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Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1<html>
2<head>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]3 <title>The XML C library for Gnome</title>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]4 <meta name="GENERATOR" content="amaya V4.1">
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]5 <meta http-equiv="Content-Type" content="text/html">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]6</head>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]7
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]8<body bgcolor="#ffffff">
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]9<p><a href="http://www.gnome.org/"><img src="smallfootonly.gif"
10alt="Gnome Logo"></a><a href="http://www.w3.org/Status"><img src="w3c.png"
11alt="W3C Logo"></a></p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]12
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]13<h1 align="center">The XML C library for Gnome</h1>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]14
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]15<h2 style="text-align: center">libxml, a.k.a. gnome-xml</h2>
16
17<p></p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]18<ul>
19 <li><a href="#Introducti">Introduction</a></li>
20 <li><a href="#Documentat">Documentation</a></li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]21 <li><a href="#Reporting">Reporting bugs and getting help</a></li>
22 <li><a href="#help">how to help</a></li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]23 <li><a href="#Downloads">Downloads</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]24 <li><a href="#News">News</a></li>
25 <li><a href="#XML">XML</a></li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]26 <li><a href="#XSLT">XSLT</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]27 <li><a href="#tree">The tree output</a></li>
28 <li><a href="#interface">The SAX interface</a></li>
29 <li><a href="#library">The XML library interfaces</a>
30 <ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]31 <li><a href="#Invoking">Invoking the parser: the pull way</a></li>
32 <li><a href="#Invoking">Invoking the parser: the push way</a></li>
33 <li><a href="#Invoking2">Invoking the parser: the SAX interface</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]34 <li><a href="#Building">Building a tree from scratch</a></li>
35 <li><a href="#Traversing">Traversing the tree</a></li>
36 <li><a href="#Modifying">Modifying the tree</a></li>
37 <li><a href="#Saving">Saving the tree</a></li>
38 <li><a href="#Compressio">Compression</a></li>
39 </ul>
40 </li>
41 <li><a href="#Entities">Entities or no entities</a></li>
42 <li><a href="#Namespaces">Namespaces</a></li>
43 <li><a href="#Validation">Validation</a></li>
44 <li><a href="#Principles">DOM principles</a></li>
45 <li><a href="#real">A real example</a></li>
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]46 <li><a href="#Contributi">Contributions</a></li>
47</ul>
48
49<p>Separate documents:</p>
50<ul>
51 <li><a href="upgrade.html">upgrade instructions for migrating to
52 libxml2</a></li>
53 <li><a href="encoding.html">libxml Internationalization support</a></li>
54 <li><a href="xmlio.html">libxml Input/Output interfaces</a></li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]55 <li><a href="xmlmem.html">libxml Memory interfaces</a></li>
Daniel Veillard300f7d62000-11-24 13:04:04 +0000[diff] [blame]56 <li><a href="xmldtd.html">a short introduction about DTDs and
57 libxml</a></li>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]58 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]59</ul>
60
61<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]62
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]63<p>This document describes libxml, the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]64href="http://www.w3.org/XML/">XML</a> C library developped for the <a
65href="http://www.gnome.org/">Gnome</a> project. <a
66href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
67structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]68
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]69<p>Here are some key points about libxml:</p>
70<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]71 <li>Libxml exports Push and Pull type parser interfaces for both XML and
72 HTML.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]73 <li>Libxml can do DTD validation at parse time, using a parsed document
74 instance, or with an arbitrary DTD.</li>
75 <li>Libxml now includes nearly complete <a
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]76 href="http://www.w3.org/TR/xpath">XPath</a> and <a
Daniel Veillard0c069222000-10-21 09:25:52 +0000[diff] [blame]77 href="http://www.w3.org/TR/xptr">XPointer</a> implementations.</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]78 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]79 sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]80 Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]81 <li>Basic support for HTTP and FTP client allowing aplications to fetch
82 remote resources</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]83 <li>The design is modular, most of the extensions can be compiled out.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]84 <li>The internal document repesentation is as close as possible to the <a
85 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
86 <li>Libxml also has a <a href="http://www.megginson.com/SAX/index.html">SAX
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]87 like interface</a>; the interface is designed to be compatible with <a
88 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]89 <li>This library is released both under the <a
90 href="http://www.w3.org/Consortium/Legal/copyright-software-19980720.html">W3C
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]91 IPR</a> and the <a href="http://www.gnu.org/copyleft/lesser.html">GNU
92 LGPL</a>. Use either at your convenience, basically this should make
93 everybody happy, if not, drop me a mail.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]94</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]95
Daniel Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]96<p>Warning: unless you are forced to because your application links with a
97Gnome library requiring it, <strong><span
98style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
99libxml2</p>
100
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]101<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]102
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]103<p>There are some on-line resources about using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]104<ol>
Daniel Veillard365e13b2000-07-02 07:56:37 +0000[diff] [blame]105 <li>Check the <a href="FAQ.html">FAQ</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]106 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]107 documentation</a> automatically extracted from code comments (using <a
108 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
109 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]110 <li>Look at the documentation about <a href="encoding.html">libxml
111 internationalization support</a></li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]112 <li>This page provides a global overview and <a href="#real">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]113 examples</a> on how to use libxml.</li>
114 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
115 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
116 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]117 <li>George Lebl wrote <a
118 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]119 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]120 <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]121 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]122 building the <a href="http://levien.com/gnome/gdome.html">DOM interface
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]123 gdome</a> on top of libxml result tree and an implementation of <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]124 href="http://www.w3.org/Graphics/SVG/">SVG</a> called <a
125 href="http://www.levien.com/svg/">gill</a>. Check his <a
126 href="http://www.levien.com/gnome/domination.html">DOMination
127 paper</a>.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]128 <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO
129 file</a></li>
130 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>. If you are
131 starting a new project using libxml you should really use the 2.x
