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blob: c8806c92eb13a9a1e4b191b66e3fc2a44a38c28a [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
56strict way. To some extent libxml2 provide some support for the following
57other specification but don't claim to implement them:</p>
58<ul>
59 <li>Document Object Model (DOM) <a
60 href="http://www.w3.org/TR/DOM-Level-2-Core/">http://www.w3.org/TR/DOM-Level-2-Core/</a>
61 it doesn't implement the API itself, gdome2 does this in top of
62 libxml2</li>
63 <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]64 : libxml implements a basic FTP client code</li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]65 <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]66 : HTTP/1.0, again a basic HTTP client code</li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]67 <li>SAX: a minimal SAX implementation compatible with early expat
68 versions</li>
69 <li>DocBook SGML v4: libxml2 includes a hackish parser to transition to
70 XML</li>
71</ul>
72
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]73<p>Libxml2 is known to be very portable, should build and work without
74serious troubles on a variety of systems (Linux, Unix, Windows, CygWin,
75MacOs, MacOsX, RISC Os, OS/2, VMS, QNX, MVS, ...)</p>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]76
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]77<p>Separate documents:</p>
78<ul>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]79 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a>
80 providing an implementation of XSLT 1.0 and extensions on top of
81 libxml2</li>
82 <li><a href="http://www.cs.unibo.it/~casarini/gdome2/">the gdome2 page</a>
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]83 : a standard DOM2 implementation based on libxml2</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]84</ul>
85
86<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]87
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]88<p>This document describes libxml, the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]89href="http://www.w3.org/XML/">XML</a> C library developped for the <a
90href="http://www.gnome.org/">Gnome</a> project. <a
91href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
92structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]93
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]94<p>Here are some key points about libxml:</p>
95<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]96 <li>Libxml exports Push and Pull type parser interfaces for both XML and
97 HTML.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]98 <li>Libxml can do DTD validation at parse time, using a parsed document
99 instance, or with an arbitrary DTD.</li>
100 <li>Libxml now includes nearly complete <a
Daniel Veillard8c2ecaf2001-07-10 17:53:07 +0000[diff] [blame]101 href="http://www.w3.org/TR/xpath">XPath</a>, <a
102 href="http://www.w3.org/TR/xptr">XPointer</a> and <a
103 href="http://www.w3.org/TR/xinclude">XInclude</a> implementations.</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]104 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]105 sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]106 Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]107 <li>Basic support for HTTP and FTP client allowing aplications to fetch
108 remote resources</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]109 <li>The design is modular, most of the extensions can be compiled out.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]110 <li>The internal document repesentation is as close as possible to the <a
111 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
112 <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]113 like interface</a>; the interface is designed to be compatible with <a
114 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]115 <li>This library is released both under the <a
116 href="http://www.w3.org/Consortium/Legal/copyright-software-19980720.html">W3C
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]117 IPR</a> and the <a href="http://www.gnu.org/copyleft/lesser.html">GNU
118 LGPL</a>. Use either at your convenience, basically this should make
119 everybody happy, if not, drop me a mail.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]120</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]121
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]122<p>Warning: unless you are forced to because your application links with a
123Gnome library requiring it, <strong><span
124style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
125libxml2</p>
126
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]127<h2><a name="FAQ">FAQ</a></h2>
128
129<p>Table of Content:</p>
130<ul>
131 <li><a href="FAQ.html#Licence">Licence(s)</a></li>
132 <li><a href="FAQ.html#Installati">Installation</a></li>
133 <li><a href="FAQ.html#Compilatio">Compilation</a></li>
134 <li><a href="FAQ.html#Developer">Developer corner</a></li>
135</ul>
136
137<h3><a name="Licence">Licence</a>(s)</h3>
138<ol>
139 <li><em>Licensing Terms for libxml</em>
140 <p>libxml is released under 2 (compatible) licences:</p>
141 <ul>
142 <li>the <a href="http://www.gnu.org/copyleft/lgpl.html">LGPL</a>: GNU
143 Library General Public License</li>
144 <li>the <a
145 href="http://www.w3.org/Consortium/Legal/copyright-software-19980720.html">W3C
146 IPR</a>: very similar to the XWindow licence</li>
147 </ul>
148 </li>
149 <li><em>Can I embed libxml in a proprietary application ?</em>
150 <p>Yes. The W3C IPR allows you to also keep proprietary the changes you
151 made to libxml, but it would be graceful to provide back bugfixes and
152 improvements as patches for possible incorporation in the main
153 development tree</p>
154 </li>
155</ol>
156
157<h3><a name="Installati">Installation</a></h3>
158<ol>
159 <li>Unless you are forced to because your application links with a Gnome
160 library requiring it, <strong><span style="background-color: #FF0000">Do
161 Not Use libxml1</span></strong>, use libxml2</li>
162 <li><em>Where can I get libxml</em>
163 ?
164 <p>The original distribution comes from <a
165 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a
166 href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">gnome.org</a></p>
167 <p>Most linux and Bsd distribution includes libxml, this is probably the
168 safer way for end-users</p>
169 <p>David Doolin provides precompiled Windows versions at <a
170 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
171 </li>
172 <li><em>I see libxml and libxml2 releases, which one should I install ?</em>
173 <ul>
174 <li>If you are not concerned by any existing backward compatibility
175 with existing application, install libxml2 only</li>
176 <li>If you are not doing development, you can safely install both.
177 usually the packages <a
178 href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a
179 href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
180 compatible (this is not the case for development packages)</li>
181 <li>If you are a developer and your system provides separate packaging
182 for shared libraries and the development components, it is possible
183 to install libxml and libxml2, and also <a
184 href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
185 and <a
186 href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
187 too for libxml2 &gt;= 2.3.0</li>
188 <li>If you are developing a new application, please develop against
189 libxml2(-devel)</li>
190 </ul>
191 </li>
192 <li><em>I can't install the libxml package it conflicts with libxml0</em>
193 <p>You probably have an old libxml0 package used to provide the shared
194 library for libxml.so.0, you can probably safely remove it. Anyway the
195 libxml packages provided on <a
196 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provides
197 libxml.so.0</p>
198 </li>
199 <li><em>I can't install the libxml(2) RPM package due to failed
200 dependancies</em>
201 <p>The most generic solution is to refetch the latest src.rpm , and
202 rebuild it locally with</p>
203 <p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code></p>
204 <p>if everything goes well it will generate two binary rpm (one providing
205 the shared libs and xmllint, and the other one, the -devel package
206 providing includes, static libraries and scripts needed to build
207 applications with libxml(2)) that you can install locally.</p>
208 </li>
209</ol>
210
211<h3><a name="Compilatio">Compilation</a></h3>
212<ol>
213 <li><em>What is the process to compile libxml ?</em>
214 <p>As most UNIX libraries libxml follows the "standard":</p>
215 <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p>
216 <p><code>cd libxml-xxxx</code></p>
217 <p><code>./configure --help</code></p>
218 <p>to see the options, then the compilation/installation proper</p>
219 <p><code>./configure [possible options]</code></p>
220 <p><code>make</code></p>
221 <p><code>make install</code></p>
222 <p>At that point you may have to rerun ldconfig or similar utility to
223 update your list of installed shared libs.</p>
224 </li>
225 <li><em>What other libraries are needed to compile/install libxml ?</em>
226 <p>Libxml does not requires any other library, the normal C ANSI API
227 should be sufficient (please report any violation to this rule you may
228 find).</p>
229 <p>However if found at configuration time libxml will detect and use the
230 following libs:</p>
231 <ul>
232 <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a>
233 : a highly portable and available widely compression library</li>
234 <li>iconv: a powerful character encoding conversion library. It's
235 included by default on recent glibc libraries, so it doesn't need to
236 be installed specifically on linux. It seems it's now <a
237 href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
238 of the official UNIX</a> specification. Here is one <a
239 href="http://clisp.cons.org/~haible/packages-libiconv.html">implementation
240 of the library</a> which source can be found <a
241 href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
242 </ul>
243 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]244 <li><em>make check fails on some platforms</em>
245 <p>Sometime the regression tests results don't completely match the value
246 produced by the parser, and the makefile uses diff to print the delta. On
247 some platforms the diff return breaks the compilation process, if the
248 diff is small this is probably not a serious problem</p>
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 Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame^]556<h3>2.4.13: Jan 14 2001</h3>
557<ul>
558 <li>update of the documentation: John Fleck and Charlie Bozeman</li>
559 <li>cleanup of timing code from Justin Fletcher</li>
560 <li>fixes for Windows and initial thread support on Win32: Igor and Serguei
561 Narojnyi</li>
562 <li>Cygwin patch from Robert Collins</li>
563 <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
564</ul>
565
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]566<h3>2.4.12: Dec 7 2001</h3>
567<ul>
568 <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
569 XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
570 (robert)</li>
571 <li>Eric Lavigne contributed project files for MacOS</li>
572 <li>some makefiles cleanups</li>
573</ul>
574
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]575<h3>2.4.11: Nov 26 2001</h3>
576<ul>
577 <li>fixed a couple of errors in the includes, fixed a few bugs, some code
578 cleanups</li>
579 <li>xmllint man pages improvement by Heiko Rupp</li>
580 <li>updated VMS build instructions from John A Fotheringham</li>
581 <li>Windows Makefiles updates from Igor</li>
582</ul>
583
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]584<h3>2.4.10: Nov 10 2001</h3>
585<ul>
586 <li>URI escaping fix (Joel Young)</li>
587 <li>added xmlGetNodePath() (for paths or XPointers generation)</li>
588 <li>Fixes namespace handling problems when using DTD and validation</li>
589 <li>improvements on xmllint: Morus Walter patches for --format and
590 --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
591 <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
592 <li>fixes to the HTML parser</li>
593</ul>
594
595<h3>2.4.9: Nov 6 2001</h3>
596<ul>
597 <li>fixes more catalog bugs</li>
598 <li>avoid a compilation problem, improve xmlGetLineNo()</li>
599</ul>
600
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]601<h3>2.4.8: Nov 4 2001</h3>
602<ul>
603 <li>fixed SGML catalogs broken in previous release, updated xmlcatalog
604 tool</li>
605 <li>fixed a compile errors and some includes troubles.</li>
606</ul>
607
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]608<h3>2.4.7: Oct 30 2001</h3>
609<ul>
610 <li>exported some debugging interfaces</li>
611 <li>serious rewrite of the catalog code</li>
612 <li>integrated Gary Pennington thread safety patch, added configure option
613 and regression tests</li>
614 <li>removed an HTML parser bug</li>
615 <li>fixed a couple of potentially serious validation bugs</li>
616 <li>integrated the SGML DocBook support in xmllint</li>
617 <li>changed the nanoftp anonymous login passwd</li>
618 <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
619 <li>general bug fixes</li>
620 <li>updated xmllint man page by John Fleck</li>
621 <li>some VMS and Windows updates</li>
622</ul>
623
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]624<h3>2.4.6: Oct 10 2001</h3>
625<ul>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]626 <li>added an updated man pages by John Fleck</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]627 <li>portability and configure fixes</li>
628 <li>an infinite loop on the HTML parser was removed (William)</li>
629 <li>Windows makefile patches from Igor</li>
630 <li>fixed half a dozen bugs reported fof libxml or libxslt</li>
631 <li>updated xmlcatalog to be able to modify SGML super catalogs</li>
632</ul>
633
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]634<h3>2.4.5: Sep 14 2001</h3>
635<ul>
636 <li>Remove a few annoying bugs in 2.4.4</li>
637 <li>forces the HTML serializer to output decimal charrefs since some
638 version of Netscape can't handle hexadecimal ones</li>
639</ul>
640
641<h3>1.8.16: Sep 14 2001</h3>
642<ul>
643 <li>maintenance release of the old libxml1 branch, couple of bug and
644 portability fixes</li>
645</ul>
646
Daniel Veillard04382ae2001-09-12 18:51:30 +0000[diff] [blame]647<h3>2.4.4: Sep 12 2001</h3>
648<ul>
649 <li>added --convert to xmlcatalog, bug fixes and cleanups of XML
650 Catalog</li>
651 <li>a few bug fixes and some portability changes</li>
652 <li>some documentation cleanups</li>
653</ul>
654
Daniel Veillard39936902001-08-24 00:49:01 +0000[diff] [blame]655<h3>2.4.3: Aug 23 2001</h3>
656<ul>
657 <li>XML Catalog support see the doc</li>
658 <li>New NaN/Infinity floating point code</li>
659 <li>A few bug fixes</li>
660</ul>
661
662<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]663<ul>
664 <li>adds xmlLineNumbersDefault() to control line number generation</li>
665 <li>lot of bug fixes</li>
666 <li>the Microsoft MSC projects files shuld now be up to date</li>
667 <li>inheritance of namespaces from DTD defaulted attributes</li>
668 <li>fixes a serious potential security bug</li>
669 <li>added a --format option to xmllint</li>
670</ul>
671
672<h3>2.4.1: July 24 2001</h3>
673<ul>
674 <li>possibility to keep line numbers in the tree</li>
675 <li>some computation NaN fixes</li>
676 <li>extension of the XPath API</li>
677 <li>cleanup for alpha and ia64 targets</li>
678 <li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]679</ul>
680
681<h3>2.4.0: July 10 2001</h3>
682<ul>
683 <li>Fixed a few bugs in XPath, validation, and tree handling.</li>
684 <li>Fixed XML Base implementation, added a coupel of examples to the
685 regression tests</li>
686 <li>A bit of cleanup</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]687</ul>
688
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]689<h3>2.3.14: July 5 2001</h3>
690<ul>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]691 <li>fixed some entities problems and reduce mem requirement when
692 substituing them</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]693 <li>lots of improvements in the XPath queries interpreter can be
694 substancially faster</li>
