Gitiles
Code Review Sign In
gerrit-public.fairphone.software / platform / external / libxml2 / ec70e917b9f5b4cc3e40e344e2c912790a9bfc33 / . / doc / xml.html
blob: 967ff694d7abfbcfff4e6e25c038441e154c9912 [file] [log] [blame]
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
2 "http://www.w3.org/TR/html4/loose.dtd">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]3<html>
4<head>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]5 <title>The XML C library for Gnome</title>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]6 <meta name="GENERATOR" content="amaya V4.1">
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]7 <meta http-equiv="Content-Type" content="text/html">
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]8</head>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]9
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]10<body bgcolor="#ffffff">
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]11<p><a href="http://www.gnome.org/"><img src="smallfootonly.gif"
12alt="Gnome Logo"></a><a href="http://www.w3.org/Status"><img src="w3c.png"
13alt="W3C Logo"></a></p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]14
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]15<h1 align="center">The XML C library for Gnome</h1>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]16
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]17<h2 style="text-align: center">libxml, a.k.a. gnome-xml</h2>
18
19<p></p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]20<ul>
21 <li><a href="#Introducti">Introduction</a></li>
22 <li><a href="#Documentat">Documentation</a></li>
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]23 <li><a href="#Reporting">Reporting bugs and getting help</a></li>
24 <li><a href="#help">how to help</a></li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]25 <li><a href="#Downloads">Downloads</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]26 <li><a href="#News">News</a></li>
27 <li><a href="#XML">XML</a></li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]28 <li><a href="#XSLT">XSLT</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]29 <li><a href="#tree">The tree output</a></li>
30 <li><a href="#interface">The SAX interface</a></li>
31 <li><a href="#library">The XML library interfaces</a>
32 <ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]33 <li><a href="#Invoking">Invoking the parser: the pull way</a></li>
34 <li><a href="#Invoking">Invoking the parser: the push way</a></li>
35 <li><a href="#Invoking2">Invoking the parser: the SAX interface</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]36 <li><a href="#Building">Building a tree from scratch</a></li>
37 <li><a href="#Traversing">Traversing the tree</a></li>
38 <li><a href="#Modifying">Modifying the tree</a></li>
39 <li><a href="#Saving">Saving the tree</a></li>
40 <li><a href="#Compressio">Compression</a></li>
41 </ul>
42 </li>
43 <li><a href="#Entities">Entities or no entities</a></li>
44 <li><a href="#Namespaces">Namespaces</a></li>
45 <li><a href="#Validation">Validation</a></li>
46 <li><a href="#Principles">DOM principles</a></li>
47 <li><a href="#real">A real example</a></li>
Daniel Veillard96984452000-08-31 13:50:12 +0000[diff] [blame]48 <li><a href="#Contributi">Contributions</a></li>
49</ul>
50
51<p>Separate documents:</p>
52<ul>
53 <li><a href="upgrade.html">upgrade instructions for migrating to
54 libxml2</a></li>
55 <li><a href="encoding.html">libxml Internationalization support</a></li>
56 <li><a href="xmlio.html">libxml Input/Output interfaces</a></li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]57 <li><a href="xmlmem.html">libxml Memory interfaces</a></li>
Daniel Veillard300f7d62000-11-24 13:04:04 +0000[diff] [blame]58 <li><a href="xmldtd.html">a short introduction about DTDs and
59 libxml</a></li>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]60 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]61</ul>
62
63<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]64
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]65<p>This document describes libxml, the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]66href="http://www.w3.org/XML/">XML</a> C library developped for the <a
67href="http://www.gnome.org/">Gnome</a> project. <a
68href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
69structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]70
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]71<p>Here are some key points about libxml:</p>
72<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]73 <li>Libxml exports Push and Pull type parser interfaces for both XML and
74 HTML.</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]75 <li>Libxml can do DTD validation at parse time, using a parsed document
76 instance, or with an arbitrary DTD.</li>
77 <li>Libxml now includes nearly complete <a
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]78 href="http://www.w3.org/TR/xpath">XPath</a> and <a
Daniel Veillard0c069222000-10-21 09:25:52 +0000[diff] [blame]79 href="http://www.w3.org/TR/xptr">XPointer</a> implementations.</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]80 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]81 sticking closely to ANSI C/POSIX for easy embedding. Works on
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]82 Linux/Unix/Windows, ported to a number of other platforms.</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]83 <li>Basic support for HTTP and FTP client allowing aplications to fetch
84 remote resources</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]85 <li>The design is modular, most of the extensions can be compiled out.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]86 <li>The internal document repesentation is as close as possible to the <a
87 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
88 <li>Libxml also has a <a href="http://www.megginson.com/SAX/index.html">SAX
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]89 like interface</a>; the interface is designed to be compatible with <a
90 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]91 <li>This library is released both under the <a
92 href="http://www.w3.org/Consortium/Legal/copyright-software-19980720.html">W3C
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]93 IPR</a> and the <a href="http://www.gnu.org/copyleft/lesser.html">GNU
94 LGPL</a>. Use either at your convenience, basically this should make
95 everybody happy, if not, drop me a mail.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]96</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]97
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]98<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]99
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]100<p>There are some on-line resources about using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]101<ol>
Daniel Veillard365e13b2000-07-02 07:56:37 +0000[diff] [blame]102 <li>Check the <a href="FAQ.html">FAQ</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]103 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]104 documentation</a> automatically extracted from code comments (using <a
105 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
106 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]107 <li>Look at the documentation about <a href="encoding.html">libxml
108 internationalization support</a></li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]109 <li>This page provides a global overview and <a href="#real">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]110 examples</a> on how to use libxml.</li>
111 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
112 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
113 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]114 <li>George Lebl wrote <a
115 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]116 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]117 <li>It is also a good idea to check to <a href="mailto:raph@levien.com">Raph
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]118 Levien</a>'s <a href="http://levien.com/gnome/">web site</a> since he is
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]119 building the <a href="http://levien.com/gnome/gdome.html">DOM interface
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]120 gdome</a> on top of libxml result tree and an implementation of <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]121 href="http://www.w3.org/Graphics/SVG/">SVG</a> called <a
122 href="http://www.levien.com/svg/">gill</a>. Check his <a
