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blob: d7662d74266566301a8812e5e70547549f734d29 [file] [log] [blame]
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1<html>
2<head>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]3 <title>The XML C library for Gnome</title>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]4 <meta name="GENERATOR" content="amaya V4.1">
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]5 <meta http-equiv="Content-Type" content="text/html">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]6</head>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]7
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]8<body bgcolor="#ffffff">
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]9<p><a href="http://www.gnome.org/"><img src="smallfootonly.gif"
10alt="Gnome Logo"></a><a href="http://www.w3.org/Status"><img src="w3c.png"
11alt="W3C Logo"></a></p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]12
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]13<h1 align="center">The XML C library for Gnome</h1>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]14
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]15<h2 style="text-align: center">libxml, a.k.a. gnome-xml</h2>
16
17<p></p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]18<ul>
19 <li><a href="#Introducti">Introduction</a></li>
20 <li><a href="#Documentat">Documentation</a></li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]21 <li><a href="#Reporting">Reporting bugs and getting help</a></li>
22 <li><a href="#help">how to help</a></li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]23 <li><a href="#Downloads">Downloads</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]24 <li><a href="#News">News</a></li>
25 <li><a href="#XML">XML</a></li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]26 <li><a href="#XSLT">XSLT</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]27 <li><a href="#tree">The tree output</a></li>
28 <li><a href="#interface">The SAX interface</a></li>
29 <li><a href="#library">The XML library interfaces</a>
30 <ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]31 <li><a href="#Invoking">Invoking the parser: the pull way</a></li>
32 <li><a href="#Invoking">Invoking the parser: the push way</a></li>
33 <li><a href="#Invoking2">Invoking the parser: the SAX interface</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]34 <li><a href="#Building">Building a tree from scratch</a></li>
35 <li><a href="#Traversing">Traversing the tree</a></li>
36 <li><a href="#Modifying">Modifying the tree</a></li>
37 <li><a href="#Saving">Saving the tree</a></li>
38 <li><a href="#Compressio">Compression</a></li>
39 </ul>
40 </li>
41 <li><a href="#Entities">Entities or no entities</a></li>
42 <li><a href="#Namespaces">Namespaces</a></li>
43 <li><a href="#Validation">Validation</a></li>
44 <li><a href="#Principles">DOM principles</a></li>
45 <li><a href="#real">A real example</a></li>
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]46 <li><a href="#Contributi">Contributions</a></li>
47</ul>
48
49<p>Separate documents:</p>
50<ul>
51 <li><a href="upgrade.html">upgrade instructions for migrating to
52 libxml2</a></li>
53 <li><a href="encoding.html">libxml Internationalization support</a></li>
54 <li><a href="xmlio.html">libxml Input/Output interfaces</a></li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]55 <li><a href="xmlmem.html">libxml Memory interfaces</a></li>
Daniel Veillard300f7d62000-11-24 13:04:04 +0000[diff] [blame]56 <li><a href="xmldtd.html">a short introduction about DTDs and
57 libxml</a></li>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]58 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]59</ul>
60
61<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]62
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]63<p>This document describes libxml, the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]64href="http://www.w3.org/XML/">XML</a> C library developped for the <a
65href="http://www.gnome.org/">Gnome</a> project. <a
66href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
67structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]68
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]69<p>Here are some key points about libxml:</p>
70<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]71 <li>Libxml exports Push and Pull type parser interfaces for both XML and
72 HTML.</li>
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 Veillard3197f162001-04-04 00:40:08 +0000[diff] [blame]149href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
150href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
151href="http://xmlsoft.org/messages">old</a>). To subscribe to this list, please
152visit the <a href="http://mail.gnome.org/mailman/listinfo/xml">associated
153Web</a> page and follow 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 Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame^]247<h3>2.3.6: April 8 2001</h3>
248<ul>
249 <li>Code cleanup using extreme gcc compiler warning options, found and
250 cleared half a dozen potential problem</li>
251 <li>the Eazel team found an XML parser bug</li>
252 <li>cleaned up the user of some of the string formatting function. used the
253 trio library code to provide the one needed when the platform is missing
254 them</li>
255 <li>xpath: removed a memory leak and fixed the predicate evaluation problem,
256 extended the testsuite and cleaned up the result. XPointer seems broken
257 ...</li>
258</ul>
259
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame]260<h3>2.3.5: Mar 23 2001</h3>
261<ul>
262 <li>Biggest change is separate parsing and evaluation of XPath expressions,
263 there is some new APIs for this too</li>
264 <li>included a number of bug fixes(XML push parser, 51876, notations,
265 52299)</li>
266 <li>Fixed some portability issues</li>
267</ul>
268
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]269<h3>2.3.4: Mar 10 2001</h3>
270<ul>
271 <li>Fixed bugs #51860 and #51861</li>
272 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
273 size to be application tunable.</li>
274 <li>Some cleanup in the validation code, still a bug left and this part
275 should probably be rewritten to support ambiguous content model :-\</li>
276 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
277 parser</li>
278 <li>Fixed another bug in xmlNodeGetContent()</li>
279 <li>Bjorn fixed XPath node collection and Number formatting</li>
280 <li>Fixed a loop reported in the HTML parsing</li>
281 <li>blank space are reported even if the Dtd content model proves that they
282 are formatting spaces, this is for XmL conformance</li>
283</ul>
284
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]285<h3>2.3.3: Mar 1 2001</h3>
286<ul>
287 <li>small change in XPath for XSLT</li>
288 <li>documentation cleanups</li>
289 <li>fix in validation by Gary Pennington</li>
290 <li>serious parsing performances improvements</li>
291</ul>
292
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]293<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]294<ul>
295 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
296 <li>fixed a Dtd parsing bug</li>
297 <li>fixed a bug in xmlNodeGetContent</li>
298 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
299</ul>
300
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]301<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]302<ul>
303 <li>some XPath and HTML bug fixes for XSLT</li>
304 <li>small extension of the hash table interfaces for DOM gdome2
305 implementation</li>
306 <li>A few bug fixes</li>
307</ul>
308
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]309<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]310<ul>
311 <li>Lots of XPath bug fixes</li>
312 <li>Add a mode with Dtd lookup but without validation error reporting for
313 XSLT</li>
314 <li>Add support for text node without escaping (XSLT)</li>
315 <li>bug fixes for xmlCheckFilename</li>
316 <li>validation code bug fixes from Gary Pennington</li>
317 <li>Patch from Paul D. Smith correcting URI path normalization</li>
318 <li>Patch to allow simultaneous install of libxml-devel and
319 libxml2-devel</li>
320 <li>the example Makefile is now fixed</li>
321 <li>added HTML to the RPM packages</li>
322 <li>tree copying bugfixes</li>
323 <li>updates to Windows makefiles</li>
324 <li>optimisation patch from Bjorn Reese</li>
325</ul>
326