695 <li>Makefiles and configure cleanups</li>
696 <li>Fixes to XPath variable eval, and compare on empty node set</li>
697 <li>HTML tag closing bug fixed</li>
698 <li>Fixed an URI reference computating problem when validating</li>
699</ul>
700
Daniel Veillard2adbb512001-06-28 16:20:36 +0000[diff] [blame]701<h3>2.3.13: June 28 2001</h3>
702<ul>
703 <li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
704 <li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
705</ul>
706
707<h3>1.8.14: June 28 2001</h3>
708<ul>
709 <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
710 <li>Small Makefile fix</li>
711</ul>
712
Daniel Veillard11648102001-06-26 16:08:24 +0000[diff] [blame]713<h3>2.3.12: June 26 2001</h3>
714<ul>
715 <li>lots of cleanup</li>
716 <li>a couple of validation fix</li>
717 <li>fixed line number counting</li>
718 <li>fixed serious problems in the XInclude processing</li>
719 <li>added support for UTF8 BOM at beginning of entities</li>
720 <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
721 miscompile uri.c (William), Thomas Leitner provided a fix for the
722 optimizer on Tru64</li>
723 <li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
724 compilation on Windows MSC</li>
725 <li>update of libxml-doc.el (Felix Natter)</li>
726 <li>fixed 2 bugs in URI normalization code</li>
727</ul>
728
Daniel Veillarde3c81b52001-06-17 14:50:34 +0000[diff] [blame]729<h3>2.3.11: June 17 2001</h3>
730<ul>
731 <li>updates to trio, Makefiles and configure should fix some portability
732 problems (alpha)</li>
733 <li>fixed some HTML serialization problems (pre, script, and block/inline
734 handling), added encoding aware APIs, cleanup of this code</li>
735 <li>added xmlHasNsProp()</li>
736 <li>implemented a specific PI for encoding support in the DocBook SGML
737 parser</li>
738 <li>some XPath fixes (-Infinity, / as a function parameter and namespaces
739 node selection)</li>
740 <li>fixed a performance problem and an error in the validation code</li>
741 <li>fixed XInclude routine to implement the recursive behaviour</li>
742 <li>fixed xmlFreeNode problem when libxml is included statically twice</li>
743 <li>added --version to xmllint for bug reports</li>
744</ul>
745
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]746<h3>2.3.10: June 1 2001</h3>
747<ul>
748 <li>fixed the SGML catalog support</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]749 <li>a number of reported bugs got fixed, in XPath, iconv detection,
750 XInclude processing</li>
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]751 <li>XPath string function should now handle unicode correctly</li>
752</ul>
753
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]754<h3>2.3.9: May 19 2001</h3>
755
756<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
757<ul>
758 <li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
759 <li>some serious speed optimisation again</li>
760 <li>some documentation cleanups</li>
761 <li>trying to get better linking on solaris (-R)</li>
762 <li>XPath API cleanup from Thomas Broyer</li>
763 <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
764 xmlValidGetValidElements()</li>
765 <li>Added an INSTALL file</li>
766 <li>Attribute removal added to API: #54433</li>
767 <li>added a basic support for SGML catalogs</li>
768 <li>fixed xmlKeepBlanksDefault(0) API</li>
769 <li>bugfix in xmlNodeGetLang()</li>
770 <li>fixed a small configure portability problem</li>
771 <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
772</ul>
773
Daniel Veillarda265af72001-05-14 11:13:58 +0000[diff] [blame]774<h3>1.8.13: May 14 2001</h3>
775<ul>
776 <li>bugfixes release of the old libxml1 branch used by Gnome</li>
777</ul>
778
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]779<h3>2.3.8: May 3 2001</h3>
780<ul>
781 <li>Integrated an SGML DocBook parser for the Gnome project</li>
782 <li>Fixed a few things in the HTML parser</li>
783 <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
784 point portability issue</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]785 <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
786 DOM+validation using the XML REC as input and a 700MHz celeron).</li>
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]787 <li>incorporated more Windows cleanup</li>
788 <li>added xmlSaveFormatFile()</li>
789 <li>fixed problems in copying nodes with entities references (gdome)</li>
790 <li>removed some troubles surrounding the new validation module</li>
791</ul>
792
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]793<h3>2.3.7: April 22 2001</h3>
794<ul>
795 <li>lots of small bug fixes, corrected XPointer</li>
796 <li>Non determinist content model validation support</li>
797 <li>added xmlDocCopyNode for gdome2</li>
798 <li>revamped the way the HTML parser handles end of tags</li>
799 <li>XPath: corrctions of namespacessupport and number formatting</li>
800 <li>Windows: Igor Zlatkovic patches for MSC compilation</li>
801 <li>HTML ouput fixes from P C Chow and William M. Brack</li>
802 <li>Improved validation speed sensible for DocBook</li>
803 <li>fixed a big bug with ID declared in external parsed entities</li>
804 <li>portability fixes, update of Trio from Bjorn Reese</li>
805</ul>
806
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]807<h3>2.3.6: April 8 2001</h3>
808<ul>
809 <li>Code cleanup using extreme gcc compiler warning options, found and
810 cleared half a dozen potential problem</li>
811 <li>the Eazel team found an XML parser bug</li>
812 <li>cleaned up the user of some of the string formatting function. used the
813 trio library code to provide the one needed when the platform is missing
814 them</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]815 <li>xpath: removed a memory leak and fixed the predicate evaluation
816 problem, extended the testsuite and cleaned up the result. XPointer seems
817 broken ...</li>
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]818</ul>
819
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame]820<h3>2.3.5: Mar 23 2001</h3>
821<ul>
822 <li>Biggest change is separate parsing and evaluation of XPath expressions,
823 there is some new APIs for this too</li>
824 <li>included a number of bug fixes(XML push parser, 51876, notations,
825 52299)</li>
826 <li>Fixed some portability issues</li>
827</ul>
828
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]829<h3>2.3.4: Mar 10 2001</h3>
830<ul>
831 <li>Fixed bugs #51860 and #51861</li>
832 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
833 size to be application tunable.</li>
834 <li>Some cleanup in the validation code, still a bug left and this part
835 should probably be rewritten to support ambiguous content model :-\</li>
836 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
837 parser</li>
838 <li>Fixed another bug in xmlNodeGetContent()</li>
839 <li>Bjorn fixed XPath node collection and Number formatting</li>
840 <li>Fixed a loop reported in the HTML parsing</li>
841 <li>blank space are reported even if the Dtd content model proves that they
842 are formatting spaces, this is for XmL conformance</li>
843</ul>
844
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]845<h3>2.3.3: Mar 1 2001</h3>
846<ul>
847 <li>small change in XPath for XSLT</li>
848 <li>documentation cleanups</li>
849 <li>fix in validation by Gary Pennington</li>
850 <li>serious parsing performances improvements</li>
851</ul>
852
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]853<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]854<ul>
855 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
856 <li>fixed a Dtd parsing bug</li>
857 <li>fixed a bug in xmlNodeGetContent</li>
858 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
859</ul>
860
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]861<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]862<ul>
863 <li>some XPath and HTML bug fixes for XSLT</li>
864 <li>small extension of the hash table interfaces for DOM gdome2
865 implementation</li>
866 <li>A few bug fixes</li>
867</ul>
868
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]869<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]870<ul>
871 <li>Lots of XPath bug fixes</li>
872 <li>Add a mode with Dtd lookup but without validation error reporting for
873 XSLT</li>
874 <li>Add support for text node without escaping (XSLT)</li>
875 <li>bug fixes for xmlCheckFilename</li>
876 <li>validation code bug fixes from Gary Pennington</li>
877 <li>Patch from Paul D. Smith correcting URI path normalization</li>
878 <li>Patch to allow simultaneous install of libxml-devel and
879 libxml2-devel</li>
880 <li>the example Makefile is now fixed</li>
881 <li>added HTML to the RPM packages</li>
882 <li>tree copying bugfixes</li>
883 <li>updates to Windows makefiles</li>
884 <li>optimisation patch from Bjorn Reese</li>
885</ul>
886
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]887<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]888<ul>
889 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
890 <li>added htmlHandleOmittedElem()</li>
891 <li>Applied Bjorn Reese's IPV6 first patch</li>
892 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]893 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]894</ul>
895
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]896<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]897<ul>
898 <li>Fix the Windows problems of 2.2.8</li>
899 <li>integrate OpenVMS patches</li>
900 <li>better handling of some nasty HTML input</li>
901 <li>Improved the XPointer implementation</li>
902 <li>integrate a number of provided patches</li>
903</ul>
904
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]905<h3>2.2.9: Nov 25 2000</h3>
906<ul>
907 <li>erroneous release :-(</li>
908</ul>
909
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]910<h3>2.2.8: Nov 13 2000</h3>
911<ul>
912 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
913 support</li>
914 <li>Patch in conditional section handling</li>
915 <li>updated MS compiler project</li>
916 <li>fixed some XPath problems</li>
917 <li>added an URI escaping function</li>
918 <li>some other bug fixes</li>
919</ul>
920
921<h3>2.2.7: Oct 31 2000</h3>
922<ul>
923 <li>added message redirection</li>
924 <li>XPath improvements (thanks TOM !)</li>
925 <li>xmlIOParseDTD() added</li>
926 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
927 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
928</ul>
929
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]930<h3>2.2.6: Oct 25 2000:</h3>
931<ul>
932 <li>Added an hash table module, migrated a number of internal structure to
933 those</li>
934 <li>Fixed a posteriori validation problems</li>
935 <li>HTTP module cleanups</li>
936 <li>HTML parser improvements (tag errors, script/style handling, attribute
937 normalization)</li>
938 <li>coalescing of adjacent text nodes</li>
939 <li>couple of XPath bug fixes, exported the internal API</li>
940</ul>
941
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]942<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]943<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]944 <li>XPointer implementation and testsuite</li>
945 <li>Lot of XPath fixes, added variable and functions registration, more
946 tests</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]947 <li>Portability fixes, lots of enhancements toward an easy Windows build
948 and release</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]949 <li>Late validation fixes</li>
950 <li>Integrated a lot of contributed patches</li>
951 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]952 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]953</ul>
954
955<h3>2.2.4: Oct 1 2000:</h3>
956<ul>
957 <li>main XPath problem fixed</li>
958 <li>Integrated portability patches for Windows</li>
959 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]960</ul>
961
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]962<h3>2.2.3: Sep 17 2000</h3>
963<ul>
964 <li>bug fixes</li>
965 <li>cleanup of entity handling code</li>
966 <li>overall review of all loops in the parsers, all sprintf usage has been
967 checked too</li>
968 <li>Far better handling of larges Dtd. Validating against Docbook XML Dtd
969 works smoothly now.</li>
970</ul>
971
972<h3>1.8.10: Sep 6 2000</h3>
973<ul>
974 <li>bug fix release for some Gnome projects</li>
975</ul>
976
977<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]978<ul>
979 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]980 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]981</ul>
982
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]983<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]984<ul>
985 <li>a purely bug fixes release</li>
986 <li>fixed an encoding support problem when parsing from a memory block</li>
987 <li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]988 <li>removed a bug in the function allowing to override the memory
989 allocation routines</li>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]990</ul>
991
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]992<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]993<ul>
994 <li>applied a lot of portability fixes</li>
995 <li>better encoding support/cleanup and saving (content is now always
996 encoded in UTF-8)</li>
997 <li>the HTML parser now correctly handles encodings</li>
998 <li>added xmlHasProp()</li>
999 <li>fixed a serious problem with &amp;#38;</li>
1000 <li>propagated the fix to FTP client</li>
1001 <li>cleanup, bugfixes, etc ...</li>
1002 <li>Added a page about <a href="encoding.html">libxml Internationalization
1003 support</a></li>
1004</ul>
1005
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1006<h3>1.8.9: July 9 2000</h3>
1007<ul>
1008 <li>fixed the spec the RPMs should be better</li>
1009 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
1010 rpmfind users problem</li>
1011</ul>
1012
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]1013<h3>2.1.1: July 1 2000</h3>
1014<ul>
1015 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
1016 <li>improvements on the HTML parser</li>
1017</ul>
1018
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1019<h3>2.1.0 and 1.8.8: June 29 2000</h3>
1020<ul>
1021 <li>1.8.8 is mostly a comodity package for upgrading to libxml2 accoding to
1022 <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
1023 about &amp;#38; charref parsing</li>
1024 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
1025 also contains numerous fixes and enhancements:
1026 <ul>
1027 <li>added xmlStopParser() to stop parsing</li>
1028 <li>improved a lot parsing speed when there is large CDATA blocs</li>
1029 <li>includes XPath patches provided by Picdar Technology</li>
1030 <li>tried to fix as much as possible DtD validation and namespace
1031 related problems</li>
1032 <li>output to a given encoding has been added/tested</li>
1033 <li>lot of various fixes</li>
1034 </ul>
1035 </li>
1036</ul>
1037
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1038<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1039<ul>
1040 <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]1041 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initally
1042 scheduled for Apr 3 the relase occured only on Apr 12 due to massive
1043 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1044 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1045 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1046 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1047 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1048 <pre>#include "xxx.h"</pre>
1049 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]1050 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
1051 <li>the memory allocation routines used by libxml can now be overloaded
1052 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1053 <li>The previously CVS only tool tester has been renamed
1054 <strong>xmllint</strong> and is now installed as part of the libxml2
1055 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1056 <li>The I/O interface has been revamped. There is now ways to plug in
1057 specific I/O modules, either at the URI scheme detection level using
1058 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
1059 parser context using xmlCreateIOParserCtxt()</li>
1060 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
