Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 1 | <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 2 | "http://www.w3.org/TR/REC-html40/loose.dtd"> |
Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 3 | <html> |
| 4 | <head> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 5 | <title>The XML library for Gnome</title> |
Daniel Veillard | 94e9060 | 2000-07-17 14:38:19 +0000 | [diff] [blame] | 6 | <meta name="GENERATOR" content="amaya V3.2.1"> |
Daniel Veillard | b24054a | 1999-12-18 15:32:46 +0000 | [diff] [blame] | 7 | <meta http-equiv="Content-Type" content="text/html"> |
Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 8 | </head> |
Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 9 | |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 10 | <body bgcolor="#ffffff"> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 11 | <p><a href="http://www.gnome.org/"><img src="smallfootonly.gif" |
| 12 | alt="Gnome Logo"></a><a href="http://www.w3.org/Status"><img src="w3c.png" |
| 13 | alt="W3C Logo"></a></p> |
Daniel Veillard | ec30341 | 2000-03-24 13:41:54 +0000 | [diff] [blame] | 14 | |
Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 15 | <h1 align="center">The XML library for Gnome</h1> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 16 | |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 17 | <h2 style="text-align: center">libxml, a.k.a. gnome-xml</h2> |
| 18 | |
| 19 | <p></p> |
Daniel Veillard | 2f4dfc4 | 1999-09-24 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 Veillard | 10a2c65 | 1999-12-12 13:03:50 +0000 | [diff] [blame] | 23 | <li><a href="#Downloads">Downloads</a></li> |
Daniel Veillard | 2f4dfc4 | 1999-09-24 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 Veillard | 0142b84 | 2000-01-14 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 Veillard | 2f4dfc4 | 1999-09-24 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 Veillard | c310d56 | 2000-06-23 18:32:15 +0000 | [diff] [blame] | 45 | <li><a href="#Contributi">Contribution</a></li> |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 46 | </ul> |
| 47 | |
| 48 | <h2><a name="Introducti">Introduction</a></h2> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 49 | |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 50 | <p>This document describes libxml, the <a |
| 51 | href="http://www.w3.org/XML/">XML</a> library provided in the <a |
| 52 | href="http://www.gnome.org/">Gnome</a> framework. XML is a standard for |
| 53 | building tag-based structured documents/data.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 54 | |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 55 | <p>Here are some key points about libxml:</p> |
| 56 | <ul> |
Daniel Veillard | 6f0adb5 | 2000-07-03 11:41:26 +0000 | [diff] [blame] | 57 | <li>It is written in plain C, making as few assumptions as possible and |
| 58 | sticking closely to ANSI C for easy embedding.</li> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 59 | <li>The internal document repesentation is as close as possible to the <a |
| 60 | href="http://www.w3.org/DOM/">DOM</a> interfaces.</li> |
| 61 | <li>Libxml also has a <a href="http://www.megginson.com/SAX/index.html">SAX |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 62 | like interface</a>; the interface is designed to be compatible with <a |
| 63 | href="http://www.jclark.com/xml/expat.html">Expat</a>.</li> |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 64 | <li>Libxml now includes a nearly complete <a |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 65 | href="http://www.w3.org/TR/xpath">XPath</a> implementation.</li> |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 66 | <li>Libxml exports Push and Pull type parser interfaces for both XML and |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 67 | HTML.</li> |
Daniel Veillard | ec30341 | 2000-03-24 13:41:54 +0000 | [diff] [blame] | 68 | <li>This library is released both under the <a |
| 69 | href="http://www.w3.org/Consortium/Legal/copyright-software-19980720.html">W3C |
| 70 | IPR</a> and the GNU LGPL. Use either at your convenience, basically this |
| 71 | should make everybody happy, if not, drop me a mail.</li> |
Daniel Veillard | c310d56 | 2000-06-23 18:32:15 +0000 | [diff] [blame] | 72 | <li>There is <a href="upgrade.html">a first set of instructions</a> |
Daniel Veillard | edfb29b | 2000-03-14 19:59:05 +0000 | [diff] [blame] | 73 | concerning upgrade from libxml-1.x to libxml-2.x</li> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 74 | </ul> |
Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 75 | |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 76 | <h2><a name="Documentat">Documentation</a></h2> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 77 | |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 78 | <p>There are some on-line resources about using libxml:</p> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 79 | <ol> |
Daniel Veillard | 365e13b | 2000-07-02 07:56:37 +0000 | [diff] [blame] | 80 | <li>Check the <a href="FAQ.html">FAQ</a></li> |
Daniel Veillard | c19fccc | 2000-07-03 11:52:01 +0000 | [diff] [blame] | 81 | <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive |
Daniel Veillard | 365e13b | 2000-07-02 07:56:37 +0000 | [diff] [blame] | 82 | documentation</a> automatically extracted from code comments.</li> |
Daniel Veillard | 8d86964 | 2000-07-14 12:12:59 +0000 | [diff] [blame] | 83 | <li>Look at the documentation about <a href="encoding.html">libxml |
| 84 | internationalization support</a></li> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 85 | <li>This page provides a global overview and <a href="#real">some |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 86 | examples</a> on how to use libxml.</li> |
| 87 | <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a |
| 88 | href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice |
| 89 | documentation</a> explaining how to use the libxml SAX interface.</li> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 90 | <li>George Lebl wrote <a |
| 91 | href="http://www-4.ibm.com/software/developer/library/gnome3/">an article |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 92 | for IBM developerWorks</a> about using libxml.</li> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 93 | <li>It is also a good idea to check to <a href="mailto:raph@levien.com">Raph |
| 94 | Levien</a> <a href="http://levien.com/gnome/">web site</a> since he is |
| 95 | building the <a href="http://levien.com/gnome/gdome.html">DOM interface |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 96 | gdome</a> on top of libxml result tree and an implementation of <a |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 97 | href="http://www.w3.org/Graphics/SVG/">SVG</a> called <a |
| 98 | href="http://www.levien.com/svg/">gill</a>. Check his <a |
| 99 | href="http://www.levien.com/gnome/domination.html">DOMination |
| 100 | paper</a>.</li> |
Daniel Veillard | ec30341 | 2000-03-24 13:41:54 +0000 | [diff] [blame] | 101 | <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO |
| 102 | file</a></li> |
| 103 | <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>. If you are |
| 104 | starting a new project using libxml you should really use the 2.x |
| 105 | version.</li> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 106 | <li>And don't forget to look at the <a href="/messages/">mailing-list |
Daniel Veillard | c310d56 | 2000-06-23 18:32:15 +0000 | [diff] [blame] | 107 | archive</a>.</li> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 108 | </ol> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 109 | |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 110 | <h3>Reporting bugs and getting help</h3> |
Daniel Veillard | 4c3a203 | 1999-11-19 17:46:26 +0000 | [diff] [blame] | 111 | |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 112 | <p>Well, bugs or missing features are always possible, and I will make a point |
