Gitiles
Code Review Sign In
gerrit-public.fairphone.software / platform / external / libxml2 / a47fb3d9f7de393cb7288d6e51e86d53bd1992d4 / . / doc / xml.html
blob: 28e73c61ba540fd88a2701f6e66edddb5fbbddd6 [file] [log] [blame]
Daniel Veillarda47fb3d2001-03-25 17:23:49 +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 Veillarde0c1d722001-03-21 10:28:36 +0000[diff] [blame]98<p>Warning: unless you are forced to because your application links with a
99Gnome library requiring it, <strong><span
100style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
101libxml2</p>
102
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]103<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]104
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]105<p>There are some on-line resources about using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]106<ol>
Daniel Veillard365e13b2000-07-02 07:56:37 +0000[diff] [blame]107 <li>Check the <a href="FAQ.html">FAQ</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]108 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]109 documentation</a> automatically extracted from code comments (using <a
110 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
111 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]112 <li>Look at the documentation about <a href="encoding.html">libxml
113 internationalization support</a></li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]114 <li>This page provides a global overview and <a href="#real">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]115 examples</a> on how to use libxml.</li>
116 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
117 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
118 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]119 <li>George Lebl wrote <a
120 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]121 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]122 <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]123 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]124 building the <a href="http://levien.com/gnome/gdome.html">DOM interface
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]125 gdome</a> on top of libxml result tree and an implementation of <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]126 href="http://www.w3.org/Graphics/SVG/">SVG</a> called <a
127 href="http://www.levien.com/svg/">gill</a>. Check his <a
128 href="http://www.levien.com/gnome/domination.html">DOMination
129 paper</a>.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]130 <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO
131 file</a></li>
132 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>. If you are
133 starting a new project using libxml you should really use the 2.x
134 version.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]135 <li>And don't forget to look at the <a href="/messages/">mailing-list
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]136 archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]137</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]138
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]139<h2><a name="Reporting">Reporting bugs and getting help</a></h2>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]140
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]141<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]142of fixing them in a timely fashion. The best way to report a bug is to use the
Daniel Veillard81781102001-03-07 09:31:47 +0000[diff] [blame]143<a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml">Gnome bug
144tracking database</a> (make sure to use the "libxml" module name). I look at
145reports there regularly and it's good to have a reminder when a bug is still
146open. Check the <a href="http://bugs.gnome.org/Reporting.html">instructions on
147reporting bugs</a> and be sure to specify that the bug is for the package
148libxml.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]149
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]150<p>There is also a mailing-list <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]151href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]152href="http://xmlsoft.org/messages">on-line archive</a>. To subscribe to this
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]153list, please visit the <a
154href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
155follow the instructions.</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]156
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]157<p>Alternatively, you can just send the bug to the <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]158href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml
Daniel Veillardf121ab72000-08-29 23:40:42 +0000[diff] [blame]159related I will approve it..</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]160
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]161<p>Of course, bugs reported with a suggested patch for fixing them will
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]162probably be processed faster.</p>
163
164<p>If you're looking for help, a quick look at <a
165href="http://xmlsoft.org/messages/#407">the list archive</a> may actually
166provide the answer, I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]167questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]168documentantion</a> is not as polished as I would like (i need to learn more
169about Docbook), but it's a good starting point.</p>
170
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]171<h2><a name="help">How to help</a></h2>
172
173<p>You can help the project in various ways, the best thing to do first is to
174subscribe to the mailing-list as explained before, check the <a
175href="http://xmlsoft.org/messages/">archives </a>and the <a
176href="http://bugs.gnome.org/db/pa/lgnome-xml.html">Gnome bug
177database:</a>:</p>
178<ol>
179 <li>provide patches when you find problems</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]180 <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]181 be integrated in all cases but help pinpointing portability problems
182 and</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]183 <li>provide documentation fixes (either as patches to the code comments or
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]184 as HTML diffs).</li>
185 <li>provide new documentations pieces (translations, examples, etc ...)</li>
186 <li>Check the TODO file and try to close one of the items</li>
187 <li>take one of the points raised in the archive or the bug database and
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]188 provide a fix. <a href="mailto:Daniel.Veillard@imag.fr">Get in touch with
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]189 me </a>before to avoid synchronization problems and check that the
190 suggested fix will fit in nicely :-)</li>
191</ol>
192
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]193<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]194
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]195<p>The latest versions of libxml can be found on <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]196href="ftp://xmlsoft.org/">xmlsoft.org</a> or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]197href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]198as a <a href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">source
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]199archive</a> or <a
200href="ftp://ftp.gnome.org/pub/GNOME/contrib/redhat/SRPMS/">RPM packages</a>.
