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blob: 6fa3583dd6eba53d6af810b180ab2c8c4b0cccfa [file] [log] [blame]
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1<html>
2<head>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]3 <title>The XML C library for Gnome</title>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]4 <meta name="GENERATOR" content="amaya V4.1">
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]5 <meta http-equiv="Content-Type" content="text/html">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]6</head>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]7
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]8<body bgcolor="#ffffff">
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]9<p><a href="http://www.gnome.org/"><img src="smallfootonly.gif"
10alt="Gnome Logo"></a><a href="http://www.w3.org/Status"><img src="w3c.png"
11alt="W3C Logo"></a></p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]12
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]13<h1 align="center">The XML C library for Gnome</h1>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]14
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]15<h2 style="text-align: center">libxml, a.k.a. gnome-xml</h2>
16
17<p></p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]18<ul>
19 <li><a href="#Introducti">Introduction</a></li>
20 <li><a href="#Documentat">Documentation</a></li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]21 <li><a href="#Reporting">Reporting bugs and getting help</a></li>
22 <li><a href="#help">how to help</a></li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]23 <li><a href="#Downloads">Downloads</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]24 <li><a href="#News">News</a></li>
25 <li><a href="#XML">XML</a></li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]26 <li><a href="#XSLT">XSLT</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]27 <li><a href="#tree">The tree output</a></li>
28 <li><a href="#interface">The SAX interface</a></li>
29 <li><a href="#library">The XML library interfaces</a>
30 <ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]31 <li><a href="#Invoking">Invoking the parser: the pull way</a></li>
32 <li><a href="#Invoking">Invoking the parser: the push way</a></li>
33 <li><a href="#Invoking2">Invoking the parser: the SAX interface</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]34 <li><a href="#Building">Building a tree from scratch</a></li>
35 <li><a href="#Traversing">Traversing the tree</a></li>
36 <li><a href="#Modifying">Modifying the tree</a></li>
37 <li><a href="#Saving">Saving the tree</a></li>
38 <li><a href="#Compressio">Compression</a></li>
39 </ul>
40 </li>
41 <li><a href="#Entities">Entities or no entities</a></li>
42 <li><a href="#Namespaces">Namespaces</a></li>
43 <li><a href="#Validation">Validation</a></li>
44 <li><a href="#Principles">DOM principles</a></li>
45 <li><a href="#real">A real example</a></li>
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]46 <li><a href="#Contributi">Contributions</a></li>
47</ul>
48
49<p>Separate documents:</p>
50<ul>
51 <li><a href="upgrade.html">upgrade instructions for migrating to
52 libxml2</a></li>
53 <li><a href="encoding.html">libxml Internationalization support</a></li>
54 <li><a href="xmlio.html">libxml Input/Output interfaces</a></li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]55 <li><a href="xmlmem.html">libxml Memory interfaces</a></li>
Daniel Veillard300f7d62000-11-24 13:04:04 +0000[diff] [blame]56 <li><a href="xmldtd.html">a short introduction about DTDs and
57 libxml</a></li>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]58 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]59</ul>
60
61<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]62
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]63<p>This document describes libxml, the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]64href="http://www.w3.org/XML/">XML</a> C library developped for the <a
65href="http://www.gnome.org/">Gnome</a> project. <a
66href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
67structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]68
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]69<p>Here are some key points about libxml:</p>
70<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]71 <li>Libxml exports Push and Pull type parser interfaces for both XML and
72 HTML.</li>
73 <li>Libxml can do Dtd validation at parse time, using a parsed document
74 instance, or with an arbitrary Dtd.</li>
75 <li>Libxml now includes a nearly complete <a
76 href="http://www.w3.org/TR/xpath">XPath</a> and <a
Daniel Veillard0c069222000-10-21 09:25:52 +0000[diff] [blame]77 href="http://www.w3.org/TR/xptr">XPointer</a> implementations.</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]78 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]79 sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]80 Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]81 <li>Basic support for HTTP and FTP client allowing to fetch remote
82 resources</li>
83 <li>The design of modular, most of the extensions can be compiled out.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]84 <li>The internal document repesentation is as close as possible to the <a
85 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
86 <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]87 like interface</a>; the interface is designed to be compatible with <a
88 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]89 <li>This library is released both under the <a
90 href="http://www.w3.org/Consortium/Legal/copyright-software-19980720.html">W3C
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]91 IPR</a> and the <a href="http://www.gnu.org/copyleft/lesser.html">GNU
92 LGPL</a>. Use either at your convenience, basically this should make
93 everybody happy, if not, drop me a mail.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]94</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]95
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]96<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]97
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]98<p>There are some on-line resources about using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]99<ol>
Daniel Veillard365e13b2000-07-02 07:56:37 +0000[diff] [blame]100 <li>Check the <a href="FAQ.html">FAQ</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]101 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]102 documentation</a> automatically extracted from code comments (using <a
103 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
104 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]105 <li>Look at the documentation about <a href="encoding.html">libxml
106 internationalization support</a></li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]107 <li>This page provides a global overview and <a href="#real">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]108 examples</a> on how to use libxml.</li>
109 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
110 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
111 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]112 <li>George Lebl wrote <a
113 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]114 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]115 <li>It is also a good idea to check to <a href="mailto:raph@levien.com">Raph
116 Levien</a> <a href="http://levien.com/gnome/">web site</a> since he is
117 building the <a href="http://levien.com/gnome/gdome.html">DOM interface
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]118 gdome</a> on top of libxml result tree and an implementation of <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]119 href="http://www.w3.org/Graphics/SVG/">SVG</a> called <a
120 href="http://www.levien.com/svg/">gill</a>. Check his <a
121 href="http://www.levien.com/gnome/domination.html">DOMination
122 paper</a>.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]123 <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO
124 file</a></li>
125 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>. If you are
126 starting a new project using libxml you should really use the 2.x
127 version.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]128 <li>And don't forget to look at the <a href="/messages/">mailing-list
