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Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
2 "http://www.w3.org/TR/html4/loose.dtd">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3<html>
4<head>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]5 <title>The XML C library for Gnome</title>
Daniel 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 Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame^]115 <li>This library is released under the <a
116 href="http://www.opensource.org/licenses/mit-license.html">MIT
117 Licence</a> see the Copyright file in the distribution for the precise
118 wording.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]119</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]120
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]121<p>Warning: unless you are forced to because your application links with a
122Gnome library requiring it, <strong><span
123style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
124libxml2</p>
125
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]126<h2><a name="FAQ">FAQ</a></h2>
127
128<p>Table of Content:</p>
129<ul>
130 <li><a href="FAQ.html#Licence">Licence(s)</a></li>
131 <li><a href="FAQ.html#Installati">Installation</a></li>
132 <li><a href="FAQ.html#Compilatio">Compilation</a></li>
133 <li><a href="FAQ.html#Developer">Developer corner</a></li>
134</ul>
135
136<h3><a name="Licence">Licence</a>(s)</h3>
137<ol>
138 <li><em>Licensing Terms for libxml</em>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame^]139 <p>libxml is released under the <a
140 href="http://www.opensource.org/licenses/mit-license.html">MIT
141 Licence</a>, see the file Copyright in the distribution for the precise
142 wording</p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]143 </li>
144 <li><em>Can I embed libxml in a proprietary application ?</em>
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame^]145 <p>Yes. The MIT Licence allows you to also keep proprietary the changes
146 you made to libxml, but it would be graceful to provide back bugfixes and
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]147 improvements as patches for possible incorporation in the main
148 development tree</p>
149 </li>
150</ol>
151
152<h3><a name="Installati">Installation</a></h3>
153<ol>
154 <li>Unless you are forced to because your application links with a Gnome
155 library requiring it, <strong><span style="background-color: #FF0000">Do
156 Not Use libxml1</span></strong>, use libxml2</li>
157 <li><em>Where can I get libxml</em>
158 ?
159 <p>The original distribution comes from <a
160 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a
161 href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">gnome.org</a></p>
162 <p>Most linux and Bsd distribution includes libxml, this is probably the
163 safer way for end-users</p>
164 <p>David Doolin provides precompiled Windows versions at <a
165 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
166 </li>
167 <li><em>I see libxml and libxml2 releases, which one should I install ?</em>
168 <ul>
169 <li>If you are not concerned by any existing backward compatibility
170 with existing application, install libxml2 only</li>
171 <li>If you are not doing development, you can safely install both.
172 usually the packages <a
173 href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a
174 href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
175 compatible (this is not the case for development packages)</li>
176 <li>If you are a developer and your system provides separate packaging
177 for shared libraries and the development components, it is possible
178 to install libxml and libxml2, and also <a
179 href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
180 and <a
181 href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
182 too for libxml2 &gt;= 2.3.0</li>
183 <li>If you are developing a new application, please develop against
184 libxml2(-devel)</li>
185 </ul>
186 </li>
187 <li><em>I can't install the libxml package it conflicts with libxml0</em>
188 <p>You probably have an old libxml0 package used to provide the shared
189 library for libxml.so.0, you can probably safely remove it. Anyway the
190 libxml packages provided on <a
191 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provides
192 libxml.so.0</p>
193 </li>
194 <li><em>I can't install the libxml(2) RPM package due to failed
195 dependancies</em>
196 <p>The most generic solution is to refetch the latest src.rpm , and
197 rebuild it locally with</p>
198 <p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code></p>
199 <p>if everything goes well it will generate two binary rpm (one providing
200 the shared libs and xmllint, and the other one, the -devel package
201 providing includes, static libraries and scripts needed to build
202 applications with libxml(2)) that you can install locally.</p>
203 </li>
204</ol>
205
206<h3><a name="Compilatio">Compilation</a></h3>
207<ol>
208 <li><em>What is the process to compile libxml ?</em>
209 <p>As most UNIX libraries libxml follows the "standard":</p>
210 <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p>
211 <p><code>cd libxml-xxxx</code></p>
212 <p><code>./configure --help</code></p>
213 <p>to see the options, then the compilation/installation proper</p>
214 <p><code>./configure [possible options]</code></p>
215 <p><code>make</code></p>
216 <p><code>make install</code></p>
217 <p>At that point you may have to rerun ldconfig or similar utility to
218 update your list of installed shared libs.</p>
219 </li>
220 <li><em>What other libraries are needed to compile/install libxml ?</em>
221 <p>Libxml does not requires any other library, the normal C ANSI API
222 should be sufficient (please report any violation to this rule you may
223 find).</p>
224 <p>However if found at configuration time libxml will detect and use the
225 following libs:</p>
226 <ul>
227 <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a>
228 : a highly portable and available widely compression library</li>
229 <li>iconv: a powerful character encoding conversion library. It's
230 included by default on recent glibc libraries, so it doesn't need to
231 be installed specifically on linux. It seems it's now <a
232 href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
233 of the official UNIX</a> specification. Here is one <a
234 href="http://clisp.cons.org/~haible/packages-libiconv.html">implementation
235 of the library</a> which source can be found <a
236 href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
237 </ul>
238 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]239 <li><em>make check fails on some platforms</em>
240 <p>Sometime the regression tests results don't completely match the value
241 produced by the parser, and the makefile uses diff to print the delta. On
242 some platforms the diff return breaks the compilation process, if the
243 diff is small this is probably not a serious problem</p>
244 </li>
245 <li><em>I use the CVS version and there is no configure script</em>
246 <p>The configure (and other Makefiles) are generated. Use the autogen.sh
247 script to regenerate the configure and Makefiles, like:</p>
248 <p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
249 </li>
250 <li><em>I have troubles when running make tests with gcc-3.0</em>
251 <p>It seems the initial release of gcc-3.0 has a problem with the
252 optimizer which miscompiles the URI module. Please use another
253 compiler</p>
254 </li>
255</ol>
256
257<h3><a name="Developer">Developer</a> corner</h3>
258<ol>
259 <li><em>xmlDocDump() generates output on one line</em>
260 <p>libxml will not <strong>invent</strong> spaces in the content of a
261 document since <strong>all spaces in the content of a document are
262 significant</strong>. If you build a tree from the API and want
263 indentation:</p>
264 <ol>
265 <li>the correct way is to generate those yourself too</li>
266 <li>the dangerous way is to ask libxml to add those blanks to your
267 content <strong>modifying the content of your document in the
268 process</strong>. The result may not be what you expect. There is
269 <strong>NO</strong> way to guarantee that such a modification won't
270 impact other part of the content of your document. See <a
271 href="http://xmlsoft.org/html/libxml-parser.html#XMLKEEPBLANKSDEFAULT">xmlKeepBlanksDefault
272 ()</a> and <a
273 href="http://xmlsoft.org/html/libxml-tree.html#XMLSAVEFORMATFILE">xmlSaveFormatFile
274 ()</a></li>
275 </ol>
276 </li>
277 <li>Extra nodes in the document:
278 <p><em>For a XML file as below:</em></p>
279 <pre>&lt;?xml version="1.0"?&gt;
280&lt;PLAN xmlns="http://www.argus.ca/autotest/1.0/"&gt;
281&lt;NODE CommFlag="0"/&gt;
282&lt;NODE CommFlag="1"/&gt;
283&lt;/PLAN&gt;</pre>
284 <p><em>after parsing it with the function
285 pxmlDoc=xmlParseFile(...);</em></p>
286 <p><em>I want to the get the content of the first node (node with the
287 CommFlag="0")</em></p>
288 <p><em>so I did it as following;</em></p>
289 <pre>xmlNodePtr pode;
290pnode=pxmlDoc-&gt;children-&gt;children;</pre>
291 <p><em>but it does not work. If I change it to</em></p>
292 <pre>pnode=pxmlDoc-&gt;children-&gt;children-&gt;next;</pre>
293 <p><em>then it works. Can someone explain it to me.</em></p>
294 <p></p>
295 <p>In XML all characters in the content of the document are significant
296 <strong>including blanks and formatting line breaks</strong>.</p>
297 <p>The extra nodes you are wondering about are just that, text nodes with
298 the formatting spaces wich are part of the document but that people tend
299 to forget. There is a function <a
300 href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
301 ()</a> to remove those at parse time, but that's an heuristic, and its
302 use should be limited to case where you are sure there is no
303 mixed-content in the document.</p>
304 </li>
305 <li><em>I get compilation errors of existing code like when accessing
306 <strong>root</strong> or <strong>childs fields</strong> of nodes</em>
307 <p>You are compiling code developed for libxml version 1 and using a
308 libxml2 development environment. Either switch back to libxml v1 devel or
309 even better fix the code to compile with libxml2 (or both) by <a
310 href="upgrade.html">following the instructions</a>.</p>
311 </li>
312 <li><em>I get compilation errors about non existing
313 <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
314 fields</em>
315 <p>The source code you are using has been <a
316 href="upgrade.html">upgraded</a> to be able to compile with both libxml
317 and libxml2, but you need to install a more recent version:
318 libxml(-devel) &gt;= 1.8.8 or libxml2(-devel) &gt;= 2.1.0</p>
319 </li>
320 <li><em>XPath implementation looks seriously broken</em>
321 <p>XPath implementation prior to 2.3.0 was really incomplete, upgrade to
322 a recent version, the implementation and debug of libxslt generated fixes
323 for most obvious problems.</p>
324 </li>
325 <li><em>The example provided in the web page does not compile</em>
326 <p>It's hard to maintain the documentation in sync with the code
327 &lt;grin/&gt; ...</p>
328 <p>Check the previous points 1/ and 2/ raised before, and send
329 patches.</p>
330 </li>
331 <li><em>Where can I get more examples and informations than in the web
332 page</em>
333 <p>Ideally a libxml book would be nice. I have no such plan ... But you
334 can:</p>
335 <ul>
336 <li>check more deeply the <a href="html/libxml-lib.html">existing
337 generated doc</a></li>
338 <li>looks for examples of use for libxml function using the Gnome code
339 for example the following will query the full Gnome CVs base for the
340 use of the <strong>xmlAddChild()</strong> function:
341 <p><a
342 href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p>
343 <p>This may be slow, a large hardware donation to the gnome project
344 could cure this :-)</p>
345 </li>
346 <li><a
347 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gnome-xml">Browse
348 the libxml source</a>
349 , I try to write code as clean and documented as possible, so
350 looking at it may be helpful</li>
351 </ul>
352 </li>
353 <li>What about C++ ?
354 <p>libxml is written in pure C in order to allow easy reuse on a number
355 of platforms, including embedded systems. I don't intend to convert to
356 C++.</p>
357 <p>There is however a C++ wrapper provided by Ari Johnson
358 &lt;ari@btigate.com&gt; which may fullfill your needs:</p>
359 <p>Website: <a
360 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
361 <p>Download: <a
362 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
363 </li>
364 <li>How to validate a document a posteriori ?
