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blob: 86fb3f37323c4df332fea59a0b18c2f484365550 [file] [log] [blame]
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]2 "http://www.w3.org/TR/REC-html40/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 Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame^]6 <meta name="GENERATOR" content="amaya V3.2.1">
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 Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]23 <li><a href="#Downloads">Downloads</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]24 <li><a href="#News">News</a></li>
25 <li><a href="#XML">XML</a></li>
26 <li><a href="#tree">The tree output</a></li>
27 <li><a href="#interface">The SAX interface</a></li>
28 <li><a href="#library">The XML library interfaces</a>
29 <ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]30 <li><a href="#Invoking">Invoking the parser: the pull way</a></li>
31 <li><a href="#Invoking">Invoking the parser: the push way</a></li>
32 <li><a href="#Invoking2">Invoking the parser: the SAX interface</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]33 <li><a href="#Building">Building a tree from scratch</a></li>
34 <li><a href="#Traversing">Traversing the tree</a></li>
35 <li><a href="#Modifying">Modifying the tree</a></li>
36 <li><a href="#Saving">Saving the tree</a></li>
37 <li><a href="#Compressio">Compression</a></li>
38 </ul>
39 </li>
40 <li><a href="#Entities">Entities or no entities</a></li>
41 <li><a href="#Namespaces">Namespaces</a></li>
42 <li><a href="#Validation">Validation</a></li>
43 <li><a href="#Principles">DOM principles</a></li>
44 <li><a href="#real">A real example</a></li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]45 <li><a href="#Contributi">Contribution</a></li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]46</ul>
47
48<h2><a name="Introducti">Introduction</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]49
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]50<p>This document describes libxml, the <a
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]51href="http://www.w3.org/XML/">XML</a> C library developped for the <a
52href="http://www.gnome.org/">Gnome</a> project. <a
53href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
54structured documents/data.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]55
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]56<p>Here are some key points about libxml:</p>
57<ul>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]58 <li>It is written in plain C, making as few assumptions as possible, and
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]59 sticking closely to ANSI C for easy embedding.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]60 <li>The internal document repesentation is as close as possible to the <a
61 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
62 <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]63 like interface</a>; the interface is designed to be compatible with <a
64 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]65 <li>Libxml now includes a nearly complete <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]66 href="http://www.w3.org/TR/xpath">XPath</a> implementation.</li>
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]67 <li>Libxml exports Push and Pull type parser interfaces for both XML and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]68 HTML.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]69 <li>This library is released both under the <a
70 href="http://www.w3.org/Consortium/Legal/copyright-software-19980720.html">W3C
71 IPR</a> and the GNU LGPL. Use either at your convenience, basically this
72 should make everybody happy, if not, drop me a mail.</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]73 <li>There is <a href="upgrade.html">a first set of instructions</a>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]74 concerning upgrade from libxml-1.x to libxml-2.x</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]75</ul>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]76
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]77<h2><a name="Documentat">Documentation</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]78
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]79<p>There are some on-line resources about using libxml:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]80<ol>
Daniel Veillard365e13b2000-07-02 07:56:37 +0000[diff] [blame]81 <li>Check the <a href="FAQ.html">FAQ</a></li>
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]82 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame^]83 documentation</a> automatically extracted from code comments (using <a
84 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gtk-doc">gtk
85 doc</a>).</li>
Daniel Veillard8d869642000-07-14 12:12:59 +0000[diff] [blame]86 <li>Look at the documentation about <a href="encoding.html">libxml
87 internationalization support</a></li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]88 <li>This page provides a global overview and <a href="#real">some
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]89 examples</a> on how to use libxml.</li>
90 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a
91 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice
92 documentation</a> explaining how to use the libxml SAX interface.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]93 <li>George Lebl wrote <a
94 href="http://www-4.ibm.com/software/developer/library/gnome3/">an article
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]95 for IBM developerWorks</a> about using libxml.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]96 <li>It is also a good idea to check to <a href="mailto:raph@levien.com">Raph
97 Levien</a> <a href="http://levien.com/gnome/">web site</a> since he is
98 building the <a href="http://levien.com/gnome/gdome.html">DOM interface
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]99 gdome</a> on top of libxml result tree and an implementation of <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]100 href="http://www.w3.org/Graphics/SVG/">SVG</a> called <a
101 href="http://www.levien.com/svg/">gill</a>. Check his <a
102 href="http://www.levien.com/gnome/domination.html">DOMination
103 paper</a>.</li>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]104 <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO
105 file</a></li>
106 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>. If you are
107 starting a new project using libxml you should really use the 2.x
108 version.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]109 <li>And don't forget to look at the <a href="/messages/">mailing-list
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]110 archive</a>.</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]111</ol>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]112
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]113<h3>Reporting bugs and getting help</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]114
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]115<p>Well, bugs or missing features are always possible, and I will make a point
116of fixing them in a timely fashion. The best way to report a bug is to <a
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]117href="http://bugs.gnome.org/db/pa/lgnome-xml.html">use the Gnome bug tracking
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]118database</a>. I look at reports there regularly and it's good to have a
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]119reminder when a bug is still open. Check the <a
120href="http://bugs.gnome.org/Reporting.html">instructions on reporting bugs</a>
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]121and be sure to specify that the bug is for the package gnome-xml.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]122
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]123<p>There is also a mailing-list <a
124href="mailto:xml@rufus.w3.org">xml@rufus.w3.org</a> for libxml, with an <a
125href="http://xmlsoft.org/messages">on-line archive</a>. To subscribe to this
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]126majordomo based list, send a mail message to <a
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]127href="mailto:majordomo@rufus.w3.org">majordomo@rufus.w3.org</a> with
128"subscribe xml" in the <strong>content</strong> of the message.</p>
129
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]130<p>Alternatively, you can just send the bug to the <a
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]131href="mailto:xml@rufus.w3.org">xml@rufus.w3.org</a> list.</p>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]132
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]133<p>Of course, bugs reports with a suggested patch for fixing them will
134probably be processed faster.</p>
135
136<p>If you're looking for help, a quick look at <a
137href="http://xmlsoft.org/messages/#407">the list archive</a> may actually
138provide the answer, I usually send source samples when answering libxml usage
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]139questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]140documentantion</a> is not as polished as I would like (i need to learn more
141about Docbook), but it's a good starting point.</p>
142
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]143<h2><a name="Downloads">Downloads</a></h2>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]144
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]145<p>The latest versions of libxml can be found on <a
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]146href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or on the <a
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]147href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]148as a <a href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">source
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]149archive</a> or <a
150href="ftp://ftp.gnome.org/pub/GNOME/contrib/redhat/SRPMS/">RPM packages</a>.