132 version.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]133 <li>And don't forget to look at the <a href="/messages/">mailing-list
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]134 archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]135</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]136
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]137<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]138
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]139<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]140of 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]141<a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
142tracking database</a> (make sure to use the "libxml" module name). I look at
143reports there regularly and it's good to have a reminder when a bug is still
144open. Check the <a href="http://bugs.gnome.org/Reporting.html">instructions on
145reporting bugs</a> and be sure to specify that the bug is for the package
146libxml.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]147
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]148<p>There is also a mailing-list <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]149href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]150href="http://xmlsoft.org/messages">on-line archive</a>. To subscribe to this
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]151list, please visit the <a
152href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
153follow the instructions.</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]154
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]155<p>Alternatively, you can just send the bug to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]156href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillardf121ab72000-08-29 23:40:42 +0000[diff] [blame]157related I will approve it..</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]158
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]159<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]160probably be processed faster.</p>
161
162<p>If you're looking for help, a quick look at <a
163href="http://xmlsoft.org/messages/#407">the list archive</a> may actually
164provide the answer, I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]165questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]166documentantion</a> is not as polished as I would like (i need to learn more
167about Docbook), but it's a good starting point.</p>
168
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]169<h2><a name="help">How to help</a></h2>
170
171<p>You can help the project in various ways, the best thing to do first is to
172subscribe to the mailing-list as explained before, check the <a
173href="http://xmlsoft.org/messages/">archives </a>and the <a
174href="http://bugs.gnome.org/db/pa/lgnome-xml.html">Gnome bug
175database:</a>:</p>
176<ol>
177 <li>provide patches when you find problems</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]178 <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]179 be integrated in all cases but help pinpointing portability problems
180 and</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]181 <li>provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]182 as HTML diffs).</li>
183 <li>provide new documentations pieces (translations, examples, etc ...)</li>
184 <li>Check the TODO file and try to close one of the items</li>
185 <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]186 provide a fix. <a href="mailto:Daniel.Veillard@imag.fr">Get in touch with
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]187 me </a>before to avoid synchronization problems and check that the
188 suggested fix will fit in nicely :-)</li>
189</ol>
190
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]191<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]192
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]193<p>The latest versions of libxml can be found on <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]194href="ftp://xmlsoft.org/">xmlsoft.org</a> or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]195href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]196as a <a href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">source
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]197archive</a> or <a
198href="ftp://ftp.gnome.org/pub/GNOME/contrib/redhat/SRPMS/">RPM packages</a>.
199(NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]200href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
201href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]202packages installed to compile applications using libxml.)</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]203
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]204<p><a name="Snapshot">Snapshot:</a></p>
205<ul>
206 <li>Code from the W3C cvs base libxml <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]207 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]208 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]209 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]210</ul>
211
212<p><a name="Contribs">Contribs:</a></p>
213
214<p>I do accept external contributions, especially if compiling on another
215platform, 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]216<a href="ftp://xmlsoft.org/contribs/">contrib directory</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]217
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]218<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]219<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]220 <li><p>The <a
221 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]222 CVS base</a>. Check the <a
223 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a> page;
224 the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]225 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]226 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]227</ul>
228
229<h2><a name="News">News</a></h2>
230
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]231<h3>CVS only : check the <a
232href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]233for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]234
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]235<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]236you want to test those</p>
237<ul>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]238 <li>Implementing <a href="http://xmlsoft.org/XSLT">XSLT</a>, this is done as
239 a separate C library on top of libxml called libxslt, not released yet but
240 available from CVS</li>
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]241 <li>Finishing up <a href="http://www.w3.org/TR/xptr">XPointer</a> and <a
242 href="http://www.w3.org/TR/xinclude">XInclude</a></li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]243 <li>(seeems working but delayed from release) parsing/import of Docbook SGML
244 docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]245</ul>
246
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame^]247<h3>2.3.5: Mar 23 2001</h3>
248<ul>
249 <li>Biggest change is separate parsing and evaluation of XPath expressions,
250 there is some new APIs for this too</li>
251 <li>included a number of bug fixes(XML push parser, 51876, notations,
252 52299)</li>
253 <li>Fixed some portability issues</li>
254</ul>
255
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]256<h3>2.3.4: Mar 10 2001</h3>
257<ul>
258 <li>Fixed bugs #51860 and #51861</li>
259 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
260 size to be application tunable.</li>
261 <li>Some cleanup in the validation code, still a bug left and this part
262 should probably be rewritten to support ambiguous content model :-\</li>
263 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
264 parser</li>
265 <li>Fixed another bug in xmlNodeGetContent()</li>
266 <li>Bjorn fixed XPath node collection and Number formatting</li>
267 <li>Fixed a loop reported in the HTML parsing</li>
268 <li>blank space are reported even if the Dtd content model proves that they
269 are formatting spaces, this is for XmL conformance</li>
270</ul>
271
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]272<h3>2.3.3: Mar 1 2001</h3>
273<ul>
274 <li>small change in XPath for XSLT</li>
275 <li>documentation cleanups</li>
276 <li>fix in validation by Gary Pennington</li>
277 <li>serious parsing performances improvements</li>
278</ul>
279
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]280<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]281<ul>
282 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
283 <li>fixed a Dtd parsing bug</li>
284 <li>fixed a bug in xmlNodeGetContent</li>
285 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
286</ul>
287
