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blob: dd9c5ba4aed84723f186ea6d5a9940337225281d [file] [log] [blame]
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
2 "http://www.w3.org/TR/html4/loose.dtd">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3<html>
4<head>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]5 <title>The XML C library for Gnome</title>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]6 <meta name="GENERATOR" content="amaya V4.1">
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]7 <meta http-equiv="Content-Type" content="text/html">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]8</head>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]9
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]10<body bgcolor="#ffffff">
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]11<p><a href="http://www.gnome.org/"><img src="smallfootonly.gif"
12alt="Gnome Logo"></a><a href="http://www.w3.org/Status"><img src="w3c.png"
13alt="W3C Logo"></a></p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]14
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]15<h1 align="center">The XML C library for Gnome</h1>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]16
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]17<h2 style="text-align: center">libxml, a.k.a. gnome-xml</h2>
18
19<p></p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]20<ul>
21 <li><a href="#Introducti">Introduction</a></li>
22 <li><a href="#Documentat">Documentation</a></li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]23 <li><a href="#Reporting">Reporting bugs and getting help</a></li>
24 <li><a href="#help">how to help</a></li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]25 <li><a href="#Downloads">Downloads</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]26 <li><a href="#News">News</a></li>
27 <li><a href="#XML">XML</a></li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]28 <li><a href="#XSLT">XSLT</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]29 <li><a href="#tree">The tree output</a></li>
30 <li><a href="#interface">The SAX interface</a></li>
31 <li><a href="#library">The XML library interfaces</a>
32 <ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]33 <li><a href="#Invoking">Invoking the parser: the pull way</a></li>
34 <li><a href="#Invoking">Invoking the parser: the push way</a></li>
35 <li><a href="#Invoking2">Invoking the parser: the SAX interface</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]36 <li><a href="#Building">Building a tree from scratch</a></li>
37 <li><a href="#Traversing">Traversing the tree</a></li>
38 <li><a href="#Modifying">Modifying the tree</a></li>
39 <li><a href="#Saving">Saving the tree</a></li>
40 <li><a href="#Compressio">Compression</a></li>
41 </ul>
42 </li>
43 <li><a href="#Entities">Entities or no entities</a></li>
44 <li><a href="#Namespaces">Namespaces</a></li>
45 <li><a href="#Validation">Validation</a></li>
46 <li><a href="#Principles">DOM principles</a></li>
47 <li><a href="#real">A real example</a></li>
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]48 <li><a href="#Contributi">Contributions</a></li>
49</ul>
50
51<p>Separate documents:</p>
52<ul>
53 <li><a href="upgrade.html">upgrade instructions for migrating to
54 libxml2</a></li>
55 <li><a href="encoding.html">libxml Internationalization support</a></li>
56 <li><a href="xmlio.html">libxml Input/Output interfaces</a></li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]57 <li><a href="xmlmem.html">libxml Memory interfaces</a></li>
Daniel Veillard300f7d62000-11-24 13:04:04 +0000[diff] [blame]58 <li><a href="xmldtd.html">a short introduction about DTDs and
59 libxml</a></li>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]60 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]61</ul>
62
63<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]64
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]65<p>This document describes libxml, the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]66href="http://www.w3.org/XML/">XML</a> C library developped for the <a
67href="http://www.gnome.org/">Gnome</a> project. <a
68href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
69structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]70
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]71<p>Here are some key points about libxml:</p>
72<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]73 <li>Libxml exports Push and Pull type parser interfaces for both XML and
74 HTML.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]75 <li>Libxml can do DTD validation at parse time, using a parsed document
76 instance, or with an arbitrary DTD.</li>
77 <li>Libxml now includes nearly complete <a
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]78 href="http://www.w3.org/TR/xpath">XPath</a> and <a
Daniel Veillard0c069222000-10-21 09:25:52 +0000[diff] [blame]79 href="http://www.w3.org/TR/xptr">XPointer</a> implementations.</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]80 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]81 sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]82 Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]83 <li>Basic support for HTTP and FTP client allowing aplications to fetch
84 remote resources</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]85 <li>The design is modular, most of the extensions can be compiled out.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]86 <li>The internal document repesentation is as close as possible to the <a
87 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
88 <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]89 like interface</a>; the interface is designed to be compatible with <a
90 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]91 <li>This library is released both under the <a
92 href="http://www.w3.org/Consortium/Legal/copyright-software-19980720.html">W3C
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]93 IPR</a> and the <a href="http://www.gnu.org/copyleft/lesser.html">GNU
94 LGPL</a>. Use either at your convenience, basically this should make
95 everybody happy, if not, drop me a mail.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]96</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]97
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]98<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]99
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]100<p>There are some on-line resources about using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]101<ol>
Daniel Veillard365e13b2000-07-02 07:56:37 +0000[diff] [blame]102 <li>Check the <a href="FAQ.html">FAQ</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]103 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]104 documentation</a> automatically extracted from code comments (using <a
105 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
106 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]107 <li>Look at the documentation about <a href="encoding.html">libxml
108 internationalization support</a></li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]109 <li>This page provides a global overview and <a href="#real">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]110 examples</a> on how to use libxml.</li>
111 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
112 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
113 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]114 <li>George Lebl wrote <a
115 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]116 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]117 <li>It is also a good idea to check to <a href="mailto:raph@levien.com">Raph
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]118 Levien</a>'s <a href="http://levien.com/gnome/">web site</a> since he is
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]119 building the <a href="http://levien.com/gnome/gdome.html">DOM interface
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]120 gdome</a> on top of libxml result tree and an implementation of <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]121 href="http://www.w3.org/Graphics/SVG/">SVG</a> called <a
122 href="http://www.levien.com/svg/">gill</a>. Check his <a
123 href="http://www.levien.com/gnome/domination.html">DOMination
124 paper</a>.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]125 <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO
126 file</a></li>
127 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>. If you are