151(NOTE that you need both the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]152href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
153href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]154packages installed to compile applications using libxml.)</p>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]155
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]156<p><a name="Snapshot">Snapshot:</a></p>
157<ul>
158 <li>Code from the W3C cvs base libxml <a
159 href="ftp://rpmfind.net/pub/libxml/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a></li>
160 <li>Docs, content of the web site, the list archive included <a
161 href="ftp://rpmfind.net/pub/libxml/libxml-docs.tar.gz">libxml-docs.tar.gz</a></li>
162</ul>
163
164<p><a name="Contribs">Contribs:</a></p>
165
166<p>I do accept external contributions, especially if compiling on another
167platform, get in touch with me to upload the package. I will keep them in the
168<a href="ftp://rpmfind.net/pub/libxml/contribs/">contrib directory</a></p>
169
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]170<p>Libxml is also available from 2 CVS bases:</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]171<ul>
172 <li><p>The <a href="http://dev.w3.org/cvsweb/XML/">W3C CVS base</a>,
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]173 available read-only using the CVS pserver authentification (I tend to use
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]174 this base for my own development, so it's updated more regularly, but the
175 content may not be as stable):</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]176 <pre>CVSROOT=:pserver:anonymous@dev.w3.org:/sources/public
Daniel Veillard365e13b2000-07-02 07:56:37 +0000[diff] [blame]177 password: anonymous
178 module: XML</pre>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]179 </li>
180 <li><p>The <a
181 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]182 CVS base</a>. Check the <a
183 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a> page;
184 the CVS module is <b>gnome-xml</b>.</p>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]185 </li>
186</ul>
187
188<h2><a name="News">News</a></h2>
189
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]190<h3>CVS only : check the <a
191href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file
192for really accurate description</h3>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]193<ul>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]194 <li>working on HTML and XML links recognition layers, get in touch with me
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]195 if you want to test those.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]196</ul>
197
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]198<h2>2.2.2: August 12 2000</h2>
199<ul>
200 <li>mostly bug fixes</li>
Daniel Veillardec78c0f2000-08-25 10:25:23 +0000[diff] [blame]201 <li>started adding routines to access xml parser context options</li>
Daniel Veillard786d7c82000-08-12 23:38:57 +0000[diff] [blame]202</ul>
203
Daniel Veillarda2679fa2000-07-22 02:38:15 +0000[diff] [blame]204<h2>2.2.1: July 21 2000</h2>
205<ul>
206 <li>a purely bug fixes release</li>
207 <li>fixed an encoding support problem when parsing from a memory block</li>
208 <li>fixed a DOCTYPE parsing problem</li>
209 <li>removed a bug in the function allowing to override the memory allocation
210 routines</li>
211</ul>
212
Daniel Veillard94e90602000-07-17 14:38:19 +0000[diff] [blame]213<h2>2.2.0: July 14 2000</h2>
214<ul>
215 <li>applied a lot of portability fixes</li>
216 <li>better encoding support/cleanup and saving (content is now always
217 encoded in UTF-8)</li>
218 <li>the HTML parser now correctly handles encodings</li>
219 <li>added xmlHasProp()</li>
220 <li>fixed a serious problem with &amp;#38;</li>
221 <li>propagated the fix to FTP client</li>
222 <li>cleanup, bugfixes, etc ...</li>
223 <li>Added a page about <a href="encoding.html">libxml Internationalization
224 support</a></li>
225</ul>
226
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]227<h3>1.8.9: July 9 2000</h3>
228<ul>
229 <li>fixed the spec the RPMs should be better</li>
230 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
231 rpmfind users problem</li>
232</ul>
233
Daniel Veillard6388e172000-07-03 16:07:19 +0000[diff] [blame]234<h3>2.1.1: July 1 2000</h3>
235<ul>
236 <li>fixes a couple of bugs in the 2.1.0 packaging</li>
237 <li>improvements on the HTML parser</li>
238</ul>
239
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]240<h3>2.1.0 and 1.8.8: June 29 2000</h3>
241<ul>
242 <li>1.8.8 is mostly a comodity package for upgrading to libxml2 accoding to
243 <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
244 about &amp;#38; charref parsing</li>
245 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
246 also contains numerous fixes and enhancements:
247 <ul>
248 <li>added xmlStopParser() to stop parsing</li>
249 <li>improved a lot parsing speed when there is large CDATA blocs</li>
250 <li>includes XPath patches provided by Picdar Technology</li>
251 <li>tried to fix as much as possible DtD validation and namespace
252 related problems</li>
253 <li>output to a given encoding has been added/tested</li>
254 <li>lot of various fixes</li>
255 </ul>
256 </li>
257</ul>
258
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]259<h3>2.0.0: Apr 12 2000</h3>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]260<ul>
261 <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]262 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initally
263 scheduled for Apr 3 the relase occured only on Apr 12 due to massive
264 workload.</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]265 <li>The include are now located under $prefix/include/libxml (instead of
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]266 $prefix/include/gnome-xml), they also are referenced by
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]267 <pre>#include &lt;libxml/xxx.h&gt;</pre>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]268 <p>instead of</p>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]269 <pre>#include "xxx.h"</pre>
270 </li>
Daniel Veillard8f621982000-03-20 13:07:15 +0000[diff] [blame]271 <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
272 <li>the memory allocation routines used by libxml can now be overloaded
273 dynamically by using xmlMemSetup()</li>
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]274 <li>The previously CVS only tool tester has been renamed
275 <strong>xmllint</strong> and is now installed as part of the libxml2
276 package</li>
Daniel Veillarde0aed302000-04-16 08:52:20 +0000[diff] [blame]277 <li>The I/O interface has been revamped. There is now ways to plug in
278 specific I/O modules, either at the URI scheme detection level using
279 xmlRegisterInputCallbacks() or by passing I/O functions when creating a
280 parser context using xmlCreateIOParserCtxt()</li>
281 <li>there is a C preprocessor macro LIBXML_VERSION providing the version
282 number of the libxml module in use</li>
283 <li>a number of optional features of libxml can now be excluded at configure
284 time (FTP/HTTP/HTML/XPath/Debug)</li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]285</ul>
286
287<h3>2.0.0beta: Mar 14 2000</h3>
288<ul>
289 <li>This is a first Beta release of libxml version 2</li>
290 <li>It's available only from<a href="ftp://rpmfind.net/pub/libxml/">
291 rpmfind.net FTP</a>, it's packaged as libxml2-2.0.0beta and available as
292 tar and RPMs</li>
293 <li>This version is now the head in the Gnome CVS base, the old one is
294 available under the tag LIB_XML_1_X</li>
295 <li>This includes a very large set of changes. Froma programmatic point of
296 view applications should not have to be modified too much, check the <a
297 href="upgrade.html">upgrade page</a></li>
298 <li>Some interfaces may changes (especially a bit about encoding).</li>
299 <li>the updates includes:
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]300 <ul>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]301 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
302 handled now</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]303 <li>Better handling of entities, especially well formedness checking and
304 proper PEref extensions in external subsets</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]305 <li>DTD conditional sections</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]306 <li>Validation now correcly handle entities content</li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]307 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
308 structures to accomodate DOM</a></li>
Daniel Veillard6c8b1172000-03-01 00:40:41 +0000[diff] [blame]309 </ul>
310 </li>
Daniel Veillardedfb29b2000-03-14 19:59:05 +0000[diff] [blame]311 <li>Serious progress were made toward compliance, <a
