff112002-02-11 18:27:20 +0000[diff] [blame]2229
Daniel Veillarde46182c2002-02-12 14:29:11 +0000[diff] [blame]2230
Daniel Veillard5f4b5992002-02-20 10:22:49 +0000[diff] [blame]2231
Daniel Veillard5b16f582002-02-20 11:38:46 +0000[diff] [blame^]2232
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2233} </pre>
2234 </li>
2235 <li>And then use it to save the document:
2236 <pre>FILE *f;
2237xmlOutputBufferPtr output;
2238xmlDocPtr doc;
2239int res;
2240
2241f = ...
2242doc = ....
2243
2244output = xmlOutputBufferCreateOwn(f, NULL);
2245res = xmlSaveFileTo(output, doc, NULL);
2246 </pre>
2247 </li>
2248</ol>
2249
2250<h2><a name="Catalog">Catalog support</a></h2>
2251
2252<p>Table of Content:</p>
2253<ol>
2254 <li><a href="General2">General overview</a></li>
2255 <li><a href="#definition">The definition</a></li>
2256 <li><a href="#Simple">Using catalogs</a></li>
2257 <li><a href="#Some">Some examples</a></li>
2258 <li><a href="#reference">How to tune catalog usage</a></li>
2259 <li><a href="#validate">How to debug catalog processing</a></li>
2260 <li><a href="#Declaring">How to create and maintain catalogs</a></li>
2261 <li><a href="#implemento">The implementor corner quick review of the
2262 API</a></li>
2263 <li><a href="#Other">Other resources</a></li>
2264</ol>
2265
2266<h3><a name="General2">General overview</a></h3>
2267
2268<p>What is a catalog? Basically it's a lookup mechanism used when an entity
2269(a file or a remote resource) references another entity. The catalog lookup
2270is inserted between the moment the reference is recognized by the software
2271(XML parser, stylesheet processing, or even images referenced for inclusion
2272in a rendering) and the time where loading that resource is actually
2273started.</p>
2274
2275<p>It is basically used for 3 things:</p>
2276<ul>
2277 <li>mapping from "logical" names, the public identifiers and a more
2278 concrete name usable for download (and URI). For example it can associate
2279 the logical name
2280 <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
2281 <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
2282 downloaded</p>
2283 <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
2284 </li>
2285 <li>remapping from a given URL to another one, like an HTTP indirection
2286 saying that
2287 <p>"http://www.oasis-open.org/committes/tr.xsl"</p>
2288 <p>should really be looked at</p>
2289 <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
2290 </li>
2291 <li>providing a local cache mechanism allowing to load the entities
2292 associated to public identifiers or remote resources, this is a really
2293 important feature for any significant deployment of XML or SGML since it
2294 allows to avoid the aleas and delays associated to fetching remote
2295 resources.</li>
2296</ul>
2297
2298<h3><a name="definition">The definitions</a></h3>
2299
2300<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
2301<ul>
2302 <li>the older SGML catalogs, the official spec is SGML Open Technical
2303 Resolution TR9401:1997, but is better understood by reading <a
2304 href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
2305 James Clark. This is relatively old and not the preferred mode of
2306 operation of libxml.</li>
2307 <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
2308 Catalogs</a>
2309 is far more flexible, more recent, uses an XML syntax and should scale
2310 quite better. This is the default option of libxml.</li>
2311</ul>
2312
2313<p></p>
2314
2315<h3><a name="Simple">Using catalog</a></h3>
2316
2317<p>In a normal environment libxml will by default check the presence of a
2318catalog in /etc/xml/catalog, and assuming it has been correctly populated,
2319the processing is completely transparent to the document user. To take a
2320concrete example, suppose you are authoring a DocBook document, this one
2321starts with the following DOCTYPE definition:</p>
2322<pre>&lt;?xml version='1.0'?&gt;
2323&lt;!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
2324 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"&gt;</pre>
2325
2326<p>When validating the document with libxml, the catalog will be
2327automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
2328DocBk XML V3.1.4//EN" and the system identifier
2329"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
2330been installed on your system and the catalogs actually point to them, libxml
2331will fetch them from the local disk.</p>
2332
2333<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
2334DOCTYPE example it's a really old version, but is fine as an example.</p>
2335
2336<p>Libxml will check the catalog each time that it is requested to load an
2337entity, this includes DTD, external parsed entities, stylesheets, etc ... If
2338your system is correctly configured all the authoring phase and processing
2339should use only local files, even if your document stays portable because it
2340uses the canonical public and system ID, referencing the remote document.</p>
2341
2342<h3><a name="Some">Some examples:</a></h3>
2343
2344<p>Here is a couple of fragments from XML Catalogs used in libxml early
2345regression tests in <code>test/catalogs</code> :</p>
2346<pre>&lt;?xml version="1.0"?&gt;
2347&lt;!DOCTYPE catalog PUBLIC
2348 "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2349 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2350&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2351 &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2352 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2353...</pre>
2354
2355<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
2356written in XML, there is a specific namespace for catalog elements
2357"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
2358catalog is a <code>public</code> mapping it allows to associate a Public
2359Identifier with an URI.</p>
2360<pre>...