365 <p>It is possible to validate documents which had not been validated at
366 initial parsing time or documents who have been built from scratch using
367 the API. Use the <a
368 href="http://xmlsoft.org/html/libxml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a>
369 function. It is also possible to simply add a Dtd to an existing
370 document:</p>
371 <pre>xmlDocPtr doc; /* your existing document */
372 xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
373 dtd-&gt;name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */
374
375 doc-&gt;intSubset = dtd;
376 if (doc-&gt;children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
377 else xmlAddPrevSibling(doc-&gt;children, (xmlNodePtr)dtd);
378 </pre>
379 </li>
380 <li>etc ...</li>
381</ol>
382
383<p></p>
384
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]385<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]386
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]387<p>There are some on-line resources about using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]388<ol>
Daniel Veillard365e13b2000-07-02 07:56:37 +0000[diff] [blame]389 <li>Check the <a href="FAQ.html">FAQ</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]390 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]391 documentation</a> automatically extracted from code comments (using <a
392 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
393 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]394 <li>Look at the documentation about <a href="encoding.html">libxml
395 internationalization support</a></li>
Daniel Veillardbc66f852002-01-14 09:49:20 +0000[diff] [blame]396 <li>This page provides a global overview and <a href="example.html">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]397 examples</a> on how to use libxml.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]398 <li><a href="mailto:james@daa.com.au">James Henstridge</a>
399 wrote <a
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]400 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
401 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]402 <li>George Lebl wrote <a
403 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]404 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]405 <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO
406 file</a></li>
407 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>. If you are
408 starting a new project using libxml you should really use the 2.x
409 version.</li>
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]410 <li>And don't forget to look at the <a
411 href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]412</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]413
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]414<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]415
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]416<p>Well, bugs or missing features are always possible, and I will make a
417point of fixing them in a timely fashion. The best way to report a bug is to
418use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome
419bug tracking database</a> (make sure to use the "libxml" module name). I look
420at 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]421still open. Be sure to specify that the bug is for the package libxml.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]422
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]423<p>There is also a mailing-list <a
Daniel Veillard3197f162001-04-04 00:40:08 +0000[diff] [blame]424href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
425href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]426href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
427please visit the <a
428href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
429follow the instructions. <strong>Do not send code, I won't debug it</strong>
430(but patches are really appreciated!).</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]431
Daniel Veillard008186f2001-09-13 14:24:44 +0000[diff] [blame]432<p>Check the following <strong><span style="color: #FF0000">before
433posting</span></strong>:</p>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]434<ul>
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]435 <li>read the <a href="FAQ.html">FAQ</a></li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]436 <li>make sure you are <a href="ftp://xmlsoft.org/">using a recent
437 version</a>, and that the problem still shows up in those</li>
438 <li>check the <a href="http://mail.gnome.org/archives/xml/">list
439 archives</a> to see if the problem was reported already, in this case
Daniel Veillarde7ead2d2001-08-22 23:44:09 +0000[diff] [blame]440 there is probably a fix available, similary check the <a
441 href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">registered
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]442 open bugs</a></li>
Daniel Veillard234547b2001-07-05 09:46:10 +0000[diff] [blame]443 <li>make sure you can reproduce the bug with xmllint or one of the test
444 programs found in source in the distribution</li>
445 <li>Please send the command showing the error as well as the input (as an
446 attachement)</li>
447</ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]448
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]449<p>Then send the bug with associated informations to reproduce it to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]450href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillard008186f2001-09-13 14:24:44 +0000[diff] [blame]451related I will approve it.. Please do not send me mail directly, it makes
452things really harder to track and in some cases I'm not the best person to
453answer a given question, ask the list instead.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]454
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]455<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]456probably be processed faster.</p>
457
458<p>If you're looking for help, a quick look at <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]459href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]460provide the answer, I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]461questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]462documentantion</a> is not as polished as I would like (i need to learn more
463about Docbook), but it's a good starting point.</p>
464
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]465<h2><a name="help">How to help</a></h2>
466
467<p>You can help the project in various ways, the best thing to do first is to
468subscribe to the mailing-list as explained before, check the <a
Daniel Veillardf7ed3362001-08-17 12:01:21 +0000[diff] [blame]469href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
470href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]471database:</a>:</p>
472<ol>
473 <li>provide patches when you find problems</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]474 <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]475 be integrated in all cases but help pinpointing portability problems
476 and</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]477 <li>provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]478 as HTML diffs).</li>
479 <li>provide new documentations pieces (translations, examples, etc ...)</li>
480 <li>Check the TODO file and try to close one of the items</li>
481 <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]482 provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me
483 </a>before to avoid synchronization problems and check that the suggested
484 fix will fit in nicely :-)</li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]485</ol>
486
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]487<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]488
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]489<p>The latest versions of libxml can be found on <a
Daniel Veillard20c8cf22001-06-26 22:47:36 +0000[diff] [blame]490href="ftp://xmlsoft.org/">xmlsoft.org</a> (<a
491href="ftp://speakeasy.rpmfind.net/pub/libxml/">Seattle</a>, <a
492href="ftp://fr.rpmfind.net/pub/libxml/">France</a>) or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]493href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]494as a <a href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">source
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]495archive</a> or <a
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]496href="ftp://ftp.gnome.org/pub/GNOME/stable/redhat/i386/libxml/">RPM
497packages</a>. (NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]498href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
499href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]500packages installed to compile applications using libxml.) <a
501href="mailto:izlatkovic@daenet.de">Igor Zlatkovic</a> is now the maintainer
502of the Windows port, <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]503href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]504provides binaries</a>. <a href="mailto:Gary.Pennington@sun.com">Gary
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]505Pennington</a> provides <a href="http://garypennington.net/libxml2/">Solaris
506binaries</a>.</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]507
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]508<p><a name="Snapshot">Snapshot:</a></p>
509<ul>
510 <li>Code from the W3C cvs base libxml <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]511 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]512 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]513 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]514</ul>
515
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]516<p><a name="Contribs">Contributions:</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]517
518<p>I do accept external contributions, especially if compiling on another
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]519platform, get in touch with me to upload the package, wrappers for various
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]520languages have been provided, and can be found in the <a
521href="contribs.html">contrib section</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]522
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]523<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]524<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]525 <li><p>The <a
526 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]527 CVS base</a>. Check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]528 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a>
529 page; the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]530 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]531 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]532</ul>
533
534<h2><a name="News">News</a></h2>
535
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]536<h3>CVS only : check the <a
537href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]538for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]539
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]540<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]541you want to test those</p>
542<ul>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]543 <li>Implementing <a href="http://xmlsoft.org/XSLT">XSLT</a>, this is done
544 as a separate C library on top of libxml called libxslt</li>
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]545 <li>Finishing up <a href="http://www.w3.org/TR/xptr">XPointer</a> and <a
546 href="http://www.w3.org/TR/xinclude">XInclude</a></li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]547 <li>(seeems working but delayed from release) parsing/import of Docbook
548 SGML docs</li>
549</ul>
550
Daniel Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame]551<h3>2.4.13: Jan 14 2001</h3>
552<ul>
553 <li>update of the documentation: John Fleck and Charlie Bozeman</li>
554 <li>cleanup of timing code from Justin Fletcher</li>
555 <li>fixes for Windows and initial thread support on Win32: Igor and Serguei
556 Narojnyi</li>
557 <li>Cygwin patch from Robert Collins</li>
558 <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
559</ul>
560
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]561<h3>2.4.12: Dec 7 2001</h3>
562<ul>
563 <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
564 XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
565 (robert)</li>
566 <li>Eric Lavigne contributed project files for MacOS</li>
567 <li>some makefiles cleanups</li>
568</ul>
569
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]570<h3>2.4.11: Nov 26 2001</h3>
571<ul>
572 <li>fixed a couple of errors in the includes, fixed a few bugs, some code
573 cleanups</li>
574 <li>xmllint man pages improvement by Heiko Rupp</li>
575 <li>updated VMS build instructions from John A Fotheringham</li>
576 <li>Windows Makefiles updates from Igor</li>
577</ul>
578
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]579<h3>2.4.10: Nov 10 2001</h3>
580<ul>
581 <li>URI escaping fix (Joel Young)</li>
582 <li>added xmlGetNodePath() (for paths or XPointers generation)</li>
583 <li>Fixes namespace handling problems when using DTD and validation</li>
584 <li>improvements on xmllint: Morus Walter patches for --format and
585 --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
586 <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
587 <li>fixes to the HTML parser</li>
588</ul>
589
590<h3>2.4.9: Nov 6 2001</h3>
591<ul>
592 <li>fixes more catalog bugs</li>
593 <li>avoid a compilation problem, improve xmlGetLineNo()</li>
594</ul>
595
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]596<h3>2.4.8: Nov 4 2001</h3>
597<ul>
598 <li>fixed SGML catalogs broken in previous release, updated xmlcatalog
599 tool</li>
600 <li>fixed a compile errors and some includes troubles.</li>
601</ul>
602
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]603<h3>2.4.7: Oct 30 2001</h3>
604<ul>
605 <li>exported some debugging interfaces</li>
606 <li>serious rewrite of the catalog code</li>
607 <li>integrated Gary Pennington thread safety patch, added configure option
608 and regression tests</li>
609 <li>removed an HTML parser bug</li>
610 <li>fixed a couple of potentially serious validation bugs</li>
611 <li>integrated the SGML DocBook support in xmllint</li>
612 <li>changed the nanoftp anonymous login passwd</li>
613 <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
614 <li>general bug fixes</li>
615 <li>updated xmllint man page by John Fleck</li>
616 <li>some VMS and Windows updates</li>
617</ul>
618
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]619<h3>2.4.6: Oct 10 2001</h3>
620<ul>
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]621 <li>added an updated man pages by John Fleck</li>
Daniel Veillard60087f32001-10-10 09:45:09 +0000[diff] [blame]622 <li>portability and configure fixes</li>
623 <li>an infinite loop on the HTML parser was removed (William)</li>
624 <li>Windows makefile patches from Igor</li>
625 <li>fixed half a dozen bugs reported fof libxml or libxslt</li>
626 <li>updated xmlcatalog to be able to modify SGML super catalogs</li>
627</ul>
628
Daniel Veillarddadd0872001-09-15 09:21:44 +0000[diff] [blame]629<h3>2.4.5: Sep 14 2001</h3>
630<ul>
631 <li>Remove a few annoying bugs in 2.4.4</li>
632 <li>forces the HTML serializer to output decimal charrefs since some
633 version of Netscape can't handle hexadecimal ones</li>
634</ul>
635
636<h3>1.8.16: Sep 14 2001</h3>
637<ul>
638 <li>maintenance release of the old libxml1 branch, couple of bug and
639 portability fixes</li>
640</ul>
641
Daniel Veillard04382ae2001-09-12 18:51:30 +0000[diff] [blame]642<h3>2.4.4: Sep 12 2001</h3>
643<ul>
644 <li>added --convert to xmlcatalog, bug fixes and cleanups of XML
645 Catalog</li>
646 <li>a few bug fixes and some portability changes</li>
647 <li>some documentation cleanups</li>
648</ul>
649
Daniel Veillard39936902001-08-24 00:49:01 +0000[diff] [blame]650<h3>2.4.3: Aug 23 2001</h3>
651<ul>
652 <li>XML Catalog support see the doc</li>
653 <li>New NaN/Infinity floating point code</li>
654 <li>A few bug fixes</li>
655</ul>
656
657<h3>2.4.2: Aug 15 2001</h3>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]658<ul>
659 <li>adds xmlLineNumbersDefault() to control line number generation</li>
660 <li>lot of bug fixes</li>
661 <li>the Microsoft MSC projects files shuld now be up to date</li>
662 <li>inheritance of namespaces from DTD defaulted attributes</li>
663 <li>fixes a serious potential security bug</li>
664 <li>added a --format option to xmllint</li>
665</ul>
666
667<h3>2.4.1: July 24 2001</h3>
668<ul>
669 <li>possibility to keep line numbers in the tree</li>
670 <li>some computation NaN fixes</li>
671 <li>extension of the XPath API</li>
672 <li>cleanup for alpha and ia64 targets</li>
673 <li>patch to allow saving through HTTP PUT or POST</li>
Daniel Veillard09ab7e12001-07-10 15:49:44 +0000[diff] [blame]674</ul>
675
676<h3>2.4.0: July 10 2001</h3>
677<ul>
678 <li>Fixed a few bugs in XPath, validation, and tree handling.</li>
679 <li>Fixed XML Base implementation, added a coupel of examples to the
680 regression tests</li>
681 <li>A bit of cleanup</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]682</ul>
683
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]684<h3>2.3.14: July 5 2001</h3>
685<ul>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]686 <li>fixed some entities problems and reduce mem requirement when
687 substituing them</li>
Daniel Veillard5b43fde2001-07-05 23:31:40 +0000[diff] [blame]688 <li>lots of improvements in the XPath queries interpreter can be
689 substancially faster</li>
690 <li>Makefiles and configure cleanups</li>
691 <li>Fixes to XPath variable eval, and compare on empty node set</li>
692 <li>HTML tag closing bug fixed</li>
693 <li>Fixed an URI reference computating problem when validating</li>
694</ul>
695
Daniel Veillard2adbb512001-06-28 16:20:36 +0000[diff] [blame]696<h3>2.3.13: June 28 2001</h3>
697<ul>
698 <li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
699 <li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
700</ul>
701
702<h3>1.8.14: June 28 2001</h3>
703<ul>
704 <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
705 <li>Small Makefile fix</li>
706</ul>
707
Daniel Veillard11648102001-06-26 16:08:24 +0000[diff] [blame]708<h3>2.3.12: June 26 2001</h3>
709<ul>
710 <li>lots of cleanup</li>
711 <li>a couple of validation fix</li>
712 <li>fixed line number counting</li>
713 <li>fixed serious problems in the XInclude processing</li>
714 <li>added support for UTF8 BOM at beginning of entities</li>
715 <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
716 miscompile uri.c (William), Thomas Leitner provided a fix for the
717 optimizer on Tru64</li>
718 <li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for
719 compilation on Windows MSC</li>
720 <li>update of libxml-doc.el (Felix Natter)</li>
721 <li>fixed 2 bugs in URI normalization code</li>
722</ul>
723
Daniel Veillarde3c81b52001-06-17 14:50:34 +0000[diff] [blame]724<h3>2.3.11: June 17 2001</h3>
725<ul>
726 <li>updates to trio, Makefiles and configure should fix some portability
727 problems (alpha)</li>
728 <li>fixed some HTML serialization problems (pre, script, and block/inline
729 handling), added encoding aware APIs, cleanup of this code</li>
730 <li>added xmlHasNsProp()</li>
731 <li>implemented a specific PI for encoding support in the DocBook SGML
732 parser</li>
733 <li>some XPath fixes (-Infinity, / as a function parameter and namespaces
734 node selection)</li>
735 <li>fixed a performance problem and an error in the validation code</li>
736 <li>fixed XInclude routine to implement the recursive behaviour</li>
737 <li>fixed xmlFreeNode problem when libxml is included statically twice</li>
738 <li>added --version to xmllint for bug reports</li>
739</ul>
740
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]741<h3>2.3.10: June 1 2001</h3>
742<ul>
743 <li>fixed the SGML catalog support</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]744 <li>a number of reported bugs got fixed, in XPath, iconv detection,
745 XInclude processing</li>
Daniel Veillard2e4f1882001-06-01 10:11:57 +0000[diff] [blame]746 <li>XPath string function should now handle unicode correctly</li>
747</ul>
748
Daniel Veillard4623acd2001-05-19 15:13:15 +0000[diff] [blame]749<h3>2.3.9: May 19 2001</h3>
750
751<p>Lots of bugfixes, and added a basic SGML catalog support:</p>
752<ul>
753 <li>HTML push bugfix #54891 and another patch from Jonas Borgström</li>
754 <li>some serious speed optimisation again</li>
755 <li>some documentation cleanups</li>
756 <li>trying to get better linking on solaris (-R)</li>
757 <li>XPath API cleanup from Thomas Broyer</li>
758 <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
759 xmlValidGetValidElements()</li>
760 <li>Added an INSTALL file</li>
761 <li>Attribute removal added to API: #54433</li>
762 <li>added a basic support for SGML catalogs</li>
763 <li>fixed xmlKeepBlanksDefault(0) API</li>
764 <li>bugfix in xmlNodeGetLang()</li>
765 <li>fixed a small configure portability problem</li>
766 <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
767</ul>
768
Daniel Veillarda265af72001-05-14 11:13:58 +0000[diff] [blame]769<h3>1.8.13: May 14 2001</h3>
770<ul>
771 <li>bugfixes release of the old libxml1 branch used by Gnome</li>
772</ul>
773
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]774<h3>2.3.8: May 3 2001</h3>
775<ul>
776 <li>Integrated an SGML DocBook parser for the Gnome project</li>
777 <li>Fixed a few things in the HTML parser</li>
778 <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
779 point portability issue</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]780 <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
781 DOM+validation using the XML REC as input and a 700MHz celeron).</li>
Daniel Veillard3bbbe6f2001-05-03 11:15:37 +0000[diff] [blame]782 <li>incorporated more Windows cleanup</li>
783 <li>added xmlSaveFormatFile()</li>
784 <li>fixed problems in copying nodes with entities references (gdome)</li>
785 <li>removed some troubles surrounding the new validation module</li>
786</ul>
787
Daniel Veillarda41123c2001-04-22 19:31:20 +0000[diff] [blame]788<h3>2.3.7: April 22 2001</h3>
789<ul>
790 <li>lots of small bug fixes, corrected XPointer</li>