| 113 | of fixing them in a timely fashion. The best way to report a bug is to <a |
Daniel Veillard | 4c3a203 | 1999-11-19 17:46:26 +0000 | [diff] [blame] | 114 | href="http://bugs.gnome.org/db/pa/lgnome-xml.html">use the Gnome bug tracking |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 115 | database</a>. I look at reports there regularly and it's good to have a |
Daniel Veillard | 4c3a203 | 1999-11-19 17:46:26 +0000 | [diff] [blame] | 116 | reminder when a bug is still open. Check the <a |
| 117 | href="http://bugs.gnome.org/Reporting.html">instructions on reporting bugs</a> |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 118 | and be sure to specify that the bug is for the package gnome-xml.</p> |
Daniel Veillard | 4c3a203 | 1999-11-19 17:46:26 +0000 | [diff] [blame] | 119 | |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 120 | <p>There is also a mailing-list <a |
| 121 | href="mailto:xml@rufus.w3.org">xml@rufus.w3.org</a> for libxml, with an <a |
| 122 | href="http://xmlsoft.org/messages">on-line archive</a>. To subscribe to this |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 123 | majordomo based list, send a mail message to <a |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 124 | href="mailto:majordomo@rufus.w3.org">majordomo@rufus.w3.org</a> with |
| 125 | "subscribe xml" in the <strong>content</strong> of the message.</p> |
| 126 | |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 127 | <p>Alternatively, you can just send the bug to the <a |
Daniel Veillard | 10a2c65 | 1999-12-12 13:03:50 +0000 | [diff] [blame] | 128 | href="mailto:xml@rufus.w3.org">xml@rufus.w3.org</a> list.</p> |
Daniel Veillard | 4c3a203 | 1999-11-19 17:46:26 +0000 | [diff] [blame] | 129 | |
Daniel Veillard | ec30341 | 2000-03-24 13:41:54 +0000 | [diff] [blame] | 130 | <p>Of course, bugs reports with a suggested patch for fixing them will |
| 131 | probably be processed faster.</p> |
| 132 | |
| 133 | <p>If you're looking for help, a quick look at <a |
| 134 | href="http://xmlsoft.org/messages/#407">the list archive</a> may actually |
| 135 | provide the answer, I usually send source samples when answering libxml usage |
Daniel Veillard | 6f0adb5 | 2000-07-03 11:41:26 +0000 | [diff] [blame] | 136 | questions. The <a href="http://xmlsoft.org/html/book1.html">auto-generated |
Daniel Veillard | ec30341 | 2000-03-24 13:41:54 +0000 | [diff] [blame] | 137 | documentantion</a> is not as polished as I would like (i need to learn more |
| 138 | about Docbook), but it's a good starting point.</p> |
| 139 | |
Daniel Veillard | 10a2c65 | 1999-12-12 13:03:50 +0000 | [diff] [blame] | 140 | <h2><a name="Downloads">Downloads</a></h2> |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 141 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 142 | <p>The latest versions of libxml can be found on <a |
Daniel Veillard | 6c8b117 | 2000-03-01 00:40:41 +0000 | [diff] [blame] | 143 | href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or on the <a |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 144 | href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> either |
Daniel Veillard | 10a2c65 | 1999-12-12 13:03:50 +0000 | [diff] [blame] | 145 | as a <a href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">source |
Daniel Veillard | 306be99 | 2000-07-03 12:38:45 +0000 | [diff] [blame] | 146 | archive</a> or <a |
| 147 | href="ftp://ftp.gnome.org/pub/GNOME/contrib/redhat/SRPMS/">RPM packages</a>. |
| 148 | (NOTE that you need both the <a |
Daniel Veillard | c19fccc | 2000-07-03 11:52:01 +0000 | [diff] [blame] | 149 | href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a |
| 150 | href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a> |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 151 | packages installed to compile applications using libxml.)</p> |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 152 | |
Daniel Veillard | 6c8b117 | 2000-03-01 00:40:41 +0000 | [diff] [blame] | 153 | <p><a name="Snapshot">Snapshot:</a></p> |
| 154 | <ul> |
| 155 | <li>Code from the W3C cvs base libxml <a |
| 156 | href="ftp://rpmfind.net/pub/libxml/cvs-snapshot.tar.gz">cvs-snapshot.tar.gz</a></li> |
| 157 | <li>Docs, content of the web site, the list archive included <a |
| 158 | href="ftp://rpmfind.net/pub/libxml/libxml-docs.tar.gz">libxml-docs.tar.gz</a></li> |
| 159 | </ul> |
| 160 | |
| 161 | <p><a name="Contribs">Contribs:</a></p> |
| 162 | |
| 163 | <p>I do accept external contributions, especially if compiling on another |
| 164 | platform, get in touch with me to upload the package. I will keep them in the |
| 165 | <a href="ftp://rpmfind.net/pub/libxml/contribs/">contrib directory</a></p> |
| 166 | |
Daniel Veillard | c310d56 | 2000-06-23 18:32:15 +0000 | [diff] [blame] | 167 | <p>Libxml is also available from 2 CVS bases:</p> |
Daniel Veillard | 10a2c65 | 1999-12-12 13:03:50 +0000 | [diff] [blame] | 168 | <ul> |
| 169 | <li><p>The <a href="http://dev.w3.org/cvsweb/XML/">W3C CVS base</a>, |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 170 | available read-only using the CVS pserver authentification (I tend to use |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 171 | this base for my own development, so it's updated more regularly, but the |
| 172 | content may not be as stable):</p> |
Daniel Veillard | 10a2c65 | 1999-12-12 13:03:50 +0000 | [diff] [blame] | 173 | <pre>CVSROOT=:pserver:anonymous@dev.w3.org:/sources/public |
Daniel Veillard | 365e13b | 2000-07-02 07:56:37 +0000 | [diff] [blame] | 174 | password: anonymous |
| 175 | module: XML</pre> |
Daniel Veillard | 10a2c65 | 1999-12-12 13:03:50 +0000 | [diff] [blame] | 176 | </li> |
| 177 | <li><p>The <a |
| 178 | href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&dir=gnome-xml">Gnome |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 179 | CVS base</a>. Check the <a |
| 180 | href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a> page; |
| 181 | the CVS module is <b>gnome-xml</b>.</p> |
Daniel Veillard | 10a2c65 | 1999-12-12 13:03:50 +0000 | [diff] [blame] | 182 | </li> |
| 183 | </ul> |
| 184 | |
| 185 | <h2><a name="News">News</a></h2> |
| 186 | |
Daniel Veillard | 944b5ff | 1999-12-15 19:08:24 +0000 | [diff] [blame] | 187 | <h3>CVS only : check the <a |
| 188 | href="http://cvs.gnome.org/lxr/source/gnome-xml/ChangeLog">Changelog</a> file |
| 189 | for really accurate description</h3> |
Daniel Veillard | 4c3a203 | 1999-11-19 17:46:26 +0000 | [diff] [blame] | 190 | <ul> |
Daniel Veillard | 10a2c65 | 1999-12-12 13:03:50 +0000 | [diff] [blame] | 191 | <li>working on HTML and XML links recognition layers, get in touch with me |
Daniel Veillard | 944b5ff | 1999-12-15 19:08:24 +0000 | [diff] [blame] | 192 | if you want to test those.</li> |
Daniel Veillard | 361d845 | 2000-04-03 19:48:13 +0000 | [diff] [blame] | 193 | </ul> |
| 194 | |
Daniel Veillard | 94e9060 | 2000-07-17 14:38:19 +0000 | [diff] [blame] | 195 | <h2>2.2.0: July 14 2000</h2> |
| 196 | <ul> |
| 197 | <li>applied a lot of portability fixes</li> |
| 198 | <li>better encoding support/cleanup and saving (content is now always |
| 199 | encoded in UTF-8)</li> |
| 200 | <li>the HTML parser now correctly handles encodings</li> |
| 201 | <li>added xmlHasProp()</li> |
| 202 | <li>fixed a serious problem with &#38;</li> |
| 203 | <li>propagated the fix to FTP client</li> |
| 204 | <li>cleanup, bugfixes, etc ...</li> |
| 205 | <li>Added a page about <a href="encoding.html">libxml Internationalization |
| 206 | support</a></li> |
| 207 | </ul> |
| 208 | |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 209 | <h3>1.8.9: July 9 2000</h3> |
| 210 | <ul> |
| 211 | <li>fixed the spec the RPMs should be better</li> |
| 212 | <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve |
| 213 | rpmfind users problem</li> |
| 214 | </ul> |
| 215 | |
Daniel Veillard | 6388e17 | 2000-07-03 16:07:19 +0000 | [diff] [blame] | 216 | <h3>2.1.1: July 1 2000</h3> |
| 217 | <ul> |
| 218 | <li>fixes a couple of bugs in the 2.1.0 packaging</li> |
| 219 | <li>improvements on the HTML parser</li> |