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]327<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]328<ul>
329 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
330 <li>added htmlHandleOmittedElem()</li>
331 <li>Applied Bjorn Reese's IPV6 first patch</li>
332 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]333 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]334</ul>
335
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]336<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]337<ul>
338 <li>Fix the Windows problems of 2.2.8</li>
339 <li>integrate OpenVMS patches</li>
340 <li>better handling of some nasty HTML input</li>
341 <li>Improved the XPointer implementation</li>
342 <li>integrate a number of provided patches</li>
343</ul>
344
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]345<h3>2.2.9: Nov 25 2000</h3>
346<ul>
347 <li>erroneous release :-(</li>
348</ul>
349
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]350<h3>2.2.8: Nov 13 2000</h3>
351<ul>
352 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
353 support</li>
354 <li>Patch in conditional section handling</li>
355 <li>updated MS compiler project</li>
356 <li>fixed some XPath problems</li>
357 <li>added an URI escaping function</li>
358 <li>some other bug fixes</li>
359</ul>
360
361<h3>2.2.7: Oct 31 2000</h3>
362<ul>
363 <li>added message redirection</li>
364 <li>XPath improvements (thanks TOM !)</li>
365 <li>xmlIOParseDTD() added</li>
366 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
367 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
368</ul>
369
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]370<h3>2.2.6: Oct 25 2000:</h3>
371<ul>
372 <li>Added an hash table module, migrated a number of internal structure to
373 those</li>
374 <li>Fixed a posteriori validation problems</li>
375 <li>HTTP module cleanups</li>
376 <li>HTML parser improvements (tag errors, script/style handling, attribute
377 normalization)</li>
378 <li>coalescing of adjacent text nodes</li>
379 <li>couple of XPath bug fixes, exported the internal API</li>
380</ul>
381
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]382<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]383<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]384 <li>XPointer implementation and testsuite</li>
385 <li>Lot of XPath fixes, added variable and functions registration, more
386 tests</li>
387 <li>Portability fixes, lots of enhancements toward an easy Windows build and
388 release</li>
389 <li>Late validation fixes</li>
390 <li>Integrated a lot of contributed patches</li>
391 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]392 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]393</ul>
394
395<h3>2.2.4: Oct 1 2000:</h3>
396<ul>
397 <li>main XPath problem fixed</li>
398 <li>Integrated portability patches for Windows</li>
399 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]400</ul>
401
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]402<h3>2.2.3: Sep 17 2000</h3>
403<ul>
404 <li>bug fixes</li>
405 <li>cleanup of entity handling code</li>
406 <li>overall review of all loops in the parsers, all sprintf usage has been
407 checked too</li>
408 <li>Far better handling of larges Dtd. Validating against Docbook XML Dtd
409 works smoothly now.</li>
410</ul>
411
412<h3>1.8.10: Sep 6 2000</h3>
413<ul>
414 <li>bug fix release for some Gnome projects</li>
415</ul>
416
417<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]418<ul>
419 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]420 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]421</ul>
422
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]423<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]424<ul>
425 <li>a purely bug fixes release</li>
426 <li>fixed an encoding support problem when parsing from a memory block</li>
427 <li>fixed a DOCTYPE parsing problem</li>
428 <li>removed a bug in the function allowing to override the memory allocation
429 routines</li>
430</ul>
431
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]432<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]433<ul>
434 <li>applied a lot of portability fixes</li>
435 <li>better encoding support/cleanup and saving (content is now always
436 encoded in UTF-8)</li>
437 <li>the HTML parser now correctly handles encodings</li>
438 <li>added xmlHasProp()</li>
439 <li>fixed a serious problem with &amp;#38;</li>
440 <li>propagated the fix to FTP client</li>
441 <li>cleanup, bugfixes, etc ...</li>
442 <li>Added a page about <a href="encoding.html">libxml Internationalization
443 support</a></li>
444</ul>
445
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]446<h3>1.8.9: July 9 2000</h3>
447<ul>
448 <li>fixed the spec the RPMs should be better</li>
449 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
450 rpmfind users problem</li>
451</ul>
452
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]453<h3>2.1.1: July 1 2000</h3>
454<ul>
455 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
456 <li>improvements on the HTML parser</li>
457</ul>
458
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]459<h3>2.1.0 and 1.8.8: June 29 2000</h3>
460<ul>
461 <li>1.8.8 is mostly a comodity package for upgrading to libxml2 accoding to
462 <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
463 about &amp;#38; charref parsing</li>
464 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
465 also contains numerous fixes and enhancements:
466 <ul>
467 <li>added xmlStopParser() to stop parsing</li>
468 <li>improved a lot parsing speed when there is large CDATA blocs</li>
469 <li>includes XPath patches provided by Picdar Technology</li>
470 <li>tried to fix as much as possible DtD validation and namespace
471 related problems</li>
472 <li>output to a given encoding has been added/tested</li>
473 <li>lot of various fixes</li>
474 </ul>
475 </li>
476</ul>
477
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]478<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]479<ul>
480 <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]481 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initally
482 scheduled for Apr 3 the relase occured only on Apr 12 due to massive
483 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]484 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]485 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]486 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]487 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]488 <pre>#include "xxx.h"</pre>
489 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]490 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
491 <li>the memory allocation routines used by libxml can now be overloaded
492 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]493 <li>The previously CVS only tool tester has been renamed
494 <strong>xmllint</strong> and is now installed as part of the libxml2
495 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]496 <li>The I/O interface has been revamped. There is now ways to plug in
497 specific I/O modules, either at the URI scheme detection level using
498 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
499 parser context using xmlCreateIOParserCtxt()</li>
500 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
501 number of the libxml module in use</li>
502 <li>a number of optional features of libxml can now be excluded at configure
503 time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]504</ul>
505
506<h3>2.0.0beta: Mar 14 2000</h3>
507<ul>
508 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]509 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
510 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
511 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]512 <li>This version is now the head in the Gnome CVS base, the old one is
513 available under the tag LIB_XML_1_X</li>
514 <li>This includes a very large set of changes. Froma programmatic point of
515 view applications should not have to be modified too much, check the <a
516 href="upgrade.html">upgrade page</a></li>
517 <li>Some interfaces may changes (especially a bit about encoding).</li>
518 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]519 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]520 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
521 handled now</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]522 <li>Better handling of entities, especially well formedness checking and