1061 number of the libxml module in use</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1062 <li>a number of optional features of libxml can now be excluded at
1063 configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1064</ul>
1065
1066<h3>2.0.0beta: Mar 14 2000</h3>
1067<ul>
1068 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1069 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
1070 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
1071 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1072 <li>This version is now the head in the Gnome CVS base, the old one is
1073 available under the tag LIB_XML_1_X</li>
1074 <li>This includes a very large set of changes. Froma programmatic point of
1075 view applications should not have to be modified too much, check the <a
1076 href="upgrade.html">upgrade page</a></li>
1077 <li>Some interfaces may changes (especially a bit about encoding).</li>
1078 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1079 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1080 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
1081 handled now</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1082 <li>Better handling of entities, especially well formedness checking
1083 and proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1084 <li>DTD conditional sections</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1085 <li>Validation now correcly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1086 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
1087 structures to accomodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1088 </ul>
1089 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1090 <li>Serious progress were made toward compliance, <a
1091 href="conf/result.html">here are the result of the test</a> against the
1092 OASIS testsuite (except the japanese tests since I don't support that
1093 encoding yet). This URL is rebuilt every couple of hours using the CVS
1094 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1095</ul>
1096
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1097<h3>1.8.7: Mar 6 2000</h3>
1098<ul>
1099 <li>This is a bug fix release:</li>
1100 <li>It is possible to disable the ignorable blanks heuristic used by
1101 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1102 that for adherence to XML spec, this behaviour will be disabled by
1103 default in 2.x . The same function will allow to keep compatibility for
1104 old code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1105 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
1106 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1107 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
1108 compilation on some platforms has been fixed</li>
1109 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
1110 URIs</li>
1111</ul>
1112
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1113<h3>1.8.6: Jan 31 2000</h3>
1114<ul>
1115 <li>added a nanoFTP transport module, debugged until the new version of <a
1116 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
1117 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]1118</ul>
1119
1120<h3>1.8.5: Jan 21 2000</h3>
1121<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1122 <li>adding APIs to parse a well balanced chunk of XML (production <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1123 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
1124 XML spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1125 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1126 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
1127 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1128 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
1129 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1130</ul>
1131
1132<h3>1.8.4: Jan 13 2000</h3>
1133<ul>
1134 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
1135 <li>all exit() call should have been removed from libxml</li>
1136 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
1137 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1138</ul>
1139
1140<h3>1.8.3: Jan 5 2000</h3>
1141<ul>
1142 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1143 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillarddbfd6411999-12-28 16:35:14 +0000[diff] [blame]1144 <li>lots of bug fixes and improvement added over XMas hollidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1145 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1146 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
1147 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1148 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1149 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1150 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1151</ul>
1152
1153<h3>1.8.2: Dec 21 1999</h3>
1154<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1155 <li>I got another problem with includes and C++, I hope this issue is fixed
1156 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1157 <li>Added a few tree modification functions: xmlReplaceNode,
1158 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
1159 xmlDocSetRootElement</li>
1160 <li>Tried to improve the HTML output with help from <a
1161 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1162</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1163
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1164<h3>1.8.1: Dec 18 1999</h3>
1165<ul>
1166 <li>various patches to avoid troubles when using libxml with C++ compilers
1167 the "namespace" keyword and C escaping in include files</li>
1168 <li>a problem in one of the core macros IS_CHAR was corrected</li>
1169 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
1170 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]1171 <li>fixed a posteriori validation (validation after parsing, or by using a
1172 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1173 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]1174</ul>
1175
1176<h3>1.8.0: Dec 12 1999</h3>
1177<ul>
1178 <li>cleanup, especially memory wise</li>
1179 <li>the parser should be more reliable, especially the HTML one, it should
1180 not crash, whatever the input !</li>
1181 <li>Integrated various patches, especially a speedup improvement for large
1182 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
1183 configure with --with-buffers to enable them.</li>
1184 <li>attribute normalization, oops should have been added long ago !</li>
1185 <li>attributes defaulted from Dtds should be available, xmlSetProp() now
1186 does entities escapting by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1187</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1188
1189<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1190<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1191 <li>Lots of HTML improvement</li>
1192 <li>Fixed some errors when saving both XML and HTML</li>
1193 <li>More examples, the regression tests should now look clean</li>
1194 <li>Fixed a bug with contiguous charref</li>
1195</ul>
1196
1197<h3>1.7.3: Sep 29 1999</h3>
1198<ul>
1199 <li>portability problems fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1200 <li>snprintf was used unconditionnally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1201 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1202</ul>
1203
1204<h3>1.7.1: Sep 24 1999</h3>
1205<ul>
1206 <li>The basic type for strings manipulated by libxml has been renamed in
1207 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1208 is that CHAR was conflicting with a predefined type on Windows. However
1209 on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1210 <strong>#define </strong>.</li>
1211 <li>Changed another error : the use of a structure field called errno, and
1212 leading to troubles on platforms where it's a macro</li>
1213</ul>
1214
1215<h3>1.7.0: sep 23 1999</h3>
1216<ul>
1217 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1218 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1219 <li>Added an errno to report errors by another mean than a simple printf
1220 like callback</li>
1221 <li>Finished ID/IDREF support and checking when validation</li>
1222 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1223 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1224 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
1225 implementation</li>
1226 <li>Added an HTML parser front-end</li>
1227</ul>
1228
1229<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1230
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1231<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]1232markup-based structured documents. Here is <a name="example">an example XML
1233document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1234<pre>&lt;?xml version="1.0"?&gt;
1235&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
1236 &lt;head&gt;
1237 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
1238 &lt;/head&gt;
1239 &lt;chapter&gt;
1240 &lt;title&gt;The Linux adventure&lt;/title&gt;
1241 &lt;p&gt;bla bla bla ...&lt;/p&gt;
1242 &lt;image href="linus.gif"/&gt;
1243 &lt;p&gt;...&lt;/p&gt;
1244 &lt;/chapter&gt;
1245&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1246
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1247<p>The first line specifies that it's an XML document and gives useful
1248information about its encoding. Then the document is a text format whose
1249structure is specified by tags between brackets. <strong>Each tag opened has
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1250to be closed</strong>. XML is pedantic about this. However, if a tag is empty
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1251(no content), a single tag can serve as both the opening and closing tag if
1252it ends with <code>/&gt;</code> rather than with <code>&gt;</code>. Note
1253that, for example, the image tag has no content (just an attribute) and is
1254closed by ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1255
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1256<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]1257structured document maintenance (where it follows the steps of SGML) to
1258simple data encoding mechanisms like configuration file formatting (glade),
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1259spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where
1260it is used to encode remote calls between a client and a server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1261
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1262<h2><a name="XSLT">XSLT</a></h2>
1263
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1264<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
1265
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1266<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
1267language for transforming XML documents into other XML documents (or
1268HTML/textual output).</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1269
1270<p>A separate library called libxslt is being built on top of libxml2. This
1271module "libxslt" can be found in the Gnome CVS base too.</p>
1272
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]1273<p>You can check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1274href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
1275supported and the progresses on the <a
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1276href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog">Changelog</a></p>
1277
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1278<h2><a name="architecture">libxml architecture</a></h2>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1279
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1280<p>Libxml is made of multiple components; some of them are optional, and most
1281of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1282<ul>
1283 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1284 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1285 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1286 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1287 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1288 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1289 <li>a SAX tree module to build an in-memory DOM representation</li>
1290 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1291 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1292 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1293 (optional)</li>
1294 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1295</ul>
1296
1297<p>Graphically this gives the following:</p>
1298
1299<p><img src="libxml.gif" alt="a graphical view of the various"></p>
1300
1301<p></p>
1302
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1303<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1304
1305<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1306returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1307<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1308as the file name, the document type, and a <strong>children</strong> pointer
1309which is the root of the document (or more exactly the first child under the
1310root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1311chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1312relationship. An xmlNode can also carry properties (a chain of xmlAttr
1313structures). An attribute may have a value which is a list of TEXT or
1314ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1315
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1316<p>Here is an example (erroneous with respect to the XML spec since there
1317should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1318
1319<p><img src="structure.gif" alt=" structure.gif "></p>
1320
1321<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1322called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1323prints them back as parsed. This is useful for detecting errors both in XML
1324code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1325which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1326result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1327<pre>DOCUMENT
1328version=1.0
1329standalone=true
1330 ELEMENT EXAMPLE
1331 ATTRIBUTE prop1
1332 TEXT
1333 content=gnome is great
1334 ATTRIBUTE prop2
1335 ENTITY_REF
1336 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1337 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1338 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1339 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1340 TEXT
1341 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1342 ELEMENT chapter
1343 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1344 TEXT
1345 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1346 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1347 TEXT
1348 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1349 ELEMENT image
1350 ATTRIBUTE href
1351 TEXT
1352 content=linus.gif
1353 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1354 TEXT
1355 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1356
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1357<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1358
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1359<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1360
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1361<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1362memory. 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]1363loaded using libxml), it's better to use the SAX interface of libxml. SAX is
1364a <strong>callback-based interface</strong> to the parser. Before parsing,
1365the application layer registers a customized set of callbacks which are
1366called by the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1367
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1368<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]1369libxml, see the <a
1370href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
1371documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1372Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1373
1374<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
1375program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1376binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1377distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1378testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1379<pre>SAX.setDocumentLocator()