312 href="conf/result.html">here are the result of the test</a> against the
313 OASIS testsuite (except the japanese tests since I don't support that
314 encoding yet). This URL is rebuilt every couple of hours using the CVS
315 head version.</li>
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]316</ul>
317
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]318<h3>1.8.7: Mar 6 2000</h3>
319<ul>
320 <li>This is a bug fix release:</li>
321 <li>It is possible to disable the ignorable blanks heuristic used by
322 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note
323 that for adherence to XML spec, this behaviour will be disabled by default
324 in 2.x . The same function will allow to keep compatibility for old
325 code.</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]326 <li>Blanks in &lt;a&gt; &lt;/a&gt; constructs are not ignored anymore,
327 avoiding heuristic is really the Right Way :-\</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]328 <li>The unchecked use of snprintf which was breaking libxml-1.8.6
329 compilation on some platforms has been fixed</li>
330 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
331 URIs</li>
332</ul>
333
Daniel Veillarde41f2b72000-01-30 20:00:07 +0000[diff] [blame]334<h3>1.8.6: Jan 31 2000</h3>
335<ul>
336 <li>added a nanoFTP transport module, debugged until the new version of <a
337 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
338 it without troubles</li>
Daniel Veillardda07c342000-01-25 18:31:22 +0000[diff] [blame]339</ul>
340
341<h3>1.8.5: Jan 21 2000</h3>
342<ul>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]343 <li>adding APIs to parse a well balanced chunk of XML (production <a
344 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the XML
345 spec)</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]346 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]347 <li>Jody Goldberg &lt;jgoldberg@home.com&gt; provided another patch trying
348 to solve the zlib checks problems</li>
Daniel Veillard461a66c2000-01-18 18:01:01 +0000[diff] [blame]349 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
350 gnumeric soon</li>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]351</ul>
352
353<h3>1.8.4: Jan 13 2000</h3>
354<ul>
355 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
356 <li>all exit() call should have been removed from libxml</li>
357 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
358 <li>added newDocFragment()</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]359</ul>
360
361<h3>1.8.3: Jan 5 2000</h3>
362<ul>
363 <li>a Push interface for the XML and HTML parsers</li>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]364 <li>a shell-like interface to the document tree (try tester --shell :-)</li>
Daniel Veillarddbfd6411999-12-28 16:35:14 +0000[diff] [blame]365 <li>lots of bug fixes and improvement added over XMas hollidays</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]366 <li>fixed the DTD parsing code to work with the xhtml DTD</li>
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]367 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
368 <li>Fixed bugs in xmlNewNs()</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]369 <li>External entity loading code has been revamped, now it uses
Daniel Veillardf84f71f2000-01-05 19:54:23 +0000[diff] [blame]370 xmlLoadExternalEntity(), some fix on entities processing were added</li>
Daniel Veillard437b87b2000-01-03 17:30:46 +0000[diff] [blame]371 <li>cleaned up WIN32 includes of socket stuff</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]372</ul>
373
374<h3>1.8.2: Dec 21 1999</h3>
375<ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]376 <li>I got another problem with includes and C++, I hope this issue is fixed
377 for good this time</li>
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]378 <li>Added a few tree modification functions: xmlReplaceNode,
379 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
380 xmlDocSetRootElement</li>
381 <li>Tried to improve the HTML output with help from <a
382 href="mailto:clahey@umich.edu">Chris Lahey</a></li>
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]383</ul>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]384
Daniel Veillarde4e51311999-12-18 15:32:46 +0000[diff] [blame]385<h3>1.8.1: Dec 18 1999</h3>
386<ul>
387 <li>various patches to avoid troubles when using libxml with C++ compilers
388 the "namespace" keyword and C escaping in include files</li>
389 <li>a problem in one of the core macros IS_CHAR was corrected</li>
390 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
391 and more specifically the Dia application</li>
Daniel Veillard944b5ff1999-12-15 19:08:24 +0000[diff] [blame]392 <li>fixed a posteriori validation (validation after parsing, or by using a
393 Dtd not specified in the original document)</li>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]394 <li>fixed a bug in</li>
Daniel Veillard10a2c651999-12-12 13:03:50 +0000[diff] [blame]395</ul>
396
397<h3>1.8.0: Dec 12 1999</h3>
398<ul>
399 <li>cleanup, especially memory wise</li>
400 <li>the parser should be more reliable, especially the HTML one, it should
401 not crash, whatever the input !</li>
402 <li>Integrated various patches, especially a speedup improvement for large
403 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>,
404 configure with --with-buffers to enable them.</li>
405 <li>attribute normalization, oops should have been added long ago !</li>
406 <li>attributes defaulted from Dtds should be available, xmlSetProp() now
407 does entities escapting by default.</li>
Daniel Veillard4c3a2031999-11-19 17:46:26 +0000[diff] [blame]408</ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]409
410<h3>1.7.4: Oct 25 1999</h3>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]411<ul>
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]412 <li>Lots of HTML improvement</li>
413 <li>Fixed some errors when saving both XML and HTML</li>
414 <li>More examples, the regression tests should now look clean</li>
415 <li>Fixed a bug with contiguous charref</li>
416</ul>
417
418<h3>1.7.3: Sep 29 1999</h3>
419<ul>
420 <li>portability problems fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]421 <li>snprintf was used unconditionnally, leading to link problems on system
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]422 were it's not available, fixed</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]423</ul>
424
425<h3>1.7.1: Sep 24 1999</h3>
426<ul>
427 <li>The basic type for strings manipulated by libxml has been renamed in
428 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
429 is that CHAR was conflicting with a predefined type on Windows. However on
430 non WIN32 environment, compatibility is provided by the way of a
431 <strong>#define </strong>.</li>
432 <li>Changed another error : the use of a structure field called errno, and
433 leading to troubles on platforms where it's a macro</li>
434</ul>
435
436<h3>1.7.0: sep 23 1999</h3>
437<ul>
438 <li>Added the ability to fetch remote DTD or parsed entities, see the <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]439 href="html/gnome-xml-nanohttp.html">nanohttp</a> module.</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]440 <li>Added an errno to report errors by another mean than a simple printf
441 like callback</li>
442 <li>Finished ID/IDREF support and checking when validation</li>
443 <li>Serious memory leaks fixed (there is now a <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]444 href="html/gnome-xml-xmlmemory.html">memory wrapper</a> module)</li>
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]445 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
446 implementation</li>
447 <li>Added an HTML parser front-end</li>
448</ul>
449
450<h2><a name="XML">XML</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]451
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]452<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]453markup-based structured documents. Here is <a name="example">an example XML
454document</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]455<pre>&lt;?xml version="1.0"?&gt;
456&lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
457 &lt;head&gt;
458 &lt;title&gt;Welcome to Gnome&lt;/title&gt;
459 &lt;/head&gt;
460 &lt;chapter&gt;
461 &lt;title&gt;The Linux adventure&lt;/title&gt;
462 &lt;p&gt;bla bla bla ...&lt;/p&gt;
463 &lt;image href="linus.gif"/&gt;
464 &lt;p&gt;...&lt;/p&gt;
465 &lt;/chapter&gt;
466&lt;/EXAMPLE&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]467
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]468<p>The first line specifies that it's an XML document and gives useful
469information about its encoding. Then the document is a text format whose
470structure is specified by tags between brackets. <strong>Each tag opened has