2361 &lt;rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2362 rewritePrefix="file:///usr/share/xml/docbook/"/&gt;
2363...</pre>
2364
2365<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
2366any URI starting with a given prefix should be looked at another URI
2367constructed by replacing the prefix with an new one. In effect this acts like
2368a cache system for a full area of the Web. In practice it is extremely useful
2369with a file prefix if you have installed a copy of those resources on your
2370local system.</p>
2371<pre>...
2372&lt;delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
2373 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2374&lt;delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
2375 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2376&lt;delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
2377 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2378&lt;delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2379 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2380&lt;delegateURI uriStartString="http://www.oasis-open.org/docbook/"
2381 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2382...</pre>
2383
2384<p>Delegation is the core features which allows to build a tree of catalogs,
2385easier to maintain than a single catalog, based on Public Identifier, System
2386Identifier or URI prefixes it instructs the catalog software to look up
2387entries in another resource. This feature allow to build hierarchies of
2388catalogs, the set of entries presented should be sufficient to redirect the
2389resolution of all DocBook references to the specific catalog in
2390<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
2391references for DocBook 4.2.1 to a specific catalog installed at the same time
2392as the DocBook resources on the local machine.</p>
2393
2394<h3><a name="reference">How to tune catalog usage:</a></h3>
2395
2396<p>The user can change the default catalog behaviour by redirecting queries
2397to its own set of catalogs, this can be done by setting the
2398<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
2399empty one should deactivate loading the default <code>/etc/xml/catalog</code>
2400default catalog</p>
2401
2402<h3><a name="validate">How to debug catalog processing:</a></h3>
2403
2404<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
2405make libxml output debugging informations for each catalog operations, for
2406example:</p>
2407<pre>orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2408warning: failed to load external entity "title.xml"
2409orchis:~/XML -&gt; export XML_DEBUG_CATALOG=
2410orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2411Failed to parse catalog /etc/xml/catalog
2412Failed to parse catalog /etc/xml/catalog
2413warning: failed to load external entity "title.xml"
2414Catalogs cleanup
2415orchis:~/XML -&gt; </pre>
2416
2417<p>The test/ent2 references an entity, running the parser from memory makes
2418the base URI unavailable and the the "title.xml" entity cannot be loaded.
2419Setting up the debug environment variable allows to detect that an attempt is
2420made to load the <code>/etc/xml/catalog</code> but since it's not present the
2421resolution fails.</p>
2422
2423<p>But the most advanced way to debug XML catalog processing is to use the
2424<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
2425catalogs and make resolution queries to see what is going on. This is also
2426used for the regression tests:</p>
2427<pre>orchis:~/XML -&gt; ./xmlcatalog test/catalogs/docbook.xml \
2428 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2429http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2430orchis:~/XML -&gt; </pre>
2431
2432<p>For debugging what is going on, adding one -v flags increase the verbosity
2433level to indicate the processing done (adding a second flag also indicate
2434what elements are recognized at parsing):</p>
2435<pre>orchis:~/XML -&gt; ./xmlcatalog -v test/catalogs/docbook.xml \
2436 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2437Parsing catalog test/catalogs/docbook.xml's content
2438Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
2439http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2440Catalogs cleanup
2441orchis:~/XML -&gt; </pre>
2442
2443<p>A shell interface is also available to debug and process multiple queries
2444(and for regression tests):</p>
2445<pre>orchis:~/XML -&gt; ./xmlcatalog -shell test/catalogs/docbook.xml \
2446 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2447&gt; help
2448Commands available:
2449public PublicID: make a PUBLIC identifier lookup
2450system SystemID: make a SYSTEM identifier lookup
2451resolve PublicID SystemID: do a full resolver lookup
2452add 'type' 'orig' 'replace' : add an entry
2453del 'values' : remove values
2454dump: print the current catalog state
2455debug: increase the verbosity level
2456quiet: decrease the verbosity level
2457exit: quit the shell
2458&gt; public "-//OASIS//DTD DocBook XML V4.1.2//EN"
2459http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2460&gt; quit
2461orchis:~/XML -&gt; </pre>
2462
2463<p>This should be sufficient for most debugging purpose, this was actually
2464used heavily to debug the XML Catalog implementation itself.</p>
2465
2466<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
2467
2468<p>Basically XML Catalogs are XML files, you can either use XML tools to
2469manage them or use <strong>xmlcatalog</strong> for this. The basic step is
2470to create a catalog the -create option provide this facility:</p>
2471<pre>orchis:~/XML -&gt; ./xmlcatalog --create tst.xml
2472&lt;?xml version="1.0"?&gt;
2473&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2474 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2475&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2476orchis:~/XML -&gt; </pre>
2477
2478<p>By default xmlcatalog does not overwrite the original catalog and save the
2479result on the standard output, this can be overridden using the -noout
2480option. The <code>-add</code> command allows to add entries in the
2481catalog:</p>
2482<pre>orchis:~/XML -&gt; ./xmlcatalog --noout --create --add "public" \
2483 "-//OASIS//DTD DocBook XML V4.1.2//EN" \
2484 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
2485orchis:~/XML -&gt; cat tst.xml
2486&lt;?xml version="1.0"?&gt;
2487&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