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]288<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]289<ul>
290 <li>some XPath and HTML bug fixes for XSLT</li>
291 <li>small extension of the hash table interfaces for DOM gdome2
292 implementation</li>
293 <li>A few bug fixes</li>
294</ul>
295
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]296<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]297<ul>
298 <li>Lots of XPath bug fixes</li>
299 <li>Add a mode with Dtd lookup but without validation error reporting for
300 XSLT</li>
301 <li>Add support for text node without escaping (XSLT)</li>
302 <li>bug fixes for xmlCheckFilename</li>
303 <li>validation code bug fixes from Gary Pennington</li>
304 <li>Patch from Paul D. Smith correcting URI path normalization</li>
305 <li>Patch to allow simultaneous install of libxml-devel and
306 libxml2-devel</li>
307 <li>the example Makefile is now fixed</li>
308 <li>added HTML to the RPM packages</li>
309 <li>tree copying bugfixes</li>
310 <li>updates to Windows makefiles</li>
311 <li>optimisation patch from Bjorn Reese</li>
312</ul>
313
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]314<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]315<ul>
316 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
317 <li>added htmlHandleOmittedElem()</li>
318 <li>Applied Bjorn Reese's IPV6 first patch</li>
319 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]320 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]321</ul>
322
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]323<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]324<ul>
325 <li>Fix the Windows problems of 2.2.8</li>
326 <li>integrate OpenVMS patches</li>
327 <li>better handling of some nasty HTML input</li>
328 <li>Improved the XPointer implementation</li>
329 <li>integrate a number of provided patches</li>
330</ul>
331
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]332<h3>2.2.9: Nov 25 2000</h3>
333<ul>
334 <li>erroneous release :-(</li>
335</ul>
336
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]337<h3>2.2.8: Nov 13 2000</h3>
338<ul>
339 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
340 support</li>
341 <li>Patch in conditional section handling</li>
342 <li>updated MS compiler project</li>
343 <li>fixed some XPath problems</li>
344 <li>added an URI escaping function</li>
345 <li>some other bug fixes</li>
346</ul>
347
348<h3>2.2.7: Oct 31 2000</h3>
349<ul>
350 <li>added message redirection</li>
351 <li>XPath improvements (thanks TOM !)</li>
352 <li>xmlIOParseDTD() added</li>
353 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
354 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
355</ul>
356
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]357<h3>2.2.6: Oct 25 2000:</h3>
358<ul>
359 <li>Added an hash table module, migrated a number of internal structure to
360 those</li>
361 <li>Fixed a posteriori validation problems</li>
362 <li>HTTP module cleanups</li>
363 <li>HTML parser improvements (tag errors, script/style handling, attribute
364 normalization)</li>
365 <li>coalescing of adjacent text nodes</li>
366 <li>couple of XPath bug fixes, exported the internal API</li>
367</ul>
368
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]369<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]370<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]371 <li>XPointer implementation and testsuite</li>
372 <li>Lot of XPath fixes, added variable and functions registration, more
373 tests</li>
374 <li>Portability fixes, lots of enhancements toward an easy Windows build and
375 release</li>
376 <li>Late validation fixes</li>
377 <li>Integrated a lot of contributed patches</li>
378 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]379 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]380</ul>
381
382<h3>2.2.4: Oct 1 2000:</h3>
383<ul>
384 <li>main XPath problem fixed</li>
385 <li>Integrated portability patches for Windows</li>
386 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]387</ul>
388
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]389<h3>2.2.3: Sep 17 2000</h3>
390<ul>
391 <li>bug fixes</li>
392 <li>cleanup of entity handling code</li>
393 <li>overall review of all loops in the parsers, all sprintf usage has been
394 checked too</li>
395 <li>Far better handling of larges Dtd. Validating against Docbook XML Dtd
396 works smoothly now.</li>
397</ul>
398
399<h3>1.8.10: Sep 6 2000</h3>
400<ul>
401 <li>bug fix release for some Gnome projects</li>
402</ul>
403
404<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]405<ul>
406 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]407 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]408</ul>
409
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]410<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]411<ul>
412 <li>a purely bug fixes release</li>
413 <li>fixed an encoding support problem when parsing from a memory block</li>
414 <li>fixed a DOCTYPE parsing problem</li>
415 <li>removed a bug in the function allowing to override the memory allocation
416 routines</li>
417</ul>
418
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]419<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]420<ul>
421 <li>applied a lot of portability fixes</li>
422 <li>better encoding support/cleanup and saving (content is now always
423 encoded in UTF-8)</li>
424 <li>the HTML parser now correctly handles encodings</li>
425 <li>added xmlHasProp()</li>
426 <li>fixed a serious problem with &amp;#38;</li>
427 <li>propagated the fix to FTP client</li>
428 <li>cleanup, bugfixes, etc ...</li>
429 <li>Added a page about <a href="encoding.html">libxml Internationalization
430 support</a></li>
431</ul>
432
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]433<h3>1.8.9: July 9 2000</h3>
434<ul>
435 <li>fixed the spec the RPMs should be better</li>
436 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
437 rpmfind users problem</li>
438</ul>
439
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]440<h3>2.1.1: July 1 2000</h3>
441<ul>
442 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
443 <li>improvements on the HTML parser</li>
444</ul>
445
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]446<h3>2.1.0 and 1.8.8: June 29 2000</h3>
447<ul>
448 <li>1.8.8 is mostly a comodity package for upgrading to libxml2 accoding to
449 <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
450 about &amp;#38; charref parsing</li>
451 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
452 also contains numerous fixes and enhancements:
453 <ul>
454 <li>added xmlStopParser() to stop parsing</li>
455 <li>improved a lot parsing speed when there is large CDATA blocs</li>
456 <li>includes XPath patches provided by Picdar Technology</li>
457 <li>tried to fix as much as possible DtD validation and namespace
458 related problems</li>
459 <li>output to a given encoding has been added/tested</li>
460 <li>lot of various fixes</li>
461 </ul>
462 </li>
463</ul>
464
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]465<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]466<ul>
467 <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]468 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initally
469 scheduled for Apr 3 the relase occured only on Apr 12 due to massive
470 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]471 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]472 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]473 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]474 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]475 <pre>#include "xxx.h"</pre>
476 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]477 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
478 <li>the memory allocation routines used by libxml can now be overloaded
479 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]480 <li>The previously CVS only tool tester has been renamed
481 <strong>xmllint</strong> and is now installed as part of the libxml2
482 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]483 <li>The I/O interface has been revamped. There is now ways to plug in
484 specific I/O modules, either at the URI scheme detection level using
485 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
486 parser context using xmlCreateIOParserCtxt()</li>
487 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
488 number of the libxml module in use</li>
489 <li>a number of optional features of libxml can now be excluded at configure
490 time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]491</ul>
492
493<h3>2.0.0beta: Mar 14 2000</h3>
494<ul>
495 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]496 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