523 proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]524 <li>DTD conditional sections</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]525 <li>Validation now correcly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]526 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
527 structures to accomodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]528 </ul>
529 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]530 <li>Serious progress were made toward compliance, <a
531 href="conf/result.html">here are the result of the test</a> against the
532 OASIS testsuite (except the japanese tests since I don't support that
533 encoding yet). This URL is rebuilt every couple of hours using the CVS
534 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]535</ul>
536
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]537<h3>1.8.7: Mar 6 2000</h3>
538<ul>
539 <li>This is a bug fix release:</li>
540 <li>It is possible to disable the ignorable blanks heuristic used by
541 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
542 that for adherence to XML spec, this behaviour will be disabled by default
543 in 2.x . The same function will allow to keep compatibility for old
544 code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]545 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
546 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]547 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
548 compilation on some platforms has been fixed</li>
549 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
550 URIs</li>
551</ul>
552
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]553<h3>1.8.6: Jan 31 2000</h3>
554<ul>
555 <li>added a nanoFTP transport module, debugged until the new version of <a
556 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
557 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]558</ul>
559
560<h3>1.8.5: Jan 21 2000</h3>
561<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]562 <li>adding APIs to parse a well balanced chunk of XML (production <a
563 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the XML
564 spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]565 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]566 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
567 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]568 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
569 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]570</ul>
571
572<h3>1.8.4: Jan 13 2000</h3>
573<ul>
574 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
575 <li>all exit() call should have been removed from libxml</li>
576 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
577 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]578</ul>
579
580<h3>1.8.3: Jan 5 2000</h3>
581<ul>
582 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]583 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillarddbfd6411999-12-28 16:35:14 +0000[diff] [blame]584 <li>lots of bug fixes and improvement added over XMas hollidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]585 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]586 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
587 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]588 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]589 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]590 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]591</ul>
592
593<h3>1.8.2: Dec 21 1999</h3>
594<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]595 <li>I got another problem with includes and C++, I hope this issue is fixed
596 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]597 <li>Added a few tree modification functions: xmlReplaceNode,
598 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
599 xmlDocSetRootElement</li>
600 <li>Tried to improve the HTML output with help from <a
601 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]602</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]603
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]604<h3>1.8.1: Dec 18 1999</h3>
605<ul>
606 <li>various patches to avoid troubles when using libxml with C++ compilers
607 the "namespace" keyword and C escaping in include files</li>
608 <li>a problem in one of the core macros IS_CHAR was corrected</li>
609 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
610 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]611 <li>fixed a posteriori validation (validation after parsing, or by using a
612 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]613 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]614</ul>
615
616<h3>1.8.0: Dec 12 1999</h3>
617<ul>
618 <li>cleanup, especially memory wise</li>
619 <li>the parser should be more reliable, especially the HTML one, it should
620 not crash, whatever the input !</li>
621 <li>Integrated various patches, especially a speedup improvement for large
622 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
623 configure with --with-buffers to enable them.</li>
624 <li>attribute normalization, oops should have been added long ago !</li>
625 <li>attributes defaulted from Dtds should be available, xmlSetProp() now
626 does entities escapting by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]627</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]628
629<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]630<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]631 <li>Lots of HTML improvement</li>
632 <li>Fixed some errors when saving both XML and HTML</li>
633 <li>More examples, the regression tests should now look clean</li>
634 <li>Fixed a bug with contiguous charref</li>
635</ul>
636
637<h3>1.7.3: Sep 29 1999</h3>
638<ul>
639 <li>portability problems fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]640 <li>snprintf was used unconditionnally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]641 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]642</ul>
643
644<h3>1.7.1: Sep 24 1999</h3>
645<ul>
646 <li>The basic type for strings manipulated by libxml has been renamed in
647 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
648 is that CHAR was conflicting with a predefined type on Windows. However on
649 non WIN32 environment, compatibility is provided by the way of a
650 <strong>#define </strong>.</li>
651 <li>Changed another error : the use of a structure field called errno, and
652 leading to troubles on platforms where it's a macro</li>
653</ul>
654
655<h3>1.7.0: sep 23 1999</h3>
656<ul>
657 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]658 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]659 <li>Added an errno to report errors by another mean than a simple printf
660 like callback</li>
661 <li>Finished ID/IDREF support and checking when validation</li>
662 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]663 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]664 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
665 implementation</li>
666 <li>Added an HTML parser front-end</li>
667</ul>
668
669<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]670
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]671<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]672markup-based structured documents. Here is <a name="example">an example XML
673document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]674<pre>&lt;?xml version="1.0"?&gt;
675&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
676 &lt;head&gt;
677 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
678 &lt;/head&gt;
679 &lt;chapter&gt;
680 &lt;title&gt;The Linux adventure&lt;/title&gt;
681 &lt;p&gt;bla bla bla ...&lt;/p&gt;
682 &lt;image href="linus.gif"/&gt;
683 &lt;p&gt;...&lt;/p&gt;
684 &lt;/chapter&gt;
685&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]686
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]687<p>The first line specifies that it's an XML document and gives useful
688information about its encoding. Then the document is a text format whose
689structure is specified by tags between brackets. <strong>Each tag opened has
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]690to be closed</strong>. XML is pedantic about this. However, if a tag is empty
691(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]692ends with <code>/&gt;</code> rather than with <code>&gt;</code>. Note that,
693for example, the image tag has no content (just an attribute) and is closed by
694ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]695