2488 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2489&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2490&lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2491 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2492&lt;/catalog&gt;
2493orchis:~/XML -&gt; </pre>
2494
2495<p>The <code>-add</code> option will always take 3 parameters even if some of
2496the XML Catalog constructs (like nextCatalog) will have only a single
2497argument, just pass a third empty string, it will be ignored.</p>
2498
2499<p>Similarly the <code>-del</code> option remove matching entries from the
2500catalog:</p>
2501<pre>orchis:~/XML -&gt; ./xmlcatalog --del \
2502 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
2503&lt;?xml version="1.0"?&gt;
2504&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2505 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2506&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2507orchis:~/XML -&gt; </pre>
2508
2509<p>The catalog is now empty. Note that the matching of <code>-del</code> is
2510exact and would have worked in a similar fashion with the Public ID
2511string.</p>
2512
2513<p>This is rudimentary but should be sufficient to manage a not too complex
2514catalog tree of resources.</p>
2515
2516<h3><a name="implemento">The implementor corner quick review of the
2517API:</a></h3>
2518
2519<p>First, and like for every other module of libxml, there is an
2520automatically generated <a href="html/libxml-catalog.html">API page for
2521catalog support</a>.</p>
2522
2523<p>The header for the catalog interfaces should be included as:</p>
2524<pre>#include &lt;libxml/catalog.h&gt;</pre>
2525
2526<p>The API is voluntarily kept very simple. First it is not obvious that
2527applications really need access to it since it is the default behaviour of
2528libxml (Note: it is possible to completely override libxml default catalog by
2529using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
2530plug an application specific resolver).</p>
2531
2532<p>Basically libxml support 2 catalog lists:</p>
2533<ul>
2534 <li>the default one, global shared by all the application</li>
2535 <li>a per-document catalog, this one is built if the document uses the
2536 <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
2537 associated to the parser context and destroyed when the parsing context
2538 is destroyed.</li>
2539</ul>
2540
2541<p>the document one will be used first if it exists.</p>
2542
2543<h4>Initialization routines:</h4>
2544
2545<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
2546used at startup to initialize the catalog, if the catalog should be
2547initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
2548should be called before xmlInitializeCatalog() which would otherwise do a
2549default initialization first.</p>
2550
2551<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
2552own catalog list if needed.</p>
2553
2554<h4>Preferences setup:</h4>
2555
2556<p>The XML Catalog spec requires the possibility to select default
2557preferences between public and system delegation,
2558xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
2559xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
2560be forbidden, allowed for global catalog, for document catalog or both, the
2561default is to allow both.</p>
2562
2563<p>And of course xmlCatalogSetDebug() allows to generate debug messages
2564(through the xmlGenericError() mechanism).</p>
2565
2566<h4>Querying routines:</h4>
2567
2568<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
2569and xmlCatalogResolveURI() are relatively explicit if you read the XML
2570Catalog specification they correspond to section 7 algorithms, they should
2571also work if you have loaded an SGML catalog with a simplified semantic.</p>
2572
2573<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
2574operate on the document catalog list</p>
2575
2576<h4>Cleanup and Miscellaneous:</h4>
2577
2578<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
2579the per-document equivalent.</p>
2580
2581<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
2582first catalog in the global list, and xmlCatalogDump() allows to dump a
2583catalog state, those routines are primarily designed for xmlcatalog, I'm not
2584sure that exposing more complex interfaces (like navigation ones) would be
2585really useful.</p>
2586
2587<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
2588it's similar as xmlParseFile() except it bypass all catalog lookups, it's
2589provided because this functionality may be useful for client tools.</p>
2590
2591<h4>threaded environments:</h4>
2592
2593<p>Since the catalog tree is built progressively, some care has been taken to
2594try to avoid troubles in multithreaded environments. The code is now thread
2595safe assuming that the libxml library has been compiled with threads
2596support.</p>
2597
2598<p></p>
2599
2600<h3><a name="Other">Other resources</a></h3>
2601
2602<p>The XML Catalog specification is relatively recent so there isn't much
2603literature to point at:</p>
2604<ul>
2605 <li>You can find an good rant from Norm Walsh about <a
2606 href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
2607 need for catalogs</a>, it provides a lot of context informations even if
2608 I don't agree with everything presented.</li>
2609 <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
2610 catalog proposal</a> from John Cowan</li>
2611 <li>The <a href="http://www.rddl.org/">Resource Directory Description
2612 Language</a> (RDDL) another catalog system but more oriented toward
2613 providing metadata for XML namespaces.</li>
2614 <li>the page from the OASIS Technical <a
2615 href="http://www.oasis-open.org/committees/entity/">Committee on Entity
2616 Resolution</a> who maintains XML Catalog, you will find pointers to the
2617 specification update, some background and pointers to others tools
2618 providing XML Catalog support</li>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]2619 <li>Here is a <a href="buildDocBookCatalog">shell script</a> to generate
2620 XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
2621 directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
2622 the resources found on the system. Otherwise it will just create
2623 ~/xmlcatalog and ~/dbkxmlcatalog and doing:
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame]2624 <p><code>export XMLCATALOG=$HOME/xmlcatalog</code></p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]2625 <p>should allow to process DocBook documentations without requiring