497 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
498 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]499 <li>This version is now the head in the Gnome CVS base, the old one is
500 available under the tag LIB_XML_1_X</li>
501 <li>This includes a very large set of changes. Froma programmatic point of
502 view applications should not have to be modified too much, check the <a
503 href="upgrade.html">upgrade page</a></li>
504 <li>Some interfaces may changes (especially a bit about encoding).</li>
505 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]506 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]507 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
508 handled now</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]509 <li>Better handling of entities, especially well formedness checking and
510 proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]511 <li>DTD conditional sections</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]512 <li>Validation now correcly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]513 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
514 structures to accomodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]515 </ul>
516 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]517 <li>Serious progress were made toward compliance, <a
518 href="conf/result.html">here are the result of the test</a> against the
519 OASIS testsuite (except the japanese tests since I don't support that
520 encoding yet). This URL is rebuilt every couple of hours using the CVS
521 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]522</ul>
523
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]524<h3>1.8.7: Mar 6 2000</h3>
525<ul>
526 <li>This is a bug fix release:</li>
527 <li>It is possible to disable the ignorable blanks heuristic used by
528 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
529 that for adherence to XML spec, this behaviour will be disabled by default
530 in 2.x . The same function will allow to keep compatibility for old
531 code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]532 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
533 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]534 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
535 compilation on some platforms has been fixed</li>
536 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
537 URIs</li>
538</ul>
539
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]540<h3>1.8.6: Jan 31 2000</h3>
541<ul>
542 <li>added a nanoFTP transport module, debugged until the new version of <a
543 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
544 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]545</ul>
546
547<h3>1.8.5: Jan 21 2000</h3>
548<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]549 <li>adding APIs to parse a well balanced chunk of XML (production <a
550 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the XML
551 spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]552 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]553 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
554 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]555 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
556 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]557</ul>
558
559<h3>1.8.4: Jan 13 2000</h3>
560<ul>
561 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
562 <li>all exit() call should have been removed from libxml</li>
563 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
564 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]565</ul>
566
567<h3>1.8.3: Jan 5 2000</h3>
568<ul>
569 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]570 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillarddbfd6411999-12-28 16:35:14 +0000[diff] [blame]571 <li>lots of bug fixes and improvement added over XMas hollidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]572 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]573 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
574 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]575 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]576 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]577 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]578</ul>
579
580<h3>1.8.2: Dec 21 1999</h3>
581<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]582 <li>I got another problem with includes and C++, I hope this issue is fixed
583 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]584 <li>Added a few tree modification functions: xmlReplaceNode,
585 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
586 xmlDocSetRootElement</li>
587 <li>Tried to improve the HTML output with help from <a
588 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]589</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]590
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]591<h3>1.8.1: Dec 18 1999</h3>
592<ul>
593 <li>various patches to avoid troubles when using libxml with C++ compilers
594 the "namespace" keyword and C escaping in include files</li>
595 <li>a problem in one of the core macros IS_CHAR was corrected</li>
596 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
597 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]598 <li>fixed a posteriori validation (validation after parsing, or by using a
599 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]600 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]601</ul>
602
603<h3>1.8.0: Dec 12 1999</h3>
604<ul>
605 <li>cleanup, especially memory wise</li>
606 <li>the parser should be more reliable, especially the HTML one, it should
607 not crash, whatever the input !</li>
608 <li>Integrated various patches, especially a speedup improvement for large
609 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
610 configure with --with-buffers to enable them.</li>
611 <li>attribute normalization, oops should have been added long ago !</li>
612 <li>attributes defaulted from Dtds should be available, xmlSetProp() now
613 does entities escapting by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]614</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]615
616<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]617<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]618 <li>Lots of HTML improvement</li>
619 <li>Fixed some errors when saving both XML and HTML</li>
620 <li>More examples, the regression tests should now look clean</li>
621 <li>Fixed a bug with contiguous charref</li>
622</ul>
623
624<h3>1.7.3: Sep 29 1999</h3>
625<ul>
626 <li>portability problems fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]627 <li>snprintf was used unconditionnally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]628 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]629</ul>
630
631<h3>1.7.1: Sep 24 1999</h3>
632<ul>
633 <li>The basic type for strings manipulated by libxml has been renamed in
634 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
635 is that CHAR was conflicting with a predefined type on Windows. However on
636 non WIN32 environment, compatibility is provided by the way of a
637 <strong>#define </strong>.</li>
638 <li>Changed another error : the use of a structure field called errno, and
639 leading to troubles on platforms where it's a macro</li>
640</ul>
641
642<h3>1.7.0: sep 23 1999</h3>
643<ul>
644 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]645 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]646 <li>Added an errno to report errors by another mean than a simple printf
647 like callback</li>
648 <li>Finished ID/IDREF support and checking when validation</li>
649 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]650 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]651 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
652 implementation</li>
653 <li>Added an HTML parser front-end</li>
654</ul>
655
656<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]657
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]658<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]659markup-based structured documents. Here is <a name="example">an example XML
660document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]661<pre>&lt;?xml version="1.0"?&gt;
662&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
663 &lt;head&gt;
664 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
665 &lt;/head&gt;
666 &lt;chapter&gt;
667 &lt;title&gt;The Linux adventure&lt;/title&gt;
668 &lt;p&gt;bla bla bla ...&lt;/p&gt;
669 &lt;image href="linus.gif"/&gt;
670 &lt;p&gt;...&lt;/p&gt;
671 &lt;/chapter&gt;
672&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]673