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]696<p>XML can be applied sucessfully to a wide range of uses, from long term
697structured document maintenance (where it follows the steps of SGML) to simple
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]698data encoding mechanisms like configuration file formatting (glade),
699spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where
700it is used to encode remote calls between a client and a server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]701
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]702<h2><a name="XSLT">XSLT</a></h2>
703
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]704<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
705
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]706<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a language
707for transforming XML documents into other XML documents (or HTML/textual
708output).</p>
709
710<p>A separate library called libxslt is being built on top of libxml2. This
711module "libxslt" can be found in the Gnome CVS base too.</p>
712
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]713<p>You can check the <a
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]714href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a> supported
715and the progresses on the <a
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]716href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog">Changelog</a></p>
717
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]718<h2>An overview of libxml architecture</h2>
719
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]720<p>Libxml is made of multiple components; some of them are optional, and most
721of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]722<ul>
723 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]724 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]725 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]726 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]727 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]728 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]729 <li>a SAX tree module to build an in-memory DOM representation</li>
730 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]731 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]732 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]733 (optional)</li>
734 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]735</ul>
736
737<p>Graphically this gives the following:</p>
738
739<p><img src="libxml.gif" alt="a graphical view of the various"></p>
740
741<p></p>
742
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]743<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]744
745<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]746returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]747<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]748as the file name, the document type, and a <strong>children</strong> pointer
749which is the root of the document (or more exactly the first child under the
750root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]751chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]752relationship. An xmlNode can also carry properties (a chain of xmlAttr
753structures). An attribute may have a value which is a list of TEXT or
754ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]755
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]756<p>Here is an example (erroneous with respect to the XML spec since there
757should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]758
759<p><img src="structure.gif" alt=" structure.gif "></p>
760
761<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]762called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]763prints them back as parsed. This is useful for detecting errors both in XML
764code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]765which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]766result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]767<pre>DOCUMENT
768version=1.0
769standalone=true
770 ELEMENT EXAMPLE
771 ATTRIBUTE prop1
772 TEXT
773 content=gnome is great
774 ATTRIBUTE prop2
775 ENTITY_REF
776 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]777 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]778 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]779 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]780 TEXT
781 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]782 ELEMENT chapter
783 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]784 TEXT
785 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]786 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]787 TEXT
788 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]789 ELEMENT image
790 ATTRIBUTE href
791 TEXT
792 content=linus.gif
793 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]794 TEXT
795 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]796
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]797<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]798
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]799<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]800
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]801<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]802memory. In that case (and if you don't expect to save back the XML document
803loaded 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]804<strong>callback-based interface</strong> to the parser. Before parsing, the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]805application layer registers a customized set of callbacks which are called by
806the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]807
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]808<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]809libxml, see the <a
810href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
811documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]812Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]813
814<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
815program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]816binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]817distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]818testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]819<pre>SAX.setDocumentLocator()
820SAX.startDocument()
821SAX.getEntity(amp)
822SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
823SAX.characters( , 3)
824SAX.startElement(head)
825SAX.characters( , 4)
826SAX.startElement(title)
827SAX.characters(Welcome to Gnome, 16)
828SAX.endElement(title)
829SAX.characters( , 3)
830SAX.endElement(head)
831SAX.characters( , 3)
832SAX.startElement(chapter)
833SAX.characters( , 4)
834SAX.startElement(title)
835SAX.characters(The Linux adventure, 19)
836SAX.endElement(title)
837SAX.characters( , 4)
838SAX.startElement(p)
839SAX.characters(bla bla bla ..., 15)
840SAX.endElement(p)
841SAX.characters( , 4)
842SAX.startElement(image, href='linus.gif')
843SAX.endElement(image)
844SAX.characters( , 4)
845SAX.startElement(p)
846SAX.characters(..., 3)
847SAX.endElement(p)
848SAX.characters( , 3)
849SAX.endElement(chapter)
850SAX.characters( , 1)
851SAX.endElement(EXAMPLE)
852SAX.endDocument()</pre>
853
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]854<p>Most of the other interfaces of libxml are based on the DOM tree-building
855facility, so nearly everything up to the end of this document presupposes the
856use of the standard DOM tree build. Note that the DOM tree itself is built by
857a set of registered default callbacks, without internal specific
858interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]859
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]860<h2><a name="library">The XML library interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]861
862<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]863using the XML library from the C language. It is not intended to be extensive.
864I hope the automatically generated documents will provide the completeness
865required, but as a separate set of documents. The interfaces of the XML
866library are by principle low level, there is nearly zero abstraction. Those
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]867interested in a higher level API should <a href="#DOM">look at DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]868