2626 network accesses for the DTd or stylesheets</p>
2627 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2628 <li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]2629 small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
2630 to work fine for me too</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2631 <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
2632 manual page</a></li>
2633</ul>
2634
2635<p>If you have suggestions for corrections or additions, simply contact
2636me:</p>
2637
2638<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2639
2640<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2641using the XML library from the C language. It is not intended to be
2642extensive. I hope the automatically generated documents will provide the
2643completeness required, but as a separate set of documents. The interfaces of
2644the XML library are by principle low level, there is nearly zero abstraction.
2645Those interested in a higher level API should <a href="#DOM">look at
2646DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]2647
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]2648<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
2649separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2650interfaces</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]2651
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2652<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2653
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2654<p>Usually, the first thing to do is to read an XML input. The parser accepts
2655documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2656defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2657<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2658 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2659 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2660 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2661</dl>
2662<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2663 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2664 <dd><p>Parse an XML document contained in a (possibly compressed)
2665 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2666 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2667</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2668
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2669<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]2670failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2671
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2672<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2673
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2674<p>In order for the application to keep the control when the document is
2675being fetched (which is common for GUI based programs) libxml provides a push
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2676interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2677<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
2678 void *user_data,
2679 const char *chunk,
2680 int size,
2681 const char *filename);
2682int xmlParseChunk (xmlParserCtxtPtr ctxt,
2683 const char *chunk,
2684 int size,
2685 int terminate);</pre>
2686
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2687<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2688<pre> FILE *f;
2689
2690 f = fopen(filename, "r");
2691 if (f != NULL) {
2692 int res, size = 1024;
2693 char chars[1024];
2694 xmlParserCtxtPtr ctxt;
2695
2696 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2697 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2698 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
2699 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2700 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2701 xmlParseChunk(ctxt, chars, res, 0);
2702 }
2703 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2704 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2705 xmlFreeParserCtxt(ctxt);
2706 }
2707 }</pre>
2708
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2709<p>The HTML parser embedded into libxml also has a push interface; the
2710functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2711
2712<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
2713
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2714<p>The tree-building interface makes the parser memory-hungry, first loading
2715the document in memory and then building the tree itself. Reading a document
2716without building the tree is possible using the SAX interfaces (see SAX.h and
2717<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]2718Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2719limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2720<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]2721
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2722<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2723
2724<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]2725there is a set of functions dedicated to building new elements. (These are
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2726also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of
2727code that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2728<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]2729 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2730 xmlNodePtr tree, subtree;
2731
2732 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2733 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
2734 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
2735 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
2736 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2737 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2738 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2739 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
2740 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
2741 subtree = xmlNewChild(tree, NULL, "image", NULL);
2742 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2743
2744<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2745
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2746<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2747
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]2748<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2749code has access to the internal structure of all the elements of the tree.