201(NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]202href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
203href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]204packages installed to compile applications using libxml.)</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]205
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]206<p><a name="Snapshot">Snapshot:</a></p>
207<ul>
208 <li>Code from the W3C cvs base libxml <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]209 href="ftp://xmlsoft.org/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]210 <li>Docs, content of the web site, the list archive included <a
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]211 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]212</ul>
213
214<p><a name="Contribs">Contribs:</a></p>
215
216<p>I do accept external contributions, especially if compiling on another
217platform, get in touch with me to upload the package. I will keep them in the
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]218<a href="ftp://xmlsoft.org/contribs/">contrib directory</a></p>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]219
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]220<p>Libxml is also available from CVS:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]221<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]222 <li><p>The <a
223 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]224 CVS base</a>. Check the <a
225 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a> page;
226 the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]227 </li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]228 <li>The <strong>libxslt</strong> module is also present there</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]229</ul>
230
231<h2><a name="News">News</a></h2>
232
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]233<h3>CVS only : check the <a
234href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]235for a really accurate description</h3>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]236
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]237<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]238you want to test those</p>
239<ul>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]240 <li>Implementing <a href="http://xmlsoft.org/XSLT">XSLT</a>, this is done as
241 a separate C library on top of libxml called libxslt, not released yet but
242 available from CVS</li>
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]243 <li>Finishing up <a href="http://www.w3.org/TR/xptr">XPointer</a> and <a
244 href="http://www.w3.org/TR/xinclude">XInclude</a></li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]245 <li>(seeems working but delayed from release) parsing/import of Docbook SGML
246 docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]247</ul>
248
Daniel Veillard56a4cb82001-03-24 17:00:36 +0000[diff] [blame]249<h3>2.3.5: Mar 23 2001</h3>
250<ul>
251 <li>Biggest change is separate parsing and evaluation of XPath expressions,
252 there is some new APIs for this too</li>
253 <li>included a number of bug fixes(XML push parser, 51876, notations,
254 52299)</li>
255 <li>Fixed some portability issues</li>
256</ul>
257
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]258<h3>2.3.4: Mar 10 2001</h3>
259<ul>
260 <li>Fixed bugs #51860 and #51861</li>
261 <li>Added a global variable xmlDefaultBufferSize to allow default buffer
262 size to be application tunable.</li>
263 <li>Some cleanup in the validation code, still a bug left and this part
264 should probably be rewritten to support ambiguous content model :-\</li>
265 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
266 parser</li>
267 <li>Fixed another bug in xmlNodeGetContent()</li>
268 <li>Bjorn fixed XPath node collection and Number formatting</li>
269 <li>Fixed a loop reported in the HTML parsing</li>
270 <li>blank space are reported even if the Dtd content model proves that they
271 are formatting spaces, this is for XmL conformance</li>
272</ul>
273
Daniel Veillardb402c072001-03-01 17:28:58 +0000[diff] [blame]274<h3>2.3.3: Mar 1 2001</h3>
275<ul>
276 <li>small change in XPath for XSLT</li>
277 <li>documentation cleanups</li>
278 <li>fix in validation by Gary Pennington</li>
279 <li>serious parsing performances improvements</li>
280</ul>
281
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]282<h3>2.3.2: Feb 24 2001</h3>
Daniel Veillard71681102001-02-24 17:48:53 +0000[diff] [blame]283<ul>
284 <li>chasing XPath bugs, found a bunch, completed some TODO</li>
285 <li>fixed a Dtd parsing bug</li>
286 <li>fixed a bug in xmlNodeGetContent</li>
287 <li>ID/IDREF support partly rewritten by Gary Pennington</li>
288</ul>
289
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]290<h3>2.3.1: Feb 15 2001</h3>
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]291<ul>
292 <li>some XPath and HTML bug fixes for XSLT</li>
293 <li>small extension of the hash table interfaces for DOM gdome2
294 implementation</li>
295 <li>A few bug fixes</li>
296</ul>
297
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]298<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]299<ul>
300 <li>Lots of XPath bug fixes</li>
301 <li>Add a mode with Dtd lookup but without validation error reporting for
302 XSLT</li>
303 <li>Add support for text node without escaping (XSLT)</li>
304 <li>bug fixes for xmlCheckFilename</li>
305 <li>validation code bug fixes from Gary Pennington</li>
306 <li>Patch from Paul D. Smith correcting URI path normalization</li>
307 <li>Patch to allow simultaneous install of libxml-devel and
308 libxml2-devel</li>
309 <li>the example Makefile is now fixed</li>
310 <li>added HTML to the RPM packages</li>
311 <li>tree copying bugfixes</li>
312 <li>updates to Windows makefiles</li>
313 <li>optimisation patch from Bjorn Reese</li>
314</ul>
315
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]316<h3>2.2.11: Jan 4 2001</h3>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]317<ul>
318 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
319 <li>added htmlHandleOmittedElem()</li>
320 <li>Applied Bjorn Reese's IPV6 first patch</li>
321 <li>Applied Paul D. Smith patches for validation of XInclude results</li>
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]322 <li>added XPointer xmlns() new scheme support</li>
Daniel Veillard503b8932001-01-05 06:36:31 +0000[diff] [blame]323</ul>
324
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]325<h3>2.2.10: Nov 25 2000</h3>
Daniel Veillard9d343c42000-11-25 10:12:43 +0000[diff] [blame]326<ul>
327 <li>Fix the Windows problems of 2.2.8</li>
328 <li>integrate OpenVMS patches</li>
329 <li>better handling of some nasty HTML input</li>
330 <li>Improved the XPointer implementation</li>
331 <li>integrate a number of provided patches</li>
332</ul>
333
Daniel Veillard2ddd23d2000-11-25 10:42:19 +0000[diff] [blame]334<h3>2.2.9: Nov 25 2000</h3>
335<ul>
336 <li>erroneous release :-(</li>
337</ul>
338
Daniel Veillard28929b22000-11-13 18:22:49 +0000[diff] [blame]339<h3>2.2.8: Nov 13 2000</h3>
340<ul>
341 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
342 support</li>
343 <li>Patch in conditional section handling</li>
344 <li>updated MS compiler project</li>
345 <li>fixed some XPath problems</li>
346 <li>added an URI escaping function</li>
347 <li>some other bug fixes</li>
348</ul>
349
350<h3>2.2.7: Oct 31 2000</h3>
351<ul>
352 <li>added message redirection</li>
353 <li>XPath improvements (thanks TOM !)</li>
354 <li>xmlIOParseDTD() added</li>
355 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
356 <li>some cleanup of the Makefile, autoconf and the distribution content</li>
357</ul>
358
Daniel Veillard29a11cc2000-10-25 13:32:39 +0000[diff] [blame]359<h3>2.2.6: Oct 25 2000:</h3>
360<ul>
361 <li>Added an hash table module, migrated a number of internal structure to
362 those</li>
363 <li>Fixed a posteriori validation problems</li>
364 <li>HTTP module cleanups</li>
365 <li>HTML parser improvements (tag errors, script/style handling, attribute