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]129 archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]130</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]131
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]132<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]133
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]134<p>Well, bugs or missing features are always possible, and I will make a point
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]135of fixing them in a timely fashion. The best way to report a bug is to use the
136<a href="http://bugs.gnome.org/db/pa/lgnome-xml.html">Gnome bug tracking
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]137database</a> (make sure to use the "gnome-xml" module name, not libxml or
138libxml2). I look at reports there regularly and it's good to have a reminder
139when a bug is still open. Check the <a
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]140href="http://bugs.gnome.org/Reporting.html">instructions on reporting bugs</a>
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]141and be sure to specify that the bug is for the package gnome-xml.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]142
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]143<p>There is also a mailing-list <a
Daniel Veillardf121ab72000-08-29 23:40:42 +0000[diff] [blame]144href="mailto:xml@rpmfind.net">xml@rpmfind.net</a> for libxml, with an <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]145href="http://xmlsoft.org/messages">on-line archive</a>. To subscribe to this
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]146majordomo based list, send a mail message to <a
Daniel Veillardf121ab72000-08-29 23:40:42 +0000[diff] [blame]147href="mailto:majordomo@rpmfind.net">majordomo@rpmfind.net</a> with "subscribe
148xml" in the <strong>content</strong> of the message.</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]149
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]150<p>Alternatively, you can just send the bug to the <a
Daniel Veillardf121ab72000-08-29 23:40:42 +0000[diff] [blame]151href="mailto:xml@rpmfind.net">xml@rpmfind.net</a> list, if it's really libxml
152related I will approve it..</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]153
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]154<p>Of course, bugs reports with a suggested patch for fixing them will
155probably be processed faster.</p>
156
157<p>If you're looking for help, a quick look at <a
158href="http://xmlsoft.org/messages/#407">the list archive</a> may actually
159provide the answer, I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]160questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]161documentantion</a> is not as polished as I would like (i need to learn more
162about Docbook), but it's a good starting point.</p>
163
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]164<h2><a name="help">How to help</a></h2>
165
166<p>You can help the project in various ways, the best thing to do first is to
167subscribe to the mailing-list as explained before, check the <a
168href="http://xmlsoft.org/messages/">archives </a>and the <a
169href="http://bugs.gnome.org/db/pa/lgnome-xml.html">Gnome bug
170database:</a>:</p>
171<ol>
172 <li>provide patches when you find problems</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]173 <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]174 be integrated in all cases but help pinpointing portability problems
175 and</li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]176 <li>provice documentation fixes (either as patches to the code comments or
177 as HTML diffs).</li>
178 <li>provide new documentations pieces (translations, examples, etc ...)</li>
179 <li>Check the TODO file and try to close one of the items</li>
180 <li>take one of the points raised in the archive or the bug database and
181 provide a fix. <a href="mailto:Daniel.Veillard@w3.org">Get in touch with
182 me </a>before to avoid synchronization problems and check that the
183 suggested fix will fit in nicely :-)</li>
184</ol>
185
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]186<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]187
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]188<p>The latest versions of libxml can be found on <a
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]189href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]190href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]191as a <a href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">source
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]192archive</a> or <a
193href="ftp://ftp.gnome.org/pub/GNOME/contrib/redhat/SRPMS/">RPM packages</a>.
194(NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]195href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
196href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]197packages installed to compile applications using libxml.)</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]198
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]199<p><a name="Snapshot">Snapshot:</a></p>
200<ul>
201 <li>Code from the W3C cvs base libxml <a
202 href="ftp://rpmfind.net/pub/libxml/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a></li>
203 <li>Docs, content of the web site, the list archive included <a
204 href="ftp://rpmfind.net/pub/libxml/libxml-docs.tar.gz">libxml-docs.tar.gz</a></li>
205</ul>
206
207<p><a name="Contribs">Contribs:</a></p>
208
209<p>I do accept external contributions, especially if compiling on another
210platform, get in touch with me to upload the package. I will keep them in the
211<a href="ftp://rpmfind.net/pub/libxml/contribs/">contrib directory</a></p>
212
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]213<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]214<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]215 <li><p>The <a
216 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]217 CVS base</a>. Check the <a
218 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a> page;
219 the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]220 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]221 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]222</ul>
223
224<h2><a name="News">News</a></h2>
225
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]226<h3>CVS only : check the <a
227href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]228for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]229
230<p>Item floating around but not actively worked on, get in touch with me if
231you want to test those</p>
232<ul>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]233 <li>Implementing <a href="http://xmlsoft.org/XSLT">XSLT</a>, this is done as
234 a separate C library on top of libxml called libxslt, not released yet but
235 available from CVS</li>
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]236 <li>Finishing up <a href="http://www.w3.org/TR/xptr">XPointer</a> and <a
237 href="http://www.w3.org/TR/xinclude">XInclude</a></li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]238 <li>(seeems working but delayed from release) parsing/import of Docbook SGML
239 docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]240</ul>
241
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame^]242<h3>2.3.2: Feb 24 2000</h3>
243<ul>
244 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
245 <li>fixed a Dtd parsing bug</li>
246 <li>fixed a bug in xmlNodeGetContent</li>
247 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
248</ul>
249
250<h3>2.3.1: Feb 15 2000</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]251<ul>
252 <li>some XPath and HTML bug fixes for XSLT</li>
253 <li>small extension of the hash table interfaces for DOM gdome2
254 implementation</li>
255 <li>A few bug fixes</li>
256</ul>
257
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame^]258<h3>2.3.0: Feb 8 2000 (2.2.12 was on 25 Jan but I didn't kept track)</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]259<ul>
260 <li>Lots of XPath bug fixes</li>
261 <li>Add a mode with Dtd lookup but without validation error reporting for
262 XSLT</li>
263 <li>Add support for text node without escaping (XSLT)</li>
264 <li>bug fixes for xmlCheckFilename</li>
265 <li>validation code bug fixes from Gary Pennington</li>
266 <li>Patch from Paul D. Smith correcting URI path normalization</li>
267 <li>Patch to allow simultaneous install of libxml-devel and
268 libxml2-devel</li>
269 <li>the example Makefile is now fixed</li>