791 <li>Non determinist content model validation support</li>
792 <li>added xmlDocCopyNode for gdome2</li>
793 <li>revamped the way the HTML parser handles end of tags</li>
794 <li>XPath: corrctions of namespacessupport and number formatting</li>
795 <li>Windows: Igor Zlatkovic patches for MSC compilation</li>
796 <li>HTML ouput fixes from P C Chow and William M. Brack</li>
797 <li>Improved validation speed sensible for DocBook</li>
798 <li>fixed a big bug with ID declared in external parsed entities</li>
799 <li>portability fixes, update of Trio from Bjorn Reese</li>
800</ul>
801
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]802<h3>2.3.6: April 8 2001</h3>
803<ul>
804 <li>Code cleanup using extreme gcc compiler warning options, found and
805 cleared half a dozen potential problem</li>
806 <li>the Eazel team found an XML parser bug</li>
807 <li>cleaned up the user of some of the string formatting function. used the
808 trio library code to provide the one needed when the platform is missing
809 them</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]810 <li>xpath: removed a memory leak and fixed the predicate evaluation
811 problem, extended the testsuite and cleaned up the result. XPointer seems
812 broken ...</li>
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame]813</ul>
814
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame]815<h3>2.3.5: Mar 23 2001</h3>
816<ul>
817 <li>Biggest change is separate parsing and evaluation of XPath expressions,
818 there is some new APIs for this too</li>
819 <li>included a number of bug fixes(XML push parser, 51876, notations,
820 52299)</li>
821 <li>Fixed some portability issues</li>
822</ul>
823
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]824<h3>2.3.4: Mar 10 2001</h3>
825<ul>
826 <li>Fixed bugs #51860 and #51861</li>
827 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
828 size to be application tunable.</li>
829 <li>Some cleanup in the validation code, still a bug left and this part
830 should probably be rewritten to support ambiguous content model :-\</li>
831 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
832 parser</li>
833 <li>Fixed another bug in xmlNodeGetContent()</li>
834 <li>Bjorn fixed XPath node collection and Number formatting</li>
835 <li>Fixed a loop reported in the HTML parsing</li>
836 <li>blank space are reported even if the Dtd content model proves that they
837 are formatting spaces, this is for XmL conformance</li>
838</ul>
839
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]840<h3>2.3.3: Mar 1 2001</h3>
841<ul>
842 <li>small change in XPath for XSLT</li>
843 <li>documentation cleanups</li>
844 <li>fix in validation by Gary Pennington</li>
845 <li>serious parsing performances improvements</li>
846</ul>
847
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]848<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]849<ul>
850 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
851 <li>fixed a Dtd parsing bug</li>
852 <li>fixed a bug in xmlNodeGetContent</li>
853 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
854</ul>
855
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]856<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]857<ul>
858 <li>some XPath and HTML bug fixes for XSLT</li>
859 <li>small extension of the hash table interfaces for DOM gdome2
860 implementation</li>
861 <li>A few bug fixes</li>
862</ul>
863
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]864<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]865<ul>
866 <li>Lots of XPath bug fixes</li>
867 <li>Add a mode with Dtd lookup but without validation error reporting for
868 XSLT</li>
869 <li>Add support for text node without escaping (XSLT)</li>
870 <li>bug fixes for xmlCheckFilename</li>
871 <li>validation code bug fixes from Gary Pennington</li>
872 <li>Patch from Paul D. Smith correcting URI path normalization</li>
873 <li>Patch to allow simultaneous install of libxml-devel and
874 libxml2-devel</li>
875 <li>the example Makefile is now fixed</li>
876 <li>added HTML to the RPM packages</li>
877 <li>tree copying bugfixes</li>
878 <li>updates to Windows makefiles</li>
879 <li>optimisation patch from Bjorn Reese</li>
880</ul>
881
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]882<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]883<ul>
884 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
885 <li>added htmlHandleOmittedElem()</li>
886 <li>Applied Bjorn Reese's IPV6 first patch</li>
887 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]888 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]889</ul>
890
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]891<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]892<ul>
893 <li>Fix the Windows problems of 2.2.8</li>
894 <li>integrate OpenVMS patches</li>
895 <li>better handling of some nasty HTML input</li>
896 <li>Improved the XPointer implementation</li>
897 <li>integrate a number of provided patches</li>
898</ul>
899
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]900<h3>2.2.9: Nov 25 2000</h3>
901<ul>
902 <li>erroneous release :-(</li>
903</ul>
904
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]905<h3>2.2.8: Nov 13 2000</h3>
906<ul>
907 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
908 support</li>
909 <li>Patch in conditional section handling</li>
910 <li>updated MS compiler project</li>
911 <li>fixed some XPath problems</li>
912 <li>added an URI escaping function</li>
913 <li>some other bug fixes</li>
914</ul>
915
916<h3>2.2.7: Oct 31 2000</h3>
917<ul>
918 <li>added message redirection</li>
919 <li>XPath improvements (thanks TOM !)</li>
920 <li>xmlIOParseDTD() added</li>
921 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
922 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
923</ul>
924
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]925<h3>2.2.6: Oct 25 2000:</h3>
926<ul>
927 <li>Added an hash table module, migrated a number of internal structure to
928 those</li>
929 <li>Fixed a posteriori validation problems</li>
930 <li>HTTP module cleanups</li>
931 <li>HTML parser improvements (tag errors, script/style handling, attribute
932 normalization)</li>
933 <li>coalescing of adjacent text nodes</li>
934 <li>couple of XPath bug fixes, exported the internal API</li>
935</ul>
936
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]937<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]938<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]939 <li>XPointer implementation and testsuite</li>
940 <li>Lot of XPath fixes, added variable and functions registration, more
941 tests</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]942 <li>Portability fixes, lots of enhancements toward an easy Windows build
943 and release</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]944 <li>Late validation fixes</li>
945 <li>Integrated a lot of contributed patches</li>
946 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]947 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]948</ul>
949
950<h3>2.2.4: Oct 1 2000:</h3>
951<ul>
952 <li>main XPath problem fixed</li>
953 <li>Integrated portability patches for Windows</li>
954 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]955</ul>
956
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]957<h3>2.2.3: Sep 17 2000</h3>
958<ul>
959 <li>bug fixes</li>
960 <li>cleanup of entity handling code</li>
961 <li>overall review of all loops in the parsers, all sprintf usage has been
962 checked too</li>
963 <li>Far better handling of larges Dtd. Validating against Docbook XML Dtd
964 works smoothly now.</li>
965</ul>
966
967<h3>1.8.10: Sep 6 2000</h3>
968<ul>
969 <li>bug fix release for some Gnome projects</li>
970</ul>
971
972<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]973<ul>
974 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]975 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]976</ul>
977
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]978<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]979<ul>
980 <li>a purely bug fixes release</li>
981 <li>fixed an encoding support problem when parsing from a memory block</li>
982 <li>fixed a DOCTYPE parsing problem</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]983 <li>removed a bug in the function allowing to override the memory
984 allocation routines</li>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]985</ul>
986
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]987<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]988<ul>
989 <li>applied a lot of portability fixes</li>
990 <li>better encoding support/cleanup and saving (content is now always
991 encoded in UTF-8)</li>
992 <li>the HTML parser now correctly handles encodings</li>
993 <li>added xmlHasProp()</li>
994 <li>fixed a serious problem with &amp;#38;</li>
995 <li>propagated the fix to FTP client</li>
996 <li>cleanup, bugfixes, etc ...</li>
997 <li>Added a page about <a href="encoding.html">libxml Internationalization
998 support</a></li>
999</ul>
1000
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1001<h3>1.8.9: July 9 2000</h3>
1002<ul>
1003 <li>fixed the spec the RPMs should be better</li>
1004 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
1005 rpmfind users problem</li>
1006</ul>
1007
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]1008<h3>2.1.1: July 1 2000</h3>
1009<ul>
1010 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
1011 <li>improvements on the HTML parser</li>
1012</ul>
1013
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1014<h3>2.1.0 and 1.8.8: June 29 2000</h3>
1015<ul>
1016 <li>1.8.8 is mostly a comodity package for upgrading to libxml2 accoding to
1017 <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
1018 about &amp;#38; charref parsing</li>
1019 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
1020 also contains numerous fixes and enhancements:
1021 <ul>
1022 <li>added xmlStopParser() to stop parsing</li>
1023 <li>improved a lot parsing speed when there is large CDATA blocs</li>
1024 <li>includes XPath patches provided by Picdar Technology</li>
1025 <li>tried to fix as much as possible DtD validation and namespace
1026 related problems</li>
1027 <li>output to a given encoding has been added/tested</li>
1028 <li>lot of various fixes</li>
1029 </ul>
1030 </li>
1031</ul>
1032
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1033<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1034<ul>
1035 <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]1036 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initally
1037 scheduled for Apr 3 the relase occured only on Apr 12 due to massive
1038 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1039 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1040 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1041 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1042 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1043 <pre>#include "xxx.h"</pre>
1044 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]1045 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
1046 <li>the memory allocation routines used by libxml can now be overloaded
1047 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1048 <li>The previously CVS only tool tester has been renamed
1049 <strong>xmllint</strong> and is now installed as part of the libxml2
1050 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]1051 <li>The I/O interface has been revamped. There is now ways to plug in
1052 specific I/O modules, either at the URI scheme detection level using
1053 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
1054 parser context using xmlCreateIOParserCtxt()</li>
1055 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
1056 number of the libxml module in use</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1057 <li>a number of optional features of libxml can now be excluded at
1058 configure time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1059</ul>
1060
1061<h3>2.0.0beta: Mar 14 2000</h3>
1062<ul>
1063 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1064 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
1065 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
1066 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1067 <li>This version is now the head in the Gnome CVS base, the old one is
1068 available under the tag LIB_XML_1_X</li>
1069 <li>This includes a very large set of changes. Froma programmatic point of
1070 view applications should not have to be modified too much, check the <a
1071 href="upgrade.html">upgrade page</a></li>
1072 <li>Some interfaces may changes (especially a bit about encoding).</li>
1073 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1074 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1075 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
1076 handled now</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1077 <li>Better handling of entities, especially well formedness checking
1078 and proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1079 <li>DTD conditional sections</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1080 <li>Validation now correcly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1081 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
1082 structures to accomodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]1083 </ul>
1084 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]1085 <li>Serious progress were made toward compliance, <a
1086 href="conf/result.html">here are the result of the test</a> against the
1087 OASIS testsuite (except the japanese tests since I don't support that
1088 encoding yet). This URL is rebuilt every couple of hours using the CVS
1089 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1090</ul>
1091
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1092<h3>1.8.7: Mar 6 2000</h3>
1093<ul>
1094 <li>This is a bug fix release:</li>
1095 <li>It is possible to disable the ignorable blanks heuristic used by
1096 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1097 that for adherence to XML spec, this behaviour will be disabled by
1098 default in 2.x . The same function will allow to keep compatibility for
1099 old code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1100 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
1101 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1102 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
1103 compilation on some platforms has been fixed</li>
1104 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
1105 URIs</li>
1106</ul>
1107
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]1108<h3>1.8.6: Jan 31 2000</h3>
1109<ul>
1110 <li>added a nanoFTP transport module, debugged until the new version of <a
1111 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
1112 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]1113</ul>
1114
1115<h3>1.8.5: Jan 21 2000</h3>
1116<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1117 <li>adding APIs to parse a well balanced chunk of XML (production <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1118 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
1119 XML spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1120 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1121 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
1122 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]1123 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
1124 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1125</ul>
1126
1127<h3>1.8.4: Jan 13 2000</h3>
1128<ul>
1129 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
1130 <li>all exit() call should have been removed from libxml</li>
1131 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
1132 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1133</ul>
1134
1135<h3>1.8.3: Jan 5 2000</h3>
1136<ul>
1137 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1138 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillarddbfd6411999-12-28 16:35:14 +0000[diff] [blame]1139 <li>lots of bug fixes and improvement added over XMas hollidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1140 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1141 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
1142 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1143 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]1144 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]1145 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1146</ul>
1147
1148<h3>1.8.2: Dec 21 1999</h3>
1149<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1150 <li>I got another problem with includes and C++, I hope this issue is fixed
1151 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]1152 <li>Added a few tree modification functions: xmlReplaceNode,
1153 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
1154 xmlDocSetRootElement</li>
1155 <li>Tried to improve the HTML output with help from <a
1156 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1157</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1158
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]1159<h3>1.8.1: Dec 18 1999</h3>
1160<ul>
1161 <li>various patches to avoid troubles when using libxml with C++ compilers
1162 the "namespace" keyword and C escaping in include files</li>
1163 <li>a problem in one of the core macros IS_CHAR was corrected</li>
1164 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
1165 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]1166 <li>fixed a posteriori validation (validation after parsing, or by using a
1167 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]1168 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]1169</ul>
1170
1171<h3>1.8.0: Dec 12 1999</h3>
1172<ul>
1173 <li>cleanup, especially memory wise</li>
1174 <li>the parser should be more reliable, especially the HTML one, it should
1175 not crash, whatever the input !</li>
1176 <li>Integrated various patches, especially a speedup improvement for large
1177 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
1178 configure with --with-buffers to enable them.</li>
1179 <li>attribute normalization, oops should have been added long ago !</li>
1180 <li>attributes defaulted from Dtds should be available, xmlSetProp() now
1181 does entities escapting by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]1182</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1183
1184<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1185<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1186 <li>Lots of HTML improvement</li>
1187 <li>Fixed some errors when saving both XML and HTML</li>
1188 <li>More examples, the regression tests should now look clean</li>
1189 <li>Fixed a bug with contiguous charref</li>
1190</ul>
1191
1192<h3>1.7.3: Sep 29 1999</h3>
1193<ul>
1194 <li>portability problems fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1195 <li>snprintf was used unconditionnally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1196 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1197</ul>
1198
1199<h3>1.7.1: Sep 24 1999</h3>
1200<ul>
1201 <li>The basic type for strings manipulated by libxml has been renamed in
1202 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1203 is that CHAR was conflicting with a predefined type on Windows. However
1204 on non WIN32 environment, compatibility is provided by the way of a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1205 <strong>#define </strong>.</li>
1206 <li>Changed another error : the use of a structure field called errno, and
1207 leading to troubles on platforms where it's a macro</li>
1208</ul>
1209
1210<h3>1.7.0: sep 23 1999</h3>
1211<ul>
1212 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1213 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1214 <li>Added an errno to report errors by another mean than a simple printf
1215 like callback</li>
1216 <li>Finished ID/IDREF support and checking when validation</li>
1217 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1218 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1219 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
1220 implementation</li>
1221 <li>Added an HTML parser front-end</li>
1222</ul>
1223
1224<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1225
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1226<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]1227markup-based structured documents. Here is <a name="example">an example XML
1228document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1229<pre>&lt;?xml version="1.0"?&gt;
1230&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
1231 &lt;head&gt;
1232 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
1233 &lt;/head&gt;
1234 &lt;chapter&gt;
1235 &lt;title&gt;The Linux adventure&lt;/title&gt;
1236 &lt;p&gt;bla bla bla ...&lt;/p&gt;
1237 &lt;image href="linus.gif"/&gt;
1238 &lt;p&gt;...&lt;/p&gt;
1239 &lt;/chapter&gt;
1240&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1241
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1242<p>The first line specifies that it's an XML document and gives useful
1243information about its encoding. Then the document is a text format whose
1244structure is specified by tags between brackets. <strong>Each tag opened has
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1245to be closed</strong>. XML is pedantic about this. However, if a tag is empty
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1246(no content), a single tag can serve as both the opening and closing tag if
1247it ends with <code>/&gt;</code> rather than with <code>&gt;</code>. Note
1248that, for example, the image tag has no content (just an attribute) and is
1249closed by ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1250
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1251<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]1252structured document maintenance (where it follows the steps of SGML) to
1253simple data encoding mechanisms like configuration file formatting (glade),
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1254spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where
1255it is used to encode remote calls between a client and a server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1256