366 normalization)</li>
367 <li>coalescing of adjacent text nodes</li>
368 <li>couple of XPath bug fixes, exported the internal API</li>
369</ul>
370
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]371<h3>2.2.5: Oct 15 2000:</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]372<ul>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]373 <li>XPointer implementation and testsuite</li>
374 <li>Lot of XPath fixes, added variable and functions registration, more
375 tests</li>
376 <li>Portability fixes, lots of enhancements toward an easy Windows build and
377 release</li>
378 <li>Late validation fixes</li>
379 <li>Integrated a lot of contributed patches</li>
380 <li>added memory management docs</li>
Daniel Veillardab8500d2000-10-15 21:06:19 +0000[diff] [blame]381 <li>a performance problem when using large buffer seems fixed</li>
Daniel Veillard189446d2000-10-13 10:23:06 +0000[diff] [blame]382</ul>
383
384<h3>2.2.4: Oct 1 2000:</h3>
385<ul>
386 <li>main XPath problem fixed</li>
387 <li>Integrated portability patches for Windows</li>
388 <li>Serious bug fixes on the URI and HTML code</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]389</ul>
390
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]391<h3>2.2.3: Sep 17 2000</h3>
392<ul>
393 <li>bug fixes</li>
394 <li>cleanup of entity handling code</li>
395 <li>overall review of all loops in the parsers, all sprintf usage has been
396 checked too</li>
397 <li>Far better handling of larges Dtd. Validating against Docbook XML Dtd
398 works smoothly now.</li>
399</ul>
400
401<h3>1.8.10: Sep 6 2000</h3>
402<ul>
403 <li>bug fix release for some Gnome projects</li>
404</ul>
405
406<h3>2.2.2: August 12 2000</h3>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]407<ul>
408 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]409 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]410</ul>
411
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]412<h3>2.2.1: July 21 2000</h3>
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]413<ul>
414 <li>a purely bug fixes release</li>
415 <li>fixed an encoding support problem when parsing from a memory block</li>
416 <li>fixed a DOCTYPE parsing problem</li>
417 <li>removed a bug in the function allowing to override the memory allocation
418 routines</li>
419</ul>
420
Daniel Veillardd5f97f82000-09-17 16:38:14 +0000[diff] [blame]421<h3>2.2.0: July 14 2000</h3>
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]422<ul>
423 <li>applied a lot of portability fixes</li>
424 <li>better encoding support/cleanup and saving (content is now always
425 encoded in UTF-8)</li>
426 <li>the HTML parser now correctly handles encodings</li>
427 <li>added xmlHasProp()</li>
428 <li>fixed a serious problem with &amp;#38;</li>
429 <li>propagated the fix to FTP client</li>
430 <li>cleanup, bugfixes, etc ...</li>
431 <li>Added a page about <a href="encoding.html">libxml Internationalization
432 support</a></li>
433</ul>
434
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]435<h3>1.8.9: July 9 2000</h3>
436<ul>
437 <li>fixed the spec the RPMs should be better</li>
438 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
439 rpmfind users problem</li>
440</ul>
441
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]442<h3>2.1.1: July 1 2000</h3>
443<ul>
444 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
445 <li>improvements on the HTML parser</li>
446</ul>
447
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]448<h3>2.1.0 and 1.8.8: June 29 2000</h3>
449<ul>
450 <li>1.8.8 is mostly a comodity package for upgrading to libxml2 accoding to
451 <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
452 about &amp;#38; charref parsing</li>
453 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
454 also contains numerous fixes and enhancements:
455 <ul>
456 <li>added xmlStopParser() to stop parsing</li>
457 <li>improved a lot parsing speed when there is large CDATA blocs</li>
458 <li>includes XPath patches provided by Picdar Technology</li>
459 <li>tried to fix as much as possible DtD validation and namespace
460 related problems</li>
461 <li>output to a given encoding has been added/tested</li>
462 <li>lot of various fixes</li>
463 </ul>
464 </li>
465</ul>
466
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]467<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]468<ul>
469 <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]470 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initally
471 scheduled for Apr 3 the relase occured only on Apr 12 due to massive
472 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]473 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]474 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]475 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]476 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]477 <pre>#include "xxx.h"</pre>
478 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]479 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
480 <li>the memory allocation routines used by libxml can now be overloaded
481 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]482 <li>The previously CVS only tool tester has been renamed
483 <strong>xmllint</strong> and is now installed as part of the libxml2
484 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]485 <li>The I/O interface has been revamped. There is now ways to plug in
486 specific I/O modules, either at the URI scheme detection level using
487 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
488 parser context using xmlCreateIOParserCtxt()</li>
489 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
490 number of the libxml module in use</li>
491 <li>a number of optional features of libxml can now be excluded at configure
492 time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]493</ul>
494
495<h3>2.0.0beta: Mar 14 2000</h3>
496<ul>
497 <li>This is a first Beta release of libxml version 2</li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]498 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org
499 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
500 RPMs</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]501 <li>This version is now the head in the Gnome CVS base, the old one is
502 available under the tag LIB_XML_1_X</li>
503 <li>This includes a very large set of changes. Froma programmatic point of
504 view applications should not have to be modified too much, check the <a
505 href="upgrade.html">upgrade page</a></li>
506 <li>Some interfaces may changes (especially a bit about encoding).</li>
507 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]508 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]509 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
510 handled now</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]511 <li>Better handling of entities, especially well formedness checking and
512 proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]513 <li>DTD conditional sections</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]514 <li>Validation now correcly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]515 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
516 structures to accomodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]517 </ul>
518 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]519 <li>Serious progress were made toward compliance, <a
520 href="conf/result.html">here are the result of the test</a> against the
521 OASIS testsuite (except the japanese tests since I don't support that
522 encoding yet). This URL is rebuilt every couple of hours using the CVS
523 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]524</ul>
525
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]526<h3>1.8.7: Mar 6 2000</h3>
527<ul>
528 <li>This is a bug fix release:</li>
529 <li>It is possible to disable the ignorable blanks heuristic used by
530 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
531 that for adherence to XML spec, this behaviour will be disabled by default
532 in 2.x . The same function will allow to keep compatibility for old