123 href="http://www.levien.com/gnome/domination.html">DOMination
124 paper</a>.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]125 <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO
126 file</a></li>
127 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>. If you are
128 starting a new project using libxml you should really use the 2.x
129 version.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]130 <li>And don't forget to look at the <a href="/messages/">mailing-list
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]131 archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]132</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]133
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]134<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]135
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]136<p>Well, bugs or missing features are always possible, and I will make a point
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]137of fixing them in a timely fashion. The best way to report a bug is to use the
138<a href="http://bugs.gnome.org/db/pa/lgnome-xml.html">Gnome bug tracking
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]139database</a> (make sure to use the "gnome-xml" module name, not libxml or
140libxml2). I look at reports there regularly and it's good to have a reminder
141when a bug is still open. Check the <a
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]142href="http://bugs.gnome.org/Reporting.html">instructions on reporting bugs</a>
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]143and be sure to specify that the bug is for the package gnome-xml.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]144
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]145<p>There is also a mailing-list <a
Daniel Veillardf121ab72000-08-29 23:40:42 +0000[diff] [blame]146href="mailto:xml@rpmfind.net">xml@rpmfind.net</a> for libxml, with an <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]147href="http://xmlsoft.org/messages">on-line archive</a>. To subscribe to this
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]148majordomo based list, send a mail message to <a
Daniel Veillardf121ab72000-08-29 23:40:42 +0000[diff] [blame]149href="mailto:majordomo@rpmfind.net">majordomo@rpmfind.net</a> with "subscribe
150xml" in the <strong>content</strong> of the message.</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]151
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]152<p>Alternatively, you can just send the bug to the <a
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]153href="mailto:xml@rpmfind.net">xml@rpmfind.net</a> list; if it's really libxml
Daniel Veillardf121ab72000-08-29 23:40:42 +0000[diff] [blame]154related I will approve it..</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]155
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]156<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]157probably be processed faster.</p>
158
159<p>If you're looking for help, a quick look at <a
160href="http://xmlsoft.org/messages/#407">the list archive</a> may actually
161provide the answer, I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]162questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]163documentantion</a> is not as polished as I would like (i need to learn more
164about Docbook), but it's a good starting point.</p>
165
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]166<h2><a name="help">How to help</a></h2>
167
168<p>You can help the project in various ways, the best thing to do first is to
169subscribe to the mailing-list as explained before, check the <a
170href="http://xmlsoft.org/messages/">archives </a>and the <a
171href="http://bugs.gnome.org/db/pa/lgnome-xml.html">Gnome bug
172database:</a>:</p>
173<ol>
174 <li>provide patches when you find problems</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]175 <li>provide the diffs when you port libxml to a new platform. They may not
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]176 be integrated in all cases but help pinpointing portability problems
177 and</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]178 <li>provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]179 as HTML diffs).</li>
180 <li>provide new documentations pieces (translations, examples, etc ...)</li>
181 <li>Check the TODO file and try to close one of the items</li>
182 <li>take one of the points raised in the archive or the bug database and
183 provide a fix. <a href="mailto:Daniel.Veillard@w3.org">Get in touch with
184 me </a>before to avoid synchronization problems and check that the
185 suggested fix will fit in nicely :-)</li>
186</ol>
187
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]188<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]189
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]190<p>The latest versions of libxml can be found on <a
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]191href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]192href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]193as a <a href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">source
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]194archive</a> or <a
195href="ftp://ftp.gnome.org/pub/GNOME/contrib/redhat/SRPMS/">RPM packages</a>.
196(NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]197href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
198href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]199packages installed to compile applications using libxml.)</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]200
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]201<p><a name="Snapshot">Snapshot:</a></p>
202<ul>
203 <li>Code from the W3C cvs base libxml <a
204 href="ftp://rpmfind.net/pub/libxml/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a></li>
205 <li>Docs, content of the web site, the list archive included <a
206 href="ftp://rpmfind.net/pub/libxml/libxml-docs.tar.gz">libxml-docs.tar.gz</a></li>
207</ul>
208
209<p><a name="Contribs">Contribs:</a></p>
210
211<p>I do accept external contributions, especially if compiling on another
212platform, get in touch with me to upload the package. I will keep them in the
213<a href="ftp://rpmfind.net/pub/libxml/contribs/">contrib directory</a></p>
214
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]215<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]216<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]217 <li><p>The <a
218 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gnome-xml">Gnome
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]219 CVS base</a>. Check the <a
220 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a> page;
221 the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]222 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]223 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]224</ul>
225
226<h2><a name="News">News</a></h2>
227
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]228<h3>CVS only : check the <a
229href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]230for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]231
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]232<p>Items floating around but not actively worked on, get in touch with me if
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]233you want to test those</p>
234<ul>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]235 <li>Implementing <a href="http://xmlsoft.org/XSLT">XSLT</a>, this is done as
236 a separate C library on top of libxml called libxslt, not released yet but
237 available from CVS</li>
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]238 <li>Finishing up <a href="http://www.w3.org/TR/xptr">XPointer</a> and <a
239 href="http://www.w3.org/TR/xinclude">XInclude</a></li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]240 <li>(seeems working but delayed from release) parsing/import of Docbook SGML
241 docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]242</ul>
243
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]244<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]245<ul>
246 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
247 <li>fixed a Dtd parsing bug</li>
248 <li>fixed a bug in xmlNodeGetContent</li>
249 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
250</ul>
251
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]252<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]253<ul>
254 <li>some XPath and HTML bug fixes for XSLT</li>
255 <li>small extension of the hash table interfaces for DOM gdome2
256 implementation</li>
257 <li>A few bug fixes</li>