1380SAX.startDocument()
1381SAX.getEntity(amp)
1382SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
1383SAX.characters( , 3)
1384SAX.startElement(head)
1385SAX.characters( , 4)
1386SAX.startElement(title)
1387SAX.characters(Welcome to Gnome, 16)
1388SAX.endElement(title)
1389SAX.characters( , 3)
1390SAX.endElement(head)
1391SAX.characters( , 3)
1392SAX.startElement(chapter)
1393SAX.characters( , 4)
1394SAX.startElement(title)
1395SAX.characters(The Linux adventure, 19)
1396SAX.endElement(title)
1397SAX.characters( , 4)
1398SAX.startElement(p)
1399SAX.characters(bla bla bla ..., 15)
1400SAX.endElement(p)
1401SAX.characters( , 4)
1402SAX.startElement(image, href='linus.gif')
1403SAX.endElement(image)
1404SAX.characters( , 4)
1405SAX.startElement(p)
1406SAX.characters(..., 3)
1407SAX.endElement(p)
1408SAX.characters( , 3)
1409SAX.endElement(chapter)
1410SAX.characters( , 1)
1411SAX.endElement(EXAMPLE)
1412SAX.endDocument()</pre>
1413
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1414<p>Most of the other interfaces of libxml are based on the DOM tree-building
1415facility, so nearly everything up to the end of this document presupposes the
1416use of the standard DOM tree build. Note that the DOM tree itself is built by
1417a set of registered default callbacks, without internal specific
1418interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1419
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1420<h2><a name="Validation">Validation &amp; DTDs</a></h2>
1421
1422<p>Table of Content:</p>
1423<ol>
1424 <li><a href="#General5">General overview</a></li>
1425 <li><a href="#definition">The definition</a></li>
1426 <li><a href="#Simple">Simple rules</a>
1427 <ol>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]1428 <li><a href="#reference">How to reference a DTD from a document</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1429 <li><a href="#Declaring">Declaring elements</a></li>
1430 <li><a href="#Declaring1">Declaring attributes</a></li>
1431 </ol>
1432 </li>
1433 <li><a href="#Some">Some examples</a></li>
1434 <li><a href="#validate">How to validate</a></li>
1435 <li><a href="#Other">Other resources</a></li>
1436</ol>
1437
1438<h3><a name="General5">General overview</a></h3>
1439
1440<p>Well what is validation and what is a DTD ?</p>
1441
1442<p>DTD is the acronym for Document Type Definition. This is a description of
1443the content for a familly of XML files. This is part of the XML 1.0
1444specification, and alows to describe and check that a given document instance
1445conforms to a set of rules detailing its structure and content.</p>
1446
1447<p>Validation is the process of checking a document against a DTD (more
1448generally against a set of construction rules).</p>
1449
1450<p>The validation process and building DTDs are the two most difficult parts
1451of the XML life cycle. Briefly a DTD defines all the possibles element to be
1452found within your document, what is the formal shape of your document tree
1453(by defining the allowed content of an element, either text, a regular
1454expression for the allowed list of children, or mixed content i.e. both text
1455and children). The DTD also defines the allowed attributes for all elements
1456and the types of the attributes.</p>
1457
1458<h3><a name="definition1">The definition</a></h3>
1459
1460<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
1461href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
1462Rev1</a>):</p>
1463<ul>
1464 <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
1465 elements</a></li>
1466 <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
1467 attributes</a></li>
1468</ul>
1469
1470<p>(unfortunately) all this is inherited from the SGML world, the syntax is
1471ancient...</p>
1472
1473<h3><a name="Simple1">Simple rules</a></h3>
1474
1475<p>Writing DTD can be done in multiple ways, the rules to build them if you
1476need something fixed or something which can evolve over time can be radically
1477different. Really complex DTD like Docbook ones are flexible but quite harder
1478to design. I will just focuse on DTDs for a formats with a fixed simple
1479structure. It is just a set of basic rules, and definitely not exhaustive nor
1480useable for complex DTD design.</p>
1481
1482<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
1483
1484<p>Assuming the top element of the document is <code>spec</code> and the dtd
1485is placed in the file <code>mydtd</code> in the subdirectory
1486<code>dtds</code> of the directory from where the document were loaded:</p>
1487
1488<p><code>&lt;!DOCTYPE spec SYSTEM "dtds/mydtd"&gt;</code></p>
1489
1490<p>Notes:</p>
1491<ul>
1492 <li>the system string is actually an URI-Reference (as defined in <a
1493 href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396</a>) so you can use a
1494 full URL string indicating the location of your DTD on the Web, this is a
1495 really good thing to do if you want others to validate your document</li>
1496 <li>it is also possible to associate a <code>PUBLIC</code> identifier (a
1497 magic string) so that the DTd is looked up in catalogs on the client side
1498 without having to locate it on the web</li>
1499 <li>a dtd contains a set of elements and attributes declarations, but they
1500 don't define what the root of the document should be. This is explicitely
1501 told to the parser/validator as the first element of the
1502 <code>DOCTYPE</code> declaration.</li>
1503</ul>
1504
1505<h4><a name="Declaring2">Declaring elements</a>:</h4>
1506
1507<p>The following declares an element <code>spec</code>:</p>
1508
1509<p><code>&lt;!ELEMENT spec (front, body, back?)&gt;</code></p>
1510
1511<p>it also expresses that the spec element contains one <code>front</code>,
1512one <code>body</code> and one optionnal <code>back</code> children elements
1513in this order. The declaration of one element of the structure and its
1514content are done in a single declaration. Similary the following declares
1515<code>div1</code> elements:</p>
1516
1517<p><code>&lt;!ELEMENT div1 (head, (p | list | note)*, div2*)&gt;</code></p>
1518
1519<p>means div1 contains one <code>head</code> then a series of optional
1520<code>p</code>, <code>list</code>s and <code>note</code>s and then an
1521optional <code>div2</code>. And last but not least an element can contain
1522text:</p>
1523
1524<p><code>&lt;!ELEMENT b (#PCDATA)&gt;</code></p>
1525
1526<p><code>b</code> contains text or being of mixed content (text and elements
1527in no particular order):</p>
1528
1529<p><code>&lt;!ELEMENT p (#PCDATA|a|ul|b|i|em)*&gt;</code></p>
1530
1531<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
1532<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
1533order.</p>
1534
1535<h4><a name="Declaring1">Declaring attributes</a>:</h4>
1536
1537<p>again the attributes declaration includes their content definition:</p>
1538
1539<p><code>&lt;!ATTLIST termdef name CDATA #IMPLIED&gt;</code></p>
1540
1541<p>means that the element <code>termdef</code> can have a <code>name</code>
1542attribute containing text (<code>CDATA</code>) and which is optionnal
1543(<code>#IMPLIED</code>). The attribute value can also be defined within a
1544set:</p>
1545
1546<p><code>&lt;!ATTLIST list type (bullets|ordered|glossary)
1547"ordered"&gt;</code></p>
1548
1549<p>means <code>list</code> element have a <code>type</code> attribute with 3
1550allowed values "bullets", "ordered" or "glossary" and which default to
1551"ordered" if the attribute is not explicitely specified.</p>
1552
1553<p>The content type of an attribute can be text (<code>CDATA</code>),
1554anchor/reference/references
1555(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
1556(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
1557(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
1558<code>chapter</code> element can have an optional <code>id</code> attribute
1559of type <code>ID</code>, usable for reference from attribute of type
1560IDREF:</p>
1561
1562<p><code>&lt;!ATTLIST chapter id ID #IMPLIED&gt;</code></p>
1563
1564<p>The last value of an attribute definition can be <code>#REQUIRED
1565</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
1566meaning that it is optional, or the default value (possibly prefixed by
1567<code>#FIXED</code> if it is the only allowed).</p>
1568
1569<p>Notes:</p>
1570<ul>
1571 <li>usually the attributes pertaining to a given element are declared in a
1572 single expression, but it is just a convention adopted by a lot of DTD
1573 writers:
1574 <pre>&lt;!ATTLIST termdef
1575 id ID #REQUIRED
1576 name CDATA #IMPLIED&gt;</pre>
1577 <p>The previous construct defines both <code>id</code> and
1578 <code>name</code> attributes for the element <code>termdef</code></p>
1579 </li>
1580</ul>
1581
1582<h3><a name="Some1">Some examples</a></h3>
1583
1584<p>The directory <code>test/valid/dtds/</code> in the libxml distribution
1585contains some complex DTD examples. The <code>test/valid/dia.xml</code>
1586example shows an XML file where the simple DTD is directly included within
1587the document.</p>
1588
1589<h3><a name="validate1">How to validate</a></h3>
1590
1591<p>The simplest is to use the xmllint program comming with libxml. The
1592<code>--valid</code> option turn on validation of the files given as input,
1593for example the following validates a copy of the first revision of the XML
15941.0 specification:</p>
1595
1596<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
1597
1598<p>the -- noout is used to not output the resulting tree.</p>
1599
1600<p>The <code>--dtdvalid dtd</code> allows to validate the document(s) against
1601a given DTD.</p>
1602
1603<p>Libxml exports an API to handle DTDs and validation, check the <a
1604href="http://xmlsoft.org/html/libxml-valid.html">associated
1605description</a>.</p>
1606
1607<h3><a name="Other1">Other resources</a></h3>
1608
1609<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
1610will just list one for now, others pointers welcome:</p>
1611<ul>
1612 <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
1613</ul>
1614
1615<p>I suggest looking at the examples found under test/valid/dtd and any of
1616the large number of books available on XML. The dia example in test/valid
1617should be both simple and complete enough to allow you to build your own.</p>
1618
1619<p></p>
1620
1621<h2><a name="Memory">Memory Management</a></h2>
1622
1623<p>Table of Content:</p>
1624<ol>
1625 <li><a href="#General3">General overview</a></li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]1626 <li><a href="#setting">Setting libxml set of memory routines</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1627 <li><a href="#cleanup">Cleaning up after parsing</a></li>
1628 <li><a href="#Debugging">Debugging routines</a></li>
1629 <li><a href="#General4">General memory requirements</a></li>
1630</ol>
1631
1632<h3><a name="General3">General overview</a></h3>
1633
1634<p>The module <code><a
1635href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
1636provides the interfaces to the libxml memory system:</p>
1637<ul>
1638 <li>libxml does not use the libc memory allocator directly but xmlFree(),
1639 xmlMalloc() and xmlRealloc()</li>
1640 <li>those routines can be reallocated to a specific set of routine, by
1641 default the libc ones i.e. free(), malloc() and realloc()</li>
1642 <li>the xmlmemory.c module includes a set of debugging routine</li>
1643</ul>
1644
1645<h3><a name="setting">Setting libxml set of memory routines</a></h3>
1646
1647<p>It is sometimes useful to not use the default memory allocator, either for
1648debugging, analysis or to implement a specific behaviour on memory management
1649(like on embedded systems). Two function calls are available to do so:</p>
1650<ul>
1651 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet ()</a>
1652 which return the current set of functions in use by the parser</li>
1653 <li><a
1654 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
1655 which allow to set up a new set of memory allocation functions</li>
1656</ul>
1657
1658<p>Of course a call to xmlMemSetup() should probably be done before calling
1659any other libxml routines (unless you are sure your allocations routines are
1660compatibles).</p>
1661
1662<h3><a name="cleanup">Cleaning up after parsing</a></h3>
1663
1664<p>Libxml is not stateless, there is a few set of memory structures needing
1665allocation before the parser is fully functionnal (some encoding structures
1666for example). This also mean that once parsing is finished there is a tiny
1667amount of memory (a few hundred bytes) which can be recollected if you don't
1668reuse the parser immediately:</p>
1669<ul>
1670 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
1671 ()</a>
1672 is a centralized routine to free the parsing states. Note that it won't
1673 deallocate any produced tree if any (use the xmlFreeDoc() and related
1674 routines for this).</li>
1675 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
1676 ()</a>
1677 is the dual routine allowing to preallocate the parsing state which can
1678 be useful for example to avoid initialization reentrancy problems when
1679 using libxml in multithreaded applications</li>
1680</ul>
1681
1682<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
1683at the next invocation of parser routines, but be careful of the consequences
1684in multithreaded applications.</p>
1685
1686<h3><a name="Debugging">Debugging routines</a></h3>
1687
1688<p>When configured using --with-mem-debug flag (off by default), libxml uses
1689a set of memory allocation debugging routineskeeping track of all allocated
1690blocks and the location in the code where the routine was called. A couple of
1691other debugging routines allow to dump the memory allocated infos to a file
1692or call a specific routine when a given block number is allocated:</p>
1693<ul>
1694 <li><a
1695 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
1696 <a
1697 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
1698 and <a
1699 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
1700 are the memory debugging replacement allocation routines</li>
1701 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
1702 ()</a>
1703 dumps all the informations about the allocated memory block lefts in the
1704 <code>.memdump</code> file</li>
1705</ul>
1706
1707<p>When developping libxml memory debug is enabled, the tests programs call
1708xmlMemoryDump () and the "make test" regression tests will check for any
1709memory leak during the full regression test sequence, this helps a lot
1710ensuring that libxml does not leak memory and bullet proof memory
1711allocations use (some libc implementations are known to be far too permissive
1712resulting in major portability problems!).</p>
1713
1714<p>If the .memdump reports a leak, it displays the allocation function and
1715also tries to give some informations about the content and structure of the
1716allocated blocks left. This is sufficient in most cases to find the culprit,
1717but not always. Assuming the allocation problem is reproductible, it is
1718possible to find more easilly:</p>
1719<ol>
1720 <li>write down the block number xxxx not allocated</li>
1721 <li>export the environement variable XML_MEM_BREAKPOINT=xxxx</li>
1722 <li>run the program under a debugger and set a breakpoint on
1723 xmlMallocBreakpoint() a specific function called when this precise block
1724 is allocated</li>
1725 <li>when the breakpoint is reached you can then do a fine analysis of the
1726 allocation an step to see the condition resulting in the missing
1727 deallocation.</li>
1728</ol>
1729
1730<p>I used to use a commercial tool to debug libxml memory problems but after
1731noticing that it was not detecting memory leaks that simple mechanism was
1732used and proved extremely efficient until now.</p>
1733
1734<h3><a name="General4">General memory requirements</a></h3>
1735
1736<p>How much libxml memory require ? It's hard to tell in average it depends
1737of a number of things:</p>
1738<ul>
1739 <li>the parser itself should work in a fixed amout of memory, except for
1740 information maintained about the stacks of names and entities locations.