128 starting a new project using libxml you should really use the 2.x
129 version.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]130 <li>And don't forget to look at the <a href="/messages/">mailing-list
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]131 archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]132</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]133
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]134<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]135
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]136<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]137of fixing them in a timely fashion. The best way to report a bug is to use the
Daniel Veillard81781102001-03-07 09:31:47 +0000[diff] [blame]138<a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
139tracking database</a> (make sure to use the "libxml" module name). I look at
140reports there regularly and it's good to have a reminder when a bug is still
141open. Check the <a href="http://bugs.gnome.org/Reporting.html">instructions on
142reporting bugs</a> and be sure to specify that the bug is for the package
143libxml.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]144
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]145<p>There is also a mailing-list <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame^]146href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]147href="http://xmlsoft.org/messages">on-line archive</a>. To subscribe to this
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame^]148list, please visit the <a
149href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
150follow the instructions.</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]151
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]152<p>Alternatively, you can just send the bug to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame^]153href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillardf121ab72000-08-29 23:40:42 +0000[diff] [blame]154related I will approve it..</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]155
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]156<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]157probably be processed faster.</p>
158
159<p>If you're looking for help, a quick look at <a
160href="http://xmlsoft.org/messages/#407">the list archive</a> may actually
161provide the answer, I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]162questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]163documentantion</a> is not as polished as I would like (i need to learn more
164about Docbook), but it's a good starting point.</p>
165
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]166<h2><a name="help">How to help</a></h2>
167
168<p>You can help the project in various ways, the best thing to do first is to
169subscribe to the mailing-list as explained before, check the <a
170href="http://xmlsoft.org/messages/">archives </a>and the <a
171href="http://bugs.gnome.org/db/pa/lgnome-xml.html">Gnome bug
172database:</a>:</p>
173<ol>
174 <li>provide patches when you find problems</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]175 <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]176 be integrated in all cases but help pinpointing portability problems
177 and</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]178 <li>provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]179 as HTML diffs).</li>
180 <li>provide new documentations pieces (translations, examples, etc ...)</li>
181 <li>Check the TODO file and try to close one of the items</li>
182 <li>take one of the points raised in the archive or the bug database and
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame^]183 provide a fix. <a href="mailto:Daniel.Veillard@imag.fr">Get in touch with
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]184 me </a>before to avoid synchronization problems and check that the
185 suggested fix will fit in nicely :-)</li>
186</ol>
187
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]188<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]189
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]190<p>The latest versions of libxml can be found on <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame^]191href="ftp://xmlsoft.org/">xmlsoft.org</a> or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]192href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]193as a <a href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">source
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]194archive</a> or <a
195href="ftp://ftp.gnome.org/pub/GNOME/contrib/redhat/SRPMS/">RPM packages</a>.
196(NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]197href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
198href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]199packages installed to compile applications using libxml.)</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]200
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]201<p><a name="Snapshot">Snapshot:</a></p>
202<ul>
203 <li>Code from the W3C cvs base libxml <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame^]204 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]205 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame^]206 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]207</ul>
208
209<p><a name="Contribs">Contribs:</a></p>
210
211<p>I do accept external contributions, especially if compiling on another
212platform, get in touch with me to upload the package. I will keep them in the
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame^]213<a href="ftp://xmlsoft.org/contribs/">contrib directory</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]214
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]215<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]216<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]217 <li><p>The <a
218 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]219 CVS base</a>. Check the <a
220 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a> page;
221 the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]222 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]223 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]224</ul>
225
226<h2><a name="News">News</a></h2>
227
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]228<h3>CVS only : check the <a
229href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]230for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]231
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]232<p>Items floating around but not actively worked on, get in touch with me if
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]233you want to test those</p>
234<ul>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]235 <li>Implementing <a href="http://xmlsoft.org/XSLT">XSLT</a>, this is done as
236 a separate C library on top of libxml called libxslt, not released yet but
237 available from CVS</li>
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]238 <li>Finishing up <a href="http://www.w3.org/TR/xptr">XPointer</a> and <a
239 href="http://www.w3.org/TR/xinclude">XInclude</a></li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]240 <li>(seeems working but delayed from release) parsing/import of Docbook SGML
241 docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]242</ul>
243
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]244<h3>2.3.3: Mar 1 2001</h3>
245<ul>
246 <li>small change in XPath for XSLT</li>
247 <li>documentation cleanups</li>
248 <li>fix in validation by Gary Pennington</li>
249 <li>serious parsing performances improvements</li>
250</ul>
251
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]252<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]253<ul>
254 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
255 <li>fixed a Dtd parsing bug</li>
256 <li>fixed a bug in xmlNodeGetContent</li>
257 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
258</ul>
259
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]260<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]261<ul>
262 <li>some XPath and HTML bug fixes for XSLT</li>
263 <li>small extension of the hash table interfaces for DOM gdome2
264 implementation</li>
265 <li>A few bug fixes</li>
266</ul>
267
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]268<h3>2.3.0: Feb 8 2001 (2.2.12 was on 25 Jan but I didn't kept track)</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]269<ul>
270 <li>Lots of XPath bug fixes</li>