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]674<p>The first line specifies that it's an XML document and gives useful
675information about its encoding. Then the document is a text format whose
676structure is specified by tags between brackets. <strong>Each tag opened has
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]677to be closed</strong>. XML is pedantic about this. However, if a tag is empty
678(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]679ends with <code>/&gt;</code> rather than with <code>&gt;</code>. Note that,
680for example, the image tag has no content (just an attribute) and is closed by
681ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]682
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]683<p>XML can be applied sucessfully to a wide range of uses, from long term
684structured document maintenance (where it follows the steps of SGML) to simple
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]685data encoding mechanisms like configuration file formatting (glade),
686spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where
687it is used to encode remote calls between a client and a server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]688
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]689<h2><a name="XSLT">XSLT</a></h2>
690
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]691<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
692
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]693<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a language
694for transforming XML documents into other XML documents (or HTML/textual
695output).</p>
696
697<p>A separate library called libxslt is being built on top of libxml2. This
698module "libxslt" can be found in the Gnome CVS base too.</p>
699
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]700<p>You can check the <a
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]701href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a> supported
702and the progresses on the <a
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]703href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog">Changelog</a></p>
704
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]705<h2>An overview of libxml architecture</h2>
706
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]707<p>Libxml is made of multiple components; some of them are optional, and most
708of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]709<ul>
710 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]711 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]712 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]713 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]714 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]715 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]716 <li>a SAX tree module to build an in-memory DOM representation</li>
717 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]718 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]719 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]720 (optional)</li>
721 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]722</ul>
723
724<p>Graphically this gives the following:</p>
725
726<p><img src="libxml.gif" alt="a graphical view of the various"></p>
727
728<p></p>
729
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]730<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]731
732<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]733returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]734<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]735as the file name, the document type, and a <strong>children</strong> pointer
736which is the root of the document (or more exactly the first child under the
737root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]738chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]739relationship. An xmlNode can also carry properties (a chain of xmlAttr
740structures). An attribute may have a value which is a list of TEXT or
741ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]742
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]743<p>Here is an example (erroneous with respect to the XML spec since there
744should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]745
746<p><img src="structure.gif" alt=" structure.gif "></p>
747
748<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]749called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]750prints them back as parsed. This is useful for detecting errors both in XML
751code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]752which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]753result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]754<pre>DOCUMENT
755version=1.0
756standalone=true
757 ELEMENT EXAMPLE
758 ATTRIBUTE prop1
759 TEXT
760 content=gnome is great
761 ATTRIBUTE prop2
762 ENTITY_REF
763 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]764 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]765 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]766 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]767 TEXT
768 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]769 ELEMENT chapter
770 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]771 TEXT
772 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]773 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]774 TEXT
775 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]776 ELEMENT image
777 ATTRIBUTE href
778 TEXT
779 content=linus.gif
780 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]781 TEXT
782 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]783
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]784<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]785
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]786<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]787
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]788<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]789memory. In that case (and if you don't expect to save back the XML document
790loaded 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]791<strong>callback-based interface</strong> to the parser. Before parsing, the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]792application layer registers a customized set of callbacks which are called by
793the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]794
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]795<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]796libxml, see the <a
797href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
798documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]799Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]800
801<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
802program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]803binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]804distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]805testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]806<pre>SAX.setDocumentLocator()
807SAX.startDocument()
808SAX.getEntity(amp)
809SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
810SAX.characters( , 3)
811SAX.startElement(head)
812SAX.characters( , 4)
813SAX.startElement(title)
814SAX.characters(Welcome to Gnome, 16)
815SAX.endElement(title)
816SAX.characters( , 3)
817SAX.endElement(head)
818SAX.characters( , 3)
819SAX.startElement(chapter)
820SAX.characters( , 4)
821SAX.startElement(title)
822SAX.characters(The Linux adventure, 19)
823SAX.endElement(title)
824SAX.characters( , 4)
825SAX.startElement(p)
826SAX.characters(bla bla bla ..., 15)
827SAX.endElement(p)
828SAX.characters( , 4)
829SAX.startElement(image, href='linus.gif')
830SAX.endElement(image)
831SAX.characters( , 4)
832SAX.startElement(p)
833SAX.characters(..., 3)
834SAX.endElement(p)
835SAX.characters( , 3)
836SAX.endElement(chapter)
837SAX.characters( , 1)
838SAX.endElement(EXAMPLE)
839SAX.endDocument()</pre>
840
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]841<p>Most of the other interfaces of libxml are based on the DOM tree-building
842facility, so nearly everything up to the end of this document presupposes the
843use of the standard DOM tree build. Note that the DOM tree itself is built by
844a set of registered default callbacks, without internal specific
845interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]846
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]847<h2><a name="library">The XML library interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]848
849<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]850using the XML library from the C language. It is not intended to be extensive.