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1257<h2><a name="XSLT">XSLT</a></h2>
1258
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]1259<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
1260
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1261<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a
1262language for transforming XML documents into other XML documents (or
1263HTML/textual output).</p>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1264
1265<p>A separate library called libxslt is being built on top of libxml2. This
1266module "libxslt" can be found in the Gnome CVS base too.</p>
1267
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]1268<p>You can check the <a
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]1269href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a>
1270supported and the progresses on the <a
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]1271href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog">Changelog</a></p>
1272
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1273<h2><a name="architecture">libxml architecture</a></h2>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1274
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1275<p>Libxml is made of multiple components; some of them are optional, and most
1276of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1277<ul>
1278 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1279 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1280 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1281 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1282 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1283 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1284 <li>a SAX tree module to build an in-memory DOM representation</li>
1285 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1286 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1287 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1288 (optional)</li>
1289 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]1290</ul>
1291
1292<p>Graphically this gives the following:</p>
1293
1294<p><img src="libxml.gif" alt="a graphical view of the various"></p>
1295
1296<p></p>
1297
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1298<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1299
1300<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1301returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1302<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1303as the file name, the document type, and a <strong>children</strong> pointer
1304which is the root of the document (or more exactly the first child under the
1305root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1306chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1307relationship. An xmlNode can also carry properties (a chain of xmlAttr
1308structures). An attribute may have a value which is a list of TEXT or
1309ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1310
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1311<p>Here is an example (erroneous with respect to the XML spec since there
1312should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1313
1314<p><img src="structure.gif" alt=" structure.gif "></p>
1315
1316<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1317called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1318prints them back as parsed. This is useful for detecting errors both in XML
1319code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1320which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1321result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1322<pre>DOCUMENT
1323version=1.0
1324standalone=true
1325 ELEMENT EXAMPLE
1326 ATTRIBUTE prop1
1327 TEXT
1328 content=gnome is great
1329 ATTRIBUTE prop2
1330 ENTITY_REF
1331 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]1332 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1333 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1334 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1335 TEXT
1336 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1337 ELEMENT chapter
1338 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1339 TEXT
1340 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1341 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1342 TEXT
1343 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1344 ELEMENT image
1345 ATTRIBUTE href
1346 TEXT
1347 content=linus.gif
1348 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1349 TEXT
1350 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1351
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1352<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1353
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1354<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1355
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1356<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1357memory. 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]1358loaded using libxml), it's better to use the SAX interface of libxml. SAX is
1359a <strong>callback-based interface</strong> to the parser. Before parsing,
1360the application layer registers a customized set of callbacks which are
1361called by the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1362
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1363<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]1364libxml, see the <a
1365href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
1366documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1367Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1368
1369<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
1370program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1371binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]1372distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1373testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1374<pre>SAX.setDocumentLocator()
1375SAX.startDocument()
1376SAX.getEntity(amp)
1377SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
1378SAX.characters( , 3)
1379SAX.startElement(head)
1380SAX.characters( , 4)
1381SAX.startElement(title)
1382SAX.characters(Welcome to Gnome, 16)
1383SAX.endElement(title)
1384SAX.characters( , 3)
1385SAX.endElement(head)
1386SAX.characters( , 3)
1387SAX.startElement(chapter)
1388SAX.characters( , 4)
1389SAX.startElement(title)
1390SAX.characters(The Linux adventure, 19)
1391SAX.endElement(title)
1392SAX.characters( , 4)
1393SAX.startElement(p)
1394SAX.characters(bla bla bla ..., 15)
1395SAX.endElement(p)
1396SAX.characters( , 4)
1397SAX.startElement(image, href='linus.gif')
1398SAX.endElement(image)
1399SAX.characters( , 4)
1400SAX.startElement(p)
1401SAX.characters(..., 3)
1402SAX.endElement(p)
1403SAX.characters( , 3)
1404SAX.endElement(chapter)
1405SAX.characters( , 1)
1406SAX.endElement(EXAMPLE)
1407SAX.endDocument()</pre>
1408
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1409<p>Most of the other interfaces of libxml are based on the DOM tree-building
1410facility, so nearly everything up to the end of this document presupposes the
1411use of the standard DOM tree build. Note that the DOM tree itself is built by
1412a set of registered default callbacks, without internal specific
1413interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1414
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1415<h2><a name="Validation">Validation &amp; DTDs</a></h2>
1416
1417<p>Table of Content:</p>
1418<ol>
1419 <li><a href="#General5">General overview</a></li>
1420 <li><a href="#definition">The definition</a></li>
1421 <li><a href="#Simple">Simple rules</a>
1422 <ol>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]1423 <li><a href="#reference">How to reference a DTD from a document</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1424 <li><a href="#Declaring">Declaring elements</a></li>
1425 <li><a href="#Declaring1">Declaring attributes</a></li>
1426 </ol>
1427 </li>
1428 <li><a href="#Some">Some examples</a></li>
1429 <li><a href="#validate">How to validate</a></li>
1430 <li><a href="#Other">Other resources</a></li>
1431</ol>
1432
1433<h3><a name="General5">General overview</a></h3>
1434
1435<p>Well what is validation and what is a DTD ?</p>
1436
1437<p>DTD is the acronym for Document Type Definition. This is a description of
1438the content for a familly of XML files. This is part of the XML 1.0
1439specification, and alows to describe and check that a given document instance
1440conforms to a set of rules detailing its structure and content.</p>
1441
1442<p>Validation is the process of checking a document against a DTD (more
1443generally against a set of construction rules).</p>
1444
1445<p>The validation process and building DTDs are the two most difficult parts
1446of the XML life cycle. Briefly a DTD defines all the possibles element to be
1447found within your document, what is the formal shape of your document tree
1448(by defining the allowed content of an element, either text, a regular
1449expression for the allowed list of children, or mixed content i.e. both text
1450and children). The DTD also defines the allowed attributes for all elements
1451and the types of the attributes.</p>
1452
1453<h3><a name="definition1">The definition</a></h3>
1454
1455<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
1456href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
1457Rev1</a>):</p>
1458<ul>
1459 <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
1460 elements</a></li>
1461 <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
1462 attributes</a></li>
1463</ul>
1464
1465<p>(unfortunately) all this is inherited from the SGML world, the syntax is
1466ancient...</p>
1467
1468<h3><a name="Simple1">Simple rules</a></h3>
1469
1470<p>Writing DTD can be done in multiple ways, the rules to build them if you
1471need something fixed or something which can evolve over time can be radically
1472different. Really complex DTD like Docbook ones are flexible but quite harder
1473to design. I will just focuse on DTDs for a formats with a fixed simple
1474structure. It is just a set of basic rules, and definitely not exhaustive nor
1475useable for complex DTD design.</p>
1476
1477<h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
1478
1479<p>Assuming the top element of the document is <code>spec</code> and the dtd
1480is placed in the file <code>mydtd</code> in the subdirectory
1481<code>dtds</code> of the directory from where the document were loaded:</p>
1482
1483<p><code>&lt;!DOCTYPE spec SYSTEM "dtds/mydtd"&gt;</code></p>
1484
1485<p>Notes:</p>
1486<ul>
1487 <li>the system string is actually an URI-Reference (as defined in <a
1488 href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396</a>) so you can use a
1489 full URL string indicating the location of your DTD on the Web, this is a
1490 really good thing to do if you want others to validate your document</li>
1491 <li>it is also possible to associate a <code>PUBLIC</code> identifier (a
1492 magic string) so that the DTd is looked up in catalogs on the client side
1493 without having to locate it on the web</li>
1494 <li>a dtd contains a set of elements and attributes declarations, but they
1495 don't define what the root of the document should be. This is explicitely
1496 told to the parser/validator as the first element of the
1497 <code>DOCTYPE</code> declaration.</li>
1498</ul>
1499
1500<h4><a name="Declaring2">Declaring elements</a>:</h4>
1501
1502<p>The following declares an element <code>spec</code>:</p>
1503
1504<p><code>&lt;!ELEMENT spec (front, body, back?)&gt;</code></p>
1505
1506<p>it also expresses that the spec element contains one <code>front</code>,
1507one <code>body</code> and one optionnal <code>back</code> children elements
1508in this order. The declaration of one element of the structure and its
1509content are done in a single declaration. Similary the following declares
1510<code>div1</code> elements:</p>
1511
Daniel Veillard51737272002-01-23 23:10:38 +0000[diff] [blame]1512<p><code>&lt;!ELEMENT div1 (head, (p | list | note)*, div2?)&gt;</code></p>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1513
1514<p>means div1 contains one <code>head</code> then a series of optional
1515<code>p</code>, <code>list</code>s and <code>note</code>s and then an
1516optional <code>div2</code>. And last but not least an element can contain
1517text:</p>
1518
1519<p><code>&lt;!ELEMENT b (#PCDATA)&gt;</code></p>
1520
1521<p><code>b</code> contains text or being of mixed content (text and elements
1522in no particular order):</p>
1523
1524<p><code>&lt;!ELEMENT p (#PCDATA|a|ul|b|i|em)*&gt;</code></p>
1525
1526<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
1527<code>b</code>, <code>i </code>or <code>em</code> elements in no particular
1528order.</p>
1529
1530<h4><a name="Declaring1">Declaring attributes</a>:</h4>
1531
1532<p>again the attributes declaration includes their content definition:</p>
1533
1534<p><code>&lt;!ATTLIST termdef name CDATA #IMPLIED&gt;</code></p>
1535
1536<p>means that the element <code>termdef</code> can have a <code>name</code>
1537attribute containing text (<code>CDATA</code>) and which is optionnal
1538(<code>#IMPLIED</code>). The attribute value can also be defined within a
1539set:</p>
1540
1541<p><code>&lt;!ATTLIST list type (bullets|ordered|glossary)
1542"ordered"&gt;</code></p>
1543
1544<p>means <code>list</code> element have a <code>type</code> attribute with 3
1545allowed values "bullets", "ordered" or "glossary" and which default to
1546"ordered" if the attribute is not explicitely specified.</p>
1547
1548<p>The content type of an attribute can be text (<code>CDATA</code>),
1549anchor/reference/references
1550(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
1551(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
1552(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
1553<code>chapter</code> element can have an optional <code>id</code> attribute
1554of type <code>ID</code>, usable for reference from attribute of type
1555IDREF:</p>
1556
1557<p><code>&lt;!ATTLIST chapter id ID #IMPLIED&gt;</code></p>
1558
1559<p>The last value of an attribute definition can be <code>#REQUIRED
1560</code>meaning that the attribute has to be given, <code>#IMPLIED</code>
1561meaning that it is optional, or the default value (possibly prefixed by
1562<code>#FIXED</code> if it is the only allowed).</p>
1563
1564<p>Notes:</p>
1565<ul>
1566 <li>usually the attributes pertaining to a given element are declared in a
1567 single expression, but it is just a convention adopted by a lot of DTD
1568 writers:
1569 <pre>&lt;!ATTLIST termdef
1570 id ID #REQUIRED
1571 name CDATA #IMPLIED&gt;</pre>
1572 <p>The previous construct defines both <code>id</code> and
1573 <code>name</code> attributes for the element <code>termdef</code></p>
1574 </li>
1575</ul>
1576
1577<h3><a name="Some1">Some examples</a></h3>
1578
1579<p>The directory <code>test/valid/dtds/</code> in the libxml distribution
1580contains some complex DTD examples. The <code>test/valid/dia.xml</code>
1581example shows an XML file where the simple DTD is directly included within
1582the document.</p>
1583
1584<h3><a name="validate1">How to validate</a></h3>
1585
1586<p>The simplest is to use the xmllint program comming with libxml. The
1587<code>--valid</code> option turn on validation of the files given as input,
1588for example the following validates a copy of the first revision of the XML
15891.0 specification:</p>
1590
1591<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
1592
1593<p>the -- noout is used to not output the resulting tree.</p>
1594
1595<p>The <code>--dtdvalid dtd</code> allows to validate the document(s) against
1596a given DTD.</p>
1597
1598<p>Libxml exports an API to handle DTDs and validation, check the <a
1599href="http://xmlsoft.org/html/libxml-valid.html">associated
1600description</a>.</p>
1601
1602<h3><a name="Other1">Other resources</a></h3>
1603
1604<p>DTDs are as old as SGML. So there may be a number of examples on-line, I
1605will just list one for now, others pointers welcome:</p>
1606<ul>
1607 <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
1608</ul>
1609
1610<p>I suggest looking at the examples found under test/valid/dtd and any of
1611the large number of books available on XML. The dia example in test/valid
1612should be both simple and complete enough to allow you to build your own.</p>
1613
1614<p></p>
1615
1616<h2><a name="Memory">Memory Management</a></h2>
1617
1618<p>Table of Content:</p>
1619<ol>
1620 <li><a href="#General3">General overview</a></li>
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]1621 <li><a href="#setting">Setting libxml set of memory routines</a></li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]1622 <li><a href="#cleanup">Cleaning up after parsing</a></li>
1623 <li><a href="#Debugging">Debugging routines</a></li>
1624 <li><a href="#General4">General memory requirements</a></li>
1625</ol>
1626
1627<h3><a name="General3">General overview</a></h3>
1628
1629<p>The module <code><a
1630href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
1631provides the interfaces to the libxml memory system:</p>
1632<ul>
1633 <li>libxml does not use the libc memory allocator directly but xmlFree(),
1634 xmlMalloc() and xmlRealloc()</li>
1635 <li>those routines can be reallocated to a specific set of routine, by
1636 default the libc ones i.e. free(), malloc() and realloc()</li>
1637 <li>the xmlmemory.c module includes a set of debugging routine</li>
1638</ul>
1639
1640<h3><a name="setting">Setting libxml set of memory routines</a></h3>
1641
1642<p>It is sometimes useful to not use the default memory allocator, either for
1643debugging, analysis or to implement a specific behaviour on memory management
1644(like on embedded systems). Two function calls are available to do so:</p>
1645<ul>
1646 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet ()</a>
1647 which return the current set of functions in use by the parser</li>
1648 <li><a
1649 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
1650 which allow to set up a new set of memory allocation functions</li>
1651</ul>
1652
1653<p>Of course a call to xmlMemSetup() should probably be done before calling
1654any other libxml routines (unless you are sure your allocations routines are
1655compatibles).</p>
1656
1657<h3><a name="cleanup">Cleaning up after parsing</a></h3>
1658
1659<p>Libxml is not stateless, there is a few set of memory structures needing
1660allocation before the parser is fully functionnal (some encoding structures
1661for example). This also mean that once parsing is finished there is a tiny
1662amount of memory (a few hundred bytes) which can be recollected if you don't
1663reuse the parser immediately:</p>
1664<ul>
1665 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
1666 ()</a>
1667 is a centralized routine to free the parsing states. Note that it won't
1668 deallocate any produced tree if any (use the xmlFreeDoc() and related
1669 routines for this).</li>
1670 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
1671 ()</a>
1672 is the dual routine allowing to preallocate the parsing state which can
1673 be useful for example to avoid initialization reentrancy problems when
1674 using libxml in multithreaded applications</li>
1675</ul>
1676
1677<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild
1678at the next invocation of parser routines, but be careful of the consequences
1679in multithreaded applications.</p>
1680
1681<h3><a name="Debugging">Debugging routines</a></h3>
1682
1683<p>When configured using --with-mem-debug flag (off by default), libxml uses
1684a set of memory allocation debugging routineskeeping track of all allocated
1685blocks and the location in the code where the routine was called. A couple of
1686other debugging routines allow to dump the memory allocated infos to a file
1687or call a specific routine when a given block number is allocated:</p>
1688<ul>
1689 <li><a
1690 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
1691 <a
1692 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
1693 and <a
1694 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
1695 are the memory debugging replacement allocation routines</li>
1696 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
1697 ()</a>
1698 dumps all the informations about the allocated memory block lefts in the
1699 <code>.memdump</code> file</li>
1700</ul>
1701
1702<p>When developping libxml memory debug is enabled, the tests programs call
1703xmlMemoryDump () and the "make test" regression tests will check for any
1704memory leak during the full regression test sequence, this helps a lot
1705ensuring that libxml does not leak memory and bullet proof memory
1706allocations use (some libc implementations are known to be far too permissive
1707resulting in major portability problems!).</p>
1708
1709<p>If the .memdump reports a leak, it displays the allocation function and
1710also tries to give some informations about the content and structure of the
1711allocated blocks left. This is sufficient in most cases to find the culprit,
1712but not always. Assuming the allocation problem is reproductible, it is
1713possible to find more easilly:</p>
1714<ol>
1715 <li>write down the block number xxxx not allocated</li>
1716 <li>export the environement variable XML_MEM_BREAKPOINT=xxxx</li>
1717 <li>run the program under a debugger and set a breakpoint on
1718 xmlMallocBreakpoint() a specific function called when this precise block
1719 is allocated</li>
1720 <li>when the breakpoint is reached you can then do a fine analysis of the
1721 allocation an step to see the condition resulting in the missing
1722 deallocation.</li>
1723</ol>
1724
1725<p>I used to use a commercial tool to debug libxml memory problems but after
1726noticing that it was not detecting memory leaks that simple mechanism was
1727used and proved extremely efficient until now.</p>
1728
1729<h3><a name="General4">General memory requirements</a></h3>
1730
1731<p>How much libxml memory require ? It's hard to tell in average it depends
1732of a number of things:</p>
1733<ul>
1734 <li>the parser itself should work in a fixed amout of memory, except for
1735 information maintained about the stacks of names and entities locations.