1741 The I/O and encoding handlers will probably account for a few KBytes.
1742 This is true for both the XML and HTML parser (though the HTML parser
1743 need more state).</li>
1744 <li>If you are generating the DOM tree then memory requirements will grow
1745 nearly lineary with the size of the data. In general for a balanced
1746 textual document the internal memory requirement is about 4 times the
1747 size of the UTF8 serialization of this document (exmple the XML-1.0
1748 recommendation is a bit more of 150KBytes and takes 650KBytes of main
1749 memory when parsed). Validation will add a amount of memory required for
1750 maintaining the external Dtd state which should be linear with the
1751 complexity of the content model defined by the Dtd</li>
1752 <li>If you don't care about the advanced features of libxml like
1753 validation, DOM, XPath or XPointer, but really need to work fixed memory
1754 requirements, then the SAX interface should be used.</li>
1755</ul>
1756
1757<p></p>
1758
1759<h2><a name="Encodings">Encodings support</a></h2>
1760
1761<p>Table of Content:</p>
1762<ol>
1763 <li><a href="encoding.html#What">What does internationalization support
1764 mean ?</a></li>
1765 <li><a href="encoding.html#internal">The internal encoding, how and
1766 why</a></li>
1767 <li><a href="encoding.html#implemente">How is it implemented ?</a></li>
1768 <li><a href="encoding.html#Default">Default supported encodings</a></li>
1769 <li><a href="encoding.html#extend">How to extend the existing
1770 support</a></li>
1771</ol>
1772
1773<h3><a name="What">What does internationalization support mean ?</a></h3>
1774
1775<p>XML was designed from the start to allow the support of any character set
1776by using Unicode. Any conformant XML parser has to support the UTF-8 and
1777UTF-16 default encodings which can both express the full unicode ranges. UTF8
1778is a variable length encoding whose greatest point are to resuse the same
1779emcoding for ASCII and to save space for Western encodings, but it is a bit
1780more complex to handle in practice. UTF-16 use 2 bytes per characters (and
1781sometimes combines two pairs), it makes implementation easier, but looks a
1782bit overkill for Western languages encoding. Moreover the XML specification
1783allows document to be encoded in other encodings at the condition that they
1784are clearly labelled as such. For example the following is a wellformed XML
1785document encoded in ISO-8859 1 and using accentuated letter that we French
1786likes for both markup and content:</p>
1787<pre>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
1788&lt;très&gt;là&lt;/très&gt;</pre>
1789
1790<p>Having internationalization support in libxml means the foolowing:</p>
1791<ul>
1792 <li>the document is properly parsed</li>
1793 <li>informations about it's encoding are saved</li>
1794 <li>it can be modified</li>
1795 <li>it can be saved in its original encoding</li>
1796 <li>it can also be saved in another encoding supported by libxml (for
1797 example straight UTF8 or even an ASCII form)</li>
1798</ul>
1799
1800<p>Another very important point is that the whole libxml API, with the
1801exception of a few routines to read with a specific encoding or save to a
1802specific encoding, is completely agnostic about the original encoding of the
1803document.</p>
1804
1805<p>It should be noted too that the HTML parser embedded in libxml now obbey
1806the same rules too, the following document will be (as of 2.2.2) handled in
1807an internationalized fashion by libxml too:</p>
1808<pre>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
1809 "http://www.w3.org/TR/REC-html40/loose.dtd"&gt;
1810&lt;html lang="fr"&gt;
1811&lt;head&gt;
1812 &lt;META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&gt;
1813&lt;/head&gt;
1814&lt;body&gt;
1815&lt;p&gt;W3C crée des standards pour le Web.&lt;/body&gt;
1816&lt;/html&gt;</pre>
1817
1818<h3><a name="internal">The internal encoding, how and why</a></h3>
1819
1820<p>One of the core decision was to force all documents to be converted to a
1821default internal encoding, and that encoding to be UTF-8, here are the
1822rationale for those choices:</p>
1823<ul>
1824 <li>keeping the native encoding in the internal form would force the libxml
1825 users (or the code associated) to be fully aware of the encoding of the
1826 original document, for examples when adding a text node to a document,
1827 the content would have to be provided in the document encoding, i.e. the
1828 client code would have to check it before hand, make sure it's conformant
1829 to the encoding, etc ... Very hard in practice, though in some specific
1830 cases this may make sense.</li>
1831 <li>the second decision was which encoding. From the XML spec only UTF8 and
1832 UTF16 really makes sense as being the two only encodings for which there
1833 is amndatory support. UCS-4 (32 bits fixed size encoding) could be
1834 considered an intelligent choice too since it's a direct Unicode mapping
1835 support. I selected UTF-8 on the basis of efficiency and compatibility
1836 with surrounding software:
1837 <ul>
1838 <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
1839 more costly to import and export CPU wise) is also far more compact
1840 than UTF-16 (and UCS-4) for a majority of the documents I see it used
1841 for right now (RPM RDF catalogs, advogato data, various configuration
1842 file formats, etc.) and the key point for today's computer
1843 architecture is efficient uses of caches. If one nearly double the
1844 memory requirement to store the same amount of data, this will trash
1845 caches (main memory/external caches/internal caches) and my take is
1846 that this harms the system far more than the CPU requirements needed
1847 for the conversion to UTF-8</li>
1848 <li>Most of libxml version 1 users were using it with straight ASCII
1849 most of the time, doing the conversion with an internal encoding
1850 requiring all their code to be rewritten was a serious show-stopper
1851 for using UTF-16 or UCS-4.</li>
1852 <li>UTF-8 is being used as the de-facto internal encoding standard for
1853 related code like the <a href="http://www.pango.org/">pango</a>
1854 upcoming Gnome text widget, and a lot of Unix code (yep another place
1855 where Unix programmer base takes a different approach from Microsoft
1856 - they are using UTF-16)</li>
1857 </ul>
1858 </li>
1859</ul>
1860
1861<p>What does this mean in practice for the libxml user:</p>
1862<ul>
1863 <li>xmlChar, the libxml data type is a byte, those bytes must be assembled
1864 as UTF-8 valid strings. The proper way to terminate an xmlChar * string
1865 is simply to append 0 byte, as usual.</li>
1866 <li>One just need to make sure that when using chars outside the ASCII set,
1867 the values has been properly converted to UTF-8</li>
1868</ul>
1869
1870<h3><a name="implemente">How is it implemented ?</a></h3>
1871
1872<p>Let's describe how all this works within libxml, basically the I18N
1873(internationalization) support get triggered only during I/O operation, i.e.
1874when reading a document or saving one. Let's look first at the reading
1875sequence:</p>
1876<ol>
1877 <li>when a document is processed, we usually don't know the encoding, a
1878 simple heuristic allows to detect UTF-18 and UCS-4 from whose where the
1879 ASCII range (0-0x7F) maps with ASCII</li>
1880 <li>the xml declaration if available is parsed, including the encoding
1881 declaration. At that point, if the autodetected encoding is different
1882 from the one declared a call to xmlSwitchEncoding() is issued.</li>
1883 <li>If there is no encoding declaration, then the input has to be in either
1884 UTF-8 or UTF-16, if it is not then at some point when processing the
1885 input, the converter/checker of UTF-8 form will raise an encoding error.
1886 You may end-up with a garbled document, or no document at all ! Example:
1887 <pre>~/XML -&gt; ./xmllint err.xml
1888err.xml:1: error: Input is not proper UTF-8, indicate encoding !
1889&lt;très&gt;là&lt;/très&gt;
1890 ^
1891err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
1892&lt;très&gt;là&lt;/très&gt;
1893 ^</pre>
1894 </li>
1895 <li>xmlSwitchEncoding() does an encoding name lookup, canonalize it, and
1896 then search the default registered encoding converters for that encoding.
1897 If it's not within the default set and iconv() support has been compiled
1898 it, it will ask iconv for such an encoder. If this fails then the parser
1899 will report an error and stops processing:
1900 <pre>~/XML -&gt; ./xmllint err2.xml
1901err2.xml:1: error: Unsupported encoding UnsupportedEnc
1902&lt;?xml version="1.0" encoding="UnsupportedEnc"?&gt;
1903 ^</pre>
1904 </li>
1905 <li>From that point the encoder process progressingly the input (it is
1906 plugged as a front-end to the I/O module) for that entity. It captures
1907 and convert on-the-fly the document to be parsed to UTF-8. The parser
1908 itself just does UTF-8 checking of this input and process it
1909 transparently. The only difference is that the encoding information has
1910 been added to the parsing context (more precisely to the input
1911 corresponding to this entity).</li>
1912 <li>The result (when using DOM) is an internal form completely in UTF-8
1913 with just an encoding information on the document node.</li>
1914</ol>
1915
1916<p>Ok then what's happen when saving the document (assuming you
1917colllected/built an xmlDoc DOM like structure) ? It depends on the function
1918called, xmlSaveFile() will just try to save in the original encoding, while
1919xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
1920encoding:</p>
1921<ol>
1922 <li>if no encoding is given, libxml will look for an encoding value
1923 associated to the document and if it exists will try to save to that
1924 encoding,
1925 <p>otherwise everything is written in the internal form, i.e. UTF-8</p>
1926 </li>
1927 <li>so if an encoding was specified, either at the API level or on the
1928 document, libxml will again canonalize the encoding name, lookup for a
1929 converter in the registered set or through iconv. If not found the
1930 function will return an error code</li>
1931 <li>the converter is placed before the I/O buffer layer, as another kind of
1932 buffer, then libxml will simply push the UTF-8 serialization to through
1933 that buffer, which will then progressively be converted and pushed onto
1934 the I/O layer.</li>
1935 <li>It is possible that the converter code fails on some input, for example
1936 trying to push an UTF-8 encoded chinese character through the UTF-8 to
1937 ISO-8859-1 converter won't work. Since the encoders are progressive they
1938 will just report the error and the number of bytes converted, at that
1939 point libxml will decode the offending character, remove it from the
1940 buffer and replace it with the associated charRef encoding &amp;#123; and
1941 resume the convertion. This guarante that any document will be saved
1942 without losses (except for markup names where this is not legal, this is
1943 a problem in the current version, in pactice avoid using non-ascci
1944 characters for tags or attributes names @@). A special "ascii" encoding
1945 name is used to save documents to a pure ascii form can be used when
1946 portability is really crucial</li>
1947</ol>
1948
1949<p>Here is a few examples based on the same test document:</p>
1950<pre>~/XML -&gt; ./xmllint isolat1
1951&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
1952&lt;très&gt;là&lt;/très&gt;
1953~/XML -&gt; ./xmllint --encode UTF-8 isolat1
1954&lt;?xml version="1.0" encoding="UTF-8"?&gt;
1955&lt;très&gt;là  &lt;/très&gt;
1956~/XML -&gt; </pre>
1957
1958<p>The same processing is applied (and reuse most of the code) for HTML I18N
1959processing. Looking up and modifying the content encoding is a bit more
1960difficult since it is located in a &lt;meta&gt; tag under the &lt;head&gt;,
1961so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
1962been provided. The parser also attempts to switch encoding on the fly when
1963detecting such a tag on input. Except for that the processing is the same
1964(and again reuses the same code).</p>
1965
1966<h3><a name="Default">Default supported encodings</a></h3>
1967
1968<p>libxml has a set of default converters for the following encodings
1969(located in encoding.c):</p>
1970<ol>
1971 <li>UTF-8 is supported by default (null handlers)</li>
1972 <li>UTF-16, both little and big endian</li>
1973 <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
1974 <li>ASCII, useful mostly for saving</li>
1975 <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
1976 predefined entities like &amp;copy; for the Copyright sign.</li>
1977</ol>
1978
1979<p>More over when compiled on an Unix platfor with iconv support the full set
1980of encodings supported by iconv can be instantly be used by libxml. On a
1981linux machine with glibc-2.1 the list of supported encodings and aliases fill
19823 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
1983various Japanese ones.</p>
1984
1985<h4>Encoding aliases</h4>
1986
1987<p>From 2.2.3, libxml has support to register encoding names aliases. The
1988goal is to be able to parse document whose encoding is supported but where
1989the name differs (for example from the default set of names accepted by
1990iconv). The following functions allow to register and handle new aliases for
1991existing encodings. Once registered libxml will automatically lookup the
1992aliases when handling a document:</p>
1993<ul>
1994 <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li>
1995 <li>int xmlDelEncodingAlias(const char *alias);</li>
1996 <li>const char * xmlGetEncodingAlias(const char *alias);</li>
1997 <li>void xmlCleanupEncodingAliases(void);</li>
1998</ul>
1999
2000<h3><a name="extend">How to extend the existing support</a></h3>
2001
2002<p>Well adding support for new encoding, or overriding one of the encoders
2003(assuming it is buggy) should not be hard, just write an input and output
2004conversion routines to/from UTF-8, and register them using
2005xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
2006called automatically if the parser(s) encounter such an encoding name
2007(register it uppercase, this will help). The description of the encoders,
2008their arguments and expected return values are described in the encoding.h
2009header.</p>
2010
2011<p>A quick note on the topic of subverting the parser to use a different
2012internal encoding than UTF-8, in some case people will absolutely want to
2013keep the internal encoding different, I think it's still possible (but the
2014encoding must be compliant with ASCII on the same subrange) though I didn't
2015tried it. The key is to override the default conversion routines (by
2016registering null encoders/decoders for your charsets), and bypass the UTF-8
2017checking of the parser by setting the parser context charset
2018(ctxt-&gt;charset) to something different than XML_CHAR_ENCODING_UTF8, but
2019there is no guarantee taht this will work. You may also have some troubles
2020saving back.</p>
2021
2022<p>Basically proper I18N support is important, this requires at least
2023libxml-2.0.0, but a lot of features and corrections are really available only
2024starting 2.2.</p>
2025
2026<h2><a name="IO">I/O Interfaces</a></h2>
2027
2028<p>Table of Content:</p>
2029<ol>
2030 <li><a href="#General1">General overview</a></li>
2031 <li><a href="#basic">The basic buffer type</a></li>
2032 <li><a href="#Input">Input I/O handlers</a></li>
2033 <li><a href="#Output">Output I/O handlers</a></li>
2034 <li><a href="#entities">The entities loader</a></li>
2035 <li><a href="#Example2">Example of customized I/O</a></li>
2036</ol>
2037
2038<h3><a name="General1">General overview</a></h3>
2039
2040<p>The module <code><a
2041href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
2042the interfaces to the libxml I/O system. This consists of 4 main parts:</p>
2043<ul>
2044 <li>Entities loader, this is a routine which tries to fetch the entities
2045 (files) based on their PUBLIC and SYSTEM identifiers. The default loader
2046 don't look at the public identifier since libxml do not maintain a
2047 catalog. You can redefine you own entity loader by using
2048 <code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2049 <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
2050 example</a>.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2051 <li>Input I/O buffers which are a commodity structure used by the parser(s)
2052 input layer to handle fetching the informations to feed the parser. This
2053 provides buffering and is also a placeholder where the encoding
2054 convertors to UTF8 are piggy-backed.</li>
2055 <li>Output I/O buffers are similar to the Input ones and fulfill similar
2056 task but when generating a serialization from a tree.</li>
2057 <li>A mechanism to register sets of I/O callbacks and associate them with
2058 specific naming schemes like the protocol part of the URIs.