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]471to be closed</strong>. XML is pedantic about this. However, if a tag is empty
472(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]473ends with <code>/&gt;</code> rather than with <code>&gt;</code>. Note that,
474for example, the image tag has no content (just an attribute) and is closed by
475ending the tag with <code>/&gt;</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]476
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]477<p>XML can be applied sucessfully to a wide range of uses, from long term
478structured document maintenance (where it follows the steps of SGML) to simple
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]479data encoding mechanisms like configuration file formatting (glade),
480spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where
481it is used to encode remote calls between a client and a server.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]482
Daniel Veillard4540be42000-08-19 16:40:28 +0000[diff] [blame]483<h2>An overview of libxml architecture</h2>
484
485<p>Libxml is made of multiple components, some of them optionals, and most of
486the block interfaces are public. The main components are:</p>
487<ul>
488 <li>an Input/Output layer</li>
489 <li>FTP and HTTP client layers (optionnal)</li>
490 <li>an Internationalization layer managing the encodings support</li>
491 <li>an URI module</li>
492 <li>the XML parser and its basic SAX interface</li>
493 <li>an HTML parser using the same SAX interface (optionnal)</li>
494 <li>a SAX tree module to build an in-memory DOM representation</li>
495 <li>a tree module to manipulate the DOM representation</li>
496 <li>a validation module using the DOM representation (optionnal)</li>
497 <li>an XPath module for global lookup in a DOM representation
498 (optionnal)</li>
499 <li>a debug module (optionnal)</li>
500</ul>
501
502<p>Graphically this gives the following:</p>
503
504<p><img src="libxml.gif" alt="a graphical view of the various"></p>
505
506<p></p>
507
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]508<h2><a name="tree">The tree output</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]509
510<p>The parser returns a tree built during the document analysis. The value
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]511returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]512<strong>xmlDoc</strong> structure). This structure contains information such
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]513as the file name, the document type, and a <strong>children</strong> pointer
514which is the root of the document (or more exactly the first child under the
515root which is the document). The tree is made of <strong>xmlNode</strong>s,
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]516chained in double-linked lists of siblings and with children&lt;-&gt;parent
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]517relationship. An xmlNode can also carry properties (a chain of xmlAttr
518structures). An attribute may have a value which is a list of TEXT or
519ENTITY_REF nodes.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]520
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]521<p>Here is an example (erroneous with respect to the XML spec since there
522should be only one ELEMENT under the root):</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]523
524<p><img src="structure.gif" alt=" structure.gif "></p>
525
526<p>In the source package there is a small program (not installed by default)
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]527called <strong>xmllint</strong> which parses XML files given as argument and
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]528prints them back as parsed. This is useful for detecting errors both in XML
529code and in the XML parser itself. It has an option <strong>--debug</strong>
530which prints the actual in-memory structure of the document, here is the
531result with the <a href="#example">example</a> given before:</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]532<pre>DOCUMENT
533version=1.0
534standalone=true
535 ELEMENT EXAMPLE
536 ATTRIBUTE prop1
537 TEXT
538 content=gnome is great
539 ATTRIBUTE prop2
540 ENTITY_REF
541 TEXT
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]542 content= linux too
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]543 ELEMENT head
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]544 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]545 TEXT
546 content=Welcome to Gnome
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]547 ELEMENT chapter
548 ELEMENT title
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]549 TEXT
550 content=The Linux adventure
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]551 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]552 TEXT
553 content=bla bla bla ...
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]554 ELEMENT image
555 ATTRIBUTE href
556 TEXT
557 content=linus.gif
558 ELEMENT p
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]559 TEXT
560 content=...</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]561
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]562<p>This should be useful for learning the internal representation model.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]563
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]564<h2><a name="interface">The SAX interface</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]565
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]566<p>Sometimes the DOM tree output is just too large to fit reasonably into
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]567memory. In that case (and if you don't expect to save back the XML document
568loaded 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]569<strong>callback-based interface</strong> to the parser. Before parsing, the
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]570application layer registers a customized set of callbacks which are called by
571the library as it progresses through the XML input.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]572
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]573<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]574libxml, see the <a
575href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice
576documentation</a>.written by <a href="mailto:james@daa.com.au">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]577Henstridge</a>.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]578
579<p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
580program located in the gnome-xml module (it's usually not shipped in the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]581binary packages of libxml, but you can find it in the tar source
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]582distribution). Here is the sequence of callbacks that would be reported by
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]583testSAX when parsing the example XML document shown earlier:</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]584<pre>SAX.setDocumentLocator()
585SAX.startDocument()
586SAX.getEntity(amp)
587SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
588SAX.characters( , 3)
589SAX.startElement(head)
590SAX.characters( , 4)
591SAX.startElement(title)
592SAX.characters(Welcome to Gnome, 16)
593SAX.endElement(title)
594SAX.characters( , 3)
595SAX.endElement(head)
596SAX.characters( , 3)
597SAX.startElement(chapter)
598SAX.characters( , 4)
599SAX.startElement(title)
600SAX.characters(The Linux adventure, 19)
601SAX.endElement(title)
602SAX.characters( , 4)
603SAX.startElement(p)
604SAX.characters(bla bla bla ..., 15)
605SAX.endElement(p)
606SAX.characters( , 4)
607SAX.startElement(image, href='linus.gif')
608SAX.endElement(image)
609SAX.characters( , 4)
610SAX.startElement(p)
611SAX.characters(..., 3)
612SAX.endElement(p)
613SAX.characters( , 3)
614SAX.endElement(chapter)
615SAX.characters( , 1)
616SAX.endElement(EXAMPLE)
617SAX.endDocument()</pre>
618
Daniel Veillard402e8c82000-02-29 22:57:47 +0000[diff] [blame]619<p>Most of the other functionalities of libxml are based on the DOM
620tree-building facility, so nearly everything up to the end of this document
621presupposes the use of the standard DOM tree build. Note that the DOM tree
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]622itself is built by a set of registered default callbacks, without internal
623specific interface.</p>
624
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]625<h2><a name="library">The XML library interfaces</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]626
627<p>This section is directly intended to help programmers getting bootstrapped
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]628using the XML library from the C language. It is not intended to be extensive.