851I hope the automatically generated documents will provide the completeness
852required, but as a separate set of documents. The interfaces of the XML
853library are by principle low level, there is nearly zero abstraction. Those
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]854interested in a higher level API should <a href="#DOM">look at DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]855
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]856<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
857separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]858interfaces</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]859
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]860<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]861
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]862<p>Usually, the first thing to do is to read an XML input. The parser accepts
863documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]864defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]865<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]866 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]867 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]868 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]869</dl>
870<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]871 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]872 <dd><p>Parse an XML document contained in a (possibly compressed)
873 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]874 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]875</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]876
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]877<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]878failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]879
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]880<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]881
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]882<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]883fetched (which is common for GUI based programs) libxml provides a push
884interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]885<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
886 void *user_data,
887 const char *chunk,
888 int size,
889 const char *filename);
890int xmlParseChunk (xmlParserCtxtPtr ctxt,
891 const char *chunk,
892 int size,
893 int terminate);</pre>
894
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]895<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]896<pre> FILE *f;
897
898 f = fopen(filename, "r");
899 if (f != NULL) {
900 int res, size = 1024;
901 char chars[1024];
902 xmlParserCtxtPtr ctxt;
903
904 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]905 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]906 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
907 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]908 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]909 xmlParseChunk(ctxt, chars, res, 0);
910 }
911 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]912 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]913 xmlFreeParserCtxt(ctxt);
914 }
915 }</pre>
916
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]917<p>The HTML parser embedded into libxml also has a push interface; the
918functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]919
920<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
921
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]922<p>The tree-building interface makes the parser memory-hungry, first loading
923the document in memory and then building the tree itself. Reading a document
924without building the tree is possible using the SAX interfaces (see SAX.h and
925<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]926Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]927limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]928<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]929
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]930<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]931
932<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]933there is a set of functions dedicated to building new elements. (These are
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]934also 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]935that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]936<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]937 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]938 xmlNodePtr tree, subtree;
939
940 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]941 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
942 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
943 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
944 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]945 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]946 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]947 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
948 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
949 subtree = xmlNewChild(tree, NULL, "image", NULL);
950 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]951
952<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]953
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]954<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]955
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]956<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]957code has access to the internal structure of all the elements of the tree. The
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]958names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]959<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]960<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]961example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]962<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]963
964<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]965<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]966
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]967<p>points to the text node containing the chapter title "The Linux
968adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]969
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]970<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]971present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]972to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]973<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]974
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]975<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]976
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]977<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]978is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]979<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]980 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
981 xmlChar *value);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]982 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node. The
983 value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]984 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]985</dl>
986<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]987 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]988 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]989 <dd><p>This function returns a pointer to new copy of the property
990 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]991 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]992</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]993
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]994<p>Two functions are provided for reading and writing the text associated with
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]995elements:</p>
996<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]997 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]998 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]999 <dd><p>This function takes an "external" string and converts it to one
1000 text node or possibly to a list of entity and text nodes. All
1001 non-predefined entity references like &amp;Gnome; will be stored
1002 internally as entity nodes, hence the result of the function may not be
1003 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1004 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1005</dl>
1006<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]1007 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1008 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1009 <dd><p>This function is the inverse of
1010 <code>xmlStringGetNodeList()</code>. It generates a new string
1011 containing the content of the text and entity nodes. Note the extra
1012 argument inLine. If this argument is set to 1, the function will expand
1013 entity references. For example, instead of returning the &amp;Gnome;
1014 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1015 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1016 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1017</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1018
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1019<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1020
1021<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1022<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]1023 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1024 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1025 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1026 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1027</dl>
1028<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1029 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1030 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1031 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1032</dl>
1033<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1034 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1035 <dd><p>Saves the document to a file. In this case, the compression
1036 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1037 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1038</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1039
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1040<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1041
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1042<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1043accesses. The level of compression on saves can be turned on either globally
1044or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1045<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1046 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1047 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1048 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1049</dl>
1050<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1051 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1052 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1053 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1054</dl>
1055<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1056 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1057 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1058 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1059</dl>
1060<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1061 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1062 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1063 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1064</dl>
1065
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1066<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1067
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1068<p>Entities in principle are similar to simple C macros. An entity defines an
1069abbreviation for a given string that you can reuse many times throughout the
1070content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1071may occur frequently within a document, or to confine the change needed to a
1072document to a restricted area in the internal subset of the document (at the
1073beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1074<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]10752 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]10763 &lt;!ENTITY xml "Extensible Markup Language"&gt;
10774 ]&gt;
10785 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]10796 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]10807 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1081
1082<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]1083its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1084are 5 predefined entities in libxml allowing you to escape charaters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1085predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1086<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1087for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1088<strong>&amp;quot;</strong> for the character '"', and
1089<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1090
1091<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]1092substitute an entity's content so that you can see the replacement text in
1093your application. Or you may prefer to keep entity references as such in the
1094content to be able to save the document back without losing this usually
1095precious information (if the user went through the pain of explicitly defining
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1096entities, he may have a a rather negative attitude if you blindly susbtitute
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1097them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1098href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1099function allows you to check and change the behaviour, which is to not
1100substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1101
1102<p>Here is the DOM tree built by libxml for the previous document in the
1103default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1104<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1105DOCUMENT
1106version=1.0
1107 ELEMENT EXAMPLE
1108 TEXT
1109 content=
1110 ENTITY_REF
1111 INTERNAL_GENERAL_ENTITY xml
1112 content=Extensible Markup Language
1113 TEXT
1114 content=</pre>
1115
1116<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1117<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1118DOCUMENT
1119version=1.0
1120 ELEMENT EXAMPLE
1121 TEXT
1122 content= Extensible Markup Language</pre>
1123
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1124<p>So, entities or no entities? Basically, it depends on your use case. I
1125suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1126entities in your XML document or data if you are not willing to handle the
1127entity references elements in the DOM tree.</p>
1128
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1129<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1130entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1131transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1132reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1133finding them in the input).</p>
1134
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1135<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1136on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1137non-predefined entities in your documents, then the learning cuvre to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1138then 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]1139strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]1140deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1141
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1142<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1143
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1144<p>The libxml library implements <a
1145href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
1146recognizing namespace contructs in the input, and does namespace lookup
1147automatically when building the DOM tree. A namespace declaration is
1148associated with an in-memory structure and all elements or attributes within
1149that namespace point to it. Hence testing the namespace is a simple and fast
1150equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1151
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1152<p>I suggest that people using libxml use a namespace, and declare it in the
1153root element of their document as the default namespace. Then they don't need
1154to 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]1155refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1156the size of the XML output significantly, but significantly increases its
1157value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1158<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
1159 &lt;elem1&gt;...&lt;/elem1&gt;
1160 &lt;elem2&gt;...&lt;/elem2&gt;
1161&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1162
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1163<p>The namespace value has to be an absolute URL, but the URL doesn't have to
1164point to any existing resource on the Web. It will bind all the element and
1165atributes with that URL. I suggest to use an URL within a domain you control,
1166and that the URL should contain some kind of version information if possible.