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]869<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
870separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]871interfaces</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]872
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]873<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]874
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]875<p>Usually, the first thing to do is to read an XML input. The parser accepts
876documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]877defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]878<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]879 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]880 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]881 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]882</dl>
883<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]884 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]885 <dd><p>Parse an XML document contained in a (possibly compressed)
886 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]887 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]888</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]889
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]890<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]891failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]892
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]893<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]894
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]895<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]896fetched (which is common for GUI based programs) libxml provides a push
897interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]898<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
899 void *user_data,
900 const char *chunk,
901 int size,
902 const char *filename);
903int xmlParseChunk (xmlParserCtxtPtr ctxt,
904 const char *chunk,
905 int size,
906 int terminate);</pre>
907
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]908<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]909<pre> FILE *f;
910
911 f = fopen(filename, "r");
912 if (f != NULL) {
913 int res, size = 1024;
914 char chars[1024];
915 xmlParserCtxtPtr ctxt;
916
917 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]918 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]919 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
920 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]921 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]922 xmlParseChunk(ctxt, chars, res, 0);
923 }
924 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]925 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]926 xmlFreeParserCtxt(ctxt);
927 }
928 }</pre>
929
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]930<p>The HTML parser embedded into libxml also has a push interface; the
931functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]932
933<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
934
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]935<p>The tree-building interface makes the parser memory-hungry, first loading
936the document in memory and then building the tree itself. Reading a document
937without building the tree is possible using the SAX interfaces (see SAX.h and
938<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]939Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]940limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]941<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]942
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]943<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]944
945<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]946there is a set of functions dedicated to building new elements. (These are
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]947also 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]948that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]949<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]950 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]951 xmlNodePtr tree, subtree;
952
953 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]954 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
955 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
956 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
957 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]958 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]959 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]960 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
961 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
962 subtree = xmlNewChild(tree, NULL, "image", NULL);
963 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]964
965<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]966
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]967<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]968
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]969<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]970code has access to the internal structure of all the elements of the tree. The
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]971names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]972<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]973<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]974example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]975<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]976
977<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]978<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]979
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]980<p>points to the text node containing the chapter title "The Linux
981adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]982
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]983<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]984present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]985to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]986<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]987
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]988<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]989
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]990<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]991is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]992<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]993 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
994 xmlChar *value);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]995 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node. The
996 value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]997 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]998</dl>
999<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]1000 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1001 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]1002 <dd><p>This function returns a pointer to new copy of the property
1003 content. Note that the user must deallocate the result.</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>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1006
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1007<p>Two functions are provided for reading and writing the text associated with
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1008elements:</p>
1009<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]1010 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1011 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1012 <dd><p>This function takes an "external" string and converts it to one
1013 text node or possibly to a list of entity and text nodes. All
1014 non-predefined entity references like &amp;Gnome; will be stored
1015 internally as entity nodes, hence the result of the function may not be
1016 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1017 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1018</dl>
1019<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]1020 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1021 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1022 <dd><p>This function is the inverse of
1023 <code>xmlStringGetNodeList()</code>. It generates a new string
1024 containing the content of the text and entity nodes. Note the extra
1025 argument inLine. If this argument is set to 1, the function will expand
1026 entity references. For example, instead of returning the &amp;Gnome;