271 <li>Add a mode with Dtd lookup but without validation error reporting for
272 XSLT</li>
273 <li>Add support for text node without escaping (XSLT)</li>
274 <li>bug fixes for xmlCheckFilename</li>
275 <li>validation code bug fixes from Gary Pennington</li>
276 <li>Patch from Paul D. Smith correcting URI path normalization</li>
277 <li>Patch to allow simultaneous install of libxml-devel and
278 libxml2-devel</li>
279 <li>the example Makefile is now fixed</li>
280 <li>added HTML to the RPM packages</li>
281 <li>tree copying bugfixes</li>
282 <li>updates to Windows makefiles</li>
283 <li>optimisation patch from Bjorn Reese</li>
284</ul>
285
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]286<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]287<ul>
288 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
289 <li>added htmlHandleOmittedElem()</li>
290 <li>Applied Bjorn Reese's IPV6 first patch</li>
291 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]292 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]293</ul>
294
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]295<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]296<ul>
297 <li>Fix the Windows problems of 2.2.8</li>
298 <li>integrate OpenVMS patches</li>
299 <li>better handling of some nasty HTML input</li>
300 <li>Improved the XPointer implementation</li>
301 <li>integrate a number of provided patches</li>
302</ul>
303
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]304<h3>2.2.9: Nov 25 2000</h3>
305<ul>
306 <li>erroneous release :-(</li>
307</ul>
308
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]309<h3>2.2.8: Nov 13 2000</h3>
310<ul>
311 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
312 support</li>
313 <li>Patch in conditional section handling</li>
314 <li>updated MS compiler project</li>
315 <li>fixed some XPath problems</li>
316 <li>added an URI escaping function</li>
317 <li>some other bug fixes</li>
318</ul>
319
320<h3>2.2.7: Oct 31 2000</h3>
321<ul>
322 <li>added message redirection</li>
323 <li>XPath improvements (thanks TOM !)</li>
324 <li>xmlIOParseDTD() added</li>
325 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
326 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
327</ul>
328
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]329<h3>2.2.6: Oct 25 2000:</h3>
330<ul>
331 <li>Added an hash table module, migrated a number of internal structure to
332 those</li>
333 <li>Fixed a posteriori validation problems</li>
334 <li>HTTP module cleanups</li>
335 <li>HTML parser improvements (tag errors, script/style handling, attribute
336 normalization)</li>
337 <li>coalescing of adjacent text nodes</li>
338 <li>couple of XPath bug fixes, exported the internal API</li>
339</ul>
340
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]341<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]342<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]343 <li>XPointer implementation and testsuite</li>
344 <li>Lot of XPath fixes, added variable and functions registration, more
345 tests</li>
346 <li>Portability fixes, lots of enhancements toward an easy Windows build and
347 release</li>
348 <li>Late validation fixes</li>
349 <li>Integrated a lot of contributed patches</li>
350 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]351 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]352</ul>
353
354<h3>2.2.4: Oct 1 2000:</h3>
355<ul>
356 <li>main XPath problem fixed</li>
357 <li>Integrated portability patches for Windows</li>
358 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]359</ul>
360
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]361<h3>2.2.3: Sep 17 2000</h3>
362<ul>
363 <li>bug fixes</li>
364 <li>cleanup of entity handling code</li>
365 <li>overall review of all loops in the parsers, all sprintf usage has been
366 checked too</li>
367 <li>Far better handling of larges Dtd. Validating against Docbook XML Dtd
368 works smoothly now.</li>
369</ul>
370
371<h3>1.8.10: Sep 6 2000</h3>
372<ul>
373 <li>bug fix release for some Gnome projects</li>
374</ul>
375
376<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]377<ul>
378 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]379 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]380</ul>
381
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]382<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]383<ul>
384 <li>a purely bug fixes release</li>
385 <li>fixed an encoding support problem when parsing from a memory block</li>
386 <li>fixed a DOCTYPE parsing problem</li>
387 <li>removed a bug in the function allowing to override the memory allocation
388 routines</li>
389</ul>
390
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]391<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]392<ul>
393 <li>applied a lot of portability fixes</li>
394 <li>better encoding support/cleanup and saving (content is now always
395 encoded in UTF-8)</li>
396 <li>the HTML parser now correctly handles encodings</li>
397 <li>added xmlHasProp()</li>
398 <li>fixed a serious problem with &amp;#38;</li>
399 <li>propagated the fix to FTP client</li>
400 <li>cleanup, bugfixes, etc ...</li>
401 <li>Added a page about <a href="encoding.html">libxml Internationalization
402 support</a></li>
403</ul>
404
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]405<h3>1.8.9: July 9 2000</h3>
406<ul>
407 <li>fixed the spec the RPMs should be better</li>
408 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
409 rpmfind users problem</li>
410</ul>
411
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]412<h3>2.1.1: July 1 2000</h3>
413<ul>
414 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
415 <li>improvements on the HTML parser</li>
416</ul>
417
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]418<h3>2.1.0 and 1.8.8: June 29 2000</h3>
419<ul>
420 <li>1.8.8 is mostly a comodity package for upgrading to libxml2 accoding to
421 <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
422 about &amp;#38; charref parsing</li>
423 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
424 also contains numerous fixes and enhancements:
425 <ul>
426 <li>added xmlStopParser() to stop parsing</li>
427 <li>improved a lot parsing speed when there is large CDATA blocs</li>
428 <li>includes XPath patches provided by Picdar Technology</li>
429 <li>tried to fix as much as possible DtD validation and namespace
430 related problems</li>
431 <li>output to a given encoding has been added/tested</li>
432 <li>lot of various fixes</li>
433 </ul>
434 </li>
435</ul>
436
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]437<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]438<ul>
439 <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]440 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initally
441 scheduled for Apr 3 the relase occured only on Apr 12 due to massive
442 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]443 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]444 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]445 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]446 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]447 <pre>#include "xxx.h"</pre>
448 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]449 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
450 <li>the memory allocation routines used by libxml can now be overloaded
451 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]452 <li>The previously CVS only tool tester has been renamed
453 <strong>xmllint</strong> and is now installed as part of the libxml2
454 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]455 <li>The I/O interface has been revamped. There is now ways to plug in
456 specific I/O modules, either at the URI scheme detection level using
457 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
458 parser context using xmlCreateIOParserCtxt()</li>
459 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
460 number of the libxml module in use</li>
461 <li>a number of optional features of libxml can now be excluded at configure
462 time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]463</ul>
464
465<h3>2.0.0beta: Mar 14 2000</h3>
466<ul>
467 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame^]468 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org FTP</a>, it's packaged as libxml2-2.0.0beta and available as
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]469 tar and RPMs</li>
470 <li>This version is now the head in the Gnome CVS base, the old one is
471 available under the tag LIB_XML_1_X</li>