| 220 | </ul> |
| 221 | |
Daniel Veillard | 3f6f7f6 | 2000-06-30 17:58:25 +0000 | [diff] [blame] | 222 | <h3>2.1.0 and 1.8.8: June 29 2000</h3> |
| 223 | <ul> |
| 224 | <li>1.8.8 is mostly a comodity package for upgrading to libxml2 accoding to |
| 225 | <a href="upgrade.html">new instructions</a>. It fixes a nasty problem |
| 226 | about &#38; charref parsing</li> |
| 227 | <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it |
| 228 | also contains numerous fixes and enhancements: |
| 229 | <ul> |
| 230 | <li>added xmlStopParser() to stop parsing</li> |
| 231 | <li>improved a lot parsing speed when there is large CDATA blocs</li> |
| 232 | <li>includes XPath patches provided by Picdar Technology</li> |
| 233 | <li>tried to fix as much as possible DtD validation and namespace |
| 234 | related problems</li> |
| 235 | <li>output to a given encoding has been added/tested</li> |
| 236 | <li>lot of various fixes</li> |
| 237 | </ul> |
| 238 | </li> |
| 239 | </ul> |
| 240 | |
Daniel Veillard | e0aed30 | 2000-04-16 08:52:20 +0000 | [diff] [blame] | 241 | <h3>2.0.0: Apr 12 2000</h3> |
Daniel Veillard | 361d845 | 2000-04-03 19:48:13 +0000 | [diff] [blame] | 242 | <ul> |
| 243 | <li>First public release of libxml2. If you are using libxml, it's a good |
Daniel Veillard | e0aed30 | 2000-04-16 08:52:20 +0000 | [diff] [blame] | 244 | idea to check the 1.x to 2.x upgrade instructions. NOTE: while initally |
| 245 | scheduled for Apr 3 the relase occured only on Apr 12 due to massive |
| 246 | workload.</li> |
Daniel Veillard | 361d845 | 2000-04-03 19:48:13 +0000 | [diff] [blame] | 247 | <li>The include are now located under $prefix/include/libxml (instead of |
Daniel Veillard | e0aed30 | 2000-04-16 08:52:20 +0000 | [diff] [blame] | 248 | $prefix/include/gnome-xml), they also are referenced by |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 249 | <pre>#include <libxml/xxx.h></pre> |
Daniel Veillard | e0aed30 | 2000-04-16 08:52:20 +0000 | [diff] [blame] | 250 | <p>instead of</p> |
Daniel Veillard | 361d845 | 2000-04-03 19:48:13 +0000 | [diff] [blame] | 251 | <pre>#include "xxx.h"</pre> |
| 252 | </li> |
Daniel Veillard | 8f62198 | 2000-03-20 13:07:15 +0000 | [diff] [blame] | 253 | <li>a new URI module for parsing URIs and following strictly RFC 2396</li> |
| 254 | <li>the memory allocation routines used by libxml can now be overloaded |
| 255 | dynamically by using xmlMemSetup()</li> |
Daniel Veillard | 361d845 | 2000-04-03 19:48:13 +0000 | [diff] [blame] | 256 | <li>The previously CVS only tool tester has been renamed |
| 257 | <strong>xmllint</strong> and is now installed as part of the libxml2 |
| 258 | package</li> |
Daniel Veillard | e0aed30 | 2000-04-16 08:52:20 +0000 | [diff] [blame] | 259 | <li>The I/O interface has been revamped. There is now ways to plug in |
| 260 | specific I/O modules, either at the URI scheme detection level using |
| 261 | xmlRegisterInputCallbacks() or by passing I/O functions when creating a |
| 262 | parser context using xmlCreateIOParserCtxt()</li> |
| 263 | <li>there is a C preprocessor macro LIBXML_VERSION providing the version |
| 264 | number of the libxml module in use</li> |
| 265 | <li>a number of optional features of libxml can now be excluded at configure |
| 266 | time (FTP/HTTP/HTML/XPath/Debug)</li> |
Daniel Veillard | edfb29b | 2000-03-14 19:59:05 +0000 | [diff] [blame] | 267 | </ul> |
| 268 | |
| 269 | <h3>2.0.0beta: Mar 14 2000</h3> |
| 270 | <ul> |
| 271 | <li>This is a first Beta release of libxml version 2</li> |
| 272 | <li>It's available only from<a href="ftp://rpmfind.net/pub/libxml/"> |
| 273 | rpmfind.net FTP</a>, it's packaged as libxml2-2.0.0beta and available as |
| 274 | tar and RPMs</li> |
| 275 | <li>This version is now the head in the Gnome CVS base, the old one is |
| 276 | available under the tag LIB_XML_1_X</li> |
| 277 | <li>This includes a very large set of changes. Froma programmatic point of |
| 278 | view applications should not have to be modified too much, check the <a |
| 279 | href="upgrade.html">upgrade page</a></li> |
| 280 | <li>Some interfaces may changes (especially a bit about encoding).</li> |
| 281 | <li>the updates includes: |
Daniel Veillard | 6c8b117 | 2000-03-01 00:40:41 +0000 | [diff] [blame] | 282 | <ul> |
Daniel Veillard | edfb29b | 2000-03-14 19:59:05 +0000 | [diff] [blame] | 283 | <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly |
| 284 | handled now</li> |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 285 | <li>Better handling of entities, especially well formedness checking and |
| 286 | proper PEref extensions in external subsets</li> |
Daniel Veillard | 6c8b117 | 2000-03-01 00:40:41 +0000 | [diff] [blame] | 287 | <li>DTD conditional sections</li> |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 288 | <li>Validation now correcly handle entities content</li> |
Daniel Veillard | 6c8b117 | 2000-03-01 00:40:41 +0000 | [diff] [blame] | 289 | <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change |
| 290 | structures to accomodate DOM</a></li> |
Daniel Veillard | 6c8b117 | 2000-03-01 00:40:41 +0000 | [diff] [blame] | 291 | </ul> |
| 292 | </li> |
Daniel Veillard | edfb29b | 2000-03-14 19:59:05 +0000 | [diff] [blame] | 293 | <li>Serious progress were made toward compliance, <a |
| 294 | href="conf/result.html">here are the result of the test</a> against the |
| 295 | OASIS testsuite (except the japanese tests since I don't support that |
| 296 | encoding yet). This URL is rebuilt every couple of hours using the CVS |
| 297 | head version.</li> |
Daniel Veillard | e41f2b7 | 2000-01-30 20:00:07 +0000 | [diff] [blame] | 298 | </ul> |
| 299 | |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 300 | <h3>1.8.7: Mar 6 2000</h3> |
| 301 | <ul> |
| 302 | <li>This is a bug fix release:</li> |
| 303 | <li>It is possible to disable the ignorable blanks heuristic used by |
| 304 | libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note |
| 305 | that for adherence to XML spec, this behaviour will be disabled by default |
| 306 | in 2.x . The same function will allow to keep compatibility for old |
| 307 | code.</li> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 308 | <li>Blanks in <a> </a> constructs are not ignored anymore, |
| 309 | avoiding heuristic is really the Right Way :-\</li> |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 310 | <li>The unchecked use of snprintf which was breaking libxml-1.8.6 |
| 311 | compilation on some platforms has been fixed</li> |
| 312 | <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing |
| 313 | URIs</li> |
| 314 | </ul> |
| 315 | |
Daniel Veillard | e41f2b7 | 2000-01-30 20:00:07 +0000 | [diff] [blame] | 316 | <h3>1.8.6: Jan 31 2000</h3> |
| 317 | <ul> |
| 318 | <li>added a nanoFTP transport module, debugged until the new version of <a |
| 319 | href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use |
| 320 | it without troubles</li> |
Daniel Veillard | da07c34 | 2000-01-25 18:31:22 +0000 | [diff] [blame] | 321 | </ul> |
| 322 | |
| 323 | <h3>1.8.5: Jan 21 2000</h3> |
| 324 | <ul> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 325 | <li>adding APIs to parse a well balanced chunk of XML (production <a |
| 326 | href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the XML |
| 327 | spec)</li> |
Daniel Veillard | 461a66c | 2000-01-18 18:01:01 +0000 | [diff] [blame] | 328 | <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 329 | <li>Jody Goldberg <jgoldberg@home.com> provided another patch trying |
| 330 | to solve the zlib checks problems</li> |
Daniel Veillard | 461a66c | 2000-01-18 18:01:01 +0000 | [diff] [blame] | 331 | <li>The current state in gnome CVS base is expected to ship as 1.8.5 with |
| 332 | gnumeric soon</li> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 333 | </ul> |
| 334 | |
| 335 | <h3>1.8.4: Jan 13 2000</h3> |
| 336 | <ul> |
| 337 | <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li> |
| 338 | <li>all exit() call should have been removed from libxml</li> |