2750The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]2751<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2752<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2753example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2754<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2755
2756<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2757<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2758
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2759<p>points to the text node containing the chapter title "The Linux
2760adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2761
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]2762<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]2763present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2764to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]2765<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]2766
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2767<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2768
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2769<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]2770is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2771<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2772 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
2773 xmlChar *value);</code></dt>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2774 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
2775 The value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2776 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2777</dl>
2778<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2779 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2780 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]2781 <dd><p>This function returns a pointer to new copy of the property
2782 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2783 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2784</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2785
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2786<p>Two functions are provided for reading and writing the text associated
2787with elements:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2788<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2789 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2790 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2791 <dd><p>This function takes an "external" string and converts it to one
2792 text node or possibly to a list of entity and text nodes. All
2793 non-predefined entity references like &amp;Gnome; will be stored
2794 internally as entity nodes, hence the result of the function may not be
2795 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2796 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2797</dl>
2798<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2799 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2800 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2801 <dd><p>This function is the inverse of
2802 <code>xmlStringGetNodeList()</code>. It generates a new string
2803 containing the content of the text and entity nodes. Note the extra
2804 argument inLine. If this argument is set to 1, the function will expand
2805 entity references. For example, instead of returning the &amp;Gnome;
2806 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2807 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2808 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2809</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2810
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2811<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2812
2813<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2814<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2815 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2816 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2817 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2818 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2819</dl>
2820<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2821 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2822 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2823 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2824</dl>
2825<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2826 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2827 <dd><p>Saves the document to a file. In this case, the compression
2828 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2829 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2830</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2831
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2832<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2833
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2834<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2835accesses. The level of compression on saves can be turned on either globally
2836or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2837<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2838 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2839 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2840 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2841</dl>
2842<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2843 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2844 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2845 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2846</dl>
2847<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2848 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2849 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2850 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2851</dl>
2852<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2853 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2854 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2855 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2856</dl>
2857
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2858<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2859
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2860<p>Entities in principle are similar to simple C macros. An entity defines an
2861abbreviation for a given string that you can reuse many times throughout the
2862content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2863may occur frequently within a document, or to confine the change needed to a
2864document to a restricted area in the internal subset of the document (at the
2865beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2866<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]28672 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]28683 &lt;!ENTITY xml "Extensible Markup Language"&gt;
28694 ]&gt;
28705 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]28716 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]28727 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2873
2874<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]2875its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2876are 5 predefined entities in libxml allowing you to escape charaters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2877predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2878<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2879for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2880<strong>&amp;quot;</strong> for the character '"', and
2881<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2882
2883<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]2884substitute an entity's content so that you can see the replacement text in
2885your application. Or you may prefer to keep entity references as such in the
2886content to be able to save the document back without losing this usually
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2887precious information (if the user went through the pain of explicitly
2888defining entities, he may have a a rather negative attitude if you blindly
2889susbtitute them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]2890href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2891function allows you to check and change the behaviour, which is to not
2892substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2893
2894<p>Here is the DOM tree built by libxml for the previous document in the
2895default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2896<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2897DOCUMENT
2898version=1.0
2899 ELEMENT EXAMPLE
2900 TEXT
2901 content=
2902 ENTITY_REF
2903 INTERNAL_GENERAL_ENTITY xml
2904 content=Extensible Markup Language
2905 TEXT
2906 content=</pre>
2907
2908<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2909<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2910DOCUMENT
2911version=1.0
2912 ELEMENT EXAMPLE
2913 TEXT
2914 content= Extensible Markup Language</pre>
2915
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2916<p>So, entities or no entities? Basically, it depends on your use case. I
2917suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2918entities in your XML document or data if you are not willing to handle the
2919entity references elements in the DOM tree.</p>
2920
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2921<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2922entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2923transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2924reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2925finding them in the input).</p>
2926
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]2927<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2928on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]2929non-predefined entities in your documents, then the learning cuvre to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2930then 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]2931strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]2932deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]2933
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2934<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2935
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]2936<p>The libxml library implements <a
2937href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
2938recognizing namespace contructs in the input, and does namespace lookup
2939automatically when building the DOM tree. A namespace declaration is
2940associated with an in-memory structure and all elements or attributes within
2941that namespace point to it. Hence testing the namespace is a simple and fast
2942equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2943
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2944<p>I suggest that people using libxml use a namespace, and declare it in the
2945root element of their document as the default namespace. Then they don't need
2946to 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]2947refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2948the size of the XML output significantly, but significantly increases its
2949value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2950<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
2951 &lt;elem1&gt;...&lt;/elem1&gt;
2952 &lt;elem2&gt;...&lt;/elem2&gt;
2953&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2954
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2955<p>The namespace value has to be an absolute URL, but the URL doesn't have to
2956point to any existing resource on the Web. It will bind all the element and
2957atributes with that URL. I suggest to use an URL within a domain you control,
2958and that the URL should contain some kind of version information if possible.
2959For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a good
2960namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]2961
2962<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2963version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2964and if the version information don't match something you know, warn the user
2965and 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]2966namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2967same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2968associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2969just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]2970<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2971prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2972
2973<p>@@Interfaces@@</p>
2974
2975<p>@@Examples@@</p>
2976
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2977<p>Usually people object to using namespaces together with validity checking.