629I hope the automatically generated documents will provide the completeness
630required, but as a separate set of documents. The interfaces of the XML
631library are by principle low level, there is nearly zero abstraction. Those
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]632interested in a higher level API should <a href="#DOM">look at DOM</a>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]633
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]634<p>The <a href="html/gnome-xml-parser.html">parser interfaces for XML</a> are
635separated from the <a href="html/gnome-xml-htmlparser.html">HTML parser
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]636interfaces</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]637
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]638<h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]639
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]640<p>Usually, the first thing to do is to read an XML input. The parser accepts
641documents either from in-memory strings or from files. The functions are
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]642defined in "parser.h":</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]643<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]644 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]645 <dd><p>Parse a null-terminated string containing the document.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]646 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]647</dl>
648<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]649 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]650 <dd><p>Parse an XML document contained in a (possibly compressed)
651 file.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]652 </dd>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]653</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]654
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]655<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]656failure).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]657
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]658<h3 id="Invoking1">Invoking the parser: the push method</h3>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]659
660<p>In order for the application to keep the control when the document is been
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]661fetched (which is common for GUI based programs) libxml provides a push
662interface, too, as of version 1.8.3. Here are the interface functions:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]663<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
664 void *user_data,
665 const char *chunk,
666 int size,
667 const char *filename);
668int xmlParseChunk (xmlParserCtxtPtr ctxt,
669 const char *chunk,
670 int size,
671 int terminate);</pre>
672
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]673<p>and here is a simple example showing how to use the interface:</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]674<pre> FILE *f;
675
676 f = fopen(filename, "r");
677 if (f != NULL) {
678 int res, size = 1024;
679 char chars[1024];
680 xmlParserCtxtPtr ctxt;
681
682 res = fread(chars, 1, 4, f);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]683 if (res &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]684 ctxt = xmlCreatePushParserCtxt(NULL, NULL,
685 chars, res, filename);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]686 while ((res = fread(chars, 1, size, f)) &gt; 0) {
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]687 xmlParseChunk(ctxt, chars, res, 0);
688 }
689 xmlParseChunk(ctxt, chars, 0, 1);
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]690 doc = ctxt-&gt;myDoc;
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]691 xmlFreeParserCtxt(ctxt);
692 }
693 }</pre>
694
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]695<p>Also note that the HTML parser embedded into libxml also has a push
696interface; the functions are just prefixed by "html" rather than "xml"</p>
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]697
698<h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
699
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]700<p>A couple of comments can be made, first this mean that the parser is
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]701memory-hungry, first to load the document in memory, second to build the tree.
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]702Reading a document without building the tree is possible using the SAX
703interfaces (see SAX.h and <a
704href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">James
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]705Henstridge's documentation</a>). Note also that the push interface can be
706limited to SAX. Just use the two first arguments of
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]707<code>xmlCreatePushParserCtxt()</code>.</p>
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]708
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]709<h3><a name="Building">Building a tree from scratch</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]710
711<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]712there is a set of functions dedicated to building new elements. (These are
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]713also 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]714that produces the XML document used in the previous examples:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]715<pre> #include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]716 xmlDocPtr doc;
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]717 xmlNodePtr tree, subtree;
718
719 doc = xmlNewDoc("1.0");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]720 doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
721 xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
722 xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
723 tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]724 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]725 tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]726 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
727 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
728 subtree = xmlNewChild(tree, NULL, "image", NULL);
729 xmlSetProp(subtree, "href", "linus.gif");</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]730
731<p>Not really rocket science ...</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]732
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]733<h3><a name="Traversing">Traversing the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]734
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]735<p>Basically by <a href="html/gnome-xml-tree.html">including "tree.h"</a> your
736code has access to the internal structure of all the elements of the tree. The
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]737names should be somewhat simple like <strong>parent</strong>,
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]738<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]739<strong>properties</strong>, etc... For example, still with the previous
Daniel Veillard0142b842000-01-14 14:45:24 +0000[diff] [blame]740example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]741<pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]742
743<p>points to the title element,</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]744<pre>doc-&gt;children-&gt;children-&gt;next-&gt;child-&gt;child</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]745
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]746<p>points to the text node containing the chapter title "The Linux
747adventure".</p>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]748
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]749<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]750present before the document root, so <code>doc-&gt;children</code> may point
751to an element which is not the document Root Element, a function
Daniel Veillard5cb5ab81999-12-21 15:35:29 +0000[diff] [blame]752<code>xmlDocGetRootElement()</code> was added for this purpose.</p>
Daniel Veillardb24054a1999-12-18 15:32:46 +0000[diff] [blame]753
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]754<h3><a name="Modifying">Modifying the tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]755
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]756<p>Functions are provided for reading and writing the document content. Here
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]757is an excerpt from the <a href="html/gnome-xml-tree.html">tree API</a>:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]758<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]759 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
760 xmlChar *value);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]761 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node. The
762 value can be NULL.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]763 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]764</dl>
765<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]766 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]767 *name);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]768 <dd><p>This function returns a pointer to the property content. Note that
769 no extra copy is made.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]770 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]771</dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]772
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]773<p>Two functions are provided for reading and writing the text associated with
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]774elements:</p>
775<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]776 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]777 *value);</code></dt>
778 <dd><p>This function takes an "external" string and convert it to one text
779 node or possibly to a list of entity and text nodes. All non-predefined
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]780 entity references like &amp;Gnome; will be stored internally as entity