258</ul>
259
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]260<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]261<ul>
262 <li>Lots of XPath bug fixes</li>
263 <li>Add a mode with Dtd lookup but without validation error reporting for
264 XSLT</li>
265 <li>Add support for text node without escaping (XSLT)</li>
266 <li>bug fixes for xmlCheckFilename</li>
267 <li>validation code bug fixes from Gary Pennington</li>
268 <li>Patch from Paul D. Smith correcting URI path normalization</li>
269 <li>Patch to allow simultaneous install of libxml-devel and
270 libxml2-devel</li>
271 <li>the example Makefile is now fixed</li>
272 <li>added HTML to the RPM packages</li>
273 <li>tree copying bugfixes</li>
274 <li>updates to Windows makefiles</li>
275 <li>optimisation patch from Bjorn Reese</li>
276</ul>
277
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]278<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]279<ul>
280 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
281 <li>added htmlHandleOmittedElem()</li>
282 <li>Applied Bjorn Reese's IPV6 first patch</li>
283 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]284 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]285</ul>
286
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]287<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]288<ul>
289 <li>Fix the Windows problems of 2.2.8</li>
290 <li>integrate OpenVMS patches</li>
291 <li>better handling of some nasty HTML input</li>
292 <li>Improved the XPointer implementation</li>
293 <li>integrate a number of provided patches</li>
294</ul>
295
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]296<h3>2.2.9: Nov 25 2000</h3>
297<ul>
298 <li>erroneous release :-(</li>
299</ul>
300
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]301<h3>2.2.8: Nov 13 2000</h3>
302<ul>
303 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
304 support</li>
305 <li>Patch in conditional section handling</li>
306 <li>updated MS compiler project</li>
307 <li>fixed some XPath problems</li>
308 <li>added an URI escaping function</li>
309 <li>some other bug fixes</li>
310</ul>
311
312<h3>2.2.7: Oct 31 2000</h3>
313<ul>
314 <li>added message redirection</li>
315 <li>XPath improvements (thanks TOM !)</li>
316 <li>xmlIOParseDTD() added</li>
317 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
318 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
319</ul>
320
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]321<h3>2.2.6: Oct 25 2000:</h3>
322<ul>
323 <li>Added an hash table module, migrated a number of internal structure to
324 those</li>
325 <li>Fixed a posteriori validation problems</li>
326 <li>HTTP module cleanups</li>
327 <li>HTML parser improvements (tag errors, script/style handling, attribute
328 normalization)</li>
329 <li>coalescing of adjacent text nodes</li>
330 <li>couple of XPath bug fixes, exported the internal API</li>
331</ul>
332
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]333<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]334<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]335 <li>XPointer implementation and testsuite</li>
336 <li>Lot of XPath fixes, added variable and functions registration, more
337 tests</li>
338 <li>Portability fixes, lots of enhancements toward an easy Windows build and
339 release</li>
340 <li>Late validation fixes</li>
341 <li>Integrated a lot of contributed patches</li>
342 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]343 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]344</ul>
345
346<h3>2.2.4: Oct 1 2000:</h3>
347<ul>
348 <li>main XPath problem fixed</li>
349 <li>Integrated portability patches for Windows</li>
350 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]351</ul>
352
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]353<h3>2.2.3: Sep 17 2000</h3>
354<ul>
355 <li>bug fixes</li>
356 <li>cleanup of entity handling code</li>
357 <li>overall review of all loops in the parsers, all sprintf usage has been
358 checked too</li>
359 <li>Far better handling of larges Dtd. Validating against Docbook XML Dtd
360 works smoothly now.</li>
361</ul>
362
363<h3>1.8.10: Sep 6 2000</h3>
364<ul>
365 <li>bug fix release for some Gnome projects</li>
366</ul>
367
368<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]369<ul>
370 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]371 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]372</ul>
373
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]374<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]375<ul>
376 <li>a purely bug fixes release</li>
377 <li>fixed an encoding support problem when parsing from a memory block</li>
378 <li>fixed a DOCTYPE parsing problem</li>
379 <li>removed a bug in the function allowing to override the memory allocation
380 routines</li>
381</ul>
382
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]383<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]384<ul>
385 <li>applied a lot of portability fixes</li>
386 <li>better encoding support/cleanup and saving (content is now always
387 encoded in UTF-8)</li>
388 <li>the HTML parser now correctly handles encodings</li>
389 <li>added xmlHasProp()</li>
390 <li>fixed a serious problem with &amp;#38;</li>
391 <li>propagated the fix to FTP client</li>
392 <li>cleanup, bugfixes, etc ...</li>
393 <li>Added a page about <a href="encoding.html">libxml Internationalization
394 support</a></li>
395</ul>
396
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]397<h3>1.8.9: July 9 2000</h3>
398<ul>
399 <li>fixed the spec the RPMs should be better</li>
400 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
401 rpmfind users problem</li>
402</ul>
403
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]404<h3>2.1.1: July 1 2000</h3>
405<ul>
406 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
407 <li>improvements on the HTML parser</li>
408</ul>
409
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]410<h3>2.1.0 and 1.8.8: June 29 2000</h3>
411<ul>
412 <li>1.8.8 is mostly a comodity package for upgrading to libxml2 accoding to
413 <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
414 about &amp;#38; charref parsing</li>
415 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
416 also contains numerous fixes and enhancements:
417 <ul>
418 <li>added xmlStopParser() to stop parsing</li>
419 <li>improved a lot parsing speed when there is large CDATA blocs</li>
420 <li>includes XPath patches provided by Picdar Technology</li>
421 <li>tried to fix as much as possible DtD validation and namespace
422 related problems</li>
423 <li>output to a given encoding has been added/tested</li>
424 <li>lot of various fixes</li>
425 </ul>
426 </li>
427</ul>
428
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]429<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]430<ul>
431 <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]432 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initally
433 scheduled for Apr 3 the relase occured only on Apr 12 due to massive
434 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]435 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]436 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]437 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]438 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]439 <pre>#include "xxx.h"</pre>
440 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]441 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
442 <li>the memory allocation routines used by libxml can now be overloaded
443 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]444 <li>The previously CVS only tool tester has been renamed
445 <strong>xmllint</strong> and is now installed as part of the libxml2
446 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]447 <li>The I/O interface has been revamped. There is now ways to plug in
448 specific I/O modules, either at the URI scheme detection level using
449 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
450 parser context using xmlCreateIOParserCtxt()</li>
451 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
452 number of the libxml module in use</li>
453 <li>a number of optional features of libxml can now be excluded at configure
454 time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]455</ul>
456
457<h3>2.0.0beta: Mar 14 2000</h3>
458<ul>
459 <li>This is a first Beta release of libxml version 2</li>
460 <li>It's available only from<a href="ftp://rpmfind.net/pub/libxml/">
461 rpmfind.net FTP</a>, it's packaged as libxml2-2.0.0beta and available as
462 tar and RPMs</li>