| 339 | <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li> |
| 340 | <li>added newDocFragment()</li> |
Daniel Veillard | f84f71f | 2000-01-05 19:54:23 +0000 | [diff] [blame] | 341 | </ul> |
| 342 | |
| 343 | <h3>1.8.3: Jan 5 2000</h3> |
| 344 | <ul> |
| 345 | <li>a Push interface for the XML and HTML parsers</li> |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 346 | <li>a shell-like interface to the document tree (try tester --shell :-)</li> |
Daniel Veillard | dbfd641 | 1999-12-28 16:35:14 +0000 | [diff] [blame] | 347 | <li>lots of bug fixes and improvement added over XMas hollidays</li> |
Daniel Veillard | 437b87b | 2000-01-03 17:30:46 +0000 | [diff] [blame] | 348 | <li>fixed the DTD parsing code to work with the xhtml DTD</li> |
Daniel Veillard | f84f71f | 2000-01-05 19:54:23 +0000 | [diff] [blame] | 349 | <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li> |
| 350 | <li>Fixed bugs in xmlNewNs()</li> |
Daniel Veillard | 437b87b | 2000-01-03 17:30:46 +0000 | [diff] [blame] | 351 | <li>External entity loading code has been revamped, now it uses |
Daniel Veillard | f84f71f | 2000-01-05 19:54:23 +0000 | [diff] [blame] | 352 | xmlLoadExternalEntity(), some fix on entities processing were added</li> |
Daniel Veillard | 437b87b | 2000-01-03 17:30:46 +0000 | [diff] [blame] | 353 | <li>cleaned up WIN32 includes of socket stuff</li> |
Daniel Veillard | 5cb5ab8 | 1999-12-21 15:35:29 +0000 | [diff] [blame] | 354 | </ul> |
| 355 | |
| 356 | <h3>1.8.2: Dec 21 1999</h3> |
| 357 | <ul> |
Daniel Veillard | b24054a | 1999-12-18 15:32:46 +0000 | [diff] [blame] | 358 | <li>I got another problem with includes and C++, I hope this issue is fixed |
| 359 | for good this time</li> |
Daniel Veillard | 5cb5ab8 | 1999-12-21 15:35:29 +0000 | [diff] [blame] | 360 | <li>Added a few tree modification functions: xmlReplaceNode, |
| 361 | xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and |
| 362 | xmlDocSetRootElement</li> |
| 363 | <li>Tried to improve the HTML output with help from <a |
| 364 | href="mailto:clahey@umich.edu">Chris Lahey</a></li> |
Daniel Veillard | e4e5131 | 1999-12-18 15:32:46 +0000 | [diff] [blame] | 365 | </ul> |
Daniel Veillard | b24054a | 1999-12-18 15:32:46 +0000 | [diff] [blame] | 366 | |
Daniel Veillard | e4e5131 | 1999-12-18 15:32:46 +0000 | [diff] [blame] | 367 | <h3>1.8.1: Dec 18 1999</h3> |
| 368 | <ul> |
| 369 | <li>various patches to avoid troubles when using libxml with C++ compilers |
| 370 | the "namespace" keyword and C escaping in include files</li> |
| 371 | <li>a problem in one of the core macros IS_CHAR was corrected</li> |
| 372 | <li>fixed a bug introduced in 1.8.0 breaking default namespace processing, |
| 373 | and more specifically the Dia application</li> |
Daniel Veillard | 944b5ff | 1999-12-15 19:08:24 +0000 | [diff] [blame] | 374 | <li>fixed a posteriori validation (validation after parsing, or by using a |
| 375 | Dtd not specified in the original document)</li> |
Daniel Veillard | b24054a | 1999-12-18 15:32:46 +0000 | [diff] [blame] | 376 | <li>fixed a bug in</li> |
Daniel Veillard | 10a2c65 | 1999-12-12 13:03:50 +0000 | [diff] [blame] | 377 | </ul> |
| 378 | |
| 379 | <h3>1.8.0: Dec 12 1999</h3> |
| 380 | <ul> |
| 381 | <li>cleanup, especially memory wise</li> |
| 382 | <li>the parser should be more reliable, especially the HTML one, it should |
| 383 | not crash, whatever the input !</li> |
| 384 | <li>Integrated various patches, especially a speedup improvement for large |
| 385 | dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>, |
| 386 | configure with --with-buffers to enable them.</li> |
| 387 | <li>attribute normalization, oops should have been added long ago !</li> |
| 388 | <li>attributes defaulted from Dtds should be available, xmlSetProp() now |
| 389 | does entities escapting by default.</li> |
Daniel Veillard | 4c3a203 | 1999-11-19 17:46:26 +0000 | [diff] [blame] | 390 | </ul> |
Daniel Veillard | 3500838 | 1999-10-25 13:15:52 +0000 | [diff] [blame] | 391 | |
| 392 | <h3>1.7.4: Oct 25 1999</h3> |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 393 | <ul> |
Daniel Veillard | 3500838 | 1999-10-25 13:15:52 +0000 | [diff] [blame] | 394 | <li>Lots of HTML improvement</li> |
| 395 | <li>Fixed some errors when saving both XML and HTML</li> |
| 396 | <li>More examples, the regression tests should now look clean</li> |
| 397 | <li>Fixed a bug with contiguous charref</li> |
| 398 | </ul> |
| 399 | |
| 400 | <h3>1.7.3: Sep 29 1999</h3> |
| 401 | <ul> |
| 402 | <li>portability problems fixed</li> |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 403 | <li>snprintf was used unconditionnally, leading to link problems on system |
Daniel Veillard | 3500838 | 1999-10-25 13:15:52 +0000 | [diff] [blame] | 404 | were it's not available, fixed</li> |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 405 | </ul> |
| 406 | |
| 407 | <h3>1.7.1: Sep 24 1999</h3> |
| 408 | <ul> |
| 409 | <li>The basic type for strings manipulated by libxml has been renamed in |
| 410 | 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason |
| 411 | is that CHAR was conflicting with a predefined type on Windows. However on |
| 412 | non WIN32 environment, compatibility is provided by the way of a |
| 413 | <strong>#define </strong>.</li> |
| 414 | <li>Changed another error : the use of a structure field called errno, and |
| 415 | leading to troubles on platforms where it's a macro</li> |
| 416 | </ul> |
| 417 | |
| 418 | <h3>1.7.0: sep 23 1999</h3> |
| 419 | <ul> |
| 420 | <li>Added the ability to fetch remote DTD or parsed entities, see the <a |
Daniel Veillard | c19fccc | 2000-07-03 11:52:01 +0000 | [diff] [blame] | 421 | href="html/gnome-xml-nanohttp.html">nanohttp</a> module.</li> |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 422 | <li>Added an errno to report errors by another mean than a simple printf |
| 423 | like callback</li> |
| 424 | <li>Finished ID/IDREF support and checking when validation</li> |
| 425 | <li>Serious memory leaks fixed (there is now a <a |
Daniel Veillard | c19fccc | 2000-07-03 11:52:01 +0000 | [diff] [blame] | 426 | href="html/gnome-xml-xmlmemory.html">memory wrapper</a> module)</li> |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 427 | <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a> |
| 428 | implementation</li> |
| 429 | <li>Added an HTML parser front-end</li> |
| 430 | </ul> |
| 431 | |
| 432 | <h2><a name="XML">XML</a></h2> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 433 | |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 434 | <p><a href="http://www.w3.org/TR/REC-xml">XML is a standard</a> for |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 435 | markup-based structured documents. Here is <a name="example">an example XML |
| 436 | document</a>:</p> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 437 | <pre><?xml version="1.0"?> |
| 438 | <EXAMPLE prop1="gnome is great" prop2="&amp; linux too"> |
| 439 | <head> |
| 440 | <title>Welcome to Gnome</title> |
| 441 | </head> |
| 442 | <chapter> |
| 443 | <title>The Linux adventure</title> |
| 444 | <p>bla bla bla ...</p> |
| 445 | <image href="linus.gif"/> |
| 446 | <p>...</p> |
| 447 | </chapter> |
| 448 | </EXAMPLE></pre> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 449 | |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 450 | <p>The first line specifies that it's an XML document and gives useful |
| 451 | information about its encoding. Then the document is a text format whose |
| 452 | structure is specified by tags between brackets. <strong>Each tag opened has |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 453 | to be closed</strong>. XML is pedantic about this. However, if a tag is empty |
| 454 | (no content), a single tag can serve as both the opening and closing tag if it |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 455 | ends with <code>/></code> rather than with <code>></code>. Note that, |
| 456 | for example, the image tag has no content (just an attribute) and is closed by |
| 457 | ending the tag with <code>/></code>.</p> |
Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 458 | |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 459 | <p>XML can be applied sucessfully to a wide range of uses, from long term |
| 460 | structured document maintenance (where it follows the steps of SGML) to simple |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 461 | data encoding mechanisms like configuration file formatting (glade), |
| 462 | spreadsheets (gnumeric), or even shorter lived documents such as WebDAV where |
| 463 | it is used to encode remote calls between a client and a server.</p> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 464 | |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 465 | <h2><a name="tree">The tree output</a></h2> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 466 | |
| 467 | <p>The parser returns a tree built during the document analysis. The value |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 468 | returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 469 | <strong>xmlDoc</strong> structure). This structure contains information such |
Daniel Veillard | 306be99 | 2000-07-03 12:38:45 +0000 | [diff] [blame] | 470 | as the file name, the document type, and a <strong>children</strong> pointer |
| 471 | which is the root of the document (or more exactly the first child under the |
| 472 | root which is the document). The tree is made of <strong>xmlNode</strong>s, |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 473 | chained in double-linked lists of siblings and with children<->parent |
Daniel Veillard | 306be99 | 2000-07-03 12:38:45 +0000 | [diff] [blame] | 474 | relationship. An xmlNode can also carry properties (a chain of xmlAttr |
| 475 | structures). An attribute may have a value which is a list of TEXT or |
| 476 | ENTITY_REF nodes.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 477 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 478 | <p>Here is an example (erroneous with respect to the XML spec since there |
| 479 | should be only one ELEMENT under the root):</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 480 | |
| 481 | <p><img src="structure.gif" alt=" structure.gif "></p> |
| 482 | |
| 483 | <p>In the source package there is a small program (not installed by default) |
Daniel Veillard | 361d845 | 2000-04-03 19:48:13 +0000 | [diff] [blame] | 484 | called <strong>xmllint</strong> which parses XML files given as argument and |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 485 | prints them back as parsed. This is useful for detecting errors both in XML |
| 486 | code and in the XML parser itself. It has an option <strong>--debug</strong> |
| 487 | which prints the actual in-memory structure of the document, here is the |
| 488 | result with the <a href="#example">example</a> given before:</p> |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 489 | <pre>DOCUMENT |
| 490 | version=1.0 |
| 491 | standalone=true |
| 492 | ELEMENT EXAMPLE |
| 493 | ATTRIBUTE prop1 |
| 494 | TEXT |
| 495 | content=gnome is great |
| 496 | ATTRIBUTE prop2 |
| 497 | ENTITY_REF |
| 498 | TEXT |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 499 | content= linux too |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 500 | ELEMENT head |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 501 | ELEMENT title |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 502 | TEXT |
| 503 | content=Welcome to Gnome |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 504 | ELEMENT chapter |
| 505 | ELEMENT title |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 506 | TEXT |
| 507 | content=The Linux adventure |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 508 | ELEMENT p |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 509 | TEXT |
| 510 | content=bla bla bla ... |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 511 | ELEMENT image |
| 512 | ATTRIBUTE href |
| 513 | TEXT |
| 514 | content=linus.gif |
| 515 | ELEMENT p |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 516 | TEXT |
| 517 | content=...</pre> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 518 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 519 | <p>This should be useful for learning the internal representation model.</p> |
Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 520 | |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 521 | <h2><a name="interface">The SAX interface</a></h2> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 522 | |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 523 | <p>Sometimes the DOM tree output is just too large to fit reasonably into |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 524 | memory. In that case (and if you don't expect to save back the XML document |
| 525 | loaded using libxml), it's better to use the SAX interface of libxml. SAX is a |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 526 | <strong>callback-based interface</strong> to the parser. Before parsing, the |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 527 | application layer registers a customized set of callbacks which are called by |
| 528 | the library as it progresses through the XML input.</p> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 529 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 530 | <p>To get more detailed step-by-step guidance on using the SAX interface of |
| 531 | libxml, see the |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 532 | href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 533 | documentation.written by <a href="mailto:james@daa.com.au">James |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 534 | Henstridge</a>.</p> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 535 | |
| 536 | <p>You can debug the SAX behaviour by using the <strong>testSAX</strong> |
| 537 | program located in the gnome-xml module (it's usually not shipped in the |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 538 | binary packages of libxml, but you can find it in the tar source |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 539 | distribution). Here is the sequence of callbacks that would be reported by |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 540 | testSAX when parsing the example XML document shown earlier:</p> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 541 | <pre>SAX.setDocumentLocator() |
| 542 | SAX.startDocument() |
| 543 | SAX.getEntity(amp) |
| 544 | SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp; linux too') |
| 545 | SAX.characters( , 3) |
| 546 | SAX.startElement(head) |
| 547 | SAX.characters( , 4) |
| 548 | SAX.startElement(title) |
| 549 | SAX.characters(Welcome to Gnome, 16) |
| 550 | SAX.endElement(title) |
| 551 | SAX.characters( , 3) |
| 552 | SAX.endElement(head) |
| 553 | SAX.characters( , 3) |
| 554 | SAX.startElement(chapter) |
| 555 | SAX.characters( , 4) |
| 556 | SAX.startElement(title) |
| 557 | SAX.characters(The Linux adventure, 19) |
| 558 | SAX.endElement(title) |
| 559 | SAX.characters( , 4) |
| 560 | SAX.startElement(p) |
| 561 | SAX.characters(bla bla bla ..., 15) |
| 562 | SAX.endElement(p) |
| 563 | SAX.characters( , 4) |
| 564 | SAX.startElement(image, href='linus.gif') |
| 565 | SAX.endElement(image) |
| 566 | SAX.characters( , 4) |
| 567 | SAX.startElement(p) |
| 568 | SAX.characters(..., 3) |
| 569 | SAX.endElement(p) |
| 570 | SAX.characters( , 3) |
| 571 | SAX.endElement(chapter) |
| 572 | SAX.characters( , 1) |
| 573 | SAX.endElement(EXAMPLE) |
| 574 | SAX.endDocument()</pre> |
| 575 | |
Daniel Veillard | 402e8c8 | 2000-02-29 22:57:47 +0000 | [diff] [blame] | 576 | <p>Most of the other functionalities of libxml are based on the DOM |
| 577 | tree-building facility, so nearly everything up to the end of this document |
| 578 | presupposes the use of the standard DOM tree build. Note that the DOM tree |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 579 | itself is built by a set of registered default callbacks, without internal |