1167For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a good
1168namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1169
1170<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1171version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1172and if the version information don't match something you know, warn the user
1173and 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]1174namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1175same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1176associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1177just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1178<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1179prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1180
1181<p>@@Interfaces@@</p>
1182
1183<p>@@Examples@@</p>
1184
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1185<p>Usually people object to using namespaces together with validity checking.
1186I will try to make sure that using namespaces won't break validity checking,
1187so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1188suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1189<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1190flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1191from multiple DTDs will certainly break current validation schemes. I will try
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1192to provide ways to do this, but this may not be portable or standardized.</p>
1193
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1194<h2><a name="Validation">Validation, or are you afraid of DTDs ?</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1195
1196<p>Well what is validation and what is a DTD ?</p>
1197
1198<p>Validation is the process of checking a document against a set of
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1199construction rules; a <strong>DTD</strong> (Document Type Definition) is such
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1200a set of rules.</p>
1201
1202<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1203of the XML life cycle. Briefly a DTD defines all the possibles element to be
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1204found within your document, what is the formal shape of your document tree (by
1205defining the allowed content of an element, either text, a regular expression
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1206for the allowed list of children, or mixed content i.e. both text and
1207children). The DTD also defines the allowed attributes for all elements and
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1208the types of the attributes. For more detailed information, I suggest that you
Daniel Veillard81781102001-03-07 09:31:47 +0000[diff] [blame]1209read the related parts of the XML specification, the examples found under
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1210gnome-xml/test/valid/dtd and any of the large number of books available on
1211XML. The dia example in gnome-xml/test/valid should be both simple and
1212complete enough to allow you to build your own.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1213
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1214<p>A word of warning, building a good DTD which will fit the needs of your
1215application in the long-term is far from trivial; however, the extra level of
1216quality it can ensure is well worth the price for some sets of applications or
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1217if you already have already a DTD defined for your application field.</p>
1218
1219<p>The validation is not completely finished but in a (very IMHO) usable
1220state. Until a real validation interface is defined the way to do it is to
1221define and set the <strong>xmlDoValidityCheckingDefaultValue</strong> external
1222variable to 1, this will of course be changed at some point:</p>
1223
1224<p>extern int xmlDoValidityCheckingDefaultValue;</p>
1225
1226<p>...</p>
1227
1228<p>xmlDoValidityCheckingDefaultValue = 1;</p>
1229
1230<p></p>
1231
1232<p>To handle external entities, use the function
1233<strong>xmlSetExternalEntityLoader</strong>(xmlExternalEntityLoader f); to
1234link in you HTTP/FTP/Entities database library to the standard libxml
1235core.</p>
1236
1237<p>@@interfaces@@</p>
1238
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1239<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1240
1241<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]1242Model</em>; this is an API for accessing XML or HTML structured documents.
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1243Native support for DOM in Gnome is on the way (module gnome-dom), and will be
1244based on gnome-xml. This will be a far cleaner interface to manipulate XML
Daniel Veillardc08a2c61999-09-08 21:35:25 +0000[diff] [blame]1245files within Gnome since it won't expose the internal structure. DOM defines a
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1246set of IDL (or Java) interfaces allowing you to traverse and manipulate a
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1247document. The DOM library will allow accessing and modifying "live" documents
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1248present in other programs like this:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1249
1250<p><img src="DOM.gif" alt=" DOM.gif "></p>
1251
1252<p>This should help greatly doing things like modifying a gnumeric spreadsheet
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1253embedded in a GWP document for example.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1254
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1255<p>The current DOM implementation on top of libxml is the <a
1256href="http://cvs.gnome.org/lxr/source/gdome/">gdome Gnome module</a>, this is
1257a full DOM interface, thanks to <a href="mailto:raph@levien.com">Raph
1258Levien</a>.</p>
1259
1260<p>The gnome-dom module in the Gnome CVS base is obsolete</p>
1261
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1262<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1263
1264<p>Here is a real size example, where the actual content of the application
1265data 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]1266a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1267storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
1268base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1269<pre>&lt;?xml version="1.0"?&gt;
1270&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
1271 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1272
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1273 &lt;gjob:Job&gt;
1274 &lt;gjob:Project ID="3"/&gt;
1275 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
1276 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1277
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1278 &lt;gjob:Update&gt;
1279 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
1280 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
1281 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
1282 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1283
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1284 &lt;gjob:Developers&gt;
1285 &lt;gjob:Developer&gt;
1286 &lt;/gjob:Developer&gt;
1287 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1288
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1289 &lt;gjob:Contact&gt;
1290 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
1291 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
1292 &lt;gjob:Company&gt;
1293 &lt;/gjob:Company&gt;
1294 &lt;gjob:Organisation&gt;
1295 &lt;/gjob:Organisation&gt;
1296 &lt;gjob:Webpage&gt;
1297 &lt;/gjob:Webpage&gt;
1298 &lt;gjob:Snailmail&gt;
1299 &lt;/gjob:Snailmail&gt;
1300 &lt;gjob:Phone&gt;
1301 &lt;/gjob:Phone&gt;
1302 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1303
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1304 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1305 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1306 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1307
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1308 &lt;gjob:Skills&gt;
1309 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1310
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1311 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1312 A GNOME based system that will allow a superuser to configure