2059 <p>This affect the default I/O operations and allows to use specific I/O
2060 handlers for certain names.</p>
2061 </li>
2062</ul>
2063
2064<p>The general mechanism used when loading http://rpmfind.net/xml.html for
2065example in the HTML parser is the following:</p>
2066<ol>
2067 <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
2068 the parsing context and the URI string.</li>
2069 <li>the URI string is checked against the existing registered handlers
2070 using their match() callback function, if the HTTP module was compiled
2071 in, it is registered and its match() function will succeeds</li>
2072 <li>the open() function of the handler is called and if successful will
2073 return an I/O Input buffer</li>
2074 <li>the parser will the start reading from this buffer and progressively
2075 fetch information from the resource, calling the read() function of the
2076 handler until the resource is exhausted</li>
2077 <li>if an encoding change is detected it will be installed on the input
2078 buffer, providing buffering and efficient use of the conversion
2079 routines</li>
2080 <li>once the parser has finished, the close() function of the handler is
2081 called once and the Input buffer and associed resources are
2082 deallocated.</li>
2083</ol>
2084
2085<p>The user defined callbacks are checked first to allow overriding of the
2086default libxml I/O routines.</p>
2087
2088<h3><a name="basic">The basic buffer type</a></h3>
2089
2090<p>All the buffer manipulation handling is done using the
2091<code>xmlBuffer</code> type define in <code><a
2092href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
2093resizable memory buffer. The buffer allocation strategy can be selected to be
2094either best-fit or use an exponential doubling one (CPU vs. memory use
2095tradeoff). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
2096<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
2097system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
2098of functions allows to manipulate buffers with names starting with the
2099<code>xmlBuffer...</code> prefix.</p>
2100
2101<h3><a name="Input">Input I/O handlers</a></h3>
2102
2103<p>An Input I/O handler is a simple structure
2104<code>xmlParserInputBuffer</code> containing a context associated to the
2105resource (file descriptor, or pointer to a protocol handler), the read() and
2106close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
2107encoding handler are also present to support charset conversion when
2108needed.</p>
2109
2110<h3><a name="Output">Output I/O handlers</a></h3>
2111
2112<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
2113Input one except the callbacks are write() and close().</p>
2114
2115<h3><a name="entities">The entities loader</a></h3>
2116
2117<p>The entity loader resolves requests for new entities and create inputs for
2118the parser. Creating an input from a filename or an URI string is done
2119through the xmlNewInputFromFile() routine. The default entity loader do not
2120handle the PUBLIC identifier associated with an entity (if any). So it just
2121calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
2122XML).</p>
2123
2124<p>If you want to hook up a catalog mechanism then you simply need to
2125override the default entity loader, here is an example:</p>
2126<pre>#include &lt;libxml/xmlIO.h&gt;
2127
2128xmlExternalEntityLoader defaultLoader = NULL;
2129
2130xmlParserInputPtr
2131xmlMyExternalEntityLoader(const char *URL, const char *ID,
2132 xmlParserCtxtPtr ctxt) {
2133 xmlParserInputPtr ret;
2134 const char *fileID = NULL;
2135 /* lookup for the fileID depending on ID */
2136
2137 ret = xmlNewInputFromFile(ctxt, fileID);
2138 if (ret != NULL)
2139 return(ret);
2140 if (defaultLoader != NULL)
2141 ret = defaultLoader(URL, ID, ctxt);
2142 return(ret);
2143}
2144
2145int main(..) {
2146 ...
2147
2148 /*
2149 * Install our own entity loader
2150 */
2151 defaultLoader = xmlGetExternalEntityLoader();
2152 xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
2153
2154 ...
2155}</pre>
2156
2157<h3><a name="Example2">Example of customized I/O</a></h3>
2158
2159<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
2160real use case</a>, xmlDocDump() closes the FILE * passed by the application
2161and this was a problem. The <a
2162href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
2163new output handler with the closing call deactivated:</p>
2164<ol>
2165 <li>First define a new I/O ouput allocator where the output don't close the
2166 file:
2167 <pre>xmlOutputBufferPtr
2168xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
2169    xmlOutputBufferPtr ret;
2170    
2171    if (xmlOutputCallbackInitialized == 0)
2172        xmlRegisterDefaultOutputCallbacks();
2173
2174    if (file == NULL) return(NULL);
2175    ret = xmlAllocOutputBuffer(encoder);
2176    if (ret != NULL) {
2177        ret-&gt;context = file;
2178        ret-&gt;writecallback = xmlFileWrite;
2179        ret-&gt;closecallback = NULL; /* No close callback */
2180    }
2181    return(ret); <br>
2182
2183
2184
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2185
2186
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]2187
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]2188
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]2189
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]2190
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]2191
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]2192
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]2193
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]2194
Daniel Veillard9ae4b7a2001-12-13 14:24:09 +0000[diff] [blame]2195
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]2196
Daniel Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame^]2197
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2198} </pre>
2199 </li>
2200 <li>And then use it to save the document:
2201 <pre>FILE *f;
2202xmlOutputBufferPtr output;
2203xmlDocPtr doc;
2204int res;
2205
2206f = ...
2207doc = ....
2208
2209output = xmlOutputBufferCreateOwn(f, NULL);
2210res = xmlSaveFileTo(output, doc, NULL);
2211 </pre>
2212 </li>
2213</ol>
2214
2215<h2><a name="Catalog">Catalog support</a></h2>
2216
2217<p>Table of Content:</p>
2218<ol>
2219 <li><a href="General2">General overview</a></li>
2220 <li><a href="#definition">The definition</a></li>
2221 <li><a href="#Simple">Using catalogs</a></li>
2222 <li><a href="#Some">Some examples</a></li>
2223 <li><a href="#reference">How to tune catalog usage</a></li>
2224 <li><a href="#validate">How to debug catalog processing</a></li>
2225 <li><a href="#Declaring">How to create and maintain catalogs</a></li>
2226 <li><a href="#implemento">The implementor corner quick review of the
2227 API</a></li>
2228 <li><a href="#Other">Other resources</a></li>
2229</ol>
2230
2231<h3><a name="General2">General overview</a></h3>
2232
2233<p>What is a catalog? Basically it's a lookup mechanism used when an entity
2234(a file or a remote resource) references another entity. The catalog lookup
2235is inserted between the moment the reference is recognized by the software
2236(XML parser, stylesheet processing, or even images referenced for inclusion
2237in a rendering) and the time where loading that resource is actually
2238started.</p>
2239
2240<p>It is basically used for 3 things:</p>
2241<ul>
2242 <li>mapping from "logical" names, the public identifiers and a more
2243 concrete name usable for download (and URI). For example it can associate
2244 the logical name
2245 <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
2246 <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
2247 downloaded</p>
2248 <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
2249 </li>
2250 <li>remapping from a given URL to another one, like an HTTP indirection
2251 saying that
2252 <p>"http://www.oasis-open.org/committes/tr.xsl"</p>
2253 <p>should really be looked at</p>
2254 <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
2255 </li>
2256 <li>providing a local cache mechanism allowing to load the entities
2257 associated to public identifiers or remote resources, this is a really
2258 important feature for any significant deployment of XML or SGML since it
2259 allows to avoid the aleas and delays associated to fetching remote
2260 resources.</li>
2261</ul>
2262
2263<h3><a name="definition">The definitions</a></h3>
2264
2265<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
2266<ul>
2267 <li>the older SGML catalogs, the official spec is SGML Open Technical
2268 Resolution TR9401:1997, but is better understood by reading <a
2269 href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
2270 James Clark. This is relatively old and not the preferred mode of
2271 operation of libxml.</li>
2272 <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
2273 Catalogs</a>
2274 is far more flexible, more recent, uses an XML syntax and should scale
2275 quite better. This is the default option of libxml.</li>
2276</ul>
2277
2278<p></p>
2279
2280<h3><a name="Simple">Using catalog</a></h3>
2281
2282<p>In a normal environment libxml will by default check the presence of a
2283catalog in /etc/xml/catalog, and assuming it has been correctly populated,
2284the processing is completely transparent to the document user. To take a
2285concrete example, suppose you are authoring a DocBook document, this one
2286starts with the following DOCTYPE definition:</p>
2287<pre>&lt;?xml version='1.0'?&gt;
2288&lt;!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
2289 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"&gt;</pre>
2290
2291<p>When validating the document with libxml, the catalog will be
2292automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
2293DocBk XML V3.1.4//EN" and the system identifier
2294"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
2295been installed on your system and the catalogs actually point to them, libxml
2296will fetch them from the local disk.</p>
2297
2298<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
2299DOCTYPE example it's a really old version, but is fine as an example.</p>
2300
2301<p>Libxml will check the catalog each time that it is requested to load an
2302entity, this includes DTD, external parsed entities, stylesheets, etc ... If
2303your system is correctly configured all the authoring phase and processing
2304should use only local files, even if your document stays portable because it
2305uses the canonical public and system ID, referencing the remote document.</p>
2306
2307<h3><a name="Some">Some examples:</a></h3>
2308
2309<p>Here is a couple of fragments from XML Catalogs used in libxml early
2310regression tests in <code>test/catalogs</code> :</p>
2311<pre>&lt;?xml version="1.0"?&gt;
2312&lt;!DOCTYPE catalog PUBLIC
2313 "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2314 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2315&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2316 &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2317 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2318...</pre>
2319
2320<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
2321written in XML, there is a specific namespace for catalog elements
2322"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
2323catalog is a <code>public</code> mapping it allows to associate a Public
2324Identifier with an URI.</p>
2325<pre>...
2326 &lt;rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2327 rewritePrefix="file:///usr/share/xml/docbook/"/&gt;
2328...</pre>
2329
2330<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
2331any URI starting with a given prefix should be looked at another URI
2332constructed by replacing the prefix with an new one. In effect this acts like
2333a cache system for a full area of the Web. In practice it is extremely useful
2334with a file prefix if you have installed a copy of those resources on your
2335local system.</p>
2336<pre>...
2337&lt;delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
2338 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2339&lt;delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
2340 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2341&lt;delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
2342 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2343&lt;delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2344 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2345&lt;delegateURI uriStartString="http://www.oasis-open.org/docbook/"
2346 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2347...</pre>
2348
2349<p>Delegation is the core features which allows to build a tree of catalogs,
2350easier to maintain than a single catalog, based on Public Identifier, System
2351Identifier or URI prefixes it instructs the catalog software to look up
2352entries in another resource. This feature allow to build hierarchies of
2353catalogs, the set of entries presented should be sufficient to redirect the
2354resolution of all DocBook references to the specific catalog in
2355<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
2356references for DocBook 4.2.1 to a specific catalog installed at the same time
2357as the DocBook resources on the local machine.</p>
2358
2359<h3><a name="reference">How to tune catalog usage:</a></h3>
2360
2361<p>The user can change the default catalog behaviour by redirecting queries
2362to its own set of catalogs, this can be done by setting the
2363<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
2364empty one should deactivate loading the default <code>/etc/xml/catalog</code>
2365default catalog</p>
2366
2367<h3><a name="validate">How to debug catalog processing:</a></h3>
2368
2369<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
2370make libxml output debugging informations for each catalog operations, for
2371example:</p>
2372<pre>orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2373warning: failed to load external entity "title.xml"
2374orchis:~/XML -&gt; export XML_DEBUG_CATALOG=
2375orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2376Failed to parse catalog /etc/xml/catalog
2377Failed to parse catalog /etc/xml/catalog
2378warning: failed to load external entity "title.xml"
2379Catalogs cleanup
2380orchis:~/XML -&gt; </pre>
2381
2382<p>The test/ent2 references an entity, running the parser from memory makes
2383the base URI unavailable and the the "title.xml" entity cannot be loaded.