463 <li>This version is now the head in the Gnome CVS base, the old one is
464 available under the tag LIB_XML_1_X</li>
465 <li>This includes a very large set of changes. Froma programmatic point of
466 view applications should not have to be modified too much, check the <a
467 href="upgrade.html">upgrade page</a></li>
468 <li>Some interfaces may changes (especially a bit about encoding).</li>
469 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]470 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]471 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
472 handled now</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]473 <li>Better handling of entities, especially well formedness checking and
474 proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]475 <li>DTD conditional sections</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]476 <li>Validation now correcly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]477 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
478 structures to accomodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]479 </ul>
480 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]481 <li>Serious progress were made toward compliance, <a
482 href="conf/result.html">here are the result of the test</a> against the
483 OASIS testsuite (except the japanese tests since I don't support that
484 encoding yet). This URL is rebuilt every couple of hours using the CVS
485 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]486</ul>
487
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]488<h3>1.8.7: Mar 6 2000</h3>
489<ul>
490 <li>This is a bug fix release:</li>
491 <li>It is possible to disable the ignorable blanks heuristic used by
492 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
493 that for adherence to XML spec, this behaviour will be disabled by default
494 in 2.x . The same function will allow to keep compatibility for old
495 code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]496 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
497 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]498 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
499 compilation on some platforms has been fixed</li>
500 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
501 URIs</li>
502</ul>
503
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]504<h3>1.8.6: Jan 31 2000</h3>
505<ul>
506 <li>added a nanoFTP transport module, debugged until the new version of <a
507 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
508 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]509</ul>
510
511<h3>1.8.5: Jan 21 2000</h3>
512<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]513 <li>adding APIs to parse a well balanced chunk of XML (production <a
514 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the XML
515 spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]516 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]517 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
518 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]519 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
520 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]521</ul>
522
523<h3>1.8.4: Jan 13 2000</h3>
524<ul>
525 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
526 <li>all exit() call should have been removed from libxml</li>
527 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
528 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]529</ul>
530
531<h3>1.8.3: Jan 5 2000</h3>
532<ul>
533 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]534 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillarddbfd6411999-12-28 16:35:14 +0000[diff] [blame]535 <li>lots of bug fixes and improvement added over XMas hollidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]536 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]537 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
538 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]539 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]540 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]541 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]542</ul>
543
544<h3>1.8.2: Dec 21 1999</h3>
545<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]546 <li>I got another problem with includes and C++, I hope this issue is fixed
547 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]548 <li>Added a few tree modification functions: xmlReplaceNode,
549 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
550 xmlDocSetRootElement</li>
551 <li>Tried to improve the HTML output with help from <a
552 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]553</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]554
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]555<h3>1.8.1: Dec 18 1999</h3>
556<ul>
557 <li>various patches to avoid troubles when using libxml with C++ compilers
558 the "namespace" keyword and C escaping in include files</li>
559 <li>a problem in one of the core macros IS_CHAR was corrected</li>
560 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
561 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]562 <li>fixed a posteriori validation (validation after parsing, or by using a
563 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]564 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]565</ul>
566
567<h3>1.8.0: Dec 12 1999</h3>
568<ul>
569 <li>cleanup, especially memory wise</li>
570 <li>the parser should be more reliable, especially the HTML one, it should
571 not crash, whatever the input !</li>
572 <li>Integrated various patches, especially a speedup improvement for large
573 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
574 configure with --with-buffers to enable them.</li>
575 <li>attribute normalization, oops should have been added long ago !</li>
576 <li>attributes defaulted from Dtds should be available, xmlSetProp() now
577 does entities escapting by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]578</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]579
580<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]581<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]582 <li>Lots of HTML improvement</li>
583 <li>Fixed some errors when saving both XML and HTML</li>
584 <li>More examples, the regression tests should now look clean</li>
585 <li>Fixed a bug with contiguous charref</li>
586</ul>
587
588<h3>1.7.3: Sep 29 1999</h3>
589<ul>
590 <li>portability problems fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]591 <li>snprintf was used unconditionnally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]592 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]593</ul>
594
595<h3>1.7.1: Sep 24 1999</h3>
596<ul>
597 <li>The basic type for strings manipulated by libxml has been renamed in
598 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
599 is that CHAR was conflicting with a predefined type on Windows. However on
600 non WIN32 environment, compatibility is provided by the way of a
601 <strong>#define </strong>.</li>
602 <li>Changed another error : the use of a structure field called errno, and
603 leading to troubles on platforms where it's a macro</li>
604</ul>
605
606<h3>1.7.0: sep 23 1999</h3>
607<ul>
608 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]609 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]610 <li>Added an errno to report errors by another mean than a simple printf
611 like callback</li>
612 <li>Finished ID/IDREF support and checking when validation</li>
613 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]614 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]615 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
616 implementation</li>
617 <li>Added an HTML parser front-end</li>
618</ul>
619
620<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]621
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]622<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]623markup-based structured documents. Here is <a name="example">an example XML
624document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]625<pre>&lt;?xml version="1.0"?&gt;
626&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
627 &lt;head&gt;
628 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
629 &lt;/head&gt;
630 &lt;chapter&gt;
631 &lt;title&gt;The Linux adventure&lt;/title&gt;
632 &lt;p&gt;bla bla bla ...&lt;/p&gt;
633 &lt;image href="linus.gif"/&gt;
634 &lt;p&gt;...&lt;/p&gt;
635 &lt;/chapter&gt;
636&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]637
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]638<p>The first line specifies that it's an XML document and gives useful