472 <li>This includes a very large set of changes. Froma programmatic point of
473 view applications should not have to be modified too much, check the <a
474 href="upgrade.html">upgrade page</a></li>
475 <li>Some interfaces may changes (especially a bit about encoding).</li>
476 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]477 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]478 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
479 handled now</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]480 <li>Better handling of entities, especially well formedness checking and
481 proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]482 <li>DTD conditional sections</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]483 <li>Validation now correcly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]484 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
485 structures to accomodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]486 </ul>
487 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]488 <li>Serious progress were made toward compliance, <a
489 href="conf/result.html">here are the result of the test</a> against the
490 OASIS testsuite (except the japanese tests since I don't support that
491 encoding yet). This URL is rebuilt every couple of hours using the CVS
492 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]493</ul>
494
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]495<h3>1.8.7: Mar 6 2000</h3>
496<ul>
497 <li>This is a bug fix release:</li>
498 <li>It is possible to disable the ignorable blanks heuristic used by
499 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
500 that for adherence to XML spec, this behaviour will be disabled by default
501 in 2.x . The same function will allow to keep compatibility for old
502 code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]503 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
504 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]505 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
506 compilation on some platforms has been fixed</li>
507 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
508 URIs</li>
509</ul>
510
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]511<h3>1.8.6: Jan 31 2000</h3>
512<ul>
513 <li>added a nanoFTP transport module, debugged until the new version of <a
514 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
515 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]516</ul>
517
518<h3>1.8.5: Jan 21 2000</h3>
519<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]520 <li>adding APIs to parse a well balanced chunk of XML (production <a
521 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the XML
522 spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]523 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]524 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
525 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]526 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
527 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]528</ul>
529
530<h3>1.8.4: Jan 13 2000</h3>
531<ul>
532 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
533 <li>all exit() call should have been removed from libxml</li>
534 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
535 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]536</ul>
537
538<h3>1.8.3: Jan 5 2000</h3>
539<ul>
540 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]541 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillarddbfd6411999-12-28 16:35:14 +0000[diff] [blame]542 <li>lots of bug fixes and improvement added over XMas hollidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]543 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]544 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
545 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]546 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]547 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]548 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]549</ul>
550
551<h3>1.8.2: Dec 21 1999</h3>
552<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]553 <li>I got another problem with includes and C++, I hope this issue is fixed
554 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]555 <li>Added a few tree modification functions: xmlReplaceNode,
556 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
557 xmlDocSetRootElement</li>
558 <li>Tried to improve the HTML output with help from <a
559 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]560</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]561
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]562<h3>1.8.1: Dec 18 1999</h3>
563<ul>
564 <li>various patches to avoid troubles when using libxml with C++ compilers
565 the "namespace" keyword and C escaping in include files</li>
566 <li>a problem in one of the core macros IS_CHAR was corrected</li>
567 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
568 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]569 <li>fixed a posteriori validation (validation after parsing, or by using a
570 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]571 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]572</ul>
573
574<h3>1.8.0: Dec 12 1999</h3>
575<ul>
576 <li>cleanup, especially memory wise</li>
577 <li>the parser should be more reliable, especially the HTML one, it should
578 not crash, whatever the input !</li>
579 <li>Integrated various patches, especially a speedup improvement for large
580 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
581 configure with --with-buffers to enable them.</li>
582 <li>attribute normalization, oops should have been added long ago !</li>
583 <li>attributes defaulted from Dtds should be available, xmlSetProp() now
584 does entities escapting by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]585</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]586
587<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]588<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]589 <li>Lots of HTML improvement</li>
590 <li>Fixed some errors when saving both XML and HTML</li>
591 <li>More examples, the regression tests should now look clean</li>
592 <li>Fixed a bug with contiguous charref</li>
593</ul>
594
595<h3>1.7.3: Sep 29 1999</h3>
596<ul>
597 <li>portability problems fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]598 <li>snprintf was used unconditionnally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]599 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]600</ul>
601
602<h3>1.7.1: Sep 24 1999</h3>
603<ul>
604 <li>The basic type for strings manipulated by libxml has been renamed in
605 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
606 is that CHAR was conflicting with a predefined type on Windows. However on
607 non WIN32 environment, compatibility is provided by the way of a
608 <strong>#define </strong>.</li>
609 <li>Changed another error : the use of a structure field called errno, and
610 leading to troubles on platforms where it's a macro</li>
611</ul>
612
613<h3>1.7.0: sep 23 1999</h3>
614<ul>
615 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]616 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]617 <li>Added an errno to report errors by another mean than a simple printf
618 like callback</li>
619 <li>Finished ID/IDREF support and checking when validation</li>
620 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]621 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]622 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
623 implementation</li>
624 <li>Added an HTML parser front-end</li>
625</ul>
626
627<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]628
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]629<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]630markup-based structured documents. Here is <a name="example">an example XML
631document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]632<pre>&lt;?xml version="1.0"?&gt;
633&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
634 &lt;head&gt;
635 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
636 &lt;/head&gt;
637 &lt;chapter&gt;
638 &lt;title&gt;The Linux adventure&lt;/title&gt;
639 &lt;p&gt;bla bla bla ...&lt;/p&gt;
640 &lt;image href="linus.gif"/&gt;
641 &lt;p&gt;...&lt;/p&gt;
642 &lt;/chapter&gt;
643&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]644
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]645<p>The first line specifies that it's an XML document and gives useful
646information about its encoding. Then the document is a text format whose