1313 compressed and uncompressed files and/or file systems to be backed
1314 up with a supported media in the system. This should be able to
1315 perform via find commands generating a list of files that are passed
1316 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
1317 or via operations performed on the filesystem itself. Email
1318 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1319 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1320
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1321 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1322
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1323 &lt;/gjob:Jobs&gt;
1324&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1325
1326<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]1327only a couple of functions, browsing the tree to gather the ata and generate
1328the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1329
1330<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1331structure. For example, the ordering of the attributes is not significant, the
1332XML specification is clear about it. It's also usually a good idea not to
1333depend on the order of the children of a given node, unless it really makes
1334things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1335<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1336 * A person record
1337 */
1338typedef struct person {
1339 char *name;
1340 char *email;
1341 char *company;
1342 char *organisation;
1343 char *smail;
1344 char *webPage;
1345 char *phone;
1346} person, *personPtr;
1347
1348/*
1349 * And the code needed to parse it
1350 */
1351personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1352 personPtr ret = NULL;
1353
1354DEBUG("parsePerson\n");
1355 /*
1356 * allocate the struct
1357 */
1358 ret = (personPtr) malloc(sizeof(person));
1359 if (ret == NULL) {
1360 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1361 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1362 }
1363 memset(ret, 0, sizeof(person));
1364
1365 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1366 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1367 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1368 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
1369 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1370 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
1371 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1372 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1373 }
1374
1375 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1376}</pre>
1377
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1378<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1379<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1380 <li>Usually a recursive parsing style is the more convenient one: XML data
1381 is by nature subject to repetitive constructs and usually exibits highly
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1382 stuctured patterns.</li>
1383 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>, i.e.
1384 the pointer to the global XML document and the namespace reserved to the
1385 application. Document wide information are needed for example to decode
1386 entities and it's a good coding practice to define a namespace for your
1387 application set of data and test that the element and attributes you're
1388 analyzing actually pertains to your application space. This is done by a
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1389 simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1390 <li>To retrieve text and attributes value, you can use the function
1391 <em>xmlNodeListGetString</em> to gather all the text and entity reference
1392 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1393</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1394
1395<p>Here is another piece of code used to parse another level of the
1396structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1397<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1398/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1399 * a Description for a Job
1400 */
1401typedef struct job {
1402 char *projectID;
1403 char *application;
1404 char *category;
1405 personPtr contact;
1406 int nbDevelopers;
1407 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
1408} job, *jobPtr;
1409
1410/*
1411 * And the code needed to parse it
1412 */
1413jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1414 jobPtr ret = NULL;
1415
1416DEBUG("parseJob\n");
1417 /*
1418 * allocate the struct
1419 */
1420 ret = (jobPtr) malloc(sizeof(job));
1421 if (ret == NULL) {
1422 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1423 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1424 }
1425 memset(ret, 0, sizeof(job));
1426
1427 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1428 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1429 while (cur != NULL) {
1430
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1431 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
1432 ret-&gt;projectID = xmlGetProp(cur, "ID");
1433 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1434 fprintf(stderr, "Project has no ID\n");
1435 }
1436 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1437 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
1438 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1439 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
1440 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1441 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
1442 ret-&gt;contact = parsePerson(doc, ns, cur);
1443 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1444 }
1445
1446 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1447}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1448
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1449<p>Once you are used to it, writing this kind of code is quite simple, but
1450boring. Ultimately, it could be possble to write stubbers taking either C data
1451structure definitions, a set of XML examples or an XML DTD and produce the
1452code needed to import and export the content between C data and XML storage.
1453This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1454
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]1455<p>Feel free to use <a href="example/gjobread.c">the code for the full C
1456parsing example</a> as a template, it is also available with Makefile in the
1457Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1458
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1459<h2><a name="Contributi">Contributions</a></h2>
1460<ul>
Daniel Veillard851c59c2000-11-24 16:06:22 +0000[diff] [blame]1461 <li><a href="mailto:ari@lusis.org">Ari Johnson</a> provides a C++ wrapper
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1462 for libxml:
1463 <p>Website: <a
1464 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
1465 <p>Download: <a
1466 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
1467 </li>
1468 <li><a href="mailto:doolin@cs.utk.edu">David Doolin</a> provides a
1469 precompiled Windows version
1470 <p><a
1471 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
1472 </li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1473 <li><a
1474 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
1475 Sergeant</a> developped <a
1476 href="http://axkit.org/download/">XML::LibXSLT</a>, a perl wrapper for
1477 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
1478 application server</a></li>
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1479 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> provided <a
1480 href="libxml-doc.el">an emacs module</a> to lookup libxml functions
1481 documentation</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1482 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
1483 href="http://xmlsoft.org/messages/0488.html">man pages</a> (not yet
1484 integrated in the distribution)</li>
1485</ul>
1486
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1487<p></p>
1488
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]1489<p><a href="mailto:Daniel.Veillard@imag.fr">Daniel Veillard</a></p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1490
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame^]1491<p>$Id: xml.html,v 1.75 2001/03/21 10:28:36 veillard Exp $</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1492</body>
1493</html>