270 <li>added HTML to the RPM packages</li>
271 <li>tree copying bugfixes</li>
272 <li>updates to Windows makefiles</li>
273 <li>optimisation patch from Bjorn Reese</li>
274</ul>
275
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]276<h3>2.2.11: Jan 4 2000</h3>
277<ul>
278 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
279 <li>added htmlHandleOmittedElem()</li>
280 <li>Applied Bjorn Reese's IPV6 first patch</li>
281 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]282 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]283</ul>
284
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]285<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]286<ul>
287 <li>Fix the Windows problems of 2.2.8</li>
288 <li>integrate OpenVMS patches</li>
289 <li>better handling of some nasty HTML input</li>
290 <li>Improved the XPointer implementation</li>
291 <li>integrate a number of provided patches</li>
292</ul>
293
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]294<h3>2.2.9: Nov 25 2000</h3>
295<ul>
296 <li>erroneous release :-(</li>
297</ul>
298
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]299<h3>2.2.8: Nov 13 2000</h3>
300<ul>
301 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
302 support</li>
303 <li>Patch in conditional section handling</li>
304 <li>updated MS compiler project</li>
305 <li>fixed some XPath problems</li>
306 <li>added an URI escaping function</li>
307 <li>some other bug fixes</li>
308</ul>
309
310<h3>2.2.7: Oct 31 2000</h3>
311<ul>
312 <li>added message redirection</li>
313 <li>XPath improvements (thanks TOM !)</li>
314 <li>xmlIOParseDTD() added</li>
315 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
316 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
317</ul>
318
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]319<h3>2.2.6: Oct 25 2000:</h3>
320<ul>
321 <li>Added an hash table module, migrated a number of internal structure to
322 those</li>
323 <li>Fixed a posteriori validation problems</li>
324 <li>HTTP module cleanups</li>
325 <li>HTML parser improvements (tag errors, script/style handling, attribute
326 normalization)</li>
327 <li>coalescing of adjacent text nodes</li>
328 <li>couple of XPath bug fixes, exported the internal API</li>
329</ul>
330
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]331<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]332<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]333 <li>XPointer implementation and testsuite</li>
334 <li>Lot of XPath fixes, added variable and functions registration, more
335 tests</li>
336 <li>Portability fixes, lots of enhancements toward an easy Windows build and
337 release</li>
338 <li>Late validation fixes</li>
339 <li>Integrated a lot of contributed patches</li>
340 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]341 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]342</ul>
343
344<h3>2.2.4: Oct 1 2000:</h3>
345<ul>
346 <li>main XPath problem fixed</li>
347 <li>Integrated portability patches for Windows</li>
348 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]349</ul>
350
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]351<h3>2.2.3: Sep 17 2000</h3>
352<ul>
353 <li>bug fixes</li>
354 <li>cleanup of entity handling code</li>
355 <li>overall review of all loops in the parsers, all sprintf usage has been
356 checked too</li>
357 <li>Far better handling of larges Dtd. Validating against Docbook XML Dtd
358 works smoothly now.</li>
359</ul>
360
361<h3>1.8.10: Sep 6 2000</h3>
362<ul>
363 <li>bug fix release for some Gnome projects</li>
364</ul>
365
366<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]367<ul>
368 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]369 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]370</ul>
371
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]372<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]373<ul>
374 <li>a purely bug fixes release</li>
375 <li>fixed an encoding support problem when parsing from a memory block</li>
376 <li>fixed a DOCTYPE parsing problem</li>
377 <li>removed a bug in the function allowing to override the memory allocation
378 routines</li>
379</ul>
380
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]381<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]382<ul>
383 <li>applied a lot of portability fixes</li>
384 <li>better encoding support/cleanup and saving (content is now always
385 encoded in UTF-8)</li>
386 <li>the HTML parser now correctly handles encodings</li>
387 <li>added xmlHasProp()</li>
388 <li>fixed a serious problem with &amp;#38;</li>
389 <li>propagated the fix to FTP client</li>
390 <li>cleanup, bugfixes, etc ...</li>
391 <li>Added a page about <a href="encoding.html">libxml Internationalization
392 support</a></li>
393</ul>
394
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]395<h3>1.8.9: July 9 2000</h3>
396<ul>
397 <li>fixed the spec the RPMs should be better</li>
398 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
399 rpmfind users problem</li>
400</ul>
401
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]402<h3>2.1.1: July 1 2000</h3>
403<ul>
404 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
405 <li>improvements on the HTML parser</li>
406</ul>
407
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]408<h3>2.1.0 and 1.8.8: June 29 2000</h3>
409<ul>
410 <li>1.8.8 is mostly a comodity package for upgrading to libxml2 accoding to
411 <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
412 about &amp;#38; charref parsing</li>
413 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
414 also contains numerous fixes and enhancements:
415 <ul>
416 <li>added xmlStopParser() to stop parsing</li>
417 <li>improved a lot parsing speed when there is large CDATA blocs</li>
418 <li>includes XPath patches provided by Picdar Technology</li>
419 <li>tried to fix as much as possible DtD validation and namespace
420 related problems</li>
421 <li>output to a given encoding has been added/tested</li>
422 <li>lot of various fixes</li>
423 </ul>
424 </li>
425</ul>
426
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]427<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]428<ul>
429 <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]430 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initally
431 scheduled for Apr 3 the relase occured only on Apr 12 due to massive
432 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]433 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]434 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]435 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]436 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]437 <pre>#include "xxx.h"</pre>
438 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]439 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
440 <li>the memory allocation routines used by libxml can now be overloaded
441 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]442 <li>The previously CVS only tool tester has been renamed
443 <strong>xmllint</strong> and is now installed as part of the libxml2
444 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]445 <li>The I/O interface has been revamped. There is now ways to plug in
446 specific I/O modules, either at the URI scheme detection level using
447 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
448 parser context using xmlCreateIOParserCtxt()</li>
449 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
450 number of the libxml module in use</li>
451 <li>a number of optional features of libxml can now be excluded at configure
452 time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]453</ul>
454
455<h3>2.0.0beta: Mar 14 2000</h3>
456<ul>
457 <li>This is a first Beta release of libxml version 2</li>
458 <li>It's available only from<a href="ftp://rpmfind.net/pub/libxml/">
459 rpmfind.net FTP</a>, it's packaged as libxml2-2.0.0beta and available as
460 tar and RPMs</li>
461 <li>This version is now the head in the Gnome CVS base, the old one is
462 available under the tag LIB_XML_1_X</li>
463 <li>This includes a very large set of changes. Froma programmatic point of
464 view applications should not have to be modified too much, check the <a
465 href="upgrade.html">upgrade page</a></li>
466 <li>Some interfaces may changes (especially a bit about encoding).</li>
467 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]468 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]469 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