| 580 | specific interface.</p> |
| 581 | |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 582 | <h2><a name="library">The XML library interfaces</a></h2> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 583 | |
| 584 | <p>This section is directly intended to help programmers getting bootstrapped |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 585 | using the XML library from the C language. It is not intended to be extensive. |
| 586 | I hope the automatically generated documents will provide the completeness |
| 587 | required, but as a separate set of documents. The interfaces of the XML |
| 588 | library are by principle low level, there is nearly zero abstraction. Those |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 589 | interested in a higher level API should <a href="#DOM">look at DOM</a>.</p> |
Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 590 | |
Daniel Veillard | c19fccc | 2000-07-03 11:52:01 +0000 | [diff] [blame] | 591 | <p>The <a href="html/gnome-xml-parser.html">parser interfaces for XML</a> are |
| 592 | separated from the <a href="html/gnome-xml-htmlparser.html">HTML parser |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 593 | interfaces</a>. Let's have a look at how the XML parser can be called:</p> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 594 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 595 | <h3><a name="Invoking">Invoking the parser : the pull method</a></h3> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 596 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 597 | <p>Usually, the first thing to do is to read an XML input. The parser accepts |
| 598 | documents either from in-memory strings or from files. The functions are |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 599 | defined in "parser.h":</p> |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 600 | <dl> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 601 | <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt> |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 602 | <dd><p>Parse a null-terminated string containing the document.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 603 | </dd> |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 604 | </dl> |
| 605 | <dl> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 606 | <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt> |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 607 | <dd><p>Parse an XML document contained in a (possibly compressed) |
| 608 | file.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 609 | </dd> |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 610 | </dl> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 611 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 612 | <p>The parser returns a pointer to the document structure (or NULL in case of |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 613 | failure).</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 614 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 615 | <h3 id="Invoking1">Invoking the parser: the push method</h3> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 616 | |
| 617 | <p>In order for the application to keep the control when the document is been |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 618 | fetched (which is common for GUI based programs) libxml provides a push |
| 619 | interface, too, as of version 1.8.3. Here are the interface functions:</p> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 620 | <pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax, |
| 621 | void *user_data, |
| 622 | const char *chunk, |
| 623 | int size, |
| 624 | const char *filename); |
| 625 | int xmlParseChunk (xmlParserCtxtPtr ctxt, |
| 626 | const char *chunk, |
| 627 | int size, |
| 628 | int terminate);</pre> |
| 629 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 630 | <p>and here is a simple example showing how to use the interface:</p> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 631 | <pre> FILE *f; |
| 632 | |
| 633 | f = fopen(filename, "r"); |
| 634 | if (f != NULL) { |
| 635 | int res, size = 1024; |
| 636 | char chars[1024]; |
| 637 | xmlParserCtxtPtr ctxt; |
| 638 | |
| 639 | res = fread(chars, 1, 4, f); |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 640 | if (res > 0) { |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 641 | ctxt = xmlCreatePushParserCtxt(NULL, NULL, |
| 642 | chars, res, filename); |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 643 | while ((res = fread(chars, 1, size, f)) > 0) { |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 644 | xmlParseChunk(ctxt, chars, res, 0); |
| 645 | } |
| 646 | xmlParseChunk(ctxt, chars, 0, 1); |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 647 | doc = ctxt->myDoc; |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 648 | xmlFreeParserCtxt(ctxt); |
| 649 | } |
| 650 | }</pre> |
| 651 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 652 | <p>Also note that the HTML parser embedded into libxml also has a push |
| 653 | interface; the functions are just prefixed by "html" rather than "xml"</p> |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 654 | |
| 655 | <h3 id="Invoking2">Invoking the parser: the SAX interface</h3> |
| 656 | |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 657 | <p>A couple of comments can be made, first this mean that the parser is |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 658 | memory-hungry, first to load the document in memory, second to build the tree. |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 659 | Reading a document without building the tree is possible using the SAX |
| 660 | interfaces (see SAX.h and <a |
| 661 | href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">James |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 662 | Henstridge's documentation</a>). Note also that the push interface can be |
| 663 | limited to SAX. Just use the two first arguments of |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 664 | <code>xmlCreatePushParserCtxt()</code>.</p> |
Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 665 | |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 666 | <h3><a name="Building">Building a tree from scratch</a></h3> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 667 | |
| 668 | <p>The other way to get an XML tree in memory is by building it. Basically |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 669 | there is a set of functions dedicated to building new elements. (These are |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 670 | also described in <libxml/tree.h>.) For example, here is a piece of code |
Daniel Veillard | 361d845 | 2000-04-03 19:48:13 +0000 | [diff] [blame] | 671 | that produces the XML document used in the previous examples:</p> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 672 | <pre> #include <libxml/tree.h> |
Daniel Veillard | 361d845 | 2000-04-03 19:48:13 +0000 | [diff] [blame] | 673 | xmlDocPtr doc; |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 674 | xmlNodePtr tree, subtree; |
| 675 | |
| 676 | doc = xmlNewDoc("1.0"); |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 677 | doc->children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL); |
| 678 | xmlSetProp(doc->children, "prop1", "gnome is great"); |
| 679 | xmlSetProp(doc->children, "prop2", "& linux too"); |
| 680 | tree = xmlNewChild(doc->children, NULL, "head", NULL); |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 681 | subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome"); |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 682 | tree = xmlNewChild(doc->children, NULL, "chapter", NULL); |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 683 | subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure"); |
| 684 | subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ..."); |
| 685 | subtree = xmlNewChild(tree, NULL, "image", NULL); |