533 code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]534 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
535 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]536 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
537 compilation on some platforms has been fixed</li>
538 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
539 URIs</li>
540</ul>
541
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]542<h3>1.8.6: Jan 31 2000</h3>
543<ul>
544 <li>added a nanoFTP transport module, debugged until the new version of <a
545 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
546 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]547</ul>
548
549<h3>1.8.5: Jan 21 2000</h3>
550<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]551 <li>adding APIs to parse a well balanced chunk of XML (production <a
552 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the XML
553 spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]554 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]555 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
556 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]557 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
558 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]559</ul>
560
561<h3>1.8.4: Jan 13 2000</h3>
562<ul>
563 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
564 <li>all exit() call should have been removed from libxml</li>
565 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
566 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]567</ul>
568
569<h3>1.8.3: Jan 5 2000</h3>
570<ul>
571 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]572 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillarddbfd6411999-12-28 16:35:14 +0000[diff] [blame]573 <li>lots of bug fixes and improvement added over XMas hollidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]574 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]575 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
576 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]577 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]578 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]579 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]580</ul>
581
582<h3>1.8.2: Dec 21 1999</h3>
583<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]584 <li>I got another problem with includes and C++, I hope this issue is fixed
585 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]586 <li>Added a few tree modification functions: xmlReplaceNode,
587 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
588 xmlDocSetRootElement</li>
589 <li>Tried to improve the HTML output with help from <a
590 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]591</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]592
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]593<h3>1.8.1: Dec 18 1999</h3>
594<ul>
595 <li>various patches to avoid troubles when using libxml with C++ compilers
596 the "namespace" keyword and C escaping in include files</li>
597 <li>a problem in one of the core macros IS_CHAR was corrected</li>
598 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
599 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]600 <li>fixed a posteriori validation (validation after parsing, or by using a
601 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]602 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]603</ul>
604
605<h3>1.8.0: Dec 12 1999</h3>
606<ul>
607 <li>cleanup, especially memory wise</li>
608 <li>the parser should be more reliable, especially the HTML one, it should
609 not crash, whatever the input !</li>
610 <li>Integrated various patches, especially a speedup improvement for large
611 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
612 configure with --with-buffers to enable them.</li>
613 <li>attribute normalization, oops should have been added long ago !</li>
614 <li>attributes defaulted from Dtds should be available, xmlSetProp() now
615 does entities escapting by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]616</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]617
618<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]619<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]620 <li>Lots of HTML improvement</li>
621 <li>Fixed some errors when saving both XML and HTML</li>
622 <li>More examples, the regression tests should now look clean</li>
623 <li>Fixed a bug with contiguous charref</li>
624</ul>
625
626<h3>1.7.3: Sep 29 1999</h3>
627<ul>
628 <li>portability problems fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]629 <li>snprintf was used unconditionnally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]630 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]631</ul>
632
633<h3>1.7.1: Sep 24 1999</h3>
634<ul>
635 <li>The basic type for strings manipulated by libxml has been renamed in
636 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
637 is that CHAR was conflicting with a predefined type on Windows. However on
638 non WIN32 environment, compatibility is provided by the way of a
639 <strong>#define </strong>.</li>
640 <li>Changed another error : the use of a structure field called errno, and
641 leading to troubles on platforms where it's a macro</li>
642</ul>
643
644<h3>1.7.0: sep 23 1999</h3>
645<ul>
646 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]647 href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]648 <li>Added an errno to report errors by another mean than a simple printf
649 like callback</li>
650 <li>Finished ID/IDREF support and checking when validation</li>
651 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]652 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]653 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
654 implementation</li>
655 <li>Added an HTML parser front-end</li>
656</ul>
657
658<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]659
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]660<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]661markup-based structured documents. Here is <a name="example">an example XML
662document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]663<pre>&lt;?xml version="1.0"?&gt;
664&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
665 &lt;head&gt;
666 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
667 &lt;/head&gt;
668 &lt;chapter&gt;
669 &lt;title&gt;The Linux adventure&lt;/title&gt;
670 &lt;p&gt;bla bla bla ...&lt;/p&gt;
671 &lt;image href="linus.gif"/&gt;
672 &lt;p&gt;...&lt;/p&gt;
673 &lt;/chapter&gt;
674&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]675
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]676<p>The first line specifies that it's an XML document and gives useful
677information about its encoding. Then the document is a text format whose
678structure is specified by tags between brackets. <strong>Each tag opened has
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]679to be closed</strong>. XML is pedantic about this. However, if a tag is empty
680(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]681ends with <code>/&gt;</code> rather than with <code>&gt;</code>. Note that,
682for example, the image tag has no content (just an attribute) and is closed by
683ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]684
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]685<p>XML can be applied sucessfully to a wide range of uses, from long term
686structured document maintenance (where it follows the steps of SGML) to simple
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]687data encoding mechanisms like configuration file formatting (glade),
688spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where
689it is used to encode remote calls between a client and a server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]690
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]691<h2><a name="XSLT">XSLT</a></h2>
692
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]693<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