470 handled now</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]471 <li>Better handling of entities, especially well formedness checking and
472 proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]473 <li>DTD conditional sections</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]474 <li>Validation now correcly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]475 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
476 structures to accomodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]477 </ul>
478 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]479 <li>Serious progress were made toward compliance, <a
480 href="conf/result.html">here are the result of the test</a> against the
481 OASIS testsuite (except the japanese tests since I don't support that
482 encoding yet). This URL is rebuilt every couple of hours using the CVS
483 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]484</ul>
485
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]486<h3>1.8.7: Mar 6 2000</h3>
487<ul>
488 <li>This is a bug fix release:</li>
489 <li>It is possible to disable the ignorable blanks heuristic used by
490 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
491 that for adherence to XML spec, this behaviour will be disabled by default
492 in 2.x . The same function will allow to keep compatibility for old
493 code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]494 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
495 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]496 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
497 compilation on some platforms has been fixed</li>
498 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
499 URIs</li>
500</ul>
501
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]502<h3>1.8.6: Jan 31 2000</h3>
503<ul>
504 <li>added a nanoFTP transport module, debugged until the new version of <a
505 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
506 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]507</ul>
508
509<h3>1.8.5: Jan 21 2000</h3>
510<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]511 <li>adding APIs to parse a well balanced chunk of XML (production <a
512 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the XML
513 spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]514 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]515 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
516 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]517 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
518 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]519</ul>
520
521<h3>1.8.4: Jan 13 2000</h3>
522<ul>
523 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
524 <li>all exit() call should have been removed from libxml</li>
525 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
526 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]527</ul>
528
529<h3>1.8.3: Jan 5 2000</h3>
530<ul>
531 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]532 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillarddbfd6411999-12-28 16:35:14 +0000[diff] [blame]533 <li>lots of bug fixes and improvement added over XMas hollidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]534 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]535 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
536 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]537 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]538 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]539 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]540</ul>
541
542<h3>1.8.2: Dec 21 1999</h3>
543<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]544 <li>I got another problem with includes and C++, I hope this issue is fixed
545 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]546 <li>Added a few tree modification functions: xmlReplaceNode,
547 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
548 xmlDocSetRootElement</li>
549 <li>Tried to improve the HTML output with help from <a
550 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]551</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]552
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]553<h3>1.8.1: Dec 18 1999</h3>
554<ul>
555 <li>various patches to avoid troubles when using libxml with C++ compilers
556 the "namespace" keyword and C escaping in include files</li>
557 <li>a problem in one of the core macros IS_CHAR was corrected</li>
558 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
559 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]560 <li>fixed a posteriori validation (validation after parsing, or by using a
561 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]562 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]563</ul>
564
565<h3>1.8.0: Dec 12 1999</h3>
566<ul>
567 <li>cleanup, especially memory wise</li>
568 <li>the parser should be more reliable, especially the HTML one, it should
569 not crash, whatever the input !</li>
570 <li>Integrated various patches, especially a speedup improvement for large
571 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
572 configure with --with-buffers to enable them.</li>
573 <li>attribute normalization, oops should have been added long ago !</li>
574 <li>attributes defaulted from Dtds should be available, xmlSetProp() now
575 does entities escapting by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]576</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]577
578<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]579<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]580 <li>Lots of HTML improvement</li>
581 <li>Fixed some errors when saving both XML and HTML</li>
582 <li>More examples, the regression tests should now look clean</li>
583 <li>Fixed a bug with contiguous charref</li>
584</ul>
585
586<h3>1.7.3: Sep 29 1999</h3>
587<ul>
588 <li>portability problems fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]589 <li>snprintf was used unconditionnally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]590 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]591</ul>
592
593<h3>1.7.1: Sep 24 1999</h3>
594<ul>
595 <li>The basic type for strings manipulated by libxml has been renamed in
596 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
597 is that CHAR was conflicting with a predefined type on Windows. However on
598 non WIN32 environment, compatibility is provided by the way of a
599 <strong>#define </strong>.</li>
600 <li>Changed another error : the use of a structure field called errno, and
601 leading to troubles on platforms where it's a macro</li>
602</ul>
603
604<h3>1.7.0: sep 23 1999</h3>
605<ul>
606 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]607 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]608 <li>Added an errno to report errors by another mean than a simple printf
609 like callback</li>
610 <li>Finished ID/IDREF support and checking when validation</li>
611 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]612 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]613 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
614 implementation</li>
615 <li>Added an HTML parser front-end</li>
616</ul>
617
618<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]619
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]620<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]621markup-based structured documents. Here is <a name="example">an example XML
622document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]623<pre>&lt;?xml version="1.0"?&gt;
624&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
625 &lt;head&gt;
626 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
627 &lt;/head&gt;
628 &lt;chapter&gt;
629 &lt;title&gt;The Linux adventure&lt;/title&gt;
630 &lt;p&gt;bla bla bla ...&lt;/p&gt;
631 &lt;image href="linus.gif"/&gt;
632 &lt;p&gt;...&lt;/p&gt;
633 &lt;/chapter&gt;
634&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]635
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]636<p>The first line specifies that it's an XML document and gives useful
637information about its encoding. Then the document is a text format whose
638structure is specified by tags between brackets. <strong>Each tag opened has
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]639to be closed</strong>. XML is pedantic about this. However, if a tag is empty