| 686 | xmlSetProp(subtree, "href", "linus.gif");</pre> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 687 | |
| 688 | <p>Not really rocket science ...</p> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 689 | |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 690 | <h3><a name="Traversing">Traversing the tree</a></h3> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 691 | |
Daniel Veillard | 306be99 | 2000-07-03 12:38:45 +0000 | [diff] [blame] | 692 | <p>Basically by <a href="html/gnome-xml-tree.html">including "tree.h"</a> your |
| 693 | code has access to the internal structure of all the elements of the tree. The |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 694 | names should be somewhat simple like <strong>parent</strong>, |
Daniel Veillard | 306be99 | 2000-07-03 12:38:45 +0000 | [diff] [blame] | 695 | <strong>children</strong>, <strong>next</strong>, <strong>prev</strong>, |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 696 | <strong>properties</strong>, etc... For example, still with the previous |
Daniel Veillard | 0142b84 | 2000-01-14 14:45:24 +0000 | [diff] [blame] | 697 | example:</p> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 698 | <pre><code>doc->children->children->children</code></pre> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 699 | |
| 700 | <p>points to the title element,</p> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 701 | <pre>doc->children->children->next->child->child</pre> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 702 | |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 703 | <p>points to the text node containing the chapter title "The Linux |
| 704 | adventure".</p> |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 705 | |
Daniel Veillard | b24054a | 1999-12-18 15:32:46 +0000 | [diff] [blame] | 706 | <p><strong>NOTE</strong>: XML allows <em>PI</em>s and <em>comments</em> to be |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 707 | present before the document root, so <code>doc->children</code> may point |
| 708 | to an element which is not the document Root Element, a function |
Daniel Veillard | 5cb5ab8 | 1999-12-21 15:35:29 +0000 | [diff] [blame] | 709 | <code>xmlDocGetRootElement()</code> was added for this purpose.</p> |
Daniel Veillard | b24054a | 1999-12-18 15:32:46 +0000 | [diff] [blame] | 710 | |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 711 | <h3><a name="Modifying">Modifying the tree</a></h3> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 712 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 713 | <p>Functions are provided for reading and writing the document content. Here |
Daniel Veillard | c19fccc | 2000-07-03 11:52:01 +0000 | [diff] [blame] | 714 | is an excerpt from the <a href="html/gnome-xml-tree.html">tree API</a>:</p> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 715 | <dl> |
Daniel Veillard | dd6b367 | 1999-09-23 22:19:22 +0000 | [diff] [blame] | 716 | <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const |
| 717 | xmlChar *value);</code></dt> |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 718 | <dd><p>This sets (or changes) an attribute carried by an ELEMENT node. The |
| 719 | value can be NULL.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 720 | </dd> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 721 | </dl> |
| 722 | <dl> |
Daniel Veillard | dd6b367 | 1999-09-23 22:19:22 +0000 | [diff] [blame] | 723 | <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 724 | *name);</code></dt> |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 725 | <dd><p>This function returns a pointer to the property content. Note that |
| 726 | no extra copy is made.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 727 | </dd> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 728 | </dl> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 729 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 730 | <p>Two functions are provided for reading and writing the text associated with |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 731 | elements:</p> |
| 732 | <dl> |
Daniel Veillard | dd6b367 | 1999-09-23 22:19:22 +0000 | [diff] [blame] | 733 | <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 734 | *value);</code></dt> |
| 735 | <dd><p>This function takes an "external" string and convert it to one text |
| 736 | node or possibly to a list of entity and text nodes. All non-predefined |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 737 | entity references like &Gnome; will be stored internally as entity |
| 738 | nodes, hence the result of the function may not be a single node.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 739 | </dd> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 740 | </dl> |
| 741 | <dl> |
Daniel Veillard | dd6b367 | 1999-09-23 22:19:22 +0000 | [diff] [blame] | 742 | <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 743 | inLine);</code></dt> |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 744 | <dd><p>This function is the inverse of |
| 745 | <code>xmlStringGetNodeList()</code>. It generates a new string |
| 746 | containing the content of the text and entity nodes. Note the extra |
| 747 | argument inLine. If this argument is set to 1, the function will expand |
| 748 | entity references. For example, instead of returning the &Gnome; |
| 749 | XML encoding in the string, it will substitute it with its value (say, |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 750 | "GNU Network Object Model Environment"). Set this argument if you want |
| 751 | to use the string for non-XML usage like User Interface.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 752 | </dd> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 753 | </dl> |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 754 | |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 755 | <h3><a name="Saving">Saving a tree</a></h3> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 756 | |
| 757 | <p>Basically 3 options are possible:</p> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 758 | <dl> |
Daniel Veillard | dd6b367 | 1999-09-23 22:19:22 +0000 | [diff] [blame] | 759 | <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 760 | *size);</code></dt> |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 761 | <dd><p>Returns a buffer into which the document has been saved.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 762 | </dd> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 763 | </dl> |
| 764 | <dl> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 765 | <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt> |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 766 | <dd><p>Dumps a document to an open file descriptor.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 767 | </dd> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 768 | </dl> |
| 769 | <dl> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 770 | <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt> |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 771 | <dd><p>Saves the document to a file. In this case, the compression |
| 772 | interface is triggered if it has been turned on.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 773 | </dd> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 774 | </dl> |
Daniel Veillard | 10c6a8f | 1998-10-28 01:00:12 +0000 | [diff] [blame] | 775 | |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 776 | <h3><a name="Compressio">Compression</a></h3> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 777 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 778 | <p>The library transparently handles compression when doing file-based |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 779 | accesses. The level of compression on saves can be turned on either globally |