639information about its encoding. Then the document is a text format whose
640structure is specified by tags between brackets. <strong>Each tag opened has
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]641to be closed</strong>. XML is pedantic about this. However, if a tag is empty
642(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]643ends with <code>/&gt;</code> rather than with <code>&gt;</code>. Note that,
644for example, the image tag has no content (just an attribute) and is closed by
645ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]646
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]647<p>XML can be applied sucessfully to a wide range of uses, from long term
648structured document maintenance (where it follows the steps of SGML) to simple
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]649data encoding mechanisms like configuration file formatting (glade),
650spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where
651it is used to encode remote calls between a client and a server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]652
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]653<h2><a name="XSLT">XSLT</a></h2>
654
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]655<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
656
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]657<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a language
658for transforming XML documents into other XML documents (or HTML/textual
659output).</p>
660
661<p>A separate library called libxslt is being built on top of libxml2. This
662module "libxslt" can be found in the Gnome CVS base too.</p>
663
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]664<p>You can check the <a
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]665href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a> supported
666and the progresses on the <a
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]667href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog">Changelog</a></p>
668
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]669<h2>An overview of libxml architecture</h2>
670
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]671<p>Libxml is made of multiple components; some of them are optional, and most
672of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]673<ul>
674 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]675 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]676 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]677 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]678 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]679 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]680 <li>a SAX tree module to build an in-memory DOM representation</li>
681 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]682 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]683 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]684 (optional)</li>
685 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]686</ul>
687
688<p>Graphically this gives the following:</p>
689
690<p><img src="libxml.gif" alt="a graphical view of the various"></p>
691
692<p></p>
693
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]694<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]695
696<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]697returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]698<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]699as the file name, the document type, and a <strong>children</strong> pointer
700which is the root of the document (or more exactly the first child under the
701root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]702chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]703relationship. An xmlNode can also carry properties (a chain of xmlAttr
704structures). An attribute may have a value which is a list of TEXT or
705ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]706
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]707<p>Here is an example (erroneous with respect to the XML spec since there
708should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]709
710<p><img src="structure.gif" alt=" structure.gif "></p>
711
712<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]713called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]714prints them back as parsed. This is useful for detecting errors both in XML
715code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]716which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]717result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]718<pre>DOCUMENT
719version=1.0
720standalone=true
721 ELEMENT EXAMPLE
722 ATTRIBUTE prop1
723 TEXT
724 content=gnome is great
725 ATTRIBUTE prop2
726 ENTITY_REF
727 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]728 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]729 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]730 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]731 TEXT
732 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]733 ELEMENT chapter
734 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]735 TEXT
736 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]737 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]738 TEXT
739 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]740 ELEMENT image
741 ATTRIBUTE href
742 TEXT
743 content=linus.gif
744 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]745 TEXT
746 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]747
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]748<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]749
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]750<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]751
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]752<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]753memory. In that case (and if you don't expect to save back the XML document
754loaded 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]755<strong>callback-based interface</strong> to the parser. Before parsing, the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]756application layer registers a customized set of callbacks which are called by
757the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]758
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]759<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]760libxml, see the <a
761href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
762documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]763Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]764
765<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
766program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]767binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]768distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]769testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]770<pre>SAX.setDocumentLocator()
771SAX.startDocument()
772SAX.getEntity(amp)
773SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
774SAX.characters( , 3)
775SAX.startElement(head)
776SAX.characters( , 4)
777SAX.startElement(title)
778SAX.characters(Welcome to Gnome, 16)
779SAX.endElement(title)
780SAX.characters( , 3)
781SAX.endElement(head)
782SAX.characters( , 3)
783SAX.startElement(chapter)
784SAX.characters( , 4)
785SAX.startElement(title)
786SAX.characters(The Linux adventure, 19)
787SAX.endElement(title)
788SAX.characters( , 4)
789SAX.startElement(p)
790SAX.characters(bla bla bla ..., 15)
791SAX.endElement(p)
792SAX.characters( , 4)
793SAX.startElement(image, href='linus.gif')
794SAX.endElement(image)
795SAX.characters( , 4)
796SAX.startElement(p)
797SAX.characters(..., 3)
798SAX.endElement(p)
799SAX.characters( , 3)
800SAX.endElement(chapter)
801SAX.characters( , 1)
802SAX.endElement(EXAMPLE)
803SAX.endDocument()</pre>
804
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]805<p>Most of the other interfaces of libxml are based on the DOM tree-building
806facility, so nearly everything up to the end of this document presupposes the
807use of the standard DOM tree build. Note that the DOM tree itself is built by
808a set of registered default callbacks, without internal specific
809interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]810
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]811<h2><a name="library">The XML library interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]812
813<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]814using the XML library from the C language. It is not intended to be extensive.