694
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]695<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a language
696for transforming XML documents into other XML documents (or HTML/textual
697output).</p>
698
699<p>A separate library called libxslt is being built on top of libxml2. This
700module "libxslt" can be found in the Gnome CVS base too.</p>
701
Daniel Veillard383b1472001-01-23 11:39:52 +0000[diff] [blame]702<p>You can check the <a
Daniel Veillard6e6a6cc2001-02-15 15:55:44 +0000[diff] [blame]703href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a> supported
704and the progresses on the <a
Daniel Veillard82687162001-01-22 15:32:01 +0000[diff] [blame]705href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog">Changelog</a></p>
706
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]707<h2>An overview of libxml architecture</h2>
708
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]709<p>Libxml is made of multiple components; some of them are optional, and most
710of the block interfaces are public. The main components are:</p>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]711<ul>
712 <li>an Input/Output layer</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]713 <li>FTP and HTTP client layers (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]714 <li>an Internationalization layer managing the encodings support</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]715 <li>a URI module</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]716 <li>the XML parser and its basic SAX interface</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]717 <li>an HTML parser using the same SAX interface (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]718 <li>a SAX tree module to build an in-memory DOM representation</li>
719 <li>a tree module to manipulate the DOM representation</li>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]720 <li>a validation module using the DOM representation (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]721 <li>an XPath module for global lookup in a DOM representation
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]722 (optional)</li>
723 <li>a debug module (optional)</li>
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]724</ul>
725
726<p>Graphically this gives the following:</p>
727
728<p><img src="libxml.gif" alt="a graphical view of the various"></p>
729
730<p></p>
731
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]732<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]733
734<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]735returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]736<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]737as the file name, the document type, and a <strong>children</strong> pointer
738which is the root of the document (or more exactly the first child under the
739root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]740chained in double-linked lists of siblings and with a children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]741relationship. An xmlNode can also carry properties (a chain of xmlAttr
742structures). An attribute may have a value which is a list of TEXT or
743ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]744
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]745<p>Here is an example (erroneous with respect to the XML spec since there
746should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]747
748<p><img src="structure.gif" alt=" structure.gif "></p>
749
750<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]751called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]752prints them back as parsed. This is useful for detecting errors both in XML
753code and in the XML parser itself. It has an option <strong>--debug</strong>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]754which prints the actual in-memory structure of the document; here is the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]755result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]756<pre>DOCUMENT
757version=1.0
758standalone=true
759 ELEMENT EXAMPLE
760 ATTRIBUTE prop1
761 TEXT
762 content=gnome is great
763 ATTRIBUTE prop2
764 ENTITY_REF
765 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]766 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]767 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]768 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]769 TEXT
770 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]771 ELEMENT chapter
772 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]773 TEXT
774 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]775 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]776 TEXT
777 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]778 ELEMENT image
779 ATTRIBUTE href
780 TEXT
781 content=linus.gif
782 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]783 TEXT
784 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]785
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]786<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]787
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]788<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]789
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]790<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]791memory. In that case (and if you don't expect to save back the XML document
792loaded 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]793<strong>callback-based interface</strong> to the parser. Before parsing, the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]794application layer registers a customized set of callbacks which are called by
795the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]796
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]797<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]798libxml, see the <a
799href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
800documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]801Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]802
803<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
804program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]805binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]806distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]807testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]808<pre>SAX.setDocumentLocator()
809SAX.startDocument()
810SAX.getEntity(amp)
811SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
812SAX.characters( , 3)
813SAX.startElement(head)
814SAX.characters( , 4)
815SAX.startElement(title)
816SAX.characters(Welcome to Gnome, 16)
817SAX.endElement(title)
818SAX.characters( , 3)
819SAX.endElement(head)
820SAX.characters( , 3)
821SAX.startElement(chapter)
822SAX.characters( , 4)
823SAX.startElement(title)
824SAX.characters(The Linux adventure, 19)
825SAX.endElement(title)
826SAX.characters( , 4)
827SAX.startElement(p)
828SAX.characters(bla bla bla ..., 15)
829SAX.endElement(p)
830SAX.characters( , 4)
831SAX.startElement(image, href='linus.gif')
832SAX.endElement(image)
833SAX.characters( , 4)
834SAX.startElement(p)
835SAX.characters(..., 3)
836SAX.endElement(p)
837SAX.characters( , 3)
838SAX.endElement(chapter)
839SAX.characters( , 1)
840SAX.endElement(EXAMPLE)
841SAX.endDocument()</pre>
842
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]843<p>Most of the other interfaces of libxml are based on the DOM tree-building
844facility, so nearly everything up to the end of this document presupposes the
845use of the standard DOM tree build. Note that the DOM tree itself is built by
846a set of registered default callbacks, without internal specific
847interface.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]848
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]849<h2><a name="library">The XML library interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]850
851<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]852using the XML library from the C language. It is not intended to be extensive.