2384Setting up the debug environment variable allows to detect that an attempt is
2385made to load the <code>/etc/xml/catalog</code> but since it's not present the
2386resolution fails.</p>
2387
2388<p>But the most advanced way to debug XML catalog processing is to use the
2389<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
2390catalogs and make resolution queries to see what is going on. This is also
2391used for the regression tests:</p>
2392<pre>orchis:~/XML -&gt; ./xmlcatalog test/catalogs/docbook.xml \
2393 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2394http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2395orchis:~/XML -&gt; </pre>
2396
2397<p>For debugging what is going on, adding one -v flags increase the verbosity
2398level to indicate the processing done (adding a second flag also indicate
2399what elements are recognized at parsing):</p>
2400<pre>orchis:~/XML -&gt; ./xmlcatalog -v test/catalogs/docbook.xml \
2401 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2402Parsing catalog test/catalogs/docbook.xml's content
2403Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
2404http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2405Catalogs cleanup
2406orchis:~/XML -&gt; </pre>
2407
2408<p>A shell interface is also available to debug and process multiple queries
2409(and for regression tests):</p>
2410<pre>orchis:~/XML -&gt; ./xmlcatalog -shell test/catalogs/docbook.xml \
2411 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2412&gt; help
2413Commands available:
2414public PublicID: make a PUBLIC identifier lookup
2415system SystemID: make a SYSTEM identifier lookup
2416resolve PublicID SystemID: do a full resolver lookup
2417add 'type' 'orig' 'replace' : add an entry
2418del 'values' : remove values
2419dump: print the current catalog state
2420debug: increase the verbosity level
2421quiet: decrease the verbosity level
2422exit: quit the shell
2423&gt; public "-//OASIS//DTD DocBook XML V4.1.2//EN"
2424http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2425&gt; quit
2426orchis:~/XML -&gt; </pre>
2427
2428<p>This should be sufficient for most debugging purpose, this was actually
2429used heavily to debug the XML Catalog implementation itself.</p>
2430
2431<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
2432
2433<p>Basically XML Catalogs are XML files, you can either use XML tools to
2434manage them or use <strong>xmlcatalog</strong> for this. The basic step is
2435to create a catalog the -create option provide this facility:</p>
2436<pre>orchis:~/XML -&gt; ./xmlcatalog --create tst.xml
2437&lt;?xml version="1.0"?&gt;
2438&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2439 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2440&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2441orchis:~/XML -&gt; </pre>
2442
2443<p>By default xmlcatalog does not overwrite the original catalog and save the
2444result on the standard output, this can be overridden using the -noout
2445option. The <code>-add</code> command allows to add entries in the
2446catalog:</p>
2447<pre>orchis:~/XML -&gt; ./xmlcatalog --noout --create --add "public" \
2448 "-//OASIS//DTD DocBook XML V4.1.2//EN" \
2449 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
2450orchis:~/XML -&gt; cat tst.xml
2451&lt;?xml version="1.0"?&gt;
2452&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
2453 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2454&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2455&lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2456 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2457&lt;/catalog&gt;
2458orchis:~/XML -&gt; </pre>
2459
2460<p>The <code>-add</code> option will always take 3 parameters even if some of
2461the XML Catalog constructs (like nextCatalog) will have only a single
2462argument, just pass a third empty string, it will be ignored.</p>
2463
2464<p>Similarly the <code>-del</code> option remove matching entries from the
2465catalog:</p>
2466<pre>orchis:~/XML -&gt; ./xmlcatalog --del \
2467 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
2468&lt;?xml version="1.0"?&gt;
2469&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2470 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2471&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2472orchis:~/XML -&gt; </pre>
2473
2474<p>The catalog is now empty. Note that the matching of <code>-del</code> is
2475exact and would have worked in a similar fashion with the Public ID
2476string.</p>
2477
2478<p>This is rudimentary but should be sufficient to manage a not too complex
2479catalog tree of resources.</p>
2480
2481<h3><a name="implemento">The implementor corner quick review of the
2482API:</a></h3>
2483
2484<p>First, and like for every other module of libxml, there is an
2485automatically generated <a href="html/libxml-catalog.html">API page for
2486catalog support</a>.</p>
2487
2488<p>The header for the catalog interfaces should be included as:</p>
2489<pre>#include &lt;libxml/catalog.h&gt;</pre>
2490
2491<p>The API is voluntarily kept very simple. First it is not obvious that
2492applications really need access to it since it is the default behaviour of
2493libxml (Note: it is possible to completely override libxml default catalog by
2494using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
2495plug an application specific resolver).</p>
2496
2497<p>Basically libxml support 2 catalog lists:</p>
2498<ul>
2499 <li>the default one, global shared by all the application</li>
2500 <li>a per-document catalog, this one is built if the document uses the
2501 <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
2502 associated to the parser context and destroyed when the parsing context
2503 is destroyed.</li>
2504</ul>
2505
2506<p>the document one will be used first if it exists.</p>
2507
2508<h4>Initialization routines:</h4>
2509
2510<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
2511used at startup to initialize the catalog, if the catalog should be
2512initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
2513should be called before xmlInitializeCatalog() which would otherwise do a
2514default initialization first.</p>
2515
2516<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
2517own catalog list if needed.</p>
2518
2519<h4>Preferences setup:</h4>
2520
2521<p>The XML Catalog spec requires the possibility to select default
2522preferences between public and system delegation,
2523xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
2524xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
2525be forbidden, allowed for global catalog, for document catalog or both, the
2526default is to allow both.</p>
2527
2528<p>And of course xmlCatalogSetDebug() allows to generate debug messages
2529(through the xmlGenericError() mechanism).</p>
2530
2531<h4>Querying routines:</h4>
2532
2533<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
2534and xmlCatalogResolveURI() are relatively explicit if you read the XML
2535Catalog specification they correspond to section 7 algorithms, they should
2536also work if you have loaded an SGML catalog with a simplified semantic.</p>
2537
2538<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
2539operate on the document catalog list</p>
2540
2541<h4>Cleanup and Miscellaneous:</h4>
2542
2543<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
2544the per-document equivalent.</p>
2545
2546<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
2547first catalog in the global list, and xmlCatalogDump() allows to dump a
2548catalog state, those routines are primarily designed for xmlcatalog, I'm not
2549sure that exposing more complex interfaces (like navigation ones) would be
2550really useful.</p>
2551
2552<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
2553it's similar as xmlParseFile() except it bypass all catalog lookups, it's
2554provided because this functionality may be useful for client tools.</p>
2555
2556<h4>threaded environments:</h4>
2557
2558<p>Since the catalog tree is built progressively, some care has been taken to
2559try to avoid troubles in multithreaded environments. The code is now thread
2560safe assuming that the libxml library has been compiled with threads
2561support.</p>
2562
2563<p></p>
2564
2565<h3><a name="Other">Other resources</a></h3>
2566
2567<p>The XML Catalog specification is relatively recent so there isn't much
2568literature to point at:</p>
2569<ul>
2570 <li>You can find an good rant from Norm Walsh about <a
2571 href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
2572 need for catalogs</a>, it provides a lot of context informations even if
2573 I don't agree with everything presented.</li>
2574 <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
2575 catalog proposal</a> from John Cowan</li>
2576 <li>The <a href="http://www.rddl.org/">Resource Directory Description
2577 Language</a> (RDDL) another catalog system but more oriented toward
2578 providing metadata for XML namespaces.</li>
2579 <li>the page from the OASIS Technical <a
2580 href="http://www.oasis-open.org/committees/entity/">Committee on Entity
2581 Resolution</a> who maintains XML Catalog, you will find pointers to the
2582 specification update, some background and pointers to others tools
2583 providing XML Catalog support</li>
2584 <li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a
2585 mall tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems to
2586 work fine for me</li>
2587 <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
2588 manual page</a></li>
2589</ul>
2590
2591<p>If you have suggestions for corrections or additions, simply contact
2592me:</p>
2593
2594<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2595
2596<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2597using the XML library from the C language. It is not intended to be
2598extensive. I hope the automatically generated documents will provide the
2599completeness required, but as a separate set of documents. The interfaces of
2600the XML library are by principle low level, there is nearly zero abstraction.
2601Those interested in a higher level API should <a href="#DOM">look at
2602DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]2603
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]2604<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
2605separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2606interfaces</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]2607
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2608<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2609
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2610<p>Usually, the first thing to do is to read an XML input. The parser accepts
2611documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2612defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2613<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2614 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2615 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2616 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2617</dl>
2618<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2619 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2620 <dd><p>Parse an XML document contained in a (possibly compressed)
2621 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2622 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2623</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2624
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2625<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]2626failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2627
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2628<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2629
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2630<p>In order for the application to keep the control when the document is
2631being fetched (which is common for GUI based programs) libxml provides a push
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2632interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2633<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
2634 void *user_data,
2635 const char *chunk,
2636 int size,
2637 const char *filename);
2638int xmlParseChunk (xmlParserCtxtPtr ctxt,
2639 const char *chunk,
2640 int size,
2641 int terminate);</pre>
2642
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2643<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2644<pre> FILE *f;
2645
2646 f = fopen(filename, "r");
2647 if (f != NULL) {
2648 int res, size = 1024;
2649 char chars[1024];
2650 xmlParserCtxtPtr ctxt;
2651
2652 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2653 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2654 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
2655 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2656 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2657 xmlParseChunk(ctxt, chars, res, 0);
2658 }
2659 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2660 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2661 xmlFreeParserCtxt(ctxt);
2662 }
2663 }</pre>
2664
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2665<p>The HTML parser embedded into libxml also has a push interface; the
2666functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2667
2668<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
2669
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2670<p>The tree-building interface makes the parser memory-hungry, first loading
2671the document in memory and then building the tree itself. Reading a document
2672without building the tree is possible using the SAX interfaces (see SAX.h and
2673<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]2674Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2675limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2676<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]2677
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2678<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2679
2680<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]2681there is a set of functions dedicated to building new elements. (These are
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2682also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of
2683code that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2684<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]2685 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2686 xmlNodePtr tree, subtree;
2687
2688 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2689 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
2690 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
2691 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
2692 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2693 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2694 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2695 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
2696 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
2697 subtree = xmlNewChild(tree, NULL, "image", NULL);
2698 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2699
2700<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2701
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2702<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2703
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]2704<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2705code has access to the internal structure of all the elements of the tree.
2706The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]2707<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2708<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2709example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2710<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2711
2712<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2713<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2714
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2715<p>points to the text node containing the chapter title "The Linux
2716adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2717
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]2718<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]2719present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2720to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]2721<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]2722
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2723<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2724
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2725<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]2726is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2727<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2728 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
2729 xmlChar *value);</code></dt>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2730 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
2731 The value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2732 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2733</dl>
2734<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2735 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2736 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]2737 <dd><p>This function returns a pointer to new copy of the property
2738 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2739 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2740</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2741
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2742<p>Two functions are provided for reading and writing the text associated
2743with elements:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2744<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2745 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2746 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2747 <dd><p>This function takes an "external" string and converts it to one
2748 text node or possibly to a list of entity and text nodes. All
2749 non-predefined entity references like &amp;Gnome; will be stored
2750 internally as entity nodes, hence the result of the function may not be
2751 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2752 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2753</dl>
2754<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2755 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2756 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2757 <dd><p>This function is the inverse of
2758 <code>xmlStringGetNodeList()</code>. It generates a new string
2759 containing the content of the text and entity nodes. Note the extra
2760 argument inLine. If this argument is set to 1, the function will expand
2761 entity references. For example, instead of returning the &amp;Gnome;
2762 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2763 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2764 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2765</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2766
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2767<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2768
2769<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2770<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2771 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2772 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2773 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2774 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2775</dl>
2776<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2777 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2778 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2779 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2780</dl>
2781<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2782 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2783 <dd><p>Saves the document to a file. In this case, the compression
2784 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2785 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2786</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2787
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2788<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2789
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2790<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2791accesses. The level of compression on saves can be turned on either globally
2792or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2793<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2794 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2795 <dd><p>Gets the document compression ratio (0-9).</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 Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2799 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2800 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2801 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2802</dl>
2803<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2804 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2805 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2806 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2807</dl>
2808<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2809 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2810 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2811 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2812</dl>
2813
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2814<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2815
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2816<p>Entities in principle are similar to simple C macros. An entity defines an
2817abbreviation for a given string that you can reuse many times throughout the
2818content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2819may occur frequently within a document, or to confine the change needed to a
2820document to a restricted area in the internal subset of the document (at the
2821beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2822<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]28232 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]28243 &lt;!ENTITY xml "Extensible Markup Language"&gt;
28254 ]&gt;
28265 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]28276 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]28287 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2829
2830<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]2831its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2832are 5 predefined entities in libxml allowing you to escape charaters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2833predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2834<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2835for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2836<strong>&amp;quot;</strong> for the character '"', and
2837<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2838
2839<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]2840substitute an entity's content so that you can see the replacement text in
2841your application. Or you may prefer to keep entity references as such in the
2842content to be able to save the document back without losing this usually
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2843precious information (if the user went through the pain of explicitly
2844defining entities, he may have a a rather negative attitude if you blindly
2845susbtitute them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]2846href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2847function allows you to check and change the behaviour, which is to not
2848substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2849
2850<p>Here is the DOM tree built by libxml for the previous document in the
2851default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2852<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2853DOCUMENT
2854version=1.0
2855 ELEMENT EXAMPLE
2856 TEXT
2857 content=
2858 ENTITY_REF
2859 INTERNAL_GENERAL_ENTITY xml
2860 content=Extensible Markup Language
2861 TEXT
2862 content=</pre>
2863
2864<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2865<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2866DOCUMENT
2867version=1.0
2868 ELEMENT EXAMPLE
2869 TEXT
2870 content= Extensible Markup Language</pre>
2871
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2872<p>So, entities or no entities? Basically, it depends on your use case. I
2873suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2874entities in your XML document or data if you are not willing to handle the
2875entity references elements in the DOM tree.</p>
2876
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2877<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2878entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2879transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2880reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2881finding them in the input).</p>
2882
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]2883<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2884on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]2885non-predefined entities in your documents, then the learning cuvre to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2886then 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]2887strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]2888deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]2889
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2890<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2891
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]2892<p>The libxml library implements <a
2893href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
2894recognizing namespace contructs in the input, and does namespace lookup
2895automatically when building the DOM tree. A namespace declaration is
2896associated with an in-memory structure and all elements or attributes within
2897that namespace point to it. Hence testing the namespace is a simple and fast
2898equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2899
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2900<p>I suggest that people using libxml use a namespace, and declare it in the
2901root element of their document as the default namespace. Then they don't need
2902to 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]2903refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2904the size of the XML output significantly, but significantly increases its
2905value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2906<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
2907 &lt;elem1&gt;...&lt;/elem1&gt;
2908 &lt;elem2&gt;...&lt;/elem2&gt;
2909&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2910
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2911<p>The namespace value has to be an absolute URL, but the URL doesn't have to
2912point to any existing resource on the Web. It will bind all the element and
2913atributes with that URL. I suggest to use an URL within a domain you control,
2914and that the URL should contain some kind of version information if possible.
2915For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a good
2916namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]2917
2918<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2919version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2920and if the version information don't match something you know, warn the user
2921and 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]2922namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2923same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2924associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2925just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]2926<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2927prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2928
2929<p>@@Interfaces@@</p>
2930
2931<p>@@Examples@@</p>
2932
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2933<p>Usually people object to using namespaces together with validity checking.