781 nodes, hence the result of the function may not be a single node.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]782 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]783</dl>
784<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]785 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]786 inLine);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]787 <dd><p>This function is the inverse of
788 <code>xmlStringGetNodeList()</code>. It generates a new string
789 containing the content of the text and entity nodes. Note the extra
790 argument inLine. If this argument is set to 1, the function will expand
791 entity references. For example, instead of returning the &amp;Gnome;
792 XML encoding in the string, it will substitute it with its value (say,
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]793 "GNU Network Object Model Environment"). Set this argument if you want
794 to use the string for non-XML usage like User Interface.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]795 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]796</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]797
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]798<h3><a name="Saving">Saving a tree</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]799
800<p>Basically 3 options are possible:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]801<dl>
Daniel Veillarddd6b3671999-09-23 22:19:22 +0000[diff] [blame]802 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]803 *size);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]804 <dd><p>Returns a buffer into which the document has been saved.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]805 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]806</dl>
807<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]808 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]809 <dd><p>Dumps a document to an open file descriptor.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]810 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]811</dl>
812<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]813 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]814 <dd><p>Saves the document to a file. In this case, the compression
815 interface is triggered if it has been turned on.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]816 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]817</dl>
Daniel Veillard10c6a8f1998-10-28 01:00:12 +0000[diff] [blame]818
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]819<h3><a name="Compressio">Compression</a></h3>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]820
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]821<p>The library transparently handles compression when doing file-based
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]822accesses. The level of compression on saves can be turned on either globally
823or individually for one file:</p>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]824<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]825 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]826 <dd><p>Gets the document compression ratio (0-9).</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]827 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]828</dl>
829<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]830 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]831 <dd><p>Sets the document compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]832 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]833</dl>
834<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]835 <dt><code>int xmlGetCompressMode(void);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]836 <dd><p>Gets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]837 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]838</dl>
839<dl>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]840 <dt><code>void xmlSetCompressMode(int mode);</code></dt>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]841 <dd><p>Sets the default compression ratio.</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]842 </dd>
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]843</dl>
844
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]845<h2><a name="Entities">Entities or no entities</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]846
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]847<p>Entities in principle are similar to simple C macros. An entity defines an
848abbreviation for a given string that you can reuse many times throughout the
849content of your document. Entities are especially useful when a given string
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]850may occur frequently within a document, or to confine the change needed to a
851document to a restricted area in the internal subset of the document (at the
852beginning). Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]853<pre>1 &lt;?xml version="1.0"?&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]8542 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]8553 &lt;!ENTITY xml "Extensible Markup Language"&gt;
8564 ]&gt;
8575 &lt;EXAMPLE&gt;
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]8586 &amp;xml;
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]8597 &lt;/EXAMPLE&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]860
861<p>Line 3 declares the xml entity. Line 6 uses the xml entity, by prefixing
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]862it's name with '&amp;' and following it by ';' without any spaces added. There
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]863are 5 predefined entities in libxml allowing you to escape charaters with
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]864predefined meaning in some parts of the xml document content:
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]865<strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]866for the character '&gt;', <strong>&amp;apos;</strong> for the character ''',
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]867<strong>&amp;quot;</strong> for the character '"', and
868<strong>&amp;amp;</strong> for the character '&amp;'.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]869
870<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]871substitute an entity's content so that you can see the replacement text in
872your application. Or you may prefer to keep entity references as such in the
873content to be able to save the document back without losing this usually
874precious information (if the user went through the pain of explicitly defining
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]875entities, he may have a a rather negative attitude if you blindly susbtitute
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]876them as saving time). The <a
Daniel Veillardc19fccc2000-07-03 11:52:01 +0000[diff] [blame]877href="html/gnome-xml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a>
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]878function allows you to check and change the behaviour, which is to not
879substitute entities by default.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]880
881<p>Here is the DOM tree built by libxml for the previous document in the
882default case:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]883<pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]884DOCUMENT
885version=1.0
886 ELEMENT EXAMPLE
887 TEXT
888 content=
889 ENTITY_REF
890 INTERNAL_GENERAL_ENTITY xml
891 content=Extensible Markup Language
892 TEXT
893 content=</pre>
894
895<p>And here is the result when substituting entities:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]896<pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]897DOCUMENT
898version=1.0
899 ELEMENT EXAMPLE
900 TEXT
901 content= Extensible Markup Language</pre>
902
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]903<p>So, entities or no entities? Basically, it depends on your use case. I
904suggest that you keep the non-substituting default behaviour and avoid using
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]905entities in your XML document or data if you are not willing to handle the
906entity references elements in the DOM tree.</p>
907
908<p>Note that at save time libxml enforce the conversion of the predefined
909entities where necessary to prevent well-formedness problems, and will also
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]910transparently replace those with chars (i.e., it will not generate entity
911reference elements in the DOM tree or call the reference() SAX callback when
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]912finding them in the input).</p>
913
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]914<p><span style="background-color: #FF0000">WARNING</span>: handling entities
915on top of libxml SAX interface is difficult !!! If you plan to use
916non-predefined entities in your documents, then the learning cuvre to handle
917then using the SAX API may be long. If you plan to use complex document, I
918strongly suggest you consider using the DOM interface instead and let libxml
Daniel Veillard8c6d6af2000-08-25 17:14:13 +0000[diff] [blame^]919deal with the complexity rather than trying to do it yourself.</p>
Daniel Veillard7b9c4b72000-08-25 16:26:50 +0000[diff] [blame]920
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]921<h2><a name="Namespaces">Namespaces</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]922
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]923<p>The libxml library implements <a
924href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
925recognizing namespace contructs in the input, and does namespace lookup
926automatically when building the DOM tree. A namespace declaration is
927associated with an in-memory structure and all elements or attributes within
928that namespace point to it. Hence testing the namespace is a simple and fast
929equality operation at the user level.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]930
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]931<p>I suggest that people using libxml use a namespace, and declare it in the
932root element of their document as the default namespace. Then they don't need