853I hope the automatically generated documents will provide the completeness
854required, but as a separate set of documents. The interfaces of the XML
855library are by principle low level, there is nearly zero abstraction. Those
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]856interested in a higher level API should <a href="#DOM">look at DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]857
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]858<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
859separated from the <a href="html/libxml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]860interfaces</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]861
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]862<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]863
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]864<p>Usually, the first thing to do is to read an XML input. The parser accepts
865documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]866defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]867<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]868 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]869 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]870 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]871</dl>
872<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]873 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]874 <dd><p>Parse an XML document contained in a (possibly compressed)
875 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]876 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]877</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]878
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]879<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]880failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]881
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]882<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]883
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]884<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]885fetched (which is common for GUI based programs) libxml provides a push
886interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]887<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
888 void *user_data,
889 const char *chunk,
890 int size,
891 const char *filename);
892int xmlParseChunk (xmlParserCtxtPtr ctxt,
893 const char *chunk,
894 int size,
895 int terminate);</pre>
896
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]897<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]898<pre> FILE *f;
899
900 f = fopen(filename, "r");
901 if (f != NULL) {
902 int res, size = 1024;
903 char chars[1024];
904 xmlParserCtxtPtr ctxt;
905
906 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]907 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]908 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
909 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]910 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]911 xmlParseChunk(ctxt, chars, res, 0);
912 }
913 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]914 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]915 xmlFreeParserCtxt(ctxt);
916 }
917 }</pre>
918
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]919<p>The HTML parser embedded into libxml also has a push interface; the
920functions are just prefixed by "html" rather than "xml".</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]921
922<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
923
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]924<p>The tree-building interface makes the parser memory-hungry, first loading
925the document in memory and then building the tree itself. Reading a document
926without building the tree is possible using the SAX interfaces (see SAX.h and
927<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]928Henstridge's documentation</a>). Note also that the push interface can be
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]929limited to SAX: just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]930<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]931
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]932<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]933
934<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]935there is a set of functions dedicated to building new elements. (These are
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]936also 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]937that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]938<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]939 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]940 xmlNodePtr tree, subtree;
941
942 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]943 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
944 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
945 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
946 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]947 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]948 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]949 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
950 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
951 subtree = xmlNewChild(tree, NULL, "image", NULL);
952 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]953
954<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]955
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]956<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]957
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]958<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]959code has access to the internal structure of all the elements of the tree. The
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]960names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]961<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]962<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]963example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]964<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]965
966<p>points to the title element,</p>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]967<pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]968
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]969<p>points to the text node containing the chapter title "The Linux
970adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]971
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]972<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]973present before the document root, so <code>doc-&gt;children</code> may point
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]974to an element which is not the document Root Element; a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]975<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]976
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]977<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]978
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]979<p>Functions are provided for reading and writing the document content. Here
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]980is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]981<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]982 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
983 xmlChar *value);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]984 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node. The
985 value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]986 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]987</dl>
988<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]989 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]990 *name);</code></dt>
Daniel Veillardc92c3042000-09-29 02:42:04 +0000[diff] [blame]991 <dd><p>This function returns a pointer to new copy of the property
992 content. Note that the user must deallocate the result.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]993 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]994</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]995
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]996<p>Two functions are provided for reading and writing the text associated with
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]997elements:</p>
998<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]999 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1000 *value);</code></dt>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1001 <dd><p>This function takes an "external" string and converts it to one
1002 text node or possibly to a list of entity and text nodes. All
1003 non-predefined entity references like &amp;Gnome; will be stored
1004 internally as entity nodes, hence the result of the function may not be
1005 a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1006 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1007</dl>
1008<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]1009 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1010 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1011 <dd><p>This function is the inverse of
1012 <code>xmlStringGetNodeList()</code>. It generates a new string
1013 containing the content of the text and entity nodes. Note the extra
1014 argument inLine. If this argument is set to 1, the function will expand
1015 entity references. For example, instead of returning the &amp;Gnome;
1016 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1017 "GNU Network Object Model Environment").</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1018 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1019</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1020
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1021<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1022
1023<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1024<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]1025 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1026 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1027 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1028 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1029</dl>
1030<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1031 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1032 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1033 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1034</dl>
1035<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1036 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1037 <dd><p>Saves the document to a file. In this case, the compression
1038 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1039 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1040</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]1041
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1042<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1043
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1044<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1045accesses. The level of compression on saves can be turned on either globally
1046or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1047<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1048 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1049 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1050 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1051</dl>
1052<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1053 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1054 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1055 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1056</dl>
1057<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1058 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1059 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1060 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1061</dl>
1062<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1063 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1064 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1065 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1066</dl>
1067
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1068<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1069
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1070<p>Entities in principle are similar to simple C macros. An entity defines an
1071abbreviation for a given string that you can reuse many times throughout the
1072content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1073may occur frequently within a document, or to confine the change needed to a
1074document to a restricted area in the internal subset of the document (at the
1075beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1076<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]10772 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]10783 &lt;!ENTITY xml "Extensible Markup Language"&gt;
10794 ]&gt;
10805 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]10816 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]10827 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1083
1084<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]1085its name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1086are 5 predefined entities in libxml allowing you to escape charaters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1087predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1088<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1089for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1090<strong>&amp;quot;</strong> for the character '"', and
1091<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1092
1093<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]1094substitute an entity's content so that you can see the replacement text in
1095your application. Or you may prefer to keep entity references as such in the
1096content to be able to save the document back without losing this usually
1097precious information (if the user went through the pain of explicitly defining
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1098entities, he may have a a rather negative attitude if you blindly susbtitute
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1099them as saving time). The <a
Daniel Veillard9cb5ff42001-01-29 08:22:21 +0000[diff] [blame]1100href="html/libxml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1101function allows you to check and change the behaviour, which is to not
1102substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1103
1104<p>Here is the DOM tree built by libxml for the previous document in the
1105default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1106<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1107DOCUMENT
1108version=1.0
1109 ELEMENT EXAMPLE
1110 TEXT
1111 content=
1112 ENTITY_REF
1113 INTERNAL_GENERAL_ENTITY xml
1114 content=Extensible Markup Language
1115 TEXT
1116 content=</pre>
1117
1118<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1119<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1120DOCUMENT
1121version=1.0
1122 ELEMENT EXAMPLE
1123 TEXT
1124 content= Extensible Markup Language</pre>
1125
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1126<p>So, entities or no entities? Basically, it depends on your use case. I
1127suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1128entities in your XML document or data if you are not willing to handle the
1129entity references elements in the DOM tree.</p>
1130
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1131<p>Note that at save time libxml enforces the conversion of the predefined
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1132entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1133transparently replace those with chars (i.e. it will not generate entity
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1134reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1135finding them in the input).</p>
1136
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1137<p><span style="background-color: #FF0000">WARNING</span>: handling entities
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1138on top of the libxml SAX interface is difficult!!! If you plan to use
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1139non-predefined entities in your documents, then the learning cuvre to handle
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1140then 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]1141strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame]1142deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]1143
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1144<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1145
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1146<p>The libxml library implements <a
1147href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
1148recognizing namespace contructs in the input, and does namespace lookup
1149automatically when building the DOM tree. A namespace declaration is
1150associated with an in-memory structure and all elements or attributes within
1151that namespace point to it. Hence testing the namespace is a simple and fast
1152equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1153
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1154<p>I suggest that people using libxml use a namespace, and declare it in the
1155root element of their document as the default namespace. Then they don't need
1156to 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]1157refinement and merging of data from different sources. This doesn't increase
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1158the size of the XML output significantly, but significantly increases its
1159value in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1160<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
1161 &lt;elem1&gt;...&lt;/elem1&gt;
1162 &lt;elem2&gt;...&lt;/elem2&gt;
1163&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1164
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1165<p>The namespace value has to be an absolute URL, but the URL doesn't have to
1166point to any existing resource on the Web. It will bind all the element and
1167atributes with that URL. I suggest to use an URL within a domain you control,
1168and that the URL should contain some kind of version information if possible.