1027 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1028 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1029 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1030</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1031
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1032<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1033
1034<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1035<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]1036 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1037 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1038 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1039 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1040</dl>
1041<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1042 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1043 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1044 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1045</dl>
1046<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1047 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1048 <dd><p>Saves the document to a file. In this case, the compression
1049 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1050 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1051</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1052
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1053<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1054
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1055<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1056accesses. The level of compression on saves can be turned on either globally
1057or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1058<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1059 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1060 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1061 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1062</dl>
1063<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1064 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1065 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1066 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1067</dl>
1068<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1069 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1070 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1071 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1072</dl>
1073<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1074 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1075 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1076 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1077</dl>
1078
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1079<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1080
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1081<p>Entities in principle are similar to simple C macros. An entity defines an
1082abbreviation for a given string that you can reuse many times throughout the
1083content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1084may occur frequently within a document, or to confine the change needed to a
1085document to a restricted area in the internal subset of the document (at the
1086beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1087<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]10882 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]10893 &lt;!ENTITY xml "Extensible Markup Language"&gt;
10904 ]&gt;
10915 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]10926 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]10937 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1094
1095<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]1096its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1097are 5 predefined entities in libxml allowing you to escape charaters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1098predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1099<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1100for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1101<strong>&amp;quot;</strong> for the character '"', and
1102<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1103
1104<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]1105substitute an entity's content so that you can see the replacement text in
1106your application. Or you may prefer to keep entity references as such in the
1107content to be able to save the document back without losing this usually
1108precious information (if the user went through the pain of explicitly defining
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1109entities, he may have a a rather negative attitude if you blindly susbtitute
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1110them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1111href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1112function allows you to check and change the behaviour, which is to not
1113substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1114
1115<p>Here is the DOM tree built by libxml for the previous document in the
1116default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1117<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1118DOCUMENT
1119version=1.0
1120 ELEMENT EXAMPLE
1121 TEXT
1122 content=
1123 ENTITY_REF
1124 INTERNAL_GENERAL_ENTITY xml
1125 content=Extensible Markup Language
1126 TEXT
1127 content=</pre>
1128
1129<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1130<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1131DOCUMENT
1132version=1.0
1133 ELEMENT EXAMPLE
1134 TEXT
1135 content= Extensible Markup Language</pre>
1136
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1137<p>So, entities or no entities? Basically, it depends on your use case. I
1138suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1139entities in your XML document or data if you are not willing to handle the
1140entity references elements in the DOM tree.</p>
1141
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1142<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1143entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1144transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1145reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1146finding them in the input).</p>
1147
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1148<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1149on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1150non-predefined entities in your documents, then the learning cuvre to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1151then 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]1152strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]1153deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1154
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1155<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1156
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1157<p>The libxml library implements <a
1158href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
1159recognizing namespace contructs in the input, and does namespace lookup
1160automatically when building the DOM tree. A namespace declaration is
1161associated with an in-memory structure and all elements or attributes within
1162that namespace point to it. Hence testing the namespace is a simple and fast
1163equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1164
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1165<p>I suggest that people using libxml use a namespace, and declare it in the
1166root element of their document as the default namespace. Then they don't need
1167to 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]1168refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1169the size of the XML output significantly, but significantly increases its
1170value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1171<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
1172 &lt;elem1&gt;...&lt;/elem1&gt;
1173 &lt;elem2&gt;...&lt;/elem2&gt;
1174&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1175
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1176<p>The namespace value has to be an absolute URL, but the URL doesn't have to
1177point to any existing resource on the Web. It will bind all the element and
1178atributes with that URL. I suggest to use an URL within a domain you control,
1179and that the URL should contain some kind of version information if possible.