2934I will try to make sure that using namespaces won't break validity checking,
2935so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2936suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2937<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2938flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2939from multiple DTDs will certainly break current validation schemes. I will
2940try to provide ways to do this, but this may not be portable or
2941standardized.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2942
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2943<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2944
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2945<p>Incompatible changes:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2946
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2947<p>Version 2 of libxml is the first version introducing serious backward
2948incompatible changes. The main goals were:</p>
2949<ul>
2950 <li>a general cleanup. A number of mistakes inherited from the very early
2951 versions couldn't be changed due to compatibility constraints. Example
2952 the "childs" element in the nodes.</li>
2953 <li>Uniformization of the various nodes, at least for their header and link
2954 parts (doc, parent, children, prev, next), the goal is a simpler
2955 programming model and simplifying the task of the DOM implementors.</li>
2956 <li>better conformances to the XML specification, for example version 1.x
2957 had an heuristic to try to detect ignorable white spaces. As a result the
2958 SAX event generated were ignorableWhitespace() while the spec requires
2959 character() in that case. This also mean that a number of DOM node
2960 containing blank text may populate the DOM tree which were not present
2961 before.</li>
2962</ul>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2963
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2964<h3>How to fix libxml-1.x code:</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2965
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2966<p>So client code of libxml designed to run with version 1.x may have to be
2967changed to compile against version 2.x of libxml. Here is a list of changes
2968that I have collected, they may not be sufficient, so in case you find other
2969change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
2970mail</a>:</p>
2971<ol>
2972 <li>The package name have changed from libxml to libxml2, the library name
2973 is now -lxml2 . There is a new xml2-config script which should be used to
2974 select the right parameters libxml2</li>
2975 <li>Node <strong>childs</strong> field has been renamed
2976 <strong>children</strong> so s/childs/children/g should be applied
2977 (probablility of having "childs" anywere else is close to 0+</li>
2978 <li>The document don't have anymore a <strong>root</strong> element it has
2979 been replaced by <strong>children</strong> and usually you will get a
2980 list of element here. For example a Dtd element for the internal subset
2981 and it's declaration may be found in that list, as well as processing
2982 instructions or comments found before or after the document root element.
2983 Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
2984 a document. Alternatively if you are sure to not reference Dtds nor have
2985 PIs or comments before or after the root element
2986 s/-&gt;root/-&gt;children/g will probably do it.</li>
2987 <li>The white space issue, this one is more complex, unless special case of
2988 validating parsing, the line breaks and spaces usually used for indenting
2989 and formatting the document content becomes significant. So they are
2990 reported by SAX and if your using the DOM tree, corresponding nodes are
2991 generated. Too approach can be taken:
2992 <ol>
2993 <li>lazy one, use the compatibility call
2994 <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
2995 relying on a special (and possibly broken) set of heuristics of
2996 libxml to detect ignorable blanks. Don't complain if it breaks or
2997 make your application not 100% clean w.r.t. to it's input.</li>
2998 <li>the Right Way: change you code to accept possibly unsignificant
2999 blanks characters, or have your tree populated with weird blank text
3000 nodes. You can spot them using the comodity function
3001 <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
3002 nodes.</li>
3003 </ol>
3004 <p>Note also that with the new default the output functions don't add any
3005 extra indentation when saving a tree in order to be able to round trip
3006 (read and save) without inflating the document with extra formatting
3007 chars.</p>
3008 </li>
3009 <li>The include path has changed to $prefix/libxml/ and the includes
3010 themselves uses this new prefix in includes instructions... If you are
3011 using (as expected) the
3012 <pre>xml2-config --cflags</pre>
3013 <p>output to generate you compile commands this will probably work out of
3014 the box</p>
3015 </li>
3016 <li>xmlDetectCharEncoding takes an extra argument indicating the lenght in
3017 byte of the head of the document available for character detection.</li>
3018</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3019
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3020<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3021
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3022<p>Two new version of libxml (1.8.11) and libxml2 (2.3.4) have been released
3023to allow smoth upgrade of existing libxml v1code while retaining
3024compatibility. They offers the following:</p>
3025<ol>
3026 <li>similar include naming, one should use
3027 <strong>#include&lt;libxml/...&gt;</strong> in both cases.</li>
3028 <li>similar identifiers defined via macros for the child and root fields:
3029 respectively <strong>xmlChildrenNode</strong> and
3030 <strong>xmlRootNode</strong></li>
3031 <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
3032 inserted once in the client code</li>
3033</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3034
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3035<p>So the roadmap to upgrade your existing libxml applications is the
3036following:</p>
3037<ol>
3038 <li>install the libxml-1.8.8 (and libxml-devel-1.8.8) packages</li>
3039 <li>find all occurences where the xmlDoc <strong>root</strong> field is
3040 used and change it to <strong>xmlRootNode</strong></li>
3041 <li>similary find all occurences where the xmlNode <strong>childs</strong>
3042 field is used and change it to <strong>xmlChildrenNode</strong></li>
3043 <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
3044 <strong>main()</strong> or in the library init entry point</li>
3045 <li>Recompile, check compatibility, it should still work</li>
3046 <li>Change your configure script to look first for xml2-config and fallback
3047 using xml-config . Use the --cflags and --libs ouptut of the command as
3048 the Include and Linking parameters needed to use libxml.</li>
3049 <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
3050 libxml-devel-1.8.y can be kept simultaneously)</li>
3051 <li>remove your config.cache, relaunch your configuration mechanism, and
3052 recompile, if steps 2 and 3 were done right it should compile as-is</li>
3053 <li>Test that your application is still running correctly, if not this may
3054 be due to extra empty nodes due to formating spaces being kept in libxml2
3055 contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
3056 code before calling the parser (next to
3057 <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
3058</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3059
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3060<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]3061
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3062<p>Let me put some emphasis on the fact that there is far more changes from
3063libxml 1.x to 2.x than the ones you may have to patch for. The overall code
3064has been considerably cleaned up and the conformance to the XML specification
3065has been drastically improved too. Don't take those changes as an excuse to
3066not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3067
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3068<h2><a name="Thread">Thread safety</a></h2>
3069
3070<p>Starting with 2.4.7, libxml makes provisions to ensure that concurent
3071threads can safely work in parallel parsing different documents. There is
3072however a couple of things to do to ensure it:</p>
3073<ul>
3074 <li>configure the library accordingly using the --with-threads options</li>
3075 <li>call xmlInitParser() in the "main" thread before using any of the
3076 libxml API (except possibly selecting a different memory allocator)</li>
3077</ul>
3078
3079<p>Note that the thread safety cannot be ensured for multiple threads sharing
3080the same document, the locking must be done at the application level, libxml
3081exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
3082The parts of the library checked for thread safety are:</p>
3083<ul>
3084 <li>concurrent loading</li>
3085 <li>file access resolution</li>
3086 <li>catalog access</li>
3087 <li>catalog building</li>
3088 <li>entities lookup/accesses</li>
3089 <li>validation</li>
3090 <li>global variables per-thread override</li>
3091 <li>memory handling</li>
3092</ul>
3093
3094<p>XPath is supposed to be thread safe now, but this wasn't tested
3095seriously.</p>
3096
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3097<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3098
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3099<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
3100Object Model</em>; this is an API for accessing XML or HTML structured
3101documents. Native support for DOM in Gnome is on the way (module gnome-dom),
3102and will be based on gnome-xml. This will be a far cleaner interface to
3103manipulate XML files within Gnome since it won't expose the internal
3104structure.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3105
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3106<p>The current DOM implementation on top of libxml is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame]3107href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
3108is a full DOM interface, thanks to Paolo Casarini, check the <a
3109href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
3110informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3111
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3112<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3113
3114<p>Here is a real size example, where the actual content of the application
3115data 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]3116a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3117storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
3118base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3119<pre>&lt;?xml version="1.0"?&gt;
3120&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
3121 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3122
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3123 &lt;gjob:Job&gt;
3124 &lt;gjob:Project ID="3"/&gt;
3125 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
3126 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3127
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3128 &lt;gjob:Update&gt;
3129 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
3130 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
3131 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
3132 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3133
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3134 &lt;gjob:Developers&gt;
3135 &lt;gjob:Developer&gt;
3136 &lt;/gjob:Developer&gt;
3137 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3138
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3139 &lt;gjob:Contact&gt;
3140 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
3141 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
3142 &lt;gjob:Company&gt;
3143 &lt;/gjob:Company&gt;
3144 &lt;gjob:Organisation&gt;
3145 &lt;/gjob:Organisation&gt;
3146 &lt;gjob:Webpage&gt;
3147 &lt;/gjob:Webpage&gt;
3148 &lt;gjob:Snailmail&gt;
3149 &lt;/gjob:Snailmail&gt;
3150 &lt;gjob:Phone&gt;
3151 &lt;/gjob:Phone&gt;
3152 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3153
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3154 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3155 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3156 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3157
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3158 &lt;gjob:Skills&gt;
3159 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3160
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3161 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3162 A GNOME based system that will allow a superuser to configure
3163 compressed and uncompressed files and/or file systems to be backed
3164 up with a supported media in the system. This should be able to
3165 perform via find commands generating a list of files that are passed
3166 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
3167 or via operations performed on the filesystem itself. Email
3168 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3169 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3170
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3171 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3172
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3173 &lt;/gjob:Jobs&gt;
3174&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3175
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3176<p>While loading the XML file into an internal DOM tree is a matter of
3177calling only a couple of functions, browsing the tree to gather the ata and
3178generate the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3179
3180<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3181structure. For example, the ordering of the attributes is not significant,
3182the 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]3183depend on the order of the children of a given node, unless it really makes
3184things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3185<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3186 * A person record
3187 */
3188typedef struct person {
3189 char *name;
3190 char *email;
3191 char *company;
3192 char *organisation;
3193 char *smail;
3194 char *webPage;
3195 char *phone;
3196} person, *personPtr;
3197
3198/*
3199 * And the code needed to parse it
3200 */
3201personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3202 personPtr ret = NULL;
3203
3204DEBUG("parsePerson\n");
3205 /*
3206 * allocate the struct
3207 */
3208 ret = (personPtr) malloc(sizeof(person));
3209 if (ret == NULL) {
3210 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3211 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3212 }
3213 memset(ret, 0, sizeof(person));
3214
3215 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3216 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3217 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3218 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
3219 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3220 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
3221 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3222 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3223 }
3224
3225 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3226}</pre>
3227
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3228<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3229<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3230 <li>Usually a recursive parsing style is the more convenient one: XML data
3231 is by nature subject to repetitive constructs and usually exibits highly
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3232 stuctured patterns.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3233 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
3234 i.e. the pointer to the global XML document and the namespace reserved to
3235 the application. Document wide information are needed for example to
3236 decode entities and it's a good coding practice to define a namespace for
3237 your application set of data and test that the element and attributes
3238 you're analyzing actually pertains to your application space. This is
3239 done by a simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3240 <li>To retrieve text and attributes value, you can use the function
3241 <em>xmlNodeListGetString</em> to gather all the text and entity reference
3242 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3243</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3244
3245<p>Here is another piece of code used to parse another level of the
3246structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3247<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3248/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3249 * a Description for a Job
3250 */
3251typedef struct job {
3252 char *projectID;
3253 char *application;
3254 char *category;
3255 personPtr contact;
3256 int nbDevelopers;
3257 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
3258} job, *jobPtr;
3259
3260/*
3261 * And the code needed to parse it
3262 */
3263jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3264 jobPtr ret = NULL;
3265
3266DEBUG("parseJob\n");
3267 /*
3268 * allocate the struct
3269 */
3270 ret = (jobPtr) malloc(sizeof(job));
3271 if (ret == NULL) {
3272 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3273 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3274 }
3275 memset(ret, 0, sizeof(job));
3276
3277 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3278 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3279 while (cur != NULL) {
3280
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3281 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
3282 ret-&gt;projectID = xmlGetProp(cur, "ID");
3283 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3284 fprintf(stderr, "Project has no ID\n");
3285 }
3286 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3287 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
3288 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3289 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
3290 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3291 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
3292 ret-&gt;contact = parsePerson(doc, ns, cur);
3293 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3294 }
3295
3296 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3297}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3298
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3299<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]3300boring. Ultimately, it could be possble to write stubbers taking either C
3301data structure definitions, a set of XML examples or an XML DTD and produce
3302the code needed to import and export the content between C data and XML
3303storage. This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3304
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]3305<p>Feel free to use <a href="example/gjobread.c">the code for the full C
3306parsing example</a> as a template, it is also available with Makefile in the
3307Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3308
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3309<h2><a name="Contributi">Contributions</a></h2>
3310<ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3311 <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
3312 patches, Gary Pennington worked on the validation API, threading support
3313 and Solaris port.</li>
3314 <li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]3315 <li><a href="mailto:ari@lusis.org">Ari Johnson</a>
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]3316 provides a C++ wrapper for libxml:<br>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]3317 Website: <a
3318 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a><br>
3319 Download: <a
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]3320 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]3321 <li><a href="mailto:izlatkovic@daenet.de">Igor Zlatkovic</a>
3322 is now the maintainer of the Windows port, <a
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]3323 href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
3324 provides binaries</a></li>
Daniel Veillardc9484202001-10-24 12:35:52 +0000[diff] [blame]3325 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a>
Daniel Veillarddb9dfd92001-11-26 17:25:02 +0000[diff] [blame]3326 provides <a href="http://garypennington.net/libxml2/">Solaris
Daniel Veillard0a702dc2001-10-19 14:50:57 +0000[diff] [blame]3327 binaries</a></li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]3328 <li><a
3329 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3330 Sergeant</a>
3331 developped <a href="http://axkit.org/download/">XML::LibXSLT</a>, a perl
3332 wrapper for libxml2/libxslt as part of the <a
3333 href="http://axkit.com/">AxKit XML application server</a></li>
3334 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a>
3335 and <a href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillardca989762001-06-23 17:39:29 +0000[diff] [blame]3336 href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]3337 documentation</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3338 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a>
3339 provided <a href="http://xmlsoft.org/messages/0488.html">man
3340 pages</a></li>
Daniel Veillard5168dbf2001-07-07 00:18:23 +0000[diff] [blame]3341 <li>there is a module for <a
3342 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
3343 in OpenNSD/AOLServer</a></li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3344 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a>
3345 provides libxml/libxslt <a href="http://www.rexx.com/~dkuhlman">wrappers
3346 for Python</a></li>
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]3347 <li>Petr Kozelka provides <a
3348 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
3349 libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3350</ul>
3351
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3352<p></p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3353</body>
3354</html>