1169For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a good
1170namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1171
1172<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1173version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1174and if the version information don't match something you know, warn the user
1175and 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]1176namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1177same as &lt;bar:text&gt; in another document. What really matters is the URI
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1178associated with the element or the attribute, not the prefix string (which is
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1179just a shortcut for the full URI). In libxml, element and attributes have an
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]1180<code>ns</code> field pointing to an xmlNs structure detailing the namespace
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1181prefix and its URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1182
1183<p>@@Interfaces@@</p>
1184
1185<p>@@Examples@@</p>
1186
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1187<p>Usually people object to using namespaces together with validity checking.
1188I will try to make sure that using namespaces won't break validity checking,
1189so even if you plan to use or currently are using validation I strongly
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1190suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1191<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1192flexible parsers. Using namespaces to mix and differentiate content coming
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]1193from multiple DTDs will certainly break current validation schemes. I will try
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1194to provide ways to do this, but this may not be portable or standardized.</p>
1195
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]1196<h2><a name="Validation">Validation, or are you afraid of DTDs ?</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1197
1198<p>Well what is validation and what is a DTD ?</p>
1199
1200<p>Validation is the process of checking a document against a set of
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1201construction rules; a <strong>DTD</strong> (Document Type Definition) is such
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1202a set of rules.</p>
1203
1204<p>The validation process and building DTDs are the two most difficult parts
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1205of the XML life cycle. Briefly a DTD defines all the possibles element to be
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1206found within your document, what is the formal shape of your document tree (by
1207defining the allowed content of an element, either text, a regular expression
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1208for the allowed list of children, or mixed content i.e. both text and
1209children). The DTD also defines the allowed attributes for all elements and
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1210the types of the attributes. For more detailed information, I suggest that you
Daniel Veillard81781102001-03-07 09:31:47 +0000[diff] [blame]1211read the related parts of the XML specification, the examples found under
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1212gnome-xml/test/valid/dtd and any of the large number of books available on
1213XML. The dia example in gnome-xml/test/valid should be both simple and
1214complete enough to allow you to build your own.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1215
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1216<p>A word of warning, building a good DTD which will fit the needs of your
1217application in the long-term is far from trivial; however, the extra level of
1218quality it can ensure is well worth the price for some sets of applications or
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1219if you already have already a DTD defined for your application field.</p>
1220
1221<p>The validation is not completely finished but in a (very IMHO) usable
1222state. Until a real validation interface is defined the way to do it is to
1223define and set the <strong>xmlDoValidityCheckingDefaultValue</strong> external
1224variable to 1, this will of course be changed at some point:</p>
1225
1226<p>extern int xmlDoValidityCheckingDefaultValue;</p>
1227
1228<p>...</p>
1229
1230<p>xmlDoValidityCheckingDefaultValue = 1;</p>
1231
1232<p></p>
1233
1234<p>To handle external entities, use the function
1235<strong>xmlSetExternalEntityLoader</strong>(xmlExternalEntityLoader f); to
1236link in you HTTP/FTP/Entities database library to the standard libxml
1237core.</p>
1238
1239<p>@@interfaces@@</p>
1240
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1241<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1242
1243<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]1244Model</em>; this is an API for accessing XML or HTML structured documents.
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1245Native support for DOM in Gnome is on the way (module gnome-dom), and will be
1246based on gnome-xml. This will be a far cleaner interface to manipulate XML
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame^]1247files within Gnome since it won't expose the internal structure. </p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1248
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1249<p>The current DOM implementation on top of libxml is the <a
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame^]1250href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this
1251is a full DOM interface, thanks to Paolo Casarini, check the <a
1252href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more
1253informations.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1254
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame^]1255<p>The gnome-dom and gdome modules in the Gnome CVS base are obsolete</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1256
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1257<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1258
1259<p>Here is a real size example, where the actual content of the application
1260data 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]1261a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1262storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
1263base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1264<pre>&lt;?xml version="1.0"?&gt;
1265&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
1266 &lt;gjob:Jobs&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:Job&gt;
1269 &lt;gjob:Project ID="3"/&gt;
1270 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
1271 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1272
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1273 &lt;gjob:Update&gt;
1274 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
1275 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
1276 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
1277 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1278
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1279 &lt;gjob:Developers&gt;
1280 &lt;gjob:Developer&gt;
1281 &lt;/gjob:Developer&gt;
1282 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1283
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1284 &lt;gjob:Contact&gt;
1285 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
1286 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
1287 &lt;gjob:Company&gt;
1288 &lt;/gjob:Company&gt;
1289 &lt;gjob:Organisation&gt;
1290 &lt;/gjob:Organisation&gt;
1291 &lt;gjob:Webpage&gt;
1292 &lt;/gjob:Webpage&gt;
1293 &lt;gjob:Snailmail&gt;
1294 &lt;/gjob:Snailmail&gt;
1295 &lt;gjob:Phone&gt;
1296 &lt;/gjob:Phone&gt;
1297 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1298
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1299 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1300 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1301 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1302
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1303 &lt;gjob:Skills&gt;
1304 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1305
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1306 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1307 A GNOME based system that will allow a superuser to configure
1308 compressed and uncompressed files and/or file systems to be backed