647structure is specified by tags between brackets. <strong>Each tag opened has
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]648to be closed</strong>. XML is pedantic about this. However, if a tag is empty
649(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]650ends with <code>/&gt;</code> rather than with <code>&gt;</code>. Note that,
651for example, the image tag has no content (just an attribute) and is closed by
652ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]653
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]654<p>XML can be applied sucessfully to a wide range of uses, from long term
655structured document maintenance (where it follows the steps of SGML) to simple
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]656data encoding mechanisms like configuration file formatting (glade),
657spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where
658it is used to encode remote calls between a client and a server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]659
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]660<h2><a name="XSLT">XSLT</a></h2>
661
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]662<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
663
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]664<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a language
665for transforming XML documents into other XML documents (or HTML/textual
666output).</p>
667
668<p>A separate library called libxslt is being built on top of libxml2. This
669module "libxslt" can be found in the Gnome CVS base too.</p>
670
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]671<p>You can check the <a
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]672href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a> supported
673and the progresses on the <a
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]674href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog">Changelog</a></p>
675
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]676<h2>An overview of libxml architecture</h2>
677
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]678<p>Libxml is made of multiple components; some of them are optional, and most
679of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]680<ul>
681 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]682 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]683 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]684 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]685 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]686 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]687 <li>a SAX tree module to build an in-memory DOM representation</li>
688 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]689 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]690 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]691 (optional)</li>
692 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]693</ul>
694
695<p>Graphically this gives the following:</p>
696
697<p><img src="libxml.gif" alt="a graphical view of the various"></p>
698
699<p></p>
700
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]701<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]702
703<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]704returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]705<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]706as the file name, the document type, and a <strong>children</strong> pointer
707which is the root of the document (or more exactly the first child under the
708root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]709chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]710relationship. An xmlNode can also carry properties (a chain of xmlAttr
711structures). An attribute may have a value which is a list of TEXT or
712ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]713
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]714<p>Here is an example (erroneous with respect to the XML spec since there
715should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]716
717<p><img src="structure.gif" alt=" structure.gif "></p>
718
719<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]720called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]721prints them back as parsed. This is useful for detecting errors both in XML
722code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]723which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]724result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]725<pre>DOCUMENT
726version=1.0
727standalone=true
728 ELEMENT EXAMPLE
729 ATTRIBUTE prop1
730 TEXT
731 content=gnome is great
732 ATTRIBUTE prop2
733 ENTITY_REF
734 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]735 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]736 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]737 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]738 TEXT
739 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]740 ELEMENT chapter
741 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]742 TEXT
743 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]744 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]745 TEXT
746 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]747 ELEMENT image
748 ATTRIBUTE href
749 TEXT
750 content=linus.gif
751 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]752 TEXT
753 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]754
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]755<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]756
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]757<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]758
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]759<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]760memory. In that case (and if you don't expect to save back the XML document
761loaded 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]762<strong>callback-based interface</strong> to the parser. Before parsing, the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]763application layer registers a customized set of callbacks which are called by
764the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]765
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]766<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]767libxml, see the <a
768href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
769documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]770Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]771
772<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
773program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]774binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]775distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]776testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]777<pre>SAX.setDocumentLocator()
778SAX.startDocument()
779SAX.getEntity(amp)
780SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
781SAX.characters( , 3)
782SAX.startElement(head)
783SAX.characters( , 4)
784SAX.startElement(title)
785SAX.characters(Welcome to Gnome, 16)
786SAX.endElement(title)
787SAX.characters( , 3)
788SAX.endElement(head)
789SAX.characters( , 3)
790SAX.startElement(chapter)
791SAX.characters( , 4)
792SAX.startElement(title)
793SAX.characters(The Linux adventure, 19)
794SAX.endElement(title)
795SAX.characters( , 4)
796SAX.startElement(p)
797SAX.characters(bla bla bla ..., 15)
798SAX.endElement(p)
799SAX.characters( , 4)
800SAX.startElement(image, href='linus.gif')
801SAX.endElement(image)
802SAX.characters( , 4)
803SAX.startElement(p)
804SAX.characters(..., 3)
805SAX.endElement(p)
806SAX.characters( , 3)
807SAX.endElement(chapter)
808SAX.characters( , 1)
809SAX.endElement(EXAMPLE)
810SAX.endDocument()</pre>
811
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]812<p>Most of the other interfaces of libxml are based on the DOM tree-building
813facility, so nearly everything up to the end of this document presupposes the
814use of the standard DOM tree build. Note that the DOM tree itself is built by
815a set of registered default callbacks, without internal specific
816interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]817
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]818<h2><a name="library">The XML library interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]819
820<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]821using the XML library from the C language. It is not intended to be extensive.