815I hope the automatically generated documents will provide the completeness
816required, but as a separate set of documents. The interfaces of the XML
817library are by principle low level, there is nearly zero abstraction. Those
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]818interested in a higher level API should <a href="#DOM">look at DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]819
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]820<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
821separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]822interfaces</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]823
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]824<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]825
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]826<p>Usually, the first thing to do is to read an XML input. The parser accepts
827documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]828defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]829<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]830 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]831 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]832 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]833</dl>
834<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]835 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]836 <dd><p>Parse an XML document contained in a (possibly compressed)
837 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]838 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]839</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]840
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]841<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]842failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]843
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]844<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]845
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]846<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]847fetched (which is common for GUI based programs) libxml provides a push
848interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]849<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
850 void *user_data,
851 const char *chunk,
852 int size,
853 const char *filename);
854int xmlParseChunk (xmlParserCtxtPtr ctxt,
855 const char *chunk,
856 int size,
857 int terminate);</pre>
858
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]859<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]860<pre> FILE *f;
861
862 f = fopen(filename, "r");
863 if (f != NULL) {
864 int res, size = 1024;
865 char chars[1024];
866 xmlParserCtxtPtr ctxt;
867
868 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]869 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]870 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
871 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]872 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]873 xmlParseChunk(ctxt, chars, res, 0);
874 }
875 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]876 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]877 xmlFreeParserCtxt(ctxt);
878 }
879 }</pre>
880
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]881<p>The HTML parser embedded into libxml also has a push interface; the
882functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]883
884<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
885
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]886<p>The tree-building interface makes the parser memory-hungry, first loading
887the document in memory and then building the tree itself. Reading a document
888without building the tree is possible using the SAX interfaces (see SAX.h and
889<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]890Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]891limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]892<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]893
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]894<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]895
896<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]897there is a set of functions dedicated to building new elements. (These are
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]898also 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]899that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]900<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]901 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]902 xmlNodePtr tree, subtree;
903
904 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]905 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
906 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
907 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
908 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]909 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]910 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]911 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
912 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
913 subtree = xmlNewChild(tree, NULL, "image", NULL);
914 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]915
916<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]917
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]918<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]919
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]920<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]921code has access to the internal structure of all the elements of the tree. The
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]922names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]923<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]924<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]925example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]926<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]927
928<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]929<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]930
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]931<p>points to the text node containing the chapter title "The Linux
932adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]933
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]934<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]935present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]936to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]937<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]938
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]939<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]940
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]941<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]942is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]943<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]944 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
945 xmlChar *value);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]946 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node. The
947 value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]948 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]949</dl>
950<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]951 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]952 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]953 <dd><p>This function returns a pointer to new copy of the property
954 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]955 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]956</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]957
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]958<p>Two functions are provided for reading and writing the text associated with
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]959elements:</p>
960<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]961 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]962 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]963 <dd><p>This function takes an "external" string and converts it to one
964 text node or possibly to a list of entity and text nodes. All
965 non-predefined entity references like &amp;Gnome; will be stored
966 internally as entity nodes, hence the result of the function may not be
967 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]968 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]969</dl>
970<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]971 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]972 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]973 <dd><p>This function is the inverse of
974 <code>xmlStringGetNodeList()</code>. It generates a new string
975 containing the content of the text and entity nodes. Note the extra
976 argument inLine. If this argument is set to 1, the function will expand
977 entity references. For example, instead of returning the &amp;Gnome;
978 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]979 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]980 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]981</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]982
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]983<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]984
985<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]986<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]987 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]988 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]989 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]990 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]991</dl>
992<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]993 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]994 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]995 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]996</dl>
997<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]998 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]999 <dd><p>Saves the document to a file. In this case, the compression
1000 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1001 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1002</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1003
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1004<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1005
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1006<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1007accesses. The level of compression on saves can be turned on either globally
1008or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1009<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1010 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1011 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1012 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1013</dl>
1014<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1015 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1016 <dd><p>Sets the document compression ratio.</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 Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1020 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1021 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1022 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1023</dl>
1024<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1025 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1026 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1027 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1028</dl>
1029
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1030<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1031
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1032<p>Entities in principle are similar to simple C macros. An entity defines an
1033abbreviation for a given string that you can reuse many times throughout the
1034content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1035may occur frequently within a document, or to confine the change needed to a
1036document to a restricted area in the internal subset of the document (at the
1037beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1038<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]10392 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]10403 &lt;!ENTITY xml "Extensible Markup Language"&gt;
10414 ]&gt;
10425 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]10436 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]10447 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1045
1046<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]1047its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1048are 5 predefined entities in libxml allowing you to escape charaters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1049predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1050<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1051for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1052<strong>&amp;quot;</strong> for the character '"', and
1053<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1054
1055<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]1056substitute an entity's content so that you can see the replacement text in
1057your application. Or you may prefer to keep entity references as such in the
1058content to be able to save the document back without losing this usually
1059precious information (if the user went through the pain of explicitly defining
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1060entities, he may have a a rather negative attitude if you blindly susbtitute
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1061them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1062href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1063function allows you to check and change the behaviour, which is to not
1064substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1065
1066<p>Here is the DOM tree built by libxml for the previous document in the
1067default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1068<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1069DOCUMENT
1070version=1.0
1071 ELEMENT EXAMPLE
1072 TEXT
1073 content=
1074 ENTITY_REF
1075 INTERNAL_GENERAL_ENTITY xml
1076 content=Extensible Markup Language
1077 TEXT
1078 content=</pre>
1079
1080<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1081<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1082DOCUMENT
1083version=1.0
1084 ELEMENT EXAMPLE
1085 TEXT
1086 content= Extensible Markup Language</pre>
1087
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1088<p>So, entities or no entities? Basically, it depends on your use case. I
1089suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1090entities in your XML document or data if you are not willing to handle the
1091entity references elements in the DOM tree.</p>
1092
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1093<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1094entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1095transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1096reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1097finding them in the input).</p>
1098
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1099<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1100on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1101non-predefined entities in your documents, then the learning cuvre to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1102then 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]1103strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]1104deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1105
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1106<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1107
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1108<p>The libxml library implements <a
1109href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
1110recognizing namespace contructs in the input, and does namespace lookup
1111automatically when building the DOM tree. A namespace declaration is
1112associated with an in-memory structure and all elements or attributes within
1113that namespace point to it. Hence testing the namespace is a simple and fast
1114equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1115
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1116<p>I suggest that people using libxml use a namespace, and declare it in the
1117root element of their document as the default namespace. Then they don't need
1118to 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]1119refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]1120the size of the XML output significantly, but significantly increases its
1121value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1122<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
1123 &lt;elem1&gt;...&lt;/elem1&gt;
1124 &lt;elem2&gt;...&lt;/elem2&gt;
1125&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1126
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]1127<p>The namespace value has to be an absolute URL, but the URL doesn't have to
1128point to any existing resource on the Web. It will bind all the element and
1129atributes with that URL. I suggest to use an URL within a domain you control,
1130and that the URL should contain some kind of version information if possible.