2978I will try to make sure that using namespaces won't break validity checking,
2979so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2980suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2981<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2982flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2983from multiple DTDs will certainly break current validation schemes. I will
2984try to provide ways to do this, but this may not be portable or
2985standardized.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2986
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2987<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2988
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2989<p>Incompatible changes:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2990
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2991<p>Version 2 of libxml is the first version introducing serious backward
2992incompatible changes. The main goals were:</p>
2993<ul>
2994 <li>a general cleanup. A number of mistakes inherited from the very early
2995 versions couldn't be changed due to compatibility constraints. Example
2996 the "childs" element in the nodes.</li>
2997 <li>Uniformization of the various nodes, at least for their header and link
2998 parts (doc, parent, children, prev, next), the goal is a simpler
2999 programming model and simplifying the task of the DOM implementors.</li>
3000 <li>better conformances to the XML specification, for example version 1.x
3001 had an heuristic to try to detect ignorable white spaces. As a result the
3002 SAX event generated were ignorableWhitespace() while the spec requires
3003 character() in that case. This also mean that a number of DOM node
3004 containing blank text may populate the DOM tree which were not present
3005 before.</li>
3006</ul>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3007
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3008<h3>How to fix libxml-1.x code:</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3009
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3010<p>So client code of libxml designed to run with version 1.x may have to be
3011changed to compile against version 2.x of libxml. Here is a list of changes
3012that I have collected, they may not be sufficient, so in case you find other
3013change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
3014mail</a>:</p>
3015<ol>
3016 <li>The package name have changed from libxml to libxml2, the library name
3017 is now -lxml2 . There is a new xml2-config script which should be used to
3018 select the right parameters libxml2</li>
3019 <li>Node <strong>childs</strong> field has been renamed
3020 <strong>children</strong> so s/childs/children/g should be applied
3021 (probablility of having "childs" anywere else is close to 0+</li>
3022 <li>The document don't have anymore a <strong>root</strong> element it has
3023 been replaced by <strong>children</strong> and usually you will get a
3024 list of element here. For example a Dtd element for the internal subset
3025 and it's declaration may be found in that list, as well as processing
3026 instructions or comments found before or after the document root element.
3027 Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
3028 a document. Alternatively if you are sure to not reference Dtds nor have
3029 PIs or comments before or after the root element
3030 s/-&gt;root/-&gt;children/g will probably do it.</li>
3031 <li>The white space issue, this one is more complex, unless special case of
3032 validating parsing, the line breaks and spaces usually used for indenting
3033 and formatting the document content becomes significant. So they are
3034 reported by SAX and if your using the DOM tree, corresponding nodes are
3035 generated. Too approach can be taken:
3036 <ol>
3037 <li>lazy one, use the compatibility call
3038 <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
3039 relying on a special (and possibly broken) set of heuristics of
3040 libxml to detect ignorable blanks. Don't complain if it breaks or
3041 make your application not 100% clean w.r.t. to it's input.</li>
3042 <li>the Right Way: change you code to accept possibly unsignificant
3043 blanks characters, or have your tree populated with weird blank text
3044 nodes. You can spot them using the comodity function
3045 <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
3046 nodes.</li>
3047 </ol>
3048 <p>Note also that with the new default the output functions don't add any
3049 extra indentation when saving a tree in order to be able to round trip
3050 (read and save) without inflating the document with extra formatting
3051 chars.</p>
3052 </li>
3053 <li>The include path has changed to $prefix/libxml/ and the includes
3054 themselves uses this new prefix in includes instructions... If you are
3055 using (as expected) the
3056 <pre>xml2-config --cflags</pre>
3057 <p>output to generate you compile commands this will probably work out of
3058 the box</p>
3059 </li>
3060 <li>xmlDetectCharEncoding takes an extra argument indicating the lenght in
3061 byte of the head of the document available for character detection.</li>
3062</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3063
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3064<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3065
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3066<p>Two new version of libxml (1.8.11) and libxml2 (2.3.4) have been released
3067to allow smoth upgrade of existing libxml v1code while retaining
3068compatibility. They offers the following:</p>
3069<ol>
3070 <li>similar include naming, one should use
3071 <strong>#include&lt;libxml/...&gt;</strong> in both cases.</li>
3072 <li>similar identifiers defined via macros for the child and root fields:
3073 respectively <strong>xmlChildrenNode</strong> and
3074 <strong>xmlRootNode</strong></li>
3075 <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
3076 inserted once in the client code</li>
3077</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3078
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3079<p>So the roadmap to upgrade your existing libxml applications is the
3080following:</p>
3081<ol>
3082 <li>install the libxml-1.8.8 (and libxml-devel-1.8.8) packages</li>
3083 <li>find all occurences where the xmlDoc <strong>root</strong> field is
3084 used and change it to <strong>xmlRootNode</strong></li>
3085 <li>similary find all occurences where the xmlNode <strong>childs</strong>
3086 field is used and change it to <strong>xmlChildrenNode</strong></li>
3087 <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
3088 <strong>main()</strong> or in the library init entry point</li>
3089 <li>Recompile, check compatibility, it should still work</li>
3090 <li>Change your configure script to look first for xml2-config and fallback
3091 using xml-config . Use the --cflags and --libs ouptut of the command as
3092 the Include and Linking parameters needed to use libxml.</li>
3093 <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
3094 libxml-devel-1.8.y can be kept simultaneously)</li>
3095 <li>remove your config.cache, relaunch your configuration mechanism, and
3096 recompile, if steps 2 and 3 were done right it should compile as-is</li>
3097 <li>Test that your application is still running correctly, if not this may
3098 be due to extra empty nodes due to formating spaces being kept in libxml2
3099 contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