933to use the prefix in the content but we will have a basis for future semantic
934refinement and merging of data from different sources. This doesn't augment
935significantly the size of the XML output, but significantly increase its value
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]936in the long-term. Example:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]937<pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
938 &lt;elem1&gt;...&lt;/elem1&gt;
939 &lt;elem2&gt;...&lt;/elem2&gt;
940&lt;/mydoc&gt;</pre>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]941
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]942<p>Concerning the namespace value, this has to be an URL, but the URL doesn't
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]943have to point to any existing resource on the Web. It will bind all the
944element and atributes with that URL. I suggest to use an URL within a domain
945you control, and that the URL should contain some kind of version information
946if possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]947a good namespace scheme.</p>
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]948
949<p>Then when you load a file, make sure that a namespace carrying the
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]950version-independent prefix is installed on the root element of your document,
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]951and if the version information don't match something you know, warn the user
952and 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]953namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
954same as &lt;bar:text&gt; in another document. What really matter is the URI
955associated with the element or the attribute, not the prefix string (which is
956just a shortcut for the full URI). In libxml element and attributes have a
Daniel Veillardec303412000-03-24 13:41:54 +0000[diff] [blame]957<code>ns</code> field pointing to an xmlNs structure detailing the namespace
958prefix and it's URI.</p>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]959
960<p>@@Interfaces@@</p>
961
962<p>@@Examples@@</p>
963
964<p>Usually people object using namespace in the case of validation, I object
965this and will make sure that using namespaces won't break validity checking,
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]966so even is you plan to use or currently are using validation I strongly
967suggest adding namespaces to your document. A default namespace scheme
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]968<code>xmlns="http://...."</code> should not break validity even on less
Daniel Veillard88f00ae2000-03-02 00:15:55 +0000[diff] [blame]969flexible parsers. Now using namespace to mix and differentiate content coming
970from multiple DTDs will certainly break current validation schemes. I will try
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]971to provide ways to do this, but this may not be portable or standardized.</p>
972
Daniel Veillard2f4dfc41999-09-24 14:03:48 +0000[diff] [blame]973<h2><a name="Validation">Validation, or are you afraid of DTDs ?</a></h2>
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]974
975<p>Well what is validation and what is a DTD ?</p>
976
977<p>Validation is the process of checking a document against a set of
978construction rules, a <strong>DTD</strong> (Document Type Definition) is such
979a set of rules.</p>
980
981<p>The validation process and building DTDs are the two most difficult parts
982of XML life cycle. Briefly a DTD defines all the possibles element to be
983found within your document, what is the formal shape of your document tree (by
984defining the allowed content of an element, either text, a regular expression
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]985for the allowed list of children, or mixed content i.e. both text and
986children). The DTD also defines the allowed attributes for all elements and
987the types of the attributes. For more detailed informations, I suggest to read
988the related parts of the XML specification, the examples found under
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]989gnome-xml/test/valid/dtd and the large amount of books available on XML. The
990dia example in gnome-xml/test/valid should be both simple and complete enough
991to allow you to build your own.</p>
992
993<p>A word of warning, building a good DTD which will fit your needs of your
994application in the long-term is far from trivial, however the extra level of
995quality it can insure is well worth the price for some sets of applications or
996if you already have already a DTD defined for your application field.</p>
997
998<p>The validation is not completely finished but in a (very IMHO) usable
999state. Until a real validation interface is defined the way to do it is to
1000define and set the <strong>xmlDoValidityCheckingDefaultValue</strong> external
1001variable to 1, this will of course be changed at some point:</p>
1002
1003<p>extern int xmlDoValidityCheckingDefaultValue;</p>
1004
1005<p>...</p>
1006
1007<p>xmlDoValidityCheckingDefaultValue = 1;</p>
1008
1009<p></p>
1010
1011<p>To handle external entities, use the function
1012<strong>xmlSetExternalEntityLoader</strong>(xmlExternalEntityLoader f); to
1013link in you HTTP/FTP/Entities database library to the standard libxml
1014core.</p>
1015
1016<p>@@interfaces@@</p>
1017
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1018<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1019
1020<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document Object
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1021Model</em> this is an API for accessing XML or HTML structured documents.
1022Native support for DOM in Gnome is on the way (module gnome-dom), and it will
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1023be based on gnome-xml. This will be a far cleaner interface to manipulate XML
Daniel Veillardc08a2c61999-09-08 21:35:25 +0000[diff] [blame]1024files within Gnome since it won't expose the internal structure. DOM defines a
Daniel Veillard25940b71998-10-29 05:51:30 +0000[diff] [blame]1025set of IDL (or Java) interfaces allowing to traverse and manipulate a
1026document. The DOM library will allow accessing and modifying "live" documents
1027presents on other programs like this:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1028
1029<p><img src="DOM.gif" alt=" DOM.gif "></p>
1030
1031<p>This should help greatly doing things like modifying a gnumeric spreadsheet
Daniel Veillardccb09631998-10-27 06:21:04 +0000[diff] [blame]1032embedded in a GWP document for example.</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1033
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1034<p>The current DOM implementation on top of libxml is the <a
1035href="http://cvs.gnome.org/lxr/source/gdome/">gdome Gnome module</a>, this is
1036a full DOM interface, thanks to <a href="mailto:raph@levien.com">Raph
1037Levien</a>.</p>
1038
1039<p>The gnome-dom module in the Gnome CVS base is obsolete</p>
1040
Daniel Veillard35008381999-10-25 13:15:52 +0000[diff] [blame]1041<h2><a name="Example"></a><a name="real">A real example</a></h2>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1042
1043<p>Here is a real size example, where the actual content of the application
1044data 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]1045a proposal to keep a database of jobs related to Gnome, with an XML based
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1046storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
1047base</a>:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1048<pre>&lt;?xml version="1.0"?&gt;
1049&lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
1050 &lt;gjob:Jobs&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1051
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1052 &lt;gjob:Job&gt;
1053 &lt;gjob:Project ID="3"/&gt;
1054 &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
1055 &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1056
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1057 &lt;gjob:Update&gt;
1058 &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
1059 &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
1060 &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
1061 &lt;/gjob:Update&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1062
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1063 &lt;gjob:Developers&gt;
1064 &lt;gjob:Developer&gt;
1065 &lt;/gjob:Developer&gt;
1066 &lt;/gjob:Developers&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1067
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1068 &lt;gjob:Contact&gt;
1069 &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
1070 &lt;gjob:Email&gt;nathan@windsofstorm.net&lt;/gjob:Email&gt;
1071 &lt;gjob:Company&gt;
1072 &lt;/gjob:Company&gt;
1073 &lt;gjob:Organisation&gt;
1074 &lt;/gjob:Organisation&gt;
1075 &lt;gjob:Webpage&gt;
1076 &lt;/gjob:Webpage&gt;
1077 &lt;gjob:Snailmail&gt;
1078 &lt;/gjob:Snailmail&gt;
1079 &lt;gjob:Phone&gt;
1080 &lt;/gjob:Phone&gt;
1081 &lt;/gjob:Contact&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1082
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1083 &lt;gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1084 The program should be released as free software, under the GPL.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1085 &lt;/gjob:Requirements&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1086
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1087 &lt;gjob:Skills&gt;
1088 &lt;/gjob:Skills&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1089
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1090 &lt;gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1091 A GNOME based system that will allow a superuser to configure
1092 compressed and uncompressed files and/or file systems to be backed
1093 up with a supported media in the system. This should be able to
1094 perform via find commands generating a list of files that are passed
1095 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine
1096 or via operations performed on the filesystem itself. Email
1097 notification and GUI status display very important.