822I hope the automatically generated documents will provide the completeness
823required, but as a separate set of documents. The interfaces of the XML
824library are by principle low level, there is nearly zero abstraction. Those
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]825interested in a higher level API should <a href="#DOM">look at DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]826
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]827<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
828separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]829interfaces</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]830
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]831<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]832
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]833<p>Usually, the first thing to do is to read an XML input. The parser accepts
834documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]835defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]836<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]837 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]838 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]839 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]840</dl>
841<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]842 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]843 <dd><p>Parse an XML document contained in a (possibly compressed)
844 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]845 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]846</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]847
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]848<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]849failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]850
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]851<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]852
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]853<p>In order for the application to keep the control when the document is being
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]854fetched (which is common for GUI based programs) libxml provides a push
855interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]856<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
857 void *user_data,
858 const char *chunk,
859 int size,
860 const char *filename);
861int xmlParseChunk (xmlParserCtxtPtr ctxt,
862 const char *chunk,
863 int size,
864 int terminate);</pre>
865
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]866<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]867<pre> FILE *f;
868
869 f = fopen(filename, "r");
870 if (f != NULL) {
871 int res, size = 1024;
872 char chars[1024];
873 xmlParserCtxtPtr ctxt;
874
875 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]876 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]877 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
878 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]879 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]880 xmlParseChunk(ctxt, chars, res, 0);
881 }
882 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]883 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]884 xmlFreeParserCtxt(ctxt);
885 }
886 }</pre>
887
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]888<p>The HTML parser embedded into libxml also has a push interface; the
889functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]890
891<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
892
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]893<p>The tree-building interface makes the parser memory-hungry, first loading
894the document in memory and then building the tree itself. Reading a document
895without building the tree is possible using the SAX interfaces (see SAX.h and
896<a href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]897Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]898limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]899<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]900
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]901<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]902
903<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]904there is a set of functions dedicated to building new elements. (These are
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]905also 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]906that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]907<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]908 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]909 xmlNodePtr tree, subtree;
910
911 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]912 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
913 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
914 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
915 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]916 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]917 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]918 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
919 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
920 subtree = xmlNewChild(tree, NULL, "image", NULL);
921 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]922
923<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]924
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]925<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]926
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]927<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]928code has access to the internal structure of all the elements of the tree. The
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]929names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]930<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]931<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]932example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]933<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]934
935<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]936<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]937
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]938<p>points to the text node containing the chapter title "The Linux
939adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]940
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]941<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]942present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]943to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]944<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]945
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]946<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]947
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]948<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]949is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]950<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]951 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
952 xmlChar *value);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]953 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node. The
954 value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]955 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]956</dl>
957<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]958 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]959 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]960 <dd><p>This function returns a pointer to new copy of the property
961 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]962 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]963</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]964
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]965<p>Two functions are provided for reading and writing the text associated with
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]966elements:</p>
967<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]968 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]969 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]970 <dd><p>This function takes an "external" string and converts it to one
971 text node or possibly to a list of entity and text nodes. All
972 non-predefined entity references like &amp;Gnome; will be stored
973 internally as entity nodes, hence the result of the function may not be
974 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]975 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]976</dl>
977<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]978 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]979 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]980 <dd><p>This function is the inverse of
981 <code>xmlStringGetNodeList()</code>. It generates a new string
982 containing the content of the text and entity nodes. Note the extra
983 argument inLine. If this argument is set to 1, the function will expand
984 entity references. For example, instead of returning the &amp;Gnome;
985 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]986 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]987 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]988</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]989
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]990<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]991
992<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]993<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]994 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]995 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]996 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]997 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]998</dl>
999<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1000 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1001 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1002 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1003</dl>
1004<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1005 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1006 <dd><p>Saves the document to a file. In this case, the compression
1007 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1008 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1009</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1010
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1011<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1012
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1013<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1014accesses. The level of compression on saves can be turned on either globally
1015or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1016<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1017 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1018 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1019 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1020</dl>
1021<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1022 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1023 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1024 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1025</dl>
1026<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1027 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1028 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1029 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1030</dl>
1031<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1032 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1033 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1034 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1035</dl>
1036
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1037<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1038
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1039<p>Entities in principle are similar to simple C macros. An entity defines an
1040abbreviation for a given string that you can reuse many times throughout the
1041content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1042may occur frequently within a document, or to confine the change needed to a
1043document to a restricted area in the internal subset of the document (at the
1044beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1045<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]10462 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]10473 &lt;!ENTITY xml "Extensible Markup Language"&gt;
10484 ]&gt;
10495 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]10506 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]10517 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1052
1053<p>Line 3 declares the xml entity. Line 6 uses the xml entity, by prefixing
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1054its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1055are 5 predefined entities in libxml allowing you to escape charaters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1056predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1057<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1058for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1059<strong>&amp;quot;</strong> for the character '"', and
1060<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1061
1062<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]1063substitute an entity's content so that you can see the replacement text in
1064your application. Or you may prefer to keep entity references as such in the
1065content to be able to save the document back without losing this usually
1066precious information (if the user went through the pain of explicitly defining
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1067entities, he may have a a rather negative attitude if you blindly susbtitute
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1068them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1069href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1070function allows you to check and change the behaviour, which is to not
1071substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1072
1073<p>Here is the DOM tree built by libxml for the previous document in the
1074default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1075<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1076DOCUMENT
1077version=1.0
1078 ELEMENT EXAMPLE
1079 TEXT
1080 content=
1081 ENTITY_REF
1082 INTERNAL_GENERAL_ENTITY xml
1083 content=Extensible Markup Language
1084 TEXT
1085 content=</pre>
1086
1087<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1088<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1089DOCUMENT
1090version=1.0
1091 ELEMENT EXAMPLE
1092 TEXT
1093 content= Extensible Markup Language</pre>
1094
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1095<p>So, entities or no entities? Basically, it depends on your use case. I
1096suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1097entities in your XML document or data if you are not willing to handle the
1098entity references elements in the DOM tree.</p>
1099
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1100<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1101entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1102transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1103reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1104finding them in the input).</p>
1105
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1106<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1107on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1108non-predefined entities in your documents, then the learning cuvre to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1109then using the SAX API may be long. If you plan to use complex documents, I
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1110strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]1111deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1112
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1113<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1114
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1115<p>The libxml library implements <a
1116href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
1117recognizing namespace contructs in the input, and does namespace lookup
1118automatically when building the DOM tree. A namespace declaration is
1119associated with an in-memory structure and all elements or attributes within
1120that namespace point to it. Hence testing the namespace is a simple and fast
1121equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1122
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1123<p>I suggest that people using libxml use a namespace, and declare it in the
1124root element of their document as the default namespace. Then they don't need
1125to use the prefix in the content but we will have a basis for future semantic
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1126refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1127the size of the XML output significantly, but significantly increases its
1128value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1129<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
1130 &lt;elem1&gt;...&lt;/elem1&gt;
1131 &lt;elem2&gt;...&lt;/elem2&gt;
1132&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1133
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1134<p>The namespace value has to be an absolute URL, but the URL doesn't have to
1135point to any existing resource on the Web. It will bind all the element and
1136atributes with that URL. I suggest to use an URL within a domain you control,
1137and that the URL should contain some kind of version information if possible.