640(no content), a single tag can serve as both the opening and closing tag if it
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]641ends with <code>/&gt;</code> rather than with <code>&gt;</code>. Note that,
642for example, the image tag has no content (just an attribute) and is closed by
643ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]644
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]645<p>XML can be applied sucessfully to a wide range of uses, from long term
646structured document maintenance (where it follows the steps of SGML) to simple
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]647data encoding mechanisms like configuration file formatting (glade),
648spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where
649it is used to encode remote calls between a client and a server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]650
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]651<h2><a name="XSLT">XSLT</a></h2>
652
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]653<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
654
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]655<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a language
656for transforming XML documents into other XML documents (or HTML/textual
657output).</p>
658
659<p>A separate library called libxslt is being built on top of libxml2. This
660module "libxslt" can be found in the Gnome CVS base too.</p>
661
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]662<p>You can check the <a
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]663href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a> supported
664and the progresses on the <a
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]665href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog">Changelog</a></p>
666
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]667<h2>An overview of libxml architecture</h2>
668
669<p>Libxml is made of multiple components, some of them optionals, and most of
670the block interfaces are public. The main components are:</p>
671<ul>
672 <li>an Input/Output layer</li>
673 <li>FTP and HTTP client layers (optionnal)</li>
674 <li>an Internationalization layer managing the encodings support</li>
675 <li>an URI module</li>
676 <li>the XML parser and its basic SAX interface</li>
677 <li>an HTML parser using the same SAX interface (optionnal)</li>
678 <li>a SAX tree module to build an in-memory DOM representation</li>
679 <li>a tree module to manipulate the DOM representation</li>
680 <li>a validation module using the DOM representation (optionnal)</li>
681 <li>an XPath module for global lookup in a DOM representation
682 (optionnal)</li>
683 <li>a debug module (optionnal)</li>
684</ul>
685
686<p>Graphically this gives the following:</p>
687
688<p><img src="libxml.gif" alt="a graphical view of the various"></p>
689
690<p></p>
691
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]692<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]693
694<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]695returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]696<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]697as the file name, the document type, and a <strong>children</strong> pointer
698which is the root of the document (or more exactly the first child under the
699root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]700chained in double-linked lists of siblings and with children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]701relationship. An xmlNode can also carry properties (a chain of xmlAttr
702structures). An attribute may have a value which is a list of TEXT or
703ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]704
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]705<p>Here is an example (erroneous with respect to the XML spec since there
706should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]707
708<p><img src="structure.gif" alt=" structure.gif "></p>
709
710<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]711called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]712prints them back as parsed. This is useful for detecting errors both in XML
713code and in the XML parser itself. It has an option <strong>--debug</strong>
714which prints the actual in-memory structure of the document, here is the
715result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]716<pre>DOCUMENT
717version=1.0
718standalone=true
719 ELEMENT EXAMPLE
720 ATTRIBUTE prop1
721 TEXT
722 content=gnome is great
723 ATTRIBUTE prop2
724 ENTITY_REF
725 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]726 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]727 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]728 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]729 TEXT
730 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]731 ELEMENT chapter
732 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]733 TEXT
734 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]735 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]736 TEXT
737 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]738 ELEMENT image
739 ATTRIBUTE href
740 TEXT
741 content=linus.gif
742 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]743 TEXT
744 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]745
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]746<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]747
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]748<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]749
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]750<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]751memory. In that case (and if you don't expect to save back the XML document
752loaded using libxml), it's better to use the SAX interface of libxml. SAX is a
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]753<strong>callback-based interface</strong> to the parser. Before parsing, the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]754application layer registers a customized set of callbacks which are called by
755the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]756
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]757<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]758libxml, see the <a
759href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
760documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]761Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]762
763<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
764program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]765binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]766distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]767testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]768<pre>SAX.setDocumentLocator()
769SAX.startDocument()
770SAX.getEntity(amp)
771SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
772SAX.characters( , 3)
773SAX.startElement(head)
774SAX.characters( , 4)
775SAX.startElement(title)
776SAX.characters(Welcome to Gnome, 16)
777SAX.endElement(title)
778SAX.characters( , 3)
779SAX.endElement(head)
780SAX.characters( , 3)
781SAX.startElement(chapter)
782SAX.characters( , 4)
783SAX.startElement(title)
784SAX.characters(The Linux adventure, 19)
785SAX.endElement(title)
786SAX.characters( , 4)
787SAX.startElement(p)
788SAX.characters(bla bla bla ..., 15)
789SAX.endElement(p)
790SAX.characters( , 4)
791SAX.startElement(image, href='linus.gif')
792SAX.endElement(image)
793SAX.characters( , 4)
794SAX.startElement(p)
795SAX.characters(..., 3)
796SAX.endElement(p)
797SAX.characters( , 3)
798SAX.endElement(chapter)
799SAX.characters( , 1)
800SAX.endElement(EXAMPLE)
801SAX.endDocument()</pre>
802
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]803<p>Most of the other functionalities of libxml are based on the DOM
804tree-building facility, so nearly everything up to the end of this document
805presupposes the use of the standard DOM tree build. Note that the DOM tree
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]806itself is built by a set of registered default callbacks, without internal
807specific interface.</p>
808
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]809<h2><a name="library">The XML library interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]810
811<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]812using the XML library from the C language. It is not intended to be extensive.