1736 The I/O and encoding handlers will probably account for a few KBytes.
1737 This is true for both the XML and HTML parser (though the HTML parser
1738 need more state).</li>
1739 <li>If you are generating the DOM tree then memory requirements will grow
1740 nearly lineary with the size of the data. In general for a balanced
1741 textual document the internal memory requirement is about 4 times the
1742 size of the UTF8 serialization of this document (exmple the XML-1.0
1743 recommendation is a bit more of 150KBytes and takes 650KBytes of main
1744 memory when parsed). Validation will add a amount of memory required for
1745 maintaining the external Dtd state which should be linear with the
1746 complexity of the content model defined by the Dtd</li>
1747 <li>If you don't care about the advanced features of libxml like
1748 validation, DOM, XPath or XPointer, but really need to work fixed memory
1749 requirements, then the SAX interface should be used.</li>
1750</ul>
1751
1752<p></p>
1753
1754<h2><a name="Encodings">Encodings support</a></h2>
1755
1756<p>Table of Content:</p>
1757<ol>
1758 <li><a href="encoding.html#What">What does internationalization support
1759 mean ?</a></li>
1760 <li><a href="encoding.html#internal">The internal encoding, how and
1761 why</a></li>
1762 <li><a href="encoding.html#implemente">How is it implemented ?</a></li>
1763 <li><a href="encoding.html#Default">Default supported encodings</a></li>
1764 <li><a href="encoding.html#extend">How to extend the existing
1765 support</a></li>
1766</ol>
1767
1768<h3><a name="What">What does internationalization support mean ?</a></h3>
1769
1770<p>XML was designed from the start to allow the support of any character set
1771by using Unicode. Any conformant XML parser has to support the UTF-8 and
1772UTF-16 default encodings which can both express the full unicode ranges. UTF8
1773is a variable length encoding whose greatest point are to resuse the same
1774emcoding for ASCII and to save space for Western encodings, but it is a bit
1775more complex to handle in practice. UTF-16 use 2 bytes per characters (and
1776sometimes combines two pairs), it makes implementation easier, but looks a
1777bit overkill for Western languages encoding. Moreover the XML specification
1778allows document to be encoded in other encodings at the condition that they
1779are clearly labelled as such. For example the following is a wellformed XML
1780document encoded in ISO-8859 1 and using accentuated letter that we French
1781likes for both markup and content:</p>
1782<pre>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
1783&lt;très&gt;là&lt;/très&gt;</pre>
1784
1785<p>Having internationalization support in libxml means the foolowing:</p>
1786<ul>
1787 <li>the document is properly parsed</li>
1788 <li>informations about it's encoding are saved</li>
1789 <li>it can be modified</li>
1790 <li>it can be saved in its original encoding</li>
1791 <li>it can also be saved in another encoding supported by libxml (for
1792 example straight UTF8 or even an ASCII form)</li>
1793</ul>
1794
1795<p>Another very important point is that the whole libxml API, with the
1796exception of a few routines to read with a specific encoding or save to a
1797specific encoding, is completely agnostic about the original encoding of the
1798document.</p>
1799
1800<p>It should be noted too that the HTML parser embedded in libxml now obbey
1801the same rules too, the following document will be (as of 2.2.2) handled in
1802an internationalized fashion by libxml too:</p>
1803<pre>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
1804 "http://www.w3.org/TR/REC-html40/loose.dtd"&gt;
1805&lt;html lang="fr"&gt;
1806&lt;head&gt;
1807 &lt;META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&gt;
1808&lt;/head&gt;
1809&lt;body&gt;
1810&lt;p&gt;W3C crée des standards pour le Web.&lt;/body&gt;
1811&lt;/html&gt;</pre>
1812
1813<h3><a name="internal">The internal encoding, how and why</a></h3>
1814
1815<p>One of the core decision was to force all documents to be converted to a
1816default internal encoding, and that encoding to be UTF-8, here are the
1817rationale for those choices:</p>
1818<ul>
1819 <li>keeping the native encoding in the internal form would force the libxml
1820 users (or the code associated) to be fully aware of the encoding of the
1821 original document, for examples when adding a text node to a document,
1822 the content would have to be provided in the document encoding, i.e. the
1823 client code would have to check it before hand, make sure it's conformant
1824 to the encoding, etc ... Very hard in practice, though in some specific
1825 cases this may make sense.</li>
1826 <li>the second decision was which encoding. From the XML spec only UTF8 and
1827 UTF16 really makes sense as being the two only encodings for which there
1828 is amndatory support. UCS-4 (32 bits fixed size encoding) could be
1829 considered an intelligent choice too since it's a direct Unicode mapping
1830 support. I selected UTF-8 on the basis of efficiency and compatibility
1831 with surrounding software:
1832 <ul>
1833 <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
1834 more costly to import and export CPU wise) is also far more compact
1835 than UTF-16 (and UCS-4) for a majority of the documents I see it used
1836 for right now (RPM RDF catalogs, advogato data, various configuration
1837 file formats, etc.) and the key point for today's computer
1838 architecture is efficient uses of caches. If one nearly double the
1839 memory requirement to store the same amount of data, this will trash
1840 caches (main memory/external caches/internal caches) and my take is
1841 that this harms the system far more than the CPU requirements needed
1842 for the conversion to UTF-8</li>
1843 <li>Most of libxml version 1 users were using it with straight ASCII
1844 most of the time, doing the conversion with an internal encoding
1845 requiring all their code to be rewritten was a serious show-stopper
1846 for using UTF-16 or UCS-4.</li>
1847 <li>UTF-8 is being used as the de-facto internal encoding standard for
1848 related code like the <a href="http://www.pango.org/">pango</a>
1849 upcoming Gnome text widget, and a lot of Unix code (yep another place
1850 where Unix programmer base takes a different approach from Microsoft
1851 - they are using UTF-16)</li>
1852 </ul>
1853 </li>
1854</ul>
1855
1856<p>What does this mean in practice for the libxml user:</p>
1857<ul>
1858 <li>xmlChar, the libxml data type is a byte, those bytes must be assembled
1859 as UTF-8 valid strings. The proper way to terminate an xmlChar * string
1860 is simply to append 0 byte, as usual.</li>
1861 <li>One just need to make sure that when using chars outside the ASCII set,
1862 the values has been properly converted to UTF-8</li>
1863</ul>
1864
1865<h3><a name="implemente">How is it implemented ?</a></h3>
1866
1867<p>Let's describe how all this works within libxml, basically the I18N
1868(internationalization) support get triggered only during I/O operation, i.e.
1869when reading a document or saving one. Let's look first at the reading
1870sequence:</p>
1871<ol>
1872 <li>when a document is processed, we usually don't know the encoding, a
1873 simple heuristic allows to detect UTF-18 and UCS-4 from whose where the
1874 ASCII range (0-0x7F) maps with ASCII</li>
1875 <li>the xml declaration if available is parsed, including the encoding
1876 declaration. At that point, if the autodetected encoding is different
1877 from the one declared a call to xmlSwitchEncoding() is issued.</li>
1878 <li>If there is no encoding declaration, then the input has to be in either
1879 UTF-8 or UTF-16, if it is not then at some point when processing the
1880 input, the converter/checker of UTF-8 form will raise an encoding error.
1881 You may end-up with a garbled document, or no document at all ! Example:
1882 <pre>~/XML -&gt; ./xmllint err.xml
1883err.xml:1: error: Input is not proper UTF-8, indicate encoding !
1884&lt;très&gt;là&lt;/très&gt;
1885 ^
1886err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
1887&lt;très&gt;là&lt;/très&gt;
1888 ^</pre>
1889 </li>
1890 <li>xmlSwitchEncoding() does an encoding name lookup, canonalize it, and
1891 then search the default registered encoding converters for that encoding.
1892 If it's not within the default set and iconv() support has been compiled
1893 it, it will ask iconv for such an encoder. If this fails then the parser
1894 will report an error and stops processing:
1895 <pre>~/XML -&gt; ./xmllint err2.xml
1896err2.xml:1: error: Unsupported encoding UnsupportedEnc
1897&lt;?xml version="1.0" encoding="UnsupportedEnc"?&gt;
1898 ^</pre>
1899 </li>
1900 <li>From that point the encoder process progressingly the input (it is
1901 plugged as a front-end to the I/O module) for that entity. It captures
1902 and convert on-the-fly the document to be parsed to UTF-8. The parser
1903 itself just does UTF-8 checking of this input and process it
1904 transparently. The only difference is that the encoding information has
1905 been added to the parsing context (more precisely to the input
1906 corresponding to this entity).</li>
1907 <li>The result (when using DOM) is an internal form completely in UTF-8
1908 with just an encoding information on the document node.</li>
1909</ol>
1910
1911<p>Ok then what's happen when saving the document (assuming you
1912colllected/built an xmlDoc DOM like structure) ? It depends on the function
1913called, xmlSaveFile() will just try to save in the original encoding, while
1914xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
1915encoding:</p>
1916<ol>
1917 <li>if no encoding is given, libxml will look for an encoding value
1918 associated to the document and if it exists will try to save to that
1919 encoding,
1920 <p>otherwise everything is written in the internal form, i.e. UTF-8</p>
1921 </li>
1922 <li>so if an encoding was specified, either at the API level or on the
1923 document, libxml will again canonalize the encoding name, lookup for a
1924 converter in the registered set or through iconv. If not found the
1925 function will return an error code</li>
1926 <li>the converter is placed before the I/O buffer layer, as another kind of
1927 buffer, then libxml will simply push the UTF-8 serialization to through
1928 that buffer, which will then progressively be converted and pushed onto
1929 the I/O layer.</li>
1930 <li>It is possible that the converter code fails on some input, for example
1931 trying to push an UTF-8 encoded chinese character through the UTF-8 to
1932 ISO-8859-1 converter won't work. Since the encoders are progressive they
1933 will just report the error and the number of bytes converted, at that
1934 point libxml will decode the offending character, remove it from the
1935 buffer and replace it with the associated charRef encoding &amp;#123; and
1936 resume the convertion. This guarante that any document will be saved
1937 without losses (except for markup names where this is not legal, this is
1938 a problem in the current version, in pactice avoid using non-ascci
1939 characters for tags or attributes names @@). A special "ascii" encoding
1940 name is used to save documents to a pure ascii form can be used when
1941 portability is really crucial</li>
1942</ol>
1943
1944<p>Here is a few examples based on the same test document:</p>
1945<pre>~/XML -&gt; ./xmllint isolat1
1946&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
1947&lt;très&gt;là&lt;/très&gt;
1948~/XML -&gt; ./xmllint --encode UTF-8 isolat1
1949&lt;?xml version="1.0" encoding="UTF-8"?&gt;
1950&lt;très&gt;là  &lt;/très&gt;
1951~/XML -&gt; </pre>
1952
1953<p>The same processing is applied (and reuse most of the code) for HTML I18N
1954processing. Looking up and modifying the content encoding is a bit more
1955difficult since it is located in a &lt;meta&gt; tag under the &lt;head&gt;,
1956so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
1957been provided. The parser also attempts to switch encoding on the fly when
1958detecting such a tag on input. Except for that the processing is the same
1959(and again reuses the same code).</p>
1960
1961<h3><a name="Default">Default supported encodings</a></h3>
1962
1963<p>libxml has a set of default converters for the following encodings
1964(located in encoding.c):</p>
1965<ol>
1966 <li>UTF-8 is supported by default (null handlers)</li>
1967 <li>UTF-16, both little and big endian</li>
1968 <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
1969 <li>ASCII, useful mostly for saving</li>
1970 <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
1971 predefined entities like &amp;copy; for the Copyright sign.</li>
1972</ol>
1973
1974<p>More over when compiled on an Unix platfor with iconv support the full set
1975of encodings supported by iconv can be instantly be used by libxml. On a
1976linux machine with glibc-2.1 the list of supported encodings and aliases fill
19773 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
1978various Japanese ones.</p>
1979
1980<h4>Encoding aliases</h4>
1981
1982<p>From 2.2.3, libxml has support to register encoding names aliases. The
1983goal is to be able to parse document whose encoding is supported but where
1984the name differs (for example from the default set of names accepted by
1985iconv). The following functions allow to register and handle new aliases for
1986existing encodings. Once registered libxml will automatically lookup the
1987aliases when handling a document:</p>
1988<ul>
1989 <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li>
1990 <li>int xmlDelEncodingAlias(const char *alias);</li>
1991 <li>const char * xmlGetEncodingAlias(const char *alias);</li>
1992 <li>void xmlCleanupEncodingAliases(void);</li>
1993</ul>
1994
1995<h3><a name="extend">How to extend the existing support</a></h3>
1996
1997<p>Well adding support for new encoding, or overriding one of the encoders
1998(assuming it is buggy) should not be hard, just write an input and output
1999conversion routines to/from UTF-8, and register them using
2000xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be
2001called automatically if the parser(s) encounter such an encoding name
2002(register it uppercase, this will help). The description of the encoders,
2003their arguments and expected return values are described in the encoding.h
2004header.</p>
2005
2006<p>A quick note on the topic of subverting the parser to use a different
2007internal encoding than UTF-8, in some case people will absolutely want to
2008keep the internal encoding different, I think it's still possible (but the
2009encoding must be compliant with ASCII on the same subrange) though I didn't
2010tried it. The key is to override the default conversion routines (by
2011registering null encoders/decoders for your charsets), and bypass the UTF-8
2012checking of the parser by setting the parser context charset
2013(ctxt-&gt;charset) to something different than XML_CHAR_ENCODING_UTF8, but
2014there is no guarantee taht this will work. You may also have some troubles
2015saving back.</p>
2016
2017<p>Basically proper I18N support is important, this requires at least
2018libxml-2.0.0, but a lot of features and corrections are really available only
2019starting 2.2.</p>
2020
2021<h2><a name="IO">I/O Interfaces</a></h2>
2022
2023<p>Table of Content:</p>
2024<ol>
2025 <li><a href="#General1">General overview</a></li>
2026 <li><a href="#basic">The basic buffer type</a></li>
2027 <li><a href="#Input">Input I/O handlers</a></li>
2028 <li><a href="#Output">Output I/O handlers</a></li>
2029 <li><a href="#entities">The entities loader</a></li>
2030 <li><a href="#Example2">Example of customized I/O</a></li>
2031</ol>
2032
2033<h3><a name="General1">General overview</a></h3>
2034
2035<p>The module <code><a
2036href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
2037the interfaces to the libxml I/O system. This consists of 4 main parts:</p>
2038<ul>
2039 <li>Entities loader, this is a routine which tries to fetch the entities
2040 (files) based on their PUBLIC and SYSTEM identifiers. The default loader
2041 don't look at the public identifier since libxml do not maintain a
2042 catalog. You can redefine you own entity loader by using
2043 <code>xmlGetExternalEntityLoader()</code> and
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2044 <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
2045 example</a>.</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2046 <li>Input I/O buffers which are a commodity structure used by the parser(s)
2047 input layer to handle fetching the informations to feed the parser. This
2048 provides buffering and is also a placeholder where the encoding
2049 convertors to UTF8 are piggy-backed.</li>
2050 <li>Output I/O buffers are similar to the Input ones and fulfill similar
2051 task but when generating a serialization from a tree.</li>
2052 <li>A mechanism to register sets of I/O callbacks and associate them with
2053 specific naming schemes like the protocol part of the URIs.