1309 up with a supported media in the system. This should be able to
1310 perform via find commands generating a list of files that are passed
1311 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
1312 or via operations performed on the filesystem itself. Email
1313 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1314 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1315
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1316 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1317
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1318 &lt;/gjob:Jobs&gt;
1319&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1320
1321<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]1322only a couple of functions, browsing the tree to gather the ata and generate
1323the internal structures is harder, and more error prone.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1324
1325<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1326structure. For example, the ordering of the attributes is not significant, the
1327XML specification is clear about it. It's also usually a good idea not to
1328depend on the order of the children of a given node, unless it really makes
1329things harder. Here is some code to parse the information for a person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1330<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1331 * A person record
1332 */
1333typedef struct person {
1334 char *name;
1335 char *email;
1336 char *company;
1337 char *organisation;
1338 char *smail;
1339 char *webPage;
1340 char *phone;
1341} person, *personPtr;
1342
1343/*
1344 * And the code needed to parse it
1345 */
1346personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1347 personPtr ret = NULL;
1348
1349DEBUG("parsePerson\n");
1350 /*
1351 * allocate the struct
1352 */
1353 ret = (personPtr) malloc(sizeof(person));
1354 if (ret == NULL) {
1355 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1356 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1357 }
1358 memset(ret, 0, sizeof(person));
1359
1360 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1361 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1362 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1363 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
1364 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1365 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
1366 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1367 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1368 }
1369
1370 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1371}</pre>
1372
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1373<p>Here are a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1374<ul>
Daniel Veillard91e9d582001-02-26 07:31:12 +0000[diff] [blame]1375 <li>Usually a recursive parsing style is the more convenient one: XML data
1376 is by nature subject to repetitive constructs and usually exibits highly
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1377 stuctured patterns.</li>
1378 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>, i.e.
1379 the pointer to the global XML document and the namespace reserved to the
1380 application. Document wide information are needed for example to decode
1381 entities and it's a good coding practice to define a namespace for your
1382 application set of data and test that the element and attributes you're
1383 analyzing actually pertains to your application space. This is done by a
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1384 simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1385 <li>To retrieve text and attributes value, you can use the function
1386 <em>xmlNodeListGetString</em> to gather all the text and entity reference
1387 nodes generated by the DOM output and produce an single text string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1388</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1389
1390<p>Here is another piece of code used to parse another level of the
1391structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1392<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1393/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1394 * a Description for a Job
1395 */
1396typedef struct job {
1397 char *projectID;
1398 char *application;
1399 char *category;
1400 personPtr contact;
1401 int nbDevelopers;
1402 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
1403} job, *jobPtr;
1404
1405/*
1406 * And the code needed to parse it
1407 */
1408jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1409 jobPtr ret = NULL;
1410
1411DEBUG("parseJob\n");
1412 /*
1413 * allocate the struct
1414 */
1415 ret = (jobPtr) malloc(sizeof(job));
1416 if (ret == NULL) {
1417 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1418 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1419 }
1420 memset(ret, 0, sizeof(job));
1421
1422 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1423 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1424 while (cur != NULL) {
1425
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1426 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
1427 ret-&gt;projectID = xmlGetProp(cur, "ID");
1428 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1429 fprintf(stderr, "Project has no ID\n");
1430 }
1431 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1432 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
1433 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1434 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
1435 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1436 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
1437 ret-&gt;contact = parsePerson(doc, ns, cur);
1438 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1439 }
1440
1441 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1442}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1443
Daniel Veillardec70e912001-02-26 20:10:45 +0000[diff] [blame]1444<p>Once you are used to it, writing this kind of code is quite simple, but
1445boring. Ultimately, it could be possble to write stubbers taking either C data
1446structure definitions, a set of XML examples or an XML DTD and produce the
1447code needed to import and export the content between C data and XML storage.
1448This is left as an exercise to the reader :-)</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1449
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]1450<p>Feel free to use <a href="example/gjobread.c">the code for the full C
1451parsing example</a> as a template, it is also available with Makefile in the
1452Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1453
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1454<h2><a name="Contributi">Contributions</a></h2>
1455<ul>
Daniel Veillard851c59c2000-11-24 16:06:22 +0000[diff] [blame]1456 <li><a href="mailto:ari@lusis.org">Ari Johnson</a> provides a C++ wrapper
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1457 for libxml:
1458 <p>Website: <a
1459 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
1460 <p>Download: <a
1461 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
1462 </li>
1463 <li><a href="mailto:doolin@cs.utk.edu">David Doolin</a> provides a
1464 precompiled Windows version
1465 <p><a
1466 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
1467 </li>
Daniel Veillarde356c282001-03-10 12:32:04 +0000[diff] [blame]1468 <li><a
1469 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
1470 Sergeant</a> developped <a
1471 href="http://axkit.org/download/">XML::LibXSLT</a>, a perl wrapper for
1472 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
1473 application server</a></li>
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1474 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> provided <a
1475 href="libxml-doc.el">an emacs module</a> to lookup libxml functions
1476 documentation</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1477 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
1478 href="http://xmlsoft.org/messages/0488.html">man pages</a> (not yet
1479 integrated in the distribution)</li>
1480</ul>
1481
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1482<p></p>
1483
Daniel Veillard33a67802001-03-07 09:44:02 +0000[diff] [blame]1484<p><a href="mailto:Daniel.Veillard@imag.fr">Daniel Veillard</a></p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1485
Daniel Veillarda47fb3d2001-03-25 17:23:49 +0000[diff] [blame^]1486<p>$Id: xml.html,v 1.76 2001/03/24 17:00:35 veillard Exp $</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1487</body>
1488</html>