1180For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a good
1181namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1182
1183<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1184version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1185and if the version information don't match something you know, warn the user
1186and 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]1187namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1188same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1189associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1190just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1191<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1192prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1193
1194<p>@@Interfaces@@</p>
1195
1196<p>@@Examples@@</p>
1197
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1198<p>Usually people object to using namespaces together with validity checking.
1199I will try to make sure that using namespaces won't break validity checking,
1200so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1201suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1202<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1203flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1204from multiple DTDs will certainly break current validation schemes. I will try
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1205to provide ways to do this, but this may not be portable or standardized.</p>
1206
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1207<h2><a name="Validation">Validation, or are you afraid of DTDs ?</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1208
1209<p>Well what is validation and what is a DTD ?</p>
1210
1211<p>Validation is the process of checking a document against a set of
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1212construction rules; a <strong>DTD</strong> (Document Type Definition) is such
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1213a set of rules.</p>
1214
1215<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1216of the XML life cycle. Briefly a DTD defines all the possibles element to be
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1217found within your document, what is the formal shape of your document tree (by
1218defining the allowed content of an element, either text, a regular expression
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1219for the allowed list of children, or mixed content i.e. both text and
1220children). The DTD also defines the allowed attributes for all elements and
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1221the types of the attributes. For more detailed information, I suggest that you
Daniel Veillard81781102001-03-07 09:31:47 +0000[diff] [blame]1222read the related parts of the XML specification, the examples found under
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1223gnome-xml/test/valid/dtd and any of the large number of books available on
1224XML. The dia example in gnome-xml/test/valid should be both simple and
1225complete enough to allow you to build your own.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1226
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1227<p>A word of warning, building a good DTD which will fit the needs of your
1228application in the long-term is far from trivial; however, the extra level of
1229quality it can ensure is well worth the price for some sets of applications or
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1230if you already have already a DTD defined for your application field.</p>
1231
1232<p>The validation is not completely finished but in a (very IMHO) usable
1233state. Until a real validation interface is defined the way to do it is to
1234define and set the <strong>xmlDoValidityCheckingDefaultValue</strong> external
1235variable to 1, this will of course be changed at some point:</p>
1236
1237<p>extern int xmlDoValidityCheckingDefaultValue;</p>
1238
1239<p>...</p>
1240
1241<p>xmlDoValidityCheckingDefaultValue = 1;</p>
1242
1243<p></p>
1244
1245<p>To handle external entities, use the function
1246<strong>xmlSetExternalEntityLoader</strong>(xmlExternalEntityLoader f); to
1247link in you HTTP/FTP/Entities database library to the standard libxml
1248core.</p>
1249
1250<p>@@interfaces@@</p>
1251
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1252<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1253
1254<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]1255Model</em>; this is an API for accessing XML or HTML structured documents.
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1256Native support for DOM in Gnome is on the way (module gnome-dom), and will be
1257based on gnome-xml. This will be a far cleaner interface to manipulate XML
Daniel Veillard3197f162001-04-04 00:40:08 +0000[diff] [blame]1258files within Gnome since it won't expose the internal structure.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1259
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1260<p>The current DOM implementation on top of libxml is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame]1261href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
1262is a full DOM interface, thanks to Paolo Casarini, check the <a
1263href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
1264informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1265
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame]1266<p>The gnome-dom and gdome modules in the Gnome CVS base are obsolete</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1267
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1268<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1269
1270<p>Here is a real size example, where the actual content of the application
1271data 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]1272a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1273storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
1274base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1275<pre>&lt;?xml version="1.0"?&gt;
1276&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
1277 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1278
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1279 &lt;gjob:Job&gt;
1280 &lt;gjob:Project ID="3"/&gt;
1281 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
1282 &lt;gjob:Category&gt;Development&lt;/gjob:Category&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:Update&gt;
1285 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
1286 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
1287 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
1288 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1289
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1290 &lt;gjob:Developers&gt;
1291 &lt;gjob:Developer&gt;
1292 &lt;/gjob:Developer&gt;
1293 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1294
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1295 &lt;gjob:Contact&gt;
1296 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
1297 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
1298 &lt;gjob:Company&gt;
1299 &lt;/gjob:Company&gt;
1300 &lt;gjob:Organisation&gt;
1301 &lt;/gjob:Organisation&gt;
1302 &lt;gjob:Webpage&gt;
1303 &lt;/gjob:Webpage&gt;
1304 &lt;gjob:Snailmail&gt;
1305 &lt;/gjob:Snailmail&gt;
1306 &lt;gjob:Phone&gt;
1307 &lt;/gjob:Phone&gt;
1308 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1309
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1310 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1311 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1312 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1313
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1314 &lt;gjob:Skills&gt;
1315 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1316
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1317 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1318 A GNOME based system that will allow a superuser to configure
1319 compressed and uncompressed files and/or file systems to be backed
1320 up with a supported media in the system. This should be able to
1321 perform via find commands generating a list of files that are passed