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1098 &lt;/gjob:Details&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1099
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1100 &lt;/gjob:Job&gt;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1101
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1102 &lt;/gjob:Jobs&gt;
1103&lt;/gjob:Helping&gt;</pre>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1104
1105<p>While loading the XML file into an internal DOM tree is a matter of calling
1106only a couple of functions, browsing the tree to gather the informations and
1107generate the internals structures is harder, and more error prone.</p>
1108
1109<p>The suggested principle is to be tolerant with respect to the input
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1110structure. For example, the ordering of the attributes is not significant,
1111Cthe XML specification is clear about it. It's also usually a good idea to not
Daniel Veillard306be992000-07-03 12:38:45 +0000[diff] [blame]1112be dependent of the orders of the children of a given node, unless it really
Daniel Veillardf13e1ed2000-03-06 07:41:49 +0000[diff] [blame]1113makes things harder. Here is some code to parse the informations for a
1114person:</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1115<pre>/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1116 * A person record
1117 */
1118typedef struct person {
1119 char *name;
1120 char *email;
1121 char *company;
1122 char *organisation;
1123 char *smail;
1124 char *webPage;
1125 char *phone;
1126} person, *personPtr;
1127
1128/*
1129 * And the code needed to parse it
1130 */
1131personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1132 personPtr ret = NULL;
1133
1134DEBUG("parsePerson\n");
1135 /*
1136 * allocate the struct
1137 */
1138 ret = (personPtr) malloc(sizeof(person));
1139 if (ret == NULL) {
1140 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1141 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1142 }
1143 memset(ret, 0, sizeof(person));
1144
1145 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1146 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1147 while (cur != NULL) {
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1148 if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
1149 ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1150 if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
1151 ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1152 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1153 }
1154
1155 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1156}</pre>
1157
1158<p>Here is a couple of things to notice:</p>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1159<ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1160 <li>Usually a recursive parsing style is the more convenient one, XML data
1161 being by nature subject to repetitive constructs and usualy exibit highly
1162 stuctured patterns.</li>
1163 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>, i.e.
1164 the pointer to the global XML document and the namespace reserved to the
1165 application. Document wide information are needed for example to decode
1166 entities and it's a good coding practice to define a namespace for your
1167 application set of data and test that the element and attributes you're
1168 analyzing actually pertains to your application space. This is done by a
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1169 simple equality test (cur-&gt;ns == ns).</li>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1170 <li>To retrieve text and attributes value, it is suggested to use the
1171 function <em>xmlNodeListGetString</em> to gather all the text and entity
1172 reference nodes generated by the DOM output and produce an single text
1173 string.</li>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1174</ul>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1175
1176<p>Here is another piece of code used to parse another level of the
1177structure:</p>
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1178<pre>#include &lt;libxml/tree.h&gt;
Daniel Veillard361d8452000-04-03 19:48:13 +0000[diff] [blame]1179/*
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1180 * a Description for a Job
1181 */
1182typedef struct job {
1183 char *projectID;
1184 char *application;
1185 char *category;
1186 personPtr contact;
1187 int nbDevelopers;
1188 personPtr developers[100]; /* using dynamic alloc is left as an exercise */
1189} job, *jobPtr;
1190
1191/*
1192 * And the code needed to parse it
1193 */
1194jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
1195 jobPtr ret = NULL;
1196
1197DEBUG("parseJob\n");
1198 /*
1199 * allocate the struct
1200 */
1201 ret = (jobPtr) malloc(sizeof(job));
1202 if (ret == NULL) {
1203 fprintf(stderr,"out of memory\n");
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1204 return(NULL);
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1205 }
1206 memset(ret, 0, sizeof(job));
1207
1208 /* We don't care what the top level element name is */
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1209 cur = cur-&gt;xmlChildrenNode;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1210 while (cur != NULL) {
1211
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1212 if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
1213 ret-&gt;projectID = xmlGetProp(cur, "ID");
1214 if (ret-&gt;projectID == NULL) {
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1215 fprintf(stderr, "Project has no ID\n");
1216 }
1217 }
Daniel Veillard60979bd2000-07-10 12:17:33 +0000[diff] [blame]1218 if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
1219 ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1220 if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
1221 ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
1222 if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
1223 ret-&gt;contact = parsePerson(doc, ns, cur);
1224 cur = cur-&gt;next;
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1225 }
1226
1227 return(ret);
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1228}</pre>
Daniel Veillard14fff061999-06-22 21:49:07 +0000[diff] [blame]1229
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1230<p>One can notice that once used to it, writing this kind of code is quite
1231simple, but boring. Ultimately, it could be possble to write stubbers taking
1232either C data structure definitions, a set of XML examples or an XML DTD and
1233produce the code needed to import and export the content between C data and
1234XML storage. This is left as an exercise to the reader :-)</p>
1235
Daniel Veillard6f0adb52000-07-03 11:41:26 +0000[diff] [blame]1236<p>Feel free to use <a href="example/gjobread.c">the code for the full C
1237parsing example</a> as a template, it is also available with Makefile in the
1238Gnome CVS base under gnome-xml/example</p>
Daniel Veillardb05deb71999-08-10 19:04:08 +0000[diff] [blame]1239
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1240<h2><a name="Contributi">Contributions</a></h2>
1241<ul>
1242 <li><a href="mailto:ari@btigate.com">Ari Johnson</a> provides a C++ wrapper
1243 for libxml:
1244 <p>Website: <a
1245 href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p>
1246 <p>Download: <a
1247 href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p>
1248 </li>
1249 <li><a href="mailto:doolin@cs.utk.edu">David Doolin</a> provides a
1250 precompiled Windows version
1251 <p><a
1252 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
1253 </li>
Daniel Veillard3f6f7f62000-06-30 17:58:25 +0000[diff] [blame]1254 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> provided <a
1255 href="libxml-doc.el">an emacs module</a> to lookup libxml functions
1256 documentation</li>
Daniel Veillardc310d562000-06-23 18:32:15 +0000[diff] [blame]1257 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a
1258 href="http://xmlsoft.org/messages/0488.html">man pages</a> (not yet
1259 integrated in the distribution)</li>
1260</ul>
1261
Daniel Veillardc8eab3a1999-09-04 18:27:23 +0000[diff] [blame]1262<p></p>
1263
1264<p><a href="mailto:Daniel.Veillard@w3.org">Daniel Veillard</a></p>
1265
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