2054 <p>This affect the default I/O operations and allows to use specific I/O
2055 handlers for certain names.</p>
2056 </li>
2057</ul>
2058
2059<p>The general mechanism used when loading http://rpmfind.net/xml.html for
2060example in the HTML parser is the following:</p>
2061<ol>
2062 <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
2063 the parsing context and the URI string.</li>
2064 <li>the URI string is checked against the existing registered handlers
2065 using their match() callback function, if the HTTP module was compiled
2066 in, it is registered and its match() function will succeeds</li>
2067 <li>the open() function of the handler is called and if successful will
2068 return an I/O Input buffer</li>
2069 <li>the parser will the start reading from this buffer and progressively
2070 fetch information from the resource, calling the read() function of the
2071 handler until the resource is exhausted</li>
2072 <li>if an encoding change is detected it will be installed on the input
2073 buffer, providing buffering and efficient use of the conversion
2074 routines</li>
2075 <li>once the parser has finished, the close() function of the handler is
2076 called once and the Input buffer and associed resources are
2077 deallocated.</li>
2078</ol>
2079
2080<p>The user defined callbacks are checked first to allow overriding of the
2081default libxml I/O routines.</p>
2082
2083<h3><a name="basic">The basic buffer type</a></h3>
2084
2085<p>All the buffer manipulation handling is done using the
2086<code>xmlBuffer</code> type define in <code><a
2087href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
2088resizable memory buffer. The buffer allocation strategy can be selected to be
2089either best-fit or use an exponential doubling one (CPU vs. memory use
2090tradeoff). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
2091<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
2092system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
2093of functions allows to manipulate buffers with names starting with the
2094<code>xmlBuffer...</code> prefix.</p>
2095
2096<h3><a name="Input">Input I/O handlers</a></h3>
2097
2098<p>An Input I/O handler is a simple structure
2099<code>xmlParserInputBuffer</code> containing a context associated to the
2100resource (file descriptor, or pointer to a protocol handler), the read() and
2101close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
2102encoding handler are also present to support charset conversion when
2103needed.</p>
2104
2105<h3><a name="Output">Output I/O handlers</a></h3>
2106
2107<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
2108Input one except the callbacks are write() and close().</p>
2109
2110<h3><a name="entities">The entities loader</a></h3>
2111
2112<p>The entity loader resolves requests for new entities and create inputs for
2113the parser. Creating an input from a filename or an URI string is done
2114through the xmlNewInputFromFile() routine. The default entity loader do not
2115handle the PUBLIC identifier associated with an entity (if any). So it just
2116calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
2117XML).</p>
2118
2119<p>If you want to hook up a catalog mechanism then you simply need to
2120override the default entity loader, here is an example:</p>
2121<pre>#include &lt;libxml/xmlIO.h&gt;
2122
2123xmlExternalEntityLoader defaultLoader = NULL;
2124
2125xmlParserInputPtr
2126xmlMyExternalEntityLoader(const char *URL, const char *ID,
2127 xmlParserCtxtPtr ctxt) {
2128 xmlParserInputPtr ret;
2129 const char *fileID = NULL;
2130 /* lookup for the fileID depending on ID */
2131
2132 ret = xmlNewInputFromFile(ctxt, fileID);
2133 if (ret != NULL)
2134 return(ret);
2135 if (defaultLoader != NULL)
2136 ret = defaultLoader(URL, ID, ctxt);
2137 return(ret);
2138}
2139
2140int main(..) {
2141 ...
2142
2143 /*
2144 * Install our own entity loader
2145 */
2146 defaultLoader = xmlGetExternalEntityLoader();
2147 xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
2148
2149 ...
2150}</pre>
2151
2152<h3><a name="Example2">Example of customized I/O</a></h3>
2153
2154<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
2155real use case</a>, xmlDocDump() closes the FILE * passed by the application
2156and this was a problem. The <a
2157href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
2158new output handler with the closing call deactivated:</p>
2159<ol>
2160 <li>First define a new I/O ouput allocator where the output don't close the
2161 file:
2162 <pre>xmlOutputBufferPtr
2163xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
2164    xmlOutputBufferPtr ret;
2165    
2166    if (xmlOutputCallbackInitialized == 0)
2167        xmlRegisterDefaultOutputCallbacks();
2168
2169    if (file == NULL) return(NULL);
2170    ret = xmlAllocOutputBuffer(encoder);
2171    if (ret != NULL) {
2172        ret-&gt;context = file;
2173        ret-&gt;writecallback = xmlFileWrite;
2174        ret-&gt;closecallback = NULL; /* No close callback */
2175    }
2176    return(ret); <br>
2177
2178
2179
Daniel Veillard9c466822001-10-25 12:03:39 +0000[diff] [blame]2180
2181
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]2182
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]2183
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]2184
Daniel Veillarded421aa2001-11-04 21:22:45 +0000[diff] [blame]2185
Daniel Veillard43d3f612001-11-10 11:57:23 +0000[diff] [blame]2186
Daniel Veillarda4871052001-11-26 13:19:48 +0000[diff] [blame]2187
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]2188
Daniel Veillardef90ba72001-12-07 14:24:22 +0000[diff] [blame]2189
Daniel Veillard9ae4b7a2001-12-13 14:24:09 +0000[diff] [blame]2190
Daniel Veillard845cce42002-01-09 11:51:37 +0000[diff] [blame]2191
Daniel Veillard744683d2002-01-14 17:30:20 +0000[diff] [blame]2192
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]2193
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame^]2194
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2195} </pre>
2196 </li>
2197 <li>And then use it to save the document:
2198 <pre>FILE *f;
2199xmlOutputBufferPtr output;
2200xmlDocPtr doc;
2201int res;
2202
2203f = ...
2204doc = ....
2205
2206output = xmlOutputBufferCreateOwn(f, NULL);
2207res = xmlSaveFileTo(output, doc, NULL);
2208 </pre>
2209 </li>
2210</ol>
2211
2212<h2><a name="Catalog">Catalog support</a></h2>
2213
2214<p>Table of Content:</p>
2215<ol>
2216 <li><a href="General2">General overview</a></li>
2217 <li><a href="#definition">The definition</a></li>
2218 <li><a href="#Simple">Using catalogs</a></li>
2219 <li><a href="#Some">Some examples</a></li>
2220 <li><a href="#reference">How to tune catalog usage</a></li>
2221 <li><a href="#validate">How to debug catalog processing</a></li>
2222 <li><a href="#Declaring">How to create and maintain catalogs</a></li>
2223 <li><a href="#implemento">The implementor corner quick review of the
2224 API</a></li>
2225 <li><a href="#Other">Other resources</a></li>
2226</ol>
2227
2228<h3><a name="General2">General overview</a></h3>
2229
2230<p>What is a catalog? Basically it's a lookup mechanism used when an entity
2231(a file or a remote resource) references another entity. The catalog lookup
2232is inserted between the moment the reference is recognized by the software
2233(XML parser, stylesheet processing, or even images referenced for inclusion
2234in a rendering) and the time where loading that resource is actually
2235started.</p>
2236
2237<p>It is basically used for 3 things:</p>
2238<ul>
2239 <li>mapping from "logical" names, the public identifiers and a more
2240 concrete name usable for download (and URI). For example it can associate
2241 the logical name
2242 <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
2243 <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
2244 downloaded</p>
2245 <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
2246 </li>
2247 <li>remapping from a given URL to another one, like an HTTP indirection
2248 saying that
2249 <p>"http://www.oasis-open.org/committes/tr.xsl"</p>
2250 <p>should really be looked at</p>
2251 <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
2252 </li>
2253 <li>providing a local cache mechanism allowing to load the entities
2254 associated to public identifiers or remote resources, this is a really
2255 important feature for any significant deployment of XML or SGML since it
2256 allows to avoid the aleas and delays associated to fetching remote
2257 resources.</li>
2258</ul>
2259
2260<h3><a name="definition">The definitions</a></h3>
2261
2262<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
2263<ul>
2264 <li>the older SGML catalogs, the official spec is SGML Open Technical
2265 Resolution TR9401:1997, but is better understood by reading <a
2266 href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
2267 James Clark. This is relatively old and not the preferred mode of
2268 operation of libxml.</li>
2269 <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
2270 Catalogs</a>
2271 is far more flexible, more recent, uses an XML syntax and should scale
2272 quite better. This is the default option of libxml.</li>
2273</ul>
2274
2275<p></p>
2276
2277<h3><a name="Simple">Using catalog</a></h3>
2278
2279<p>In a normal environment libxml will by default check the presence of a
2280catalog in /etc/xml/catalog, and assuming it has been correctly populated,
2281the processing is completely transparent to the document user. To take a
2282concrete example, suppose you are authoring a DocBook document, this one
2283starts with the following DOCTYPE definition:</p>
2284<pre>&lt;?xml version='1.0'?&gt;
2285&lt;!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
2286 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"&gt;</pre>
2287
2288<p>When validating the document with libxml, the catalog will be
2289automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
2290DocBk XML V3.1.4//EN" and the system identifier
2291"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
2292been installed on your system and the catalogs actually point to them, libxml
2293will fetch them from the local disk.</p>
2294
2295<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
2296DOCTYPE example it's a really old version, but is fine as an example.</p>
2297
2298<p>Libxml will check the catalog each time that it is requested to load an
2299entity, this includes DTD, external parsed entities, stylesheets, etc ... If
2300your system is correctly configured all the authoring phase and processing
2301should use only local files, even if your document stays portable because it
2302uses the canonical public and system ID, referencing the remote document.</p>
2303
2304<h3><a name="Some">Some examples:</a></h3>
2305
2306<p>Here is a couple of fragments from XML Catalogs used in libxml early
2307regression tests in <code>test/catalogs</code> :</p>
2308<pre>&lt;?xml version="1.0"?&gt;
2309&lt;!DOCTYPE catalog PUBLIC
2310 "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2311 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2312&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2313 &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2314 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2315...</pre>
2316
2317<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
2318written in XML, there is a specific namespace for catalog elements
2319"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
2320catalog is a <code>public</code> mapping it allows to associate a Public
2321Identifier with an URI.</p>
2322<pre>...
2323 &lt;rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2324 rewritePrefix="file:///usr/share/xml/docbook/"/&gt;
2325...</pre>
2326
2327<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
2328any URI starting with a given prefix should be looked at another URI
2329constructed by replacing the prefix with an new one. In effect this acts like
2330a cache system for a full area of the Web. In practice it is extremely useful
2331with a file prefix if you have installed a copy of those resources on your
2332local system.</p>
2333<pre>...
2334&lt;delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
2335 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2336&lt;delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
2337 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2338&lt;delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
2339 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2340&lt;delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
2341 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2342&lt;delegateURI uriStartString="http://www.oasis-open.org/docbook/"
2343 catalog="file:///usr/share/xml/docbook.xml"/&gt;
2344...</pre>
2345
2346<p>Delegation is the core features which allows to build a tree of catalogs,
2347easier to maintain than a single catalog, based on Public Identifier, System
2348Identifier or URI prefixes it instructs the catalog software to look up
2349entries in another resource. This feature allow to build hierarchies of
2350catalogs, the set of entries presented should be sufficient to redirect the
2351resolution of all DocBook references to the specific catalog in
2352<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
2353references for DocBook 4.2.1 to a specific catalog installed at the same time
2354as the DocBook resources on the local machine.</p>
2355
2356<h3><a name="reference">How to tune catalog usage:</a></h3>
2357
2358<p>The user can change the default catalog behaviour by redirecting queries
2359to its own set of catalogs, this can be done by setting the
2360<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
2361empty one should deactivate loading the default <code>/etc/xml/catalog</code>
2362default catalog</p>
2363
2364<h3><a name="validate">How to debug catalog processing:</a></h3>
2365
2366<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
2367make libxml output debugging informations for each catalog operations, for
2368example:</p>
2369<pre>orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2370warning: failed to load external entity "title.xml"
2371orchis:~/XML -&gt; export XML_DEBUG_CATALOG=
2372orchis:~/XML -&gt; xmllint --memory --noout test/ent2
2373Failed to parse catalog /etc/xml/catalog
2374Failed to parse catalog /etc/xml/catalog
2375warning: failed to load external entity "title.xml"
2376Catalogs cleanup
2377orchis:~/XML -&gt; </pre>
2378
2379<p>The test/ent2 references an entity, running the parser from memory makes
2380the base URI unavailable and the the "title.xml" entity cannot be loaded.