813I hope the automatically generated documents will provide the completeness
814required, but as a separate set of documents. The interfaces of the XML
815library are by principle low level, there is nearly zero abstraction. Those
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]816interested in a higher level API should <a href="#DOM">look at DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]817
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]818<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
819separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]820interfaces</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]821
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]822<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]823
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]824<p>Usually, the first thing to do is to read an XML input. The parser accepts
825documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]826defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]827<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]828 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]829 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]830 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]831</dl>
832<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]833 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]834 <dd><p>Parse an XML document contained in a (possibly compressed)
835 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]836 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]837</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]838
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]839<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]840failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]841
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]842<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]843
844<p>In order for the application to keep the control when the document is been
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]845fetched (which is common for GUI based programs) libxml provides a push
846interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]847<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
848 void *user_data,
849 const char *chunk,
850 int size,
851 const char *filename);
852int xmlParseChunk (xmlParserCtxtPtr ctxt,
853 const char *chunk,
854 int size,
855 int terminate);</pre>
856
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]857<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]858<pre> FILE *f;
859
860 f = fopen(filename, "r");
861 if (f != NULL) {
862 int res, size = 1024;
863 char chars[1024];
864 xmlParserCtxtPtr ctxt;
865
866 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]867 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]868 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
869 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]870 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]871 xmlParseChunk(ctxt, chars, res, 0);
872 }
873 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]874 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]875 xmlFreeParserCtxt(ctxt);
876 }
877 }</pre>
878
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]879<p>Also note that the HTML parser embedded into libxml also has a push
880interface; the functions are just prefixed by "html" rather than "xml"</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]881
882<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
883
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]884<p>A couple of comments can be made, first this mean that the parser is
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]885memory-hungry, first to load the document in memory, second to build the tree.
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]886Reading a document without building the tree is possible using the SAX
887interfaces (see SAX.h and <a
888href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]889Henstridge's documentation</a>). Note also that the push interface can be
890limited to SAX. Just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]891<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]892
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]893<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]894
895<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]896there is a set of functions dedicated to building new elements. (These are
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]897also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of code
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]898that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]899<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]900 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]901 xmlNodePtr tree, subtree;
902
903 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]904 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
905 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
906 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
907 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]908 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]909 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]910 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
911 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
912 subtree = xmlNewChild(tree, NULL, "image", NULL);
913 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]914
915<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]916
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]917<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]918
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]919<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]920code has access to the internal structure of all the elements of the tree. The
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]921names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]922<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]923<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]924example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]925<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]926
927<p>points to the title element,</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]928<pre>doc-&gt;children-&gt;children-&gt;next-&gt;child-&gt;child</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]929
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]930<p>points to the text node containing the chapter title "The Linux
931adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]932
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]933<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]934present before the document root, so <code>doc-&gt;children</code> may point
935to an element which is not the document Root Element, a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]936<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]937
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]938<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]939
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]940<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]941is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]942<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]943 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
944 xmlChar *value);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]945 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node. The
946 value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]947 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]948</dl>
949<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]950 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]951 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]952 <dd><p>This function returns a pointer to new copy of the property
953 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]954 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]955</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]956
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]957<p>Two functions are provided for reading and writing the text associated with
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]958elements:</p>
959<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]960 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]961 *value);</code></dt>
962 <dd><p>This function takes an "external" string and convert it to one text
963 node or possibly to a list of entity and text nodes. All non-predefined
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]964 entity references like &amp;Gnome; will be stored internally as entity
965 nodes, hence the result of the function may not be a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]966 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]967</dl>
968<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]969 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]970 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]971 <dd><p>This function is the inverse of
972 <code>xmlStringGetNodeList()</code>. It generates a new string
973 containing the content of the text and entity nodes. Note the extra
974 argument inLine. If this argument is set to 1, the function will expand
975 entity references. For example, instead of returning the &amp;Gnome;
976 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]977 "GNU Network Object Model Environment"). Set this argument if you want
978 to use the string for non-XML usage like User Interface.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]979 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]980</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]981
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]982<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]983
984<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]985<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]986 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]987 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]988 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]989 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]990</dl>
991<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]992 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]993 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]994 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]995</dl>
996<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]997 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]998 <dd><p>Saves the document to a file. In this case, the compression
999 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1000 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1001</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1002
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1003<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1004
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1005<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1006accesses. The level of compression on saves can be turned on either globally
1007or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1008<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1009 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1010 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1011 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1012</dl>