1131For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a good
1132namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1133
1134<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1135version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1136and if the version information don't match something you know, warn the user
1137and 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]1138namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1139same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1140associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1141just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1142<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1143prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1144
1145<p>@@Interfaces@@</p>
1146
1147<p>@@Examples@@</p>
1148
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1149<p>Usually people object to using namespaces together with validity checking.
1150I will try to make sure that using namespaces won't break validity checking,
1151so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1152suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1153<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1154flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1155from multiple DTDs will certainly break current validation schemes. I will try
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1156to provide ways to do this, but this may not be portable or standardized.</p>
1157
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1158<h2><a name="Validation">Validation, or are you afraid of DTDs ?</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1159
1160<p>Well what is validation and what is a DTD ?</p>
1161
1162<p>Validation is the process of checking a document against a set of
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1163construction rules; a <strong>DTD</strong> (Document Type Definition) is such
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1164a set of rules.</p>
1165
1166<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1167of the XML life cycle. Briefly a DTD defines all the possibles element to be
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1168found within your document, what is the formal shape of your document tree (by
1169defining the allowed content of an element, either text, a regular expression
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1170for the allowed list of children, or mixed content i.e. both text and
1171children). The DTD also defines the allowed attributes for all elements and
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]1172the types of the attributes. For more detailed information, I suggest that you
1173 read the related parts of the XML specification, the examples found under
1174gnome-xml/test/valid/dtd and any of the large number of books available on
1175XML. The dia example in gnome-xml/test/valid should be both simple and
1176complete enough to allow you to build your own.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1177
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1178<p>A word of warning, building a good DTD which will fit the needs of your
1179application in the long-term is far from trivial; however, the extra level of
1180quality it can ensure is well worth the price for some sets of applications or
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1181if you already have already a DTD defined for your application field.</p>
1182
1183<p>The validation is not completely finished but in a (very IMHO) usable
1184state. Until a real validation interface is defined the way to do it is to
1185define and set the <strong>xmlDoValidityCheckingDefaultValue</strong> external
1186variable to 1, this will of course be changed at some point:</p>
1187
1188<p>extern int xmlDoValidityCheckingDefaultValue;</p>
1189
1190<p>...</p>
1191
1192<p>xmlDoValidityCheckingDefaultValue = 1;</p>
1193
1194<p></p>
1195
1196<p>To handle external entities, use the function
1197<strong>xmlSetExternalEntityLoader</strong>(xmlExternalEntityLoader f); to
1198link in you HTTP/FTP/Entities database library to the standard libxml
1199core.</p>
1200
1201<p>@@interfaces@@</p>
1202
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1203<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1204
1205<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]1206Model</em>; this is an API for accessing XML or HTML structured documents.