2381Setting up the debug environment variable allows to detect that an attempt is
2382made to load the <code>/etc/xml/catalog</code> but since it's not present the
2383resolution fails.</p>
2384
2385<p>But the most advanced way to debug XML catalog processing is to use the
2386<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
2387catalogs and make resolution queries to see what is going on. This is also
2388used for the regression tests:</p>
2389<pre>orchis:~/XML -&gt; ./xmlcatalog test/catalogs/docbook.xml \
2390 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2391http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2392orchis:~/XML -&gt; </pre>
2393
2394<p>For debugging what is going on, adding one -v flags increase the verbosity
2395level to indicate the processing done (adding a second flag also indicate
2396what elements are recognized at parsing):</p>
2397<pre>orchis:~/XML -&gt; ./xmlcatalog -v test/catalogs/docbook.xml \
2398 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2399Parsing catalog test/catalogs/docbook.xml's content
2400Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
2401http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2402Catalogs cleanup
2403orchis:~/XML -&gt; </pre>
2404
2405<p>A shell interface is also available to debug and process multiple queries
2406(and for regression tests):</p>
2407<pre>orchis:~/XML -&gt; ./xmlcatalog -shell test/catalogs/docbook.xml \
2408 "-//OASIS//DTD DocBook XML V4.1.2//EN"
2409&gt; help
2410Commands available:
2411public PublicID: make a PUBLIC identifier lookup
2412system SystemID: make a SYSTEM identifier lookup
2413resolve PublicID SystemID: do a full resolver lookup
2414add 'type' 'orig' 'replace' : add an entry
2415del 'values' : remove values
2416dump: print the current catalog state
2417debug: increase the verbosity level
2418quiet: decrease the verbosity level
2419exit: quit the shell
2420&gt; public "-//OASIS//DTD DocBook XML V4.1.2//EN"
2421http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
2422&gt; quit
2423orchis:~/XML -&gt; </pre>
2424
2425<p>This should be sufficient for most debugging purpose, this was actually
2426used heavily to debug the XML Catalog implementation itself.</p>
2427
2428<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
2429
2430<p>Basically XML Catalogs are XML files, you can either use XML tools to
2431manage them or use <strong>xmlcatalog</strong> for this. The basic step is
2432to create a catalog the -create option provide this facility:</p>
2433<pre>orchis:~/XML -&gt; ./xmlcatalog --create tst.xml
2434&lt;?xml version="1.0"?&gt;
2435&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2436 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2437&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2438orchis:~/XML -&gt; </pre>
2439
2440<p>By default xmlcatalog does not overwrite the original catalog and save the
2441result on the standard output, this can be overridden using the -noout
2442option. The <code>-add</code> command allows to add entries in the
2443catalog:</p>
2444<pre>orchis:~/XML -&gt; ./xmlcatalog --noout --create --add "public" \
2445 "-//OASIS//DTD DocBook XML V4.1.2//EN" \
2446 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
2447orchis:~/XML -&gt; cat tst.xml
2448&lt;?xml version="1.0"?&gt;
2449&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
2450 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2451&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
2452&lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
2453 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
2454&lt;/catalog&gt;
2455orchis:~/XML -&gt; </pre>
2456
2457<p>The <code>-add</code> option will always take 3 parameters even if some of
2458the XML Catalog constructs (like nextCatalog) will have only a single
2459argument, just pass a third empty string, it will be ignored.</p>
2460
2461<p>Similarly the <code>-del</code> option remove matching entries from the
2462catalog:</p>
2463<pre>orchis:~/XML -&gt; ./xmlcatalog --del \
2464 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
2465&lt;?xml version="1.0"?&gt;
2466&lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
2467 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
2468&lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
2469orchis:~/XML -&gt; </pre>
2470
2471<p>The catalog is now empty. Note that the matching of <code>-del</code> is
2472exact and would have worked in a similar fashion with the Public ID
2473string.</p>
2474
2475<p>This is rudimentary but should be sufficient to manage a not too complex
2476catalog tree of resources.</p>
2477
2478<h3><a name="implemento">The implementor corner quick review of the
2479API:</a></h3>
2480
2481<p>First, and like for every other module of libxml, there is an
2482automatically generated <a href="html/libxml-catalog.html">API page for
2483catalog support</a>.</p>
2484
2485<p>The header for the catalog interfaces should be included as:</p>
2486<pre>#include &lt;libxml/catalog.h&gt;</pre>
2487
2488<p>The API is voluntarily kept very simple. First it is not obvious that
2489applications really need access to it since it is the default behaviour of
2490libxml (Note: it is possible to completely override libxml default catalog by
2491using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
2492plug an application specific resolver).</p>
2493
2494<p>Basically libxml support 2 catalog lists:</p>
2495<ul>
2496 <li>the default one, global shared by all the application</li>
2497 <li>a per-document catalog, this one is built if the document uses the
2498 <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
2499 associated to the parser context and destroyed when the parsing context
2500 is destroyed.</li>
2501</ul>
2502
2503<p>the document one will be used first if it exists.</p>
2504
2505<h4>Initialization routines:</h4>
2506
2507<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
2508used at startup to initialize the catalog, if the catalog should be
2509initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs()
2510should be called before xmlInitializeCatalog() which would otherwise do a
2511default initialization first.</p>
2512
2513<p>The xmlCatalogAddLocal() call is used by the parser to grow the document
2514own catalog list if needed.</p>
2515
2516<h4>Preferences setup:</h4>
2517
2518<p>The XML Catalog spec requires the possibility to select default
2519preferences between public and system delegation,
2520xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
2521xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should
2522be forbidden, allowed for global catalog, for document catalog or both, the
2523default is to allow both.</p>
2524
2525<p>And of course xmlCatalogSetDebug() allows to generate debug messages
2526(through the xmlGenericError() mechanism).</p>
2527
2528<h4>Querying routines:</h4>
2529
2530<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
2531and xmlCatalogResolveURI() are relatively explicit if you read the XML
2532Catalog specification they correspond to section 7 algorithms, they should
2533also work if you have loaded an SGML catalog with a simplified semantic.</p>
2534
2535<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
2536operate on the document catalog list</p>
2537
2538<h4>Cleanup and Miscellaneous:</h4>
2539
2540<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
2541the per-document equivalent.</p>
2542
2543<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
2544first catalog in the global list, and xmlCatalogDump() allows to dump a
2545catalog state, those routines are primarily designed for xmlcatalog, I'm not
2546sure that exposing more complex interfaces (like navigation ones) would be
2547really useful.</p>
2548
2549<p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
2550it's similar as xmlParseFile() except it bypass all catalog lookups, it's
2551provided because this functionality may be useful for client tools.</p>
2552
2553<h4>threaded environments:</h4>
2554
2555<p>Since the catalog tree is built progressively, some care has been taken to
2556try to avoid troubles in multithreaded environments. The code is now thread
2557safe assuming that the libxml library has been compiled with threads
2558support.</p>
2559
2560<p></p>
2561
2562<h3><a name="Other">Other resources</a></h3>
2563
2564<p>The XML Catalog specification is relatively recent so there isn't much
2565literature to point at:</p>
2566<ul>
2567 <li>You can find an good rant from Norm Walsh about <a
2568 href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
2569 need for catalogs</a>, it provides a lot of context informations even if
2570 I don't agree with everything presented.</li>
2571 <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
2572 catalog proposal</a> from John Cowan</li>
2573 <li>The <a href="http://www.rddl.org/">Resource Directory Description
2574 Language</a> (RDDL) another catalog system but more oriented toward
2575 providing metadata for XML namespaces.</li>
2576 <li>the page from the OASIS Technical <a
2577 href="http://www.oasis-open.org/committees/entity/">Committee on Entity
2578 Resolution</a> who maintains XML Catalog, you will find pointers to the
2579 specification update, some background and pointers to others tools
2580 providing XML Catalog support</li>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]2581 <li>Here is a <a href="buildDocBookCatalog">shell script</a> to generate
2582 XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
2583 directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
2584 the resources found on the system. Otherwise it will just create
2585 ~/xmlcatalog and ~/dbkxmlcatalog and doing:
Daniel Veillardc575b992002-02-08 13:28:40 +0000[diff] [blame^]2586 <p><code>export XMLCATALOG=$HOME/xmlcatalog</code></p>
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]2587 <p>should allow to process DocBook documentations without requiring
2588 network accesses for the DTd or stylesheets</p>
2589 </li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2590 <li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a
Daniel Veillard35e937a2002-01-19 22:21:54 +0000[diff] [blame]2591 small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
2592 to work fine for me too</li>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2593 <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
2594 manual page</a></li>
2595</ul>
2596
2597<p>If you have suggestions for corrections or additions, simply contact
2598me:</p>
2599
2600<h2><a name="library">The parser interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2601
2602<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2603using the XML library from the C language. It is not intended to be
2604extensive. I hope the automatically generated documents will provide the
2605completeness required, but as a separate set of documents. The interfaces of
2606the XML library are by principle low level, there is nearly zero abstraction.
2607Those interested in a higher level API should <a href="#DOM">look at
2608DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]2609
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]2610<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
2611separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2612interfaces</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]2613
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2614<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2615
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2616<p>Usually, the first thing to do is to read an XML input. The parser accepts
2617documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2618defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2619<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2620 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2621 <dd><p>Parse a null-terminated string containing the document.</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>
2624<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2625 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2626 <dd><p>Parse an XML document contained in a (possibly compressed)
2627 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2628 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2629</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2630
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2631<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]2632failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2633
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2634<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2635
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2636<p>In order for the application to keep the control when the document is
2637being fetched (which is common for GUI based programs) libxml provides a push
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2638interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2639<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
2640 void *user_data,
2641 const char *chunk,
2642 int size,
2643 const char *filename);
2644int xmlParseChunk (xmlParserCtxtPtr ctxt,
2645 const char *chunk,
2646 int size,
2647 int terminate);</pre>
2648
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2649<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2650<pre> FILE *f;
2651
2652 f = fopen(filename, "r");
2653 if (f != NULL) {
2654 int res, size = 1024;
2655 char chars[1024];
2656 xmlParserCtxtPtr ctxt;
2657
2658 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2659 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2660 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
2661 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2662 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2663 xmlParseChunk(ctxt, chars, res, 0);
2664 }
2665 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2666 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2667 xmlFreeParserCtxt(ctxt);
2668 }
2669 }</pre>
2670
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2671<p>The HTML parser embedded into libxml also has a push interface; the
2672functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2673
2674<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
2675
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2676<p>The tree-building interface makes the parser memory-hungry, first loading
2677the document in memory and then building the tree itself. Reading a document
2678without building the tree is possible using the SAX interfaces (see SAX.h and
2679<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]2680Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2681limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2682<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]2683
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2684<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2685
2686<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]2687there is a set of functions dedicated to building new elements. (These are
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2688also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of
2689code that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2690<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]2691 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2692 xmlNodePtr tree, subtree;
2693
2694 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2695 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
2696 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
2697 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
2698 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2699 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2700 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2701 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
2702 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
2703 subtree = xmlNewChild(tree, NULL, "image", NULL);
2704 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2705
2706<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2707
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2708<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2709
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]2710<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2711code has access to the internal structure of all the elements of the tree.
2712The names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]2713<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2714<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]2715example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2716<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2717
2718<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2719<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2720
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2721<p>points to the text node containing the chapter title "The Linux
2722adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2723
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]2724<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]2725present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2726to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]2727<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]2728
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2729<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2730
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2731<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]2732is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2733<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2734 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
2735 xmlChar *value);</code></dt>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2736 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
2737 The value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2738 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2739</dl>
2740<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2741 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2742 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]2743 <dd><p>This function returns a pointer to new copy of the property
2744 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2745 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2746</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2747
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2748<p>Two functions are provided for reading and writing the text associated
2749with elements:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2750<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2751 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2752 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2753 <dd><p>This function takes an "external" string and converts it to one
2754 text node or possibly to a list of entity and text nodes. All
2755 non-predefined entity references like &amp;Gnome; will be stored
2756 internally as entity nodes, hence the result of the function may not be
2757 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2758 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2759</dl>
2760<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2761 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2762 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2763 <dd><p>This function is the inverse of
2764 <code>xmlStringGetNodeList()</code>. It generates a new string
2765 containing the content of the text and entity nodes. Note the extra
2766 argument inLine. If this argument is set to 1, the function will expand
2767 entity references. For example, instead of returning the &amp;Gnome;
2768 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2769 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2770 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2771</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2772
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2773<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2774
2775<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2776<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]2777 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2778 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2779 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2780 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2781</dl>
2782<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2783 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2784 <dd><p>Dumps a document to an open file descriptor.</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>
2787<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2788 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2789 <dd><p>Saves the document to a file. In this case, the compression
2790 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2791 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2792</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]2793
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2794<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2795
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2796<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2797accesses. The level of compression on saves can be turned on either globally
2798or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2799<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2800 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2801 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2802 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2803</dl>
2804<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2805 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2806 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2807 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2808</dl>
2809<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2810 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2811 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2812 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2813</dl>
2814<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2815 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2816 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2817 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]2818</dl>
2819
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2820<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2821
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2822<p>Entities in principle are similar to simple C macros. An entity defines an
2823abbreviation for a given string that you can reuse many times throughout the
2824content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2825may occur frequently within a document, or to confine the change needed to a
2826document to a restricted area in the internal subset of the document (at the
2827beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2828<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]28292 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]28303 &lt;!ENTITY xml "Extensible Markup Language"&gt;
28314 ]&gt;
28325 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]28336 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]28347 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2835
2836<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]2837its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2838are 5 predefined entities in libxml allowing you to escape charaters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2839predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2840<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2841for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2842<strong>&amp;quot;</strong> for the character '"', and
2843<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2844
2845<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]2846substitute an entity's content so that you can see the replacement text in
2847your application. Or you may prefer to keep entity references as such in the
2848content to be able to save the document back without losing this usually
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2849precious information (if the user went through the pain of explicitly
2850defining entities, he may have a a rather negative attitude if you blindly
2851susbtitute them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]2852href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2853function allows you to check and change the behaviour, which is to not
2854substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2855
2856<p>Here is the DOM tree built by libxml for the previous document in the
2857default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2858<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2859DOCUMENT
2860version=1.0
2861 ELEMENT EXAMPLE
2862 TEXT
2863 content=
2864 ENTITY_REF
2865 INTERNAL_GENERAL_ENTITY xml
2866 content=Extensible Markup Language
2867 TEXT
2868 content=</pre>
2869
2870<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2871<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2872DOCUMENT
2873version=1.0
2874 ELEMENT EXAMPLE
2875 TEXT
2876 content= Extensible Markup Language</pre>
2877
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2878<p>So, entities or no entities? Basically, it depends on your use case. I
2879suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2880entities in your XML document or data if you are not willing to handle the
2881entity references elements in the DOM tree.</p>
2882
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2883<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2884entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2885transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2886reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2887finding them in the input).</p>
2888
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]2889<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2890on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]2891non-predefined entities in your documents, then the learning cuvre to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2892then 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]2893strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]2894deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]2895
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]2896<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2897
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]2898<p>The libxml library implements <a
2899href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
2900recognizing namespace contructs in the input, and does namespace lookup
2901automatically when building the DOM tree. A namespace declaration is
2902associated with an in-memory structure and all elements or attributes within
2903that namespace point to it. Hence testing the namespace is a simple and fast
2904equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2905
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2906<p>I suggest that people using libxml use a namespace, and declare it in the
2907root element of their document as the default namespace. Then they don't need
2908to 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]2909refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2910the size of the XML output significantly, but significantly increases its
2911value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2912<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
2913 &lt;elem1&gt;...&lt;/elem1&gt;
2914 &lt;elem2&gt;...&lt;/elem2&gt;
2915&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2916
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]2917<p>The namespace value has to be an absolute URL, but the URL doesn't have to
2918point to any existing resource on the Web. It will bind all the element and
2919atributes with that URL. I suggest to use an URL within a domain you control,
2920and that the URL should contain some kind of version information if possible.
2921For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a good
2922namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]2923
2924<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]2925version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2926and if the version information don't match something you know, warn the user
2927and 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]2928namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2929same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]2930associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2931just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]2932<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2933prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2934
2935<p>@@Interfaces@@</p>
2936
2937<p>@@Examples@@</p>
2938
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2939<p>Usually people object to using namespaces together with validity checking.