1013<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1014 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1015 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1016 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1017</dl>
1018<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1019 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1020 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1021 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1022</dl>
1023<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1024 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1025 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1026 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1027</dl>
1028
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1029<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1030
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1031<p>Entities in principle are similar to simple C macros. An entity defines an
1032abbreviation for a given string that you can reuse many times throughout the
1033content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1034may occur frequently within a document, or to confine the change needed to a
1035document to a restricted area in the internal subset of the document (at the
1036beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1037<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]10382 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]10393 &lt;!ENTITY xml "Extensible Markup Language"&gt;
10404 ]&gt;
10415 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]10426 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]10437 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1044
1045<p>Line 3 declares the xml entity. Line 6 uses the xml entity, by prefixing
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1046it's name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1047are 5 predefined entities in libxml allowing you to escape charaters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1048predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1049<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1050for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1051<strong>&amp;quot;</strong> for the character '"', and
1052<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1053
1054<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]1055substitute an entity's content so that you can see the replacement text in
1056your application. Or you may prefer to keep entity references as such in the
1057content to be able to save the document back without losing this usually
1058precious information (if the user went through the pain of explicitly defining
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1059entities, he may have a a rather negative attitude if you blindly susbtitute
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1060them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1061href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1062function allows you to check and change the behaviour, which is to not
1063substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1064
1065<p>Here is the DOM tree built by libxml for the previous document in the
1066default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1067<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1068DOCUMENT
1069version=1.0
1070 ELEMENT EXAMPLE
1071 TEXT
1072 content=
1073 ENTITY_REF
1074 INTERNAL_GENERAL_ENTITY xml
1075 content=Extensible Markup Language
1076 TEXT
1077 content=</pre>
1078
1079<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1080<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1081DOCUMENT
1082version=1.0
1083 ELEMENT EXAMPLE
1084 TEXT
1085 content= Extensible Markup Language</pre>
1086
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1087<p>So, entities or no entities? Basically, it depends on your use case. I
1088suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1089entities in your XML document or data if you are not willing to handle the
1090entity references elements in the DOM tree.</p>
1091
1092<p>Note that at save time libxml enforce the conversion of the predefined
1093entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1094transparently replace those with chars (i.e., it will not generate entity
1095reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1096finding them in the input).</p>
1097
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1098<p><span style="background-color: #FF0000">WARNING</span>: handling entities
1099on top of libxml SAX interface is difficult !!! If you plan to use
1100non-predefined entities in your documents, then the learning cuvre to handle
1101then using the SAX API may be long. If you plan to use complex document, I
1102strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]1103deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1104
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1105<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1106
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1107<p>The libxml library implements <a
1108href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
1109recognizing namespace contructs in the input, and does namespace lookup
1110automatically when building the DOM tree. A namespace declaration is
1111associated with an in-memory structure and all elements or attributes within
1112that namespace point to it. Hence testing the namespace is a simple and fast
1113equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1114
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1115<p>I suggest that people using libxml use a namespace, and declare it in the
1116root element of their document as the default namespace. Then they don't need
1117to use the prefix in the content but we will have a basis for future semantic
1118refinement and merging of data from different sources. This doesn't augment
1119significantly the size of the XML output, but significantly increase its value
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1120in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1121<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
1122 &lt;elem1&gt;...&lt;/elem1&gt;
1123 &lt;elem2&gt;...&lt;/elem2&gt;
1124&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1125
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1126<p>Concerning the namespace value, this has to be an URL, but the URL doesn't
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1127have to point to any existing resource on the Web. It will bind all the
1128element and atributes with that URL. I suggest to use an URL within a domain
1129you control, and that the URL should contain some kind of version information
1130if possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1131a good namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1132
1133<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1134version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1135and if the version information don't match something you know, warn the user
1136and 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]1137namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
1138same as &lt;bar:text&gt; in another document. What really matter is the URI
1139associated with the element or the attribute, not the prefix string (which is
1140just a shortcut for the full URI). In libxml element and attributes have a
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1141<code>ns</code> field pointing to an xmlNs structure detailing the namespace
1142prefix and it's URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1143
1144<p>@@Interfaces@@</p>
1145
1146<p>@@Examples@@</p>
1147
1148<p>Usually people object using namespace in the case of validation, I object
1149this and will make sure that using namespaces won't break validity checking,
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1150so even is you plan to use or currently are using validation I strongly
1151suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1152<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1153flexible parsers. Now using namespace to mix and differentiate content coming
1154from multiple DTDs will certainly break current validation schemes. I will try
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1155to provide ways to do this, but this may not be portable or standardized.</p>
1156
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1157<h2><a name="Validation">Validation, or are you afraid of DTDs ?</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1158
1159<p>Well what is validation and what is a DTD ?</p>
1160
1161<p>Validation is the process of checking a document against a set of
1162construction rules, a <strong>DTD</strong> (Document Type Definition) is such
1163a set of rules.</p>
1164
1165<p>The validation process and building DTDs are the two most difficult parts
1166of XML life cycle. Briefly a DTD defines all the possibles element to be
1167found within your document, what is the formal shape of your document tree (by
1168defining the allowed content of an element, either text, a regular expression
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1169for the allowed list of children, or mixed content i.e. both text and
1170children). The DTD also defines the allowed attributes for all elements and
1171the types of the attributes. For more detailed informations, I suggest to read
1172the related parts of the XML specification, the examples found under
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1173gnome-xml/test/valid/dtd and the large amount of books available on XML. The
1174dia example in gnome-xml/test/valid should be both simple and complete enough
1175to allow you to build your own.</p>
1176
1177<p>A word of warning, building a good DTD which will fit your needs of your
1178application in the long-term is far from trivial, however the extra level of
1179quality it can insure is well worth the price for some sets of applications or
1180if you already have already a DTD defined for your application field.</p>
1181
1182<p>The validation is not completely finished but in a (very IMHO) usable
1183state. Until a real validation interface is defined the way to do it is to
1184define and set the <strong>xmlDoValidityCheckingDefaultValue</strong> external
1185variable to 1, this will of course be changed at some point:</p>
1186
1187<p>extern int xmlDoValidityCheckingDefaultValue;</p>
1188
1189<p>...</p>
1190
1191<p>xmlDoValidityCheckingDefaultValue = 1;</p>
1192
1193<p></p>
1194
1195<p>To handle external entities, use the function
1196<strong>xmlSetExternalEntityLoader</strong>(xmlExternalEntityLoader f); to
1197link in you HTTP/FTP/Entities database library to the standard libxml
1198core.</p>
1199
1200<p>@@interfaces@@</p>
1201
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1202<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1203
1204<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document Object
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1205Model</em> this is an API for accessing XML or HTML structured documents.