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]1207Native support for DOM in Gnome is on the way (module gnome-dom), and will be
1208based on gnome-xml. This will be a far cleaner interface to manipulate XML
Daniel Veillardc08a2c61999-09-08 21:35:25 +0000[diff] [blame]1209files within Gnome since it won't expose the internal structure. DOM defines a
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1210set of IDL (or Java) interfaces allowing you to traverse and manipulate a
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1211document. The DOM library will allow accessing and modifying "live" documents
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1212present in other programs like this:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1213
1214<p><img src="DOM.gif" alt=" DOM.gif "></p>
1215
1216<p>This should help greatly doing things like modifying a gnumeric spreadsheet
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1217embedded in a GWP document for example.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1218
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1219<p>The current DOM implementation on top of libxml is the <a
1220href="http://cvs.gnome.org/lxr/source/gdome/">gdome Gnome module</a>, this is
1221a full DOM interface, thanks to <a href="mailto:raph@levien.com">Raph
1222Levien</a>.</p>
1223
1224<p>The gnome-dom module in the Gnome CVS base is obsolete</p>
1225
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1226<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1227
1228<p>Here is a real size example, where the actual content of the application
1229data 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]1230a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1231storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
1232base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1233<pre>&lt;?xml version="1.0"?&gt;
1234&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
1235 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1236
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1237 &lt;gjob:Job&gt;
1238 &lt;gjob:Project ID="3"/&gt;
1239 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
1240 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1241
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1242 &lt;gjob:Update&gt;
1243 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
1244 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
1245 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
1246 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1247
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1248 &lt;gjob:Developers&gt;
1249 &lt;gjob:Developer&gt;
1250 &lt;/gjob:Developer&gt;
1251 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1252
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1253 &lt;gjob:Contact&gt;
1254 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
1255 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
1256 &lt;gjob:Company&gt;
1257 &lt;/gjob:Company&gt;
1258 &lt;gjob:Organisation&gt;
1259 &lt;/gjob:Organisation&gt;
1260 &lt;gjob:Webpage&gt;
1261 &lt;/gjob:Webpage&gt;
1262 &lt;gjob:Snailmail&gt;
1263 &lt;/gjob:Snailmail&gt;
1264 &lt;gjob:Phone&gt;
1265 &lt;/gjob:Phone&gt;
1266 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1267
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1268 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1269 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1270 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1271
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1272 &lt;gjob:Skills&gt;
1273 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1274
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1275 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1276 A GNOME based system that will allow a superuser to configure
1277 compressed and uncompressed files and/or file systems to be backed
1278 up with a supported media in the system. This should be able to
1279 perform via find commands generating a list of files that are passed
1280 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
1281 or via operations performed on the filesystem itself. Email
1282 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1283 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1284
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1285 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1286
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1287 &lt;/gjob:Jobs&gt;
1288&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1289
1290<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^]1291only a couple of functions, browsing the tree to gather the ata and generate
1292the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1293
1294<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]1295structure. For example, the ordering of the attributes is not significant, the
1296XML specification is clear about it. It's also usually a good idea not to
1297depend on the order of the children of a given node, unless it really makes
1298things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1299<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1300 * A person record
1301 */
1302typedef struct person {
1303 char *name;
1304 char *email;
1305 char *company;
1306 char *organisation;
1307 char *smail;
1308 char *webPage;
1309 char *phone;
1310} person, *personPtr;
1311
1312/*
1313 * And the code needed to parse it
1314 */
1315personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1316 personPtr ret = NULL;
1317
1318DEBUG("parsePerson\n");
1319 /*
1320 * allocate the struct
1321 */
1322 ret = (personPtr) malloc(sizeof(person));
1323 if (ret == NULL) {
1324 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1325 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1326 }
1327 memset(ret, 0, sizeof(person));
1328
1329 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1330 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1331 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1332 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
1333 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1334 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
1335 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1336 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1337 }
1338
1339 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1340}</pre>
1341
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1342<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1343<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1344 <li>Usually a recursive parsing style is the more convenient one: XML data
1345 is by nature subject to repetitive constructs and usually exibits highly
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1346 stuctured patterns.</li>
1347 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>, i.e.
1348 the pointer to the global XML document and the namespace reserved to the
1349 application. Document wide information are needed for example to decode
1350 entities and it's a good coding practice to define a namespace for your
1351 application set of data and test that the element and attributes you're
1352 analyzing actually pertains to your application space. This is done by a
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1353 simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]1354 <li>To retrieve text and attributes value, you can use the function
1355 <em>xmlNodeListGetString</em> to gather all the text and entity reference
1356 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1357</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1358
1359<p>Here is another piece of code used to parse another level of the
1360structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1361<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1362/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1363 * a Description for a Job
1364 */
1365typedef struct job {
1366 char *projectID;
1367 char *application;
1368 char *category;
1369 personPtr contact;
1370 int nbDevelopers;
1371 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
1372} job, *jobPtr;
1373
1374/*
1375 * And the code needed to parse it
1376 */
1377jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1378 jobPtr ret = NULL;
1379
1380DEBUG("parseJob\n");
1381 /*
1382 * allocate the struct
1383 */
1384 ret = (jobPtr) malloc(sizeof(job));
1385 if (ret == NULL) {
1386 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1387 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1388 }
1389 memset(ret, 0, sizeof(job));
1390
1391 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1392 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1393 while (cur != NULL) {
1394
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1395 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
1396 ret-&gt;projectID = xmlGetProp(cur, "ID");
1397 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1398 fprintf(stderr, "Project has no ID\n");
1399 }
1400 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1401 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
1402 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1403 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
1404 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1405 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
1406 ret-&gt;contact = parsePerson(doc, ns, cur);
1407 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1408 }
1409
1410 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1411}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1412
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]1413<p>Once you are used to it, writing this kind of code is quite simple, but
1414boring. Ultimately, it could be possble to write stubbers taking either C data
1415structure definitions, a set of XML examples or an XML DTD and produce the
1416code needed to import and export the content between C data and XML storage.
1417This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1418
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]1419<p>Feel free to use <a href="example/gjobread.c">the code for the full C
1420parsing example</a> as a template, it is also available with Makefile in the
1421Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1422
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1423<h2><a name="Contributi">Contributions</a></h2>
1424<ul>
Daniel Veillard851c59c2000-11-24 16:06:22 +0000[diff] [blame]1425 <li><a href="mailto:ari@lusis.org">Ari Johnson</a> provides a C++ wrapper
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1426 for libxml:
1427 <p>Website: <a
1428 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
1429 <p>Download: <a
1430 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
1431 </li>
1432 <li><a href="mailto:doolin@cs.utk.edu">David Doolin</a> provides a
1433 precompiled Windows version
1434 <p><a
1435 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
1436 </li>
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1437 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> provided <a
1438 href="libxml-doc.el">an emacs module</a> to lookup libxml functions
1439 documentation</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1440 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
1441 href="http://xmlsoft.org/messages/0488.html">man pages</a> (not yet
1442 integrated in the distribution)</li>
1443</ul>
1444
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1445<p></p>
1446
1447<p><a href="mailto:Daniel.Veillard@w3.org">Daniel Veillard</a></p>
1448
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame^]1449<p>$Id: xml.html,v 1.69 2001/02/26 07:31:12 veillard Exp $</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1450</body>
1451</html>