1322 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
1323 or via operations performed on the filesystem itself. Email
1324 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1325 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1326
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1327 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1328
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1329 &lt;/gjob:Jobs&gt;
1330&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1331
1332<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]1333only a couple of functions, browsing the tree to gather the ata and generate
1334the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1335
1336<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1337structure. For example, the ordering of the attributes is not significant, the
1338XML specification is clear about it. It's also usually a good idea not to
1339depend on the order of the children of a given node, unless it really makes
1340things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1341<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1342 * A person record
1343 */
1344typedef struct person {
1345 char *name;
1346 char *email;
1347 char *company;
1348 char *organisation;
1349 char *smail;
1350 char *webPage;
1351 char *phone;
1352} person, *personPtr;
1353
1354/*
1355 * And the code needed to parse it
1356 */
1357personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1358 personPtr ret = NULL;
1359
1360DEBUG("parsePerson\n");
1361 /*
1362 * allocate the struct
1363 */
1364 ret = (personPtr) malloc(sizeof(person));
1365 if (ret == NULL) {
1366 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1367 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1368 }
1369 memset(ret, 0, sizeof(person));
1370
1371 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1372 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1373 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1374 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
1375 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1376 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
1377 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1378 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1379 }
1380
1381 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1382}</pre>
1383
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1384<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1385<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1386 <li>Usually a recursive parsing style is the more convenient one: XML data
1387 is by nature subject to repetitive constructs and usually exibits highly
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1388 stuctured patterns.</li>
1389 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>, i.e.
1390 the pointer to the global XML document and the namespace reserved to the
1391 application. Document wide information are needed for example to decode
1392 entities and it's a good coding practice to define a namespace for your
1393 application set of data and test that the element and attributes you're
1394 analyzing actually pertains to your application space. This is done by a
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1395 simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1396 <li>To retrieve text and attributes value, you can use the function
1397 <em>xmlNodeListGetString</em> to gather all the text and entity reference
1398 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1399</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1400
1401<p>Here is another piece of code used to parse another level of the
1402structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1403<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1404/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1405 * a Description for a Job
1406 */
1407typedef struct job {
1408 char *projectID;
1409 char *application;
1410 char *category;
1411 personPtr contact;
1412 int nbDevelopers;
1413 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
1414} job, *jobPtr;
1415
1416/*
1417 * And the code needed to parse it
1418 */
1419jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1420 jobPtr ret = NULL;
1421
1422DEBUG("parseJob\n");
1423 /*
1424 * allocate the struct
1425 */
1426 ret = (jobPtr) malloc(sizeof(job));
1427 if (ret == NULL) {
1428 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1429 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1430 }
1431 memset(ret, 0, sizeof(job));
1432
1433 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1434 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1435 while (cur != NULL) {
1436
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1437 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
1438 ret-&gt;projectID = xmlGetProp(cur, "ID");
1439 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1440 fprintf(stderr, "Project has no ID\n");
1441 }
1442 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1443 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
1444 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1445 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
1446 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1447 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
1448 ret-&gt;contact = parsePerson(doc, ns, cur);
1449 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1450 }
1451
1452 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1453}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1454
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1455<p>Once you are used to it, writing this kind of code is quite simple, but
1456boring. Ultimately, it could be possble to write stubbers taking either C data
1457structure definitions, a set of XML examples or an XML DTD and produce the
1458code needed to import and export the content between C data and XML storage.
1459This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1460
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]1461<p>Feel free to use <a href="example/gjobread.c">the code for the full C
1462parsing example</a> as a template, it is also available with Makefile in the
1463Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1464
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1465<h2><a name="Contributi">Contributions</a></h2>
1466<ul>
Daniel Veillard851c59c2000-11-24 16:06:22 +0000[diff] [blame]1467 <li><a href="mailto:ari@lusis.org">Ari Johnson</a> provides a C++ wrapper
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1468 for libxml:
1469 <p>Website: <a
1470 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
1471 <p>Download: <a
1472 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
1473 </li>
1474 <li><a href="mailto:doolin@cs.utk.edu">David Doolin</a> provides a
1475 precompiled Windows version
1476 <p><a
1477 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
1478 </li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1479 <li><a
1480 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
1481 Sergeant</a> developped <a
1482 href="http://axkit.org/download/">XML::LibXSLT</a>, a perl wrapper for
1483 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
1484 application server</a></li>
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1485 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> provided <a
1486 href="libxml-doc.el">an emacs module</a> to lookup libxml functions
1487 documentation</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1488 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
1489 href="http://xmlsoft.org/messages/0488.html">man pages</a> (not yet
1490 integrated in the distribution)</li>
1491</ul>
1492
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1493<p></p>
1494
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]1495<p><a href="mailto:Daniel.Veillard@imag.fr">Daniel Veillard</a></p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1496
Daniel Veillardafc73112001-04-11 11:51:41 +0000[diff] [blame^]1497<p>$Id: xml.html,v 1.78 2001/04/04 00:40:08 veillard Exp $</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1498</body>
1499</html>