3100 code before calling the parser (next to
3101 <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
3102</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3103
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3104<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]3105
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3106<p>Let me put some emphasis on the fact that there is far more changes from
3107libxml 1.x to 2.x than the ones you may have to patch for. The overall code
3108has been considerably cleaned up and the conformance to the XML specification
3109has been drastically improved too. Don't take those changes as an excuse to
3110not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3111
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3112<h2><a name="Thread">Thread safety</a></h2>
3113
3114<p>Starting with 2.4.7, libxml makes provisions to ensure that concurent
3115threads can safely work in parallel parsing different documents. There is
3116however a couple of things to do to ensure it:</p>
3117<ul>
3118 <li>configure the library accordingly using the --with-threads options</li>
3119 <li>call xmlInitParser() in the "main" thread before using any of the
3120 libxml API (except possibly selecting a different memory allocator)</li>
3121</ul>
3122
3123<p>Note that the thread safety cannot be ensured for multiple threads sharing
3124the same document, the locking must be done at the application level, libxml
3125exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
3126The parts of the library checked for thread safety are:</p>
3127<ul>
3128 <li>concurrent loading</li>
3129 <li>file access resolution</li>
3130 <li>catalog access</li>
3131 <li>catalog building</li>
3132 <li>entities lookup/accesses</li>
3133 <li>validation</li>
3134 <li>global variables per-thread override</li>
3135 <li>memory handling</li>
3136</ul>
3137
3138<p>XPath is supposed to be thread safe now, but this wasn't tested
3139seriously.</p>
3140
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3141<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3142
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3143<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
3144Object Model</em>; this is an API for accessing XML or HTML structured
3145documents. Native support for DOM in Gnome is on the way (module gnome-dom),
3146and will be based on gnome-xml. This will be a far cleaner interface to
3147manipulate XML files within Gnome since it won't expose the internal
3148structure.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3149
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3150<p>The current DOM implementation on top of libxml is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame]3151href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
3152is a full DOM interface, thanks to Paolo Casarini, check the <a
3153href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
3154informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3155
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3156<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3157
3158<p>Here is a real size example, where the actual content of the application
3159data 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]3160a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3161storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
3162base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3163<pre>&lt;?xml version="1.0"?&gt;
3164&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
3165 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3166
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3167 &lt;gjob:Job&gt;
3168 &lt;gjob:Project ID="3"/&gt;
3169 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
3170 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3171
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3172 &lt;gjob:Update&gt;
3173 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
3174 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
3175 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
3176 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3177
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3178 &lt;gjob:Developers&gt;
3179 &lt;gjob:Developer&gt;
3180 &lt;/gjob:Developer&gt;
3181 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3182
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3183 &lt;gjob:Contact&gt;
3184 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
3185 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
3186 &lt;gjob:Company&gt;
3187 &lt;/gjob:Company&gt;
3188 &lt;gjob:Organisation&gt;
3189 &lt;/gjob:Organisation&gt;
3190 &lt;gjob:Webpage&gt;
3191 &lt;/gjob:Webpage&gt;
3192 &lt;gjob:Snailmail&gt;
3193 &lt;/gjob:Snailmail&gt;
3194 &lt;gjob:Phone&gt;
3195 &lt;/gjob:Phone&gt;
3196 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3197
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3198 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3199 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3200 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3201
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3202 &lt;gjob:Skills&gt;
3203 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3204
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3205 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3206 A GNOME based system that will allow a superuser to configure
3207 compressed and uncompressed files and/or file systems to be backed
3208 up with a supported media in the system. This should be able to
3209 perform via find commands generating a list of files that are passed
3210 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
3211 or via operations performed on the filesystem itself. Email
3212 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3213 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3214
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3215 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3216
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3217 &lt;/gjob:Jobs&gt;
3218&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3219
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3220<p>While loading the XML file into an internal DOM tree is a matter of
3221calling only a couple of functions, browsing the tree to gather the ata and
3222generate the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3223
3224<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3225structure. For example, the ordering of the attributes is not significant,
3226the 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]3227depend on the order of the children of a given node, unless it really makes
3228things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3229<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3230 * A person record
3231 */
3232typedef struct person {
3233 char *name;
3234 char *email;
3235 char *company;
3236 char *organisation;
3237 char *smail;
3238 char *webPage;
3239 char *phone;
3240} person, *personPtr;
3241
3242/*
3243 * And the code needed to parse it
3244 */
3245personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3246 personPtr ret = NULL;
3247
3248DEBUG("parsePerson\n");
3249 /*
3250 * allocate the struct
3251 */
3252 ret = (personPtr) malloc(sizeof(person));
3253 if (ret == NULL) {
3254 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3255 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3256 }