1138For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a good
1139namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1140
1141<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1142version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1143and if the version information don't match something you know, warn the user
1144and 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]1145namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1146same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1147associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1148just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1149<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1150prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1151
1152<p>@@Interfaces@@</p>
1153
1154<p>@@Examples@@</p>
1155
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1156<p>Usually people object to using namespaces together with validity checking.
1157I will try to make sure that using namespaces won't break validity checking,
1158so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1159suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1160<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1161flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1162from multiple DTDs will certainly break current validation schemes. I will try
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1163to provide ways to do this, but this may not be portable or standardized.</p>
1164
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1165<h2><a name="Validation">Validation, or are you afraid of DTDs ?</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1166
1167<p>Well what is validation and what is a DTD ?</p>
1168
1169<p>Validation is the process of checking a document against a set of
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1170construction rules; a <strong>DTD</strong> (Document Type Definition) is such
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1171a set of rules.</p>
1172
1173<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1174of the XML life cycle. Briefly a DTD defines all the possibles element to be
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1175found within your document, what is the formal shape of your document tree (by
1176defining the allowed content of an element, either text, a regular expression
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1177for the allowed list of children, or mixed content i.e. both text and
1178children). The DTD also defines the allowed attributes for all elements and
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1179the types of the attributes. For more detailed information, I suggest that you
Daniel Veillard81781102001-03-07 09:31:47 +0000[diff] [blame]1180read the related parts of the XML specification, the examples found under
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1181gnome-xml/test/valid/dtd and any of the large number of books available on
1182XML. The dia example in gnome-xml/test/valid should be both simple and
1183complete enough to allow you to build your own.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1184
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1185<p>A word of warning, building a good DTD which will fit the needs of your
1186application in the long-term is far from trivial; however, the extra level of
1187quality it can ensure is well worth the price for some sets of applications or
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1188if you already have already a DTD defined for your application field.</p>
1189
1190<p>The validation is not completely finished but in a (very IMHO) usable
1191state. Until a real validation interface is defined the way to do it is to
1192define and set the <strong>xmlDoValidityCheckingDefaultValue</strong> external
1193variable to 1, this will of course be changed at some point:</p>
1194
1195<p>extern int xmlDoValidityCheckingDefaultValue;</p>
1196
1197<p>...</p>
1198
1199<p>xmlDoValidityCheckingDefaultValue = 1;</p>
1200
1201<p></p>
1202
1203<p>To handle external entities, use the function
1204<strong>xmlSetExternalEntityLoader</strong>(xmlExternalEntityLoader f); to
1205link in you HTTP/FTP/Entities database library to the standard libxml
1206core.</p>
1207
1208<p>@@interfaces@@</p>
1209
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1210<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1211
1212<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document Object
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1213Model</em>; this is an API for accessing XML or HTML structured documents.
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1214Native support for DOM in Gnome is on the way (module gnome-dom), and will be
1215based on gnome-xml. This will be a far cleaner interface to manipulate XML
Daniel Veillardc08a2c61999-09-08 21:35:25 +0000[diff] [blame]1216files within Gnome since it won't expose the internal structure. DOM defines a
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1217set of IDL (or Java) interfaces allowing you to traverse and manipulate a
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1218document. The DOM library will allow accessing and modifying "live" documents
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1219present in other programs like this:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1220
1221<p><img src="DOM.gif" alt=" DOM.gif "></p>
1222
1223<p>This should help greatly doing things like modifying a gnumeric spreadsheet
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1224embedded in a GWP document for example.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1225
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1226<p>The current DOM implementation on top of libxml is the <a
1227href="http://cvs.gnome.org/lxr/source/gdome/">gdome Gnome module</a>, this is
1228a full DOM interface, thanks to <a href="mailto:raph@levien.com">Raph
1229Levien</a>.</p>
1230
1231<p>The gnome-dom module in the Gnome CVS base is obsolete</p>
1232
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1233<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1234
1235<p>Here is a real size example, where the actual content of the application
1236data 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]1237a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1238storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
1239base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1240<pre>&lt;?xml version="1.0"?&gt;
1241&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
1242 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1243
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1244 &lt;gjob:Job&gt;
1245 &lt;gjob:Project ID="3"/&gt;
1246 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
1247 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1248
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1249 &lt;gjob:Update&gt;
1250 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
1251 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
1252 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
1253 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1254
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1255 &lt;gjob:Developers&gt;
1256 &lt;gjob:Developer&gt;
1257 &lt;/gjob:Developer&gt;
1258 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1259
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1260 &lt;gjob:Contact&gt;
1261 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
1262 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
1263 &lt;gjob:Company&gt;
1264 &lt;/gjob:Company&gt;
1265 &lt;gjob:Organisation&gt;
1266 &lt;/gjob:Organisation&gt;
1267 &lt;gjob:Webpage&gt;
1268 &lt;/gjob:Webpage&gt;
1269 &lt;gjob:Snailmail&gt;
1270 &lt;/gjob:Snailmail&gt;
1271 &lt;gjob:Phone&gt;
1272 &lt;/gjob:Phone&gt;
1273 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1274
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1275 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1276 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1277 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1278
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1279 &lt;gjob:Skills&gt;