2940I will try to make sure that using namespaces won't break validity checking,
2941so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]2942suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2943<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]2944flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]2945from multiple DTDs will certainly break current validation schemes. I will
2946try to provide ways to do this, but this may not be portable or
2947standardized.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2948
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2949<h2><a name="Upgrading">Upgrading 1.x code</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2950
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2951<p>Incompatible changes:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2952
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2953<p>Version 2 of libxml is the first version introducing serious backward
2954incompatible changes. The main goals were:</p>
2955<ul>
2956 <li>a general cleanup. A number of mistakes inherited from the very early
2957 versions couldn't be changed due to compatibility constraints. Example
2958 the "childs" element in the nodes.</li>
2959 <li>Uniformization of the various nodes, at least for their header and link
2960 parts (doc, parent, children, prev, next), the goal is a simpler
2961 programming model and simplifying the task of the DOM implementors.</li>
2962 <li>better conformances to the XML specification, for example version 1.x
2963 had an heuristic to try to detect ignorable white spaces. As a result the
2964 SAX event generated were ignorableWhitespace() while the spec requires
2965 character() in that case. This also mean that a number of DOM node
2966 containing blank text may populate the DOM tree which were not present
2967 before.</li>
2968</ul>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2969
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2970<h3>How to fix libxml-1.x code:</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]2971
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]2972<p>So client code of libxml designed to run with version 1.x may have to be
2973changed to compile against version 2.x of libxml. Here is a list of changes
2974that I have collected, they may not be sufficient, so in case you find other
2975change which are required, <a href="mailto:Daniel.Ïeillardw3.org">drop me a
2976mail</a>:</p>
2977<ol>
2978 <li>The package name have changed from libxml to libxml2, the library name
2979 is now -lxml2 . There is a new xml2-config script which should be used to
2980 select the right parameters libxml2</li>
2981 <li>Node <strong>childs</strong> field has been renamed
2982 <strong>children</strong> so s/childs/children/g should be applied
2983 (probablility of having "childs" anywere else is close to 0+</li>
2984 <li>The document don't have anymore a <strong>root</strong> element it has
2985 been replaced by <strong>children</strong> and usually you will get a
2986 list of element here. For example a Dtd element for the internal subset
2987 and it's declaration may be found in that list, as well as processing
2988 instructions or comments found before or after the document root element.
2989 Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
2990 a document. Alternatively if you are sure to not reference Dtds nor have
2991 PIs or comments before or after the root element
2992 s/-&gt;root/-&gt;children/g will probably do it.</li>
2993 <li>The white space issue, this one is more complex, unless special case of
2994 validating parsing, the line breaks and spaces usually used for indenting
2995 and formatting the document content becomes significant. So they are
2996 reported by SAX and if your using the DOM tree, corresponding nodes are
2997 generated. Too approach can be taken:
2998 <ol>
2999 <li>lazy one, use the compatibility call
3000 <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
3001 relying on a special (and possibly broken) set of heuristics of
3002 libxml to detect ignorable blanks. Don't complain if it breaks or
3003 make your application not 100% clean w.r.t. to it's input.</li>
3004 <li>the Right Way: change you code to accept possibly unsignificant
3005 blanks characters, or have your tree populated with weird blank text
3006 nodes. You can spot them using the comodity function
3007 <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
3008 nodes.</li>
3009 </ol>
3010 <p>Note also that with the new default the output functions don't add any
3011 extra indentation when saving a tree in order to be able to round trip
3012 (read and save) without inflating the document with extra formatting
3013 chars.</p>
3014 </li>
3015 <li>The include path has changed to $prefix/libxml/ and the includes
3016 themselves uses this new prefix in includes instructions... If you are
3017 using (as expected) the
3018 <pre>xml2-config --cflags</pre>
3019 <p>output to generate you compile commands this will probably work out of
3020 the box</p>
3021 </li>
3022 <li>xmlDetectCharEncoding takes an extra argument indicating the lenght in
3023 byte of the head of the document available for character detection.</li>
3024</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3025
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3026<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3027
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3028<p>Two new version of libxml (1.8.11) and libxml2 (2.3.4) have been released
3029to allow smoth upgrade of existing libxml v1code while retaining
3030compatibility. They offers the following:</p>
3031<ol>
3032 <li>similar include naming, one should use
3033 <strong>#include&lt;libxml/...&gt;</strong> in both cases.</li>
3034 <li>similar identifiers defined via macros for the child and root fields:
3035 respectively <strong>xmlChildrenNode</strong> and
3036 <strong>xmlRootNode</strong></li>
3037 <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
3038 inserted once in the client code</li>
3039</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3040
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3041<p>So the roadmap to upgrade your existing libxml applications is the
3042following:</p>
3043<ol>
3044 <li>install the libxml-1.8.8 (and libxml-devel-1.8.8) packages</li>
3045 <li>find all occurences where the xmlDoc <strong>root</strong> field is
3046 used and change it to <strong>xmlRootNode</strong></li>
3047 <li>similary find all occurences where the xmlNode <strong>childs</strong>
3048 field is used and change it to <strong>xmlChildrenNode</strong></li>
3049 <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
3050 <strong>main()</strong> or in the library init entry point</li>
3051 <li>Recompile, check compatibility, it should still work</li>
3052 <li>Change your configure script to look first for xml2-config and fallback
3053 using xml-config . Use the --cflags and --libs ouptut of the command as
3054 the Include and Linking parameters needed to use libxml.</li>
3055 <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and
3056 libxml-devel-1.8.y can be kept simultaneously)</li>
3057 <li>remove your config.cache, relaunch your configuration mechanism, and
3058 recompile, if steps 2 and 3 were done right it should compile as-is</li>
3059 <li>Test that your application is still running correctly, if not this may
3060 be due to extra empty nodes due to formating spaces being kept in libxml2
3061 contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
3062 code before calling the parser (next to
3063 <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
3064</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3065
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3066<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]3067
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3068<p>Let me put some emphasis on the fact that there is far more changes from
3069libxml 1.x to 2.x than the ones you may have to patch for. The overall code
3070has been considerably cleaned up and the conformance to the XML specification
3071has been drastically improved too. Don't take those changes as an excuse to
3072not upgrade, it may cost a lot on the long term ...</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3073
Daniel Veillard52dcab32001-10-30 12:51:17 +0000[diff] [blame]3074<h2><a name="Thread">Thread safety</a></h2>
3075
3076<p>Starting with 2.4.7, libxml makes provisions to ensure that concurent
3077threads can safely work in parallel parsing different documents. There is
3078however a couple of things to do to ensure it:</p>
3079<ul>
3080 <li>configure the library accordingly using the --with-threads options</li>
3081 <li>call xmlInitParser() in the "main" thread before using any of the
3082 libxml API (except possibly selecting a different memory allocator)</li>
3083</ul>
3084
3085<p>Note that the thread safety cannot be ensured for multiple threads sharing
3086the same document, the locking must be done at the application level, libxml
3087exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
3088The parts of the library checked for thread safety are:</p>
3089<ul>
3090 <li>concurrent loading</li>
3091 <li>file access resolution</li>
3092 <li>catalog access</li>
3093 <li>catalog building</li>
3094 <li>entities lookup/accesses</li>
3095 <li>validation</li>
3096 <li>global variables per-thread override</li>
3097 <li>memory handling</li>
3098</ul>
3099
3100<p>XPath is supposed to be thread safe now, but this wasn't tested
3101seriously.</p>
3102
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3103<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3104
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3105<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
3106Object Model</em>; this is an API for accessing XML or HTML structured
3107documents. Native support for DOM in Gnome is on the way (module gnome-dom),
3108and will be based on gnome-xml. This will be a far cleaner interface to
3109manipulate XML files within Gnome since it won't expose the internal
3110structure.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3111
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3112<p>The current DOM implementation on top of libxml is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame]3113href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
3114is a full DOM interface, thanks to Paolo Casarini, check the <a
3115href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
3116informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3117
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]3118<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3119
3120<p>Here is a real size example, where the actual content of the application
3121data 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]3122a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3123storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
3124base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3125<pre>&lt;?xml version="1.0"?&gt;
3126&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
3127 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3128
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3129 &lt;gjob:Job&gt;
3130 &lt;gjob:Project ID="3"/&gt;
3131 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
3132 &lt;gjob:Category&gt;Development&lt;/gjob:Category&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:Update&gt;
3135 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
3136 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
3137 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
3138 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3139
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3140 &lt;gjob:Developers&gt;
3141 &lt;gjob:Developer&gt;
3142 &lt;/gjob:Developer&gt;
3143 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3144
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3145 &lt;gjob:Contact&gt;
3146 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
3147 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
3148 &lt;gjob:Company&gt;
3149 &lt;/gjob:Company&gt;
3150 &lt;gjob:Organisation&gt;
3151 &lt;/gjob:Organisation&gt;
3152 &lt;gjob:Webpage&gt;
3153 &lt;/gjob:Webpage&gt;
3154 &lt;gjob:Snailmail&gt;
3155 &lt;/gjob:Snailmail&gt;
3156 &lt;gjob:Phone&gt;
3157 &lt;/gjob:Phone&gt;
3158 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3159
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3160 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3161 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3162 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3163
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3164 &lt;gjob:Skills&gt;
3165 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3166
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3167 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3168 A GNOME based system that will allow a superuser to configure
3169 compressed and uncompressed files and/or file systems to be backed
3170 up with a supported media in the system. This should be able to
3171 perform via find commands generating a list of files that are passed
3172 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
3173 or via operations performed on the filesystem itself. Email
3174 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3175 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3176
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3177 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3178
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3179 &lt;/gjob:Jobs&gt;
3180&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3181
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3182<p>While loading the XML file into an internal DOM tree is a matter of
3183calling only a couple of functions, browsing the tree to gather the ata and
3184generate the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3185
3186<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3187structure. For example, the ordering of the attributes is not significant,
3188the 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]3189depend on the order of the children of a given node, unless it really makes
3190things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3191<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3192 * A person record
3193 */
3194typedef struct person {
3195 char *name;
3196 char *email;
3197 char *company;
3198 char *organisation;
3199 char *smail;
3200 char *webPage;
3201 char *phone;
3202} person, *personPtr;
3203
3204/*
3205 * And the code needed to parse it
3206 */
3207personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3208 personPtr ret = NULL;
3209
3210DEBUG("parsePerson\n");
3211 /*
3212 * allocate the struct
3213 */
3214 ret = (personPtr) malloc(sizeof(person));
3215 if (ret == NULL) {
3216 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3217 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3218 }
3219 memset(ret, 0, sizeof(person));
3220
3221 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3222 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3223 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3224 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
3225 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3226 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
3227 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3228 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3229 }
3230
3231 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3232}</pre>
3233
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3234<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3235<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]3236 <li>Usually a recursive parsing style is the more convenient one: XML data
3237 is by nature subject to repetitive constructs and usually exibits highly
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3238 stuctured patterns.</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3239 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
3240 i.e. the pointer to the global XML document and the namespace reserved to
3241 the application. Document wide information are needed for example to
3242 decode entities and it's a good coding practice to define a namespace for
3243 your application set of data and test that the element and attributes
3244 you're analyzing actually pertains to your application space. This is
3245 done by a simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3246 <li>To retrieve text and attributes value, you can use the function
3247 <em>xmlNodeListGetString</em> to gather all the text and entity reference
3248 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3249</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3250
3251<p>Here is another piece of code used to parse another level of the
3252structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3253<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]3254/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3255 * a Description for a Job
3256 */
3257typedef struct job {
3258 char *projectID;
3259 char *application;
3260 char *category;
3261 personPtr contact;
3262 int nbDevelopers;
3263 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
3264} job, *jobPtr;
3265
3266/*
3267 * And the code needed to parse it
3268 */
3269jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
3270 jobPtr ret = NULL;
3271
3272DEBUG("parseJob\n");
3273 /*
3274 * allocate the struct
3275 */
3276 ret = (jobPtr) malloc(sizeof(job));
3277 if (ret == NULL) {
3278 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3279 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3280 }
3281 memset(ret, 0, sizeof(job));
3282
3283 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3284 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3285 while (cur != NULL) {
3286
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3287 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
3288 ret-&gt;projectID = xmlGetProp(cur, "ID");
3289 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3290 fprintf(stderr, "Project has no ID\n");
3291 }
3292 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]3293 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
3294 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3295 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
3296 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
3297 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
3298 ret-&gt;contact = parsePerson(doc, ns, cur);
3299 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3300 }
3301
3302 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3303}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]3304
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]3305<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]3306boring. Ultimately, it could be possble to write stubbers taking either C
3307data structure definitions, a set of XML examples or an XML DTD and produce
3308the code needed to import and export the content between C data and XML
3309storage. This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3310
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]3311<p>Feel free to use <a href="example/gjobread.c">the code for the full C
3312parsing example</a> as a template, it is also available with Makefile in the
3313Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]3314
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3315<h2><a name="Contributi">Contributions</a></h2>
3316<ul>
Daniel Veillardb8cfbd12001-10-25 10:53:28 +0000[diff] [blame]3317 <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
3318 patches, Gary Pennington worked on the validation API, threading support
3319 and Solaris port.</li>
3320 <li>John Fleck helps maintaining the documentation and man pages.</li>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]3321 <li><a href="mailto:ari@lusis.org">Ari Johnson</a>
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]3322 provides a C++ wrapper for libxml:<br>
Daniel Veillardc6271d22001-10-27 07:50:58 +0000[diff] [blame]3323 Website: <a
3324 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a><br>
3325 Download: <a
Daniel Veillard51095312001-10-28 18:51:57 +0000[diff] [blame]3326 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]3327 <li><a href="mailto:izlatkovic@daenet.de">Igor Zlatkovic</a>
3328 is now the maintainer of the Windows port, <a
Daniel Veillard95189532001-07-26 18:30:26 +0000[diff] [blame]3329 href="http://www.fh-frankfurt.de/~igor/projects/libxml/index.html">he
3330 provides binaries</a></li>
Daniel Veillardc9484202001-10-24 12:35:52 +0000[diff] [blame]3331 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a>
Daniel Veillarddb9dfd92001-11-26 17:25:02 +0000[diff] [blame]3332 provides <a href="http://garypennington.net/libxml2/">Solaris
Daniel Veillard0a702dc2001-10-19 14:50:57 +0000[diff] [blame]3333 binaries</a></li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]3334 <li><a
3335 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3336 Sergeant</a>
3337 developped <a href="http://axkit.org/download/">XML::LibXSLT</a>, a perl
3338 wrapper for libxml2/libxslt as part of the <a
3339 href="http://axkit.com/">AxKit XML application server</a></li>
3340 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a>
3341 and <a href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a
Daniel Veillardca989762001-06-23 17:39:29 +0000[diff] [blame]3342 href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]3343 documentation</li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3344 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a>
3345 provided <a href="http://xmlsoft.org/messages/0488.html">man
3346 pages</a></li>
Daniel Veillard5168dbf2001-07-07 00:18:23 +0000[diff] [blame]3347 <li>there is a module for <a
3348 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
3349 in OpenNSD/AOLServer</a></li>
Daniel Veillard3d6ae1c2001-08-15 13:12:39 +0000[diff] [blame]3350 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a>
3351 provides libxml/libxslt <a href="http://www.rexx.com/~dkuhlman">wrappers
3352 for Python</a></li>
Daniel Veillard1aadc442001-11-28 13:10:32 +0000[diff] [blame]3353 <li>Petr Kozelka provides <a
3354 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
3355 libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]3356</ul>
3357
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]3358<p></p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3359</body>
3360</html>