3257 memset(ret, 0, sizeof(person));
3258
3259 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3260 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3261 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3262 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
3263 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3264 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
3265 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3266 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3267 }
3268
3269 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3270}</pre>
3271
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3272<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3273<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3274 <li>Usually a recursive parsing style is the more convenient one: XML data
3275 is by nature subject to repetitive constructs and usually exibits highly
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3276 stuctured patterns.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3277 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
3278 i.e. the pointer to the global XML document and the namespace reserved to
3279 the application. Document wide information are needed for example to
3280 decode entities and it's a good coding practice to define a namespace for
3281 your application set of data and test that the element and attributes
3282 you're analyzing actually pertains to your application space. This is
3283 done by a simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3284 <li>To retrieve text and attributes value, you can use the function
3285 <em>xmlNodeListGetString</em> to gather all the text and entity reference
3286 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3287</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3288
3289<p>Here is another piece of code used to parse another level of the
3290structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3291<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3292/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3293 * a Description for a Job
3294 */
3295typedef struct job {
3296 char *projectID;
3297 char *application;
3298 char *category;
3299 personPtr contact;
3300 int nbDevelopers;
3301 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
3302} job, *jobPtr;
3303
3304/*
3305 * And the code needed to parse it
3306 */
3307jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3308 jobPtr ret = NULL;
3309
3310DEBUG("parseJob\n");
3311 /*
3312 * allocate the struct
3313 */
3314 ret = (jobPtr) malloc(sizeof(job));
3315 if (ret == NULL) {
3316 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3317 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3318 }
3319 memset(ret, 0, sizeof(job));
3320
3321 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3322 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3323 while (cur != NULL) {
3324
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3325 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
3326 ret-&gt;projectID = xmlGetProp(cur, "ID");
3327 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3328 fprintf(stderr, "Project has no ID\n");
3329 }
3330 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3331 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
3332 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3333 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
3334 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3335 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
3336 ret-&gt;contact = parsePerson(doc, ns, cur);
3337 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3338 }
3339
3340 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3341}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3342
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3343<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]3344boring. Ultimately, it could be possble to write stubbers taking either C
3345data structure definitions, a set of XML examples or an XML DTD and produce
3346the code needed to import and export the content between C data and XML
3347storage. This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3348
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]3349<p>Feel free to use <a href="example/gjobread.c">the code for the full C
3350parsing example</a> as a template, it is also available with Makefile in the
3351Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3352
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3353<h2><a name="Contributi">Contributions</a></h2>
3354<ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3355 <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
3356 patches, Gary Pennington worked on the validation API, threading support
3357 and Solaris port.</li>
3358 <li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]3359 <li><a href="mailto:ari@lusis.org">Ari Johnson</a>
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]3360 provides a C++ wrapper for libxml:<br>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]3361 Website: <a
3362 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a><br>
3363 Download: <a
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]3364 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3365 <li><a href="mailto:izlatkovic@daenet.de">Igor Zlatkovic</a>
3366 is now the maintainer of the Windows port, <a
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]3367 href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
3368 provides binaries</a></li>
Daniel Veillardc9484202001-10-24 12:35:52 +0000[diff] [blame]3369 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a>
Daniel Veillarddb9dfd92001-11-26 17:25:02 +0000[diff] [blame]3370 provides <a href="http://garypennington.net/libxml2/">Solaris
Daniel Veillard0a702dc2001-10-19 14:50:57 +0000[diff] [blame]3371 binaries</a></li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]3372 <li><a
3373 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3374 Sergeant</a>
3375 developped <a href="http://axkit.org/download/">XML::LibXSLT</a>, a perl
3376 wrapper for libxml2/libxslt as part of the <a
3377 href="http://axkit.com/">AxKit XML application server</a></li>
3378 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a>
3379 and <a href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillardca989762001-06-23 17:39:29 +0000[diff] [blame]3380 href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]3381 documentation</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3382 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a>
3383 provided <a href="http://xmlsoft.org/messages/0488.html">man
3384 pages</a></li>
Daniel Veillard5168dbf2001-07-07 00:18:23 +0000[diff] [blame]3385 <li>there is a module for <a
3386 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
3387 in OpenNSD/AOLServer</a></li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3388 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a>
3389 provides libxml/libxslt <a href="http://www.rexx.com/~dkuhlman">wrappers
3390 for Python</a></li>
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]3391 <li>Petr Kozelka provides <a
3392 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
3393 libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3394</ul>
3395
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3396<p></p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3397</body>
3398</html>