1280 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1281
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 A GNOME based system that will allow a superuser to configure
1284 compressed and uncompressed files and/or file systems to be backed
1285 up with a supported media in the system. This should be able to
1286 perform via find commands generating a list of files that are passed
1287 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
1288 or via operations performed on the filesystem itself. Email
1289 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1290 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1291
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1292 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1293
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1294 &lt;/gjob:Jobs&gt;
1295&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1296
1297<p>While loading the XML file into an internal DOM tree is a matter of calling
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1298only a couple of functions, browsing the tree to gather the ata and generate
1299the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1300
1301<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1302structure. For example, the ordering of the attributes is not significant, the
1303XML specification is clear about it. It's also usually a good idea not to
1304depend on the order of the children of a given node, unless it really makes
1305things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1306<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1307 * A person record
1308 */
1309typedef struct person {
1310 char *name;
1311 char *email;
1312 char *company;
1313 char *organisation;
1314 char *smail;
1315 char *webPage;
1316 char *phone;
1317} person, *personPtr;
1318
1319/*
1320 * And the code needed to parse it
1321 */
1322personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1323 personPtr ret = NULL;
1324
1325DEBUG("parsePerson\n");
1326 /*
1327 * allocate the struct
1328 */
1329 ret = (personPtr) malloc(sizeof(person));
1330 if (ret == NULL) {
1331 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1332 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1333 }
1334 memset(ret, 0, sizeof(person));
1335
1336 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1337 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1338 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1339 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
1340 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1341 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
1342 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1343 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1344 }
1345
1346 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1347}</pre>
1348
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1349<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1350<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1351 <li>Usually a recursive parsing style is the more convenient one: XML data
1352 is by nature subject to repetitive constructs and usually exibits highly
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1353 stuctured patterns.</li>
1354 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>, i.e.
1355 the pointer to the global XML document and the namespace reserved to the
1356 application. Document wide information are needed for example to decode
1357 entities and it's a good coding practice to define a namespace for your
1358 application set of data and test that the element and attributes you're
1359 analyzing actually pertains to your application space. This is done by a
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1360 simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1361 <li>To retrieve text and attributes value, you can use the function
1362 <em>xmlNodeListGetString</em> to gather all the text and entity reference
1363 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1364</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1365
1366<p>Here is another piece of code used to parse another level of the
1367structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1368<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1369/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1370 * a Description for a Job
1371 */
1372typedef struct job {
1373 char *projectID;
1374 char *application;
1375 char *category;
1376 personPtr contact;
1377 int nbDevelopers;
1378 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
1379} job, *jobPtr;
1380
1381/*
1382 * And the code needed to parse it
1383 */
1384jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1385 jobPtr ret = NULL;
1386
1387DEBUG("parseJob\n");
1388 /*
1389 * allocate the struct
1390 */
1391 ret = (jobPtr) malloc(sizeof(job));
1392 if (ret == NULL) {
1393 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1394 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1395 }
1396 memset(ret, 0, sizeof(job));
1397
1398 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1399 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1400 while (cur != NULL) {
1401
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1402 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
1403 ret-&gt;projectID = xmlGetProp(cur, "ID");
1404 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1405 fprintf(stderr, "Project has no ID\n");
1406 }
1407 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1408 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
1409 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1410 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
1411 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1412 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
1413 ret-&gt;contact = parsePerson(doc, ns, cur);
1414 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1415 }
1416
1417 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1418}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1419
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1420<p>Once you are used to it, writing this kind of code is quite simple, but
1421boring. Ultimately, it could be possble to write stubbers taking either C data
1422structure definitions, a set of XML examples or an XML DTD and produce the
1423code needed to import and export the content between C data and XML storage.
1424This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1425
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]1426<p>Feel free to use <a href="example/gjobread.c">the code for the full C
1427parsing example</a> as a template, it is also available with Makefile in the
1428Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1429
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1430<h2><a name="Contributi">Contributions</a></h2>
1431<ul>
Daniel Veillard851c59c2000-11-24 16:06:22 +0000[diff] [blame]1432 <li><a href="mailto:ari@lusis.org">Ari Johnson</a> provides a C++ wrapper
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1433 for libxml:
1434 <p>Website: <a
1435 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
1436 <p>Download: <a
1437 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
1438 </li>
1439 <li><a href="mailto:doolin@cs.utk.edu">David Doolin</a> provides a
1440 precompiled Windows version
1441 <p><a
1442 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
1443 </li>
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1444 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> provided <a
1445 href="libxml-doc.el">an emacs module</a> to lookup libxml functions
1446 documentation</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1447 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
1448 href="http://xmlsoft.org/messages/0488.html">man pages</a> (not yet
1449 integrated in the distribution)</li>
1450</ul>
1451
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1452<p></p>
1453
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame^]1454<p><a href="mailto:Daniel.Veillard@imag.fr">Daniel Veillard</a></p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1455
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame^]1456<p>$Id: xml.html,v 1.72 2001/03/07 09:31:47 veillard Exp $</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1457</body>
1458</html>