1206Native support for DOM in Gnome is on the way (module gnome-dom), and it will
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1207be based on gnome-xml. This will be a far cleaner interface to manipulate XML
Daniel Veillardc08a2c61999-09-08 21:35:25 +0000[diff] [blame]1208files within Gnome since it won't expose the internal structure. DOM defines a
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1209set of IDL (or Java) interfaces allowing to traverse and manipulate a
1210document. The DOM library will allow accessing and modifying "live" documents
1211presents on other programs like this:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1212
1213<p><img src="DOM.gif" alt=" DOM.gif "></p>
1214
1215<p>This should help greatly doing things like modifying a gnumeric spreadsheet
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1216embedded in a GWP document for example.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1217
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1218<p>The current DOM implementation on top of libxml is the <a
1219href="http://cvs.gnome.org/lxr/source/gdome/">gdome Gnome module</a>, this is
1220a full DOM interface, thanks to <a href="mailto:raph@levien.com">Raph
1221Levien</a>.</p>
1222
1223<p>The gnome-dom module in the Gnome CVS base is obsolete</p>
1224
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1225<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1226
1227<p>Here is a real size example, where the actual content of the application
1228data 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]1229a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1230storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
1231base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1232<pre>&lt;?xml version="1.0"?&gt;
1233&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
1234 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1235
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1236 &lt;gjob:Job&gt;
1237 &lt;gjob:Project ID="3"/&gt;
1238 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
1239 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1240
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1241 &lt;gjob:Update&gt;
1242 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
1243 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
1244 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
1245 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1246
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1247 &lt;gjob:Developers&gt;
1248 &lt;gjob:Developer&gt;
1249 &lt;/gjob:Developer&gt;
1250 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1251
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1252 &lt;gjob:Contact&gt;
1253 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
1254 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
1255 &lt;gjob:Company&gt;
1256 &lt;/gjob:Company&gt;
1257 &lt;gjob:Organisation&gt;
1258 &lt;/gjob:Organisation&gt;
1259 &lt;gjob:Webpage&gt;
1260 &lt;/gjob:Webpage&gt;
1261 &lt;gjob:Snailmail&gt;
1262 &lt;/gjob:Snailmail&gt;
1263 &lt;gjob:Phone&gt;
1264 &lt;/gjob:Phone&gt;
1265 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1266
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1267 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1268 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1269 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1270
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1271 &lt;gjob:Skills&gt;
1272 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1273
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1274 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1275 A GNOME based system that will allow a superuser to configure
1276 compressed and uncompressed files and/or file systems to be backed
1277 up with a supported media in the system. This should be able to
1278 perform via find commands generating a list of files that are passed
1279 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
1280 or via operations performed on the filesystem itself. Email
1281 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1282 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1283
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1284 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1285
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1286 &lt;/gjob:Jobs&gt;
1287&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1288
1289<p>While loading the XML file into an internal DOM tree is a matter of calling
1290only a couple of functions, browsing the tree to gather the informations and
1291generate the internals structures is harder, and more error prone.</p>
1292
1293<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1294structure. For example, the ordering of the attributes is not significant,
1295Cthe XML specification is clear about it. It's also usually a good idea to not
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1296be dependent of the orders of the children of a given node, unless it really
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1297makes things harder. Here is some code to parse the informations for a
1298person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1299<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1300 * A person record
1301 */
1302typedef struct person {
1303 char *name;
1304 char *email;
1305 char *company;
1306 char *organisation;
1307 char *smail;
1308 char *webPage;
1309 char *phone;
1310} person, *personPtr;
1311
1312/*
1313 * And the code needed to parse it
1314 */
1315personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1316 personPtr ret = NULL;
1317
1318DEBUG("parsePerson\n");
1319 /*
1320 * allocate the struct
1321 */
1322 ret = (personPtr) malloc(sizeof(person));
1323 if (ret == NULL) {
1324 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1325 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1326 }
1327 memset(ret, 0, sizeof(person));
1328
1329 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1330 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1331 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1332 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
1333 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1334 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
1335 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1336 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1337 }
1338
1339 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1340}</pre>
1341
1342<p>Here is a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1343<ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1344 <li>Usually a recursive parsing style is the more convenient one, XML data
1345 being by nature subject to repetitive constructs and usualy exibit highly
1346 stuctured patterns.</li>
1347 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>, i.e.
1348 the pointer to the global XML document and the namespace reserved to the
1349 application. Document wide information are needed for example to decode
1350 entities and it's a good coding practice to define a namespace for your
1351 application set of data and test that the element and attributes you're
1352 analyzing actually pertains to your application space. This is done by a
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1353 simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1354 <li>To retrieve text and attributes value, it is suggested to use the
1355 function <em>xmlNodeListGetString</em> to gather all the text and entity
1356 reference nodes generated by the DOM output and produce an single text
1357 string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1358</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1359
1360<p>Here is another piece of code used to parse another level of the
1361structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1362<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1363/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1364 * a Description for a Job
1365 */
1366typedef struct job {
1367 char *projectID;
1368 char *application;
1369 char *category;
1370 personPtr contact;
1371 int nbDevelopers;
1372 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
1373} job, *jobPtr;
1374
1375/*
1376 * And the code needed to parse it
1377 */
1378jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1379 jobPtr ret = NULL;
1380
1381DEBUG("parseJob\n");
1382 /*
1383 * allocate the struct
1384 */
1385 ret = (jobPtr) malloc(sizeof(job));
1386 if (ret == NULL) {
1387 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1388 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1389 }
1390 memset(ret, 0, sizeof(job));
1391
1392 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1393 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1394 while (cur != NULL) {
1395
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1396 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
1397 ret-&gt;projectID = xmlGetProp(cur, "ID");
1398 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1399 fprintf(stderr, "Project has no ID\n");
1400 }
1401 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1402 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
1403 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1404 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
1405 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1406 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
1407 ret-&gt;contact = parsePerson(doc, ns, cur);
1408 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1409 }
1410
1411 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1412}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1413
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1414<p>One can notice that once used to it, writing this kind of code is quite
1415simple, but boring. Ultimately, it could be possble to write stubbers taking
1416either C data structure definitions, a set of XML examples or an XML DTD and
1417produce the code needed to import and export the content between C data and
1418XML storage. This is left as an exercise to the reader :-)</p>
1419
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]1420<p>Feel free to use <a href="example/gjobread.c">the code for the full C
1421parsing example</a> as a template, it is also available with Makefile in the
1422Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1423
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1424<h2><a name="Contributi">Contributions</a></h2>
1425<ul>
Daniel Veillard851c59c2000-11-24 16:06:22 +0000[diff] [blame]1426 <li><a href="mailto:ari@lusis.org">Ari Johnson</a> provides a C++ wrapper
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1427 for libxml:
1428 <p>Website: <a
1429 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
1430 <p>Download: <a
1431 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
1432 </li>
1433 <li><a href="mailto:doolin@cs.utk.edu">David Doolin</a> provides a
1434 precompiled Windows version
1435 <p><a
1436 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
1437 </li>
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1438 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> provided <a
1439 href="libxml-doc.el">an emacs module</a> to lookup libxml functions
1440 documentation</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1441 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
1442 href="http://xmlsoft.org/messages/0488.html">man pages</a> (not yet
1443 integrated in the distribution)</li>
1444</ul>
1445
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1446<p></p>
1447
1448<p><a href="mailto:Daniel.Veillard@w3.org">Daniel Veillard</a></p>
1449
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame^]1450<p>$Id: xml.html,v 1.67 2001/02/15 15:55:44 veillard Exp $</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1451</body>
1452</html>