| 780 | or individually for one file:</p> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 781 | <dl> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 782 | <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt> |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 783 | <dd><p>Gets the document compression ratio (0-9).</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 784 | </dd> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 785 | </dl> |
| 786 | <dl> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 787 | <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt> |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 788 | <dd><p>Sets the document compression ratio.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 789 | </dd> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 790 | </dl> |
| 791 | <dl> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 792 | <dt><code>int xmlGetCompressMode(void);</code></dt> |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 793 | <dd><p>Gets the default compression ratio.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 794 | </dd> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 795 | </dl> |
| 796 | <dl> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 797 | <dt><code>void xmlSetCompressMode(int mode);</code></dt> |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 798 | <dd><p>Sets the default compression ratio.</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 799 | </dd> |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 800 | </dl> |
| 801 | |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 802 | <h2><a name="Entities">Entities or no entities</a></h2> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 803 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 804 | <p>Entities in principle are similar to simple C macros. An entity defines an |
| 805 | abbreviation for a given string that you can reuse many times throughout the |
| 806 | content of your document. Entities are especially useful when a given string |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 807 | may occur frequently within a document, or to confine the change needed to a |
| 808 | document to a restricted area in the internal subset of the document (at the |
| 809 | beginning). Example:</p> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 810 | <pre>1 <?xml version="1.0"?> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 811 | 2 <!DOCTYPE EXAMPLE SYSTEM "example.dtd" [ |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 812 | 3 <!ENTITY xml "Extensible Markup Language"> |
| 813 | 4 ]> |
| 814 | 5 <EXAMPLE> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 815 | 6 &xml; |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 816 | 7 </EXAMPLE></pre> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 817 | |
| 818 | <p>Line 3 declares the xml entity. Line 6 uses the xml entity, by prefixing |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 819 | it's name with '&' and following it by ';' without any spaces added. There |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 820 | are 5 predefined entities in libxml allowing you to escape charaters with |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 821 | predefined meaning in some parts of the xml document content: |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 822 | <strong>&lt;</strong> for the character '<', <strong>&gt;</strong> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 823 | for the character '>', <strong>&apos;</strong> for the character ''', |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 824 | <strong>&quot;</strong> for the character '"', and |
| 825 | <strong>&amp;</strong> for the character '&'.</p> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 826 | |
| 827 | <p>One of the problems related to entities is that you may want the parser to |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 828 | substitute an entity's content so that you can see the replacement text in |
| 829 | your application. Or you may prefer to keep entity references as such in the |
| 830 | content to be able to save the document back without losing this usually |
| 831 | precious information (if the user went through the pain of explicitly defining |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 832 | entities, he may have a a rather negative attitude if you blindly susbtitute |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 833 | them as saving time). The <a |
Daniel Veillard | c19fccc | 2000-07-03 11:52:01 +0000 | [diff] [blame] | 834 | href="html/gnome-xml-parser.html#XMLSUBSTITUTEENTITIESDEFAULT">xmlSubstituteEntitiesDefault()</a> |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 835 | function allows you to check and change the behaviour, which is to not |
| 836 | substitute entities by default.</p> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 837 | |
| 838 | <p>Here is the DOM tree built by libxml for the previous document in the |
| 839 | default case:</p> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 840 | <pre>/gnome/src/gnome-xml -> ./xmllint --debug test/ent1 |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 841 | DOCUMENT |
| 842 | version=1.0 |
| 843 | ELEMENT EXAMPLE |
| 844 | TEXT |
| 845 | content= |
| 846 | ENTITY_REF |
| 847 | INTERNAL_GENERAL_ENTITY xml |
| 848 | content=Extensible Markup Language |
| 849 | TEXT |
| 850 | content=</pre> |
| 851 | |
| 852 | <p>And here is the result when substituting entities:</p> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 853 | <pre>/gnome/src/gnome-xml -> ./tester --debug --noent test/ent1 |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 854 | DOCUMENT |
| 855 | version=1.0 |
| 856 | ELEMENT EXAMPLE |
| 857 | TEXT |
| 858 | content= Extensible Markup Language</pre> |
| 859 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 860 | <p>So, entities or no entities? Basically, it depends on your use case. I |
| 861 | suggest that you keep the non-substituting default behaviour and avoid using |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 862 | entities in your XML document or data if you are not willing to handle the |
| 863 | entity references elements in the DOM tree.</p> |
| 864 | |
| 865 | <p>Note that at save time libxml enforce the conversion of the predefined |
| 866 | entities where necessary to prevent well-formedness problems, and will also |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 867 | transparently replace those with chars (i.e., it will not generate entity |
| 868 | reference elements in the DOM tree or call the reference() SAX callback when |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 869 | finding them in the input).</p> |
| 870 | |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 871 | <h2><a name="Namespaces">Namespaces</a></h2> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 872 | |
Daniel Veillard | ec30341 | 2000-03-24 13:41:54 +0000 | [diff] [blame] | 873 | <p>The libxml library implements <a |
| 874 | href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by |
| 875 | recognizing namespace contructs in the input, and does namespace lookup |
| 876 | automatically when building the DOM tree. A namespace declaration is |
| 877 | associated with an in-memory structure and all elements or attributes within |
| 878 | that namespace point to it. Hence testing the namespace is a simple and fast |
| 879 | equality operation at the user level.</p> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 880 | |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 881 | <p>I suggest that people using libxml use a namespace, and declare it in the |
| 882 | root element of their document as the default namespace. Then they don't need |
| 883 | to use the prefix in the content but we will have a basis for future semantic |
| 884 | refinement and merging of data from different sources. This doesn't augment |
| 885 | significantly the size of the XML output, but significantly increase its value |
Daniel Veillard | ec30341 | 2000-03-24 13:41:54 +0000 | [diff] [blame] | 886 | in the long-term. Example:</p> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 887 | <pre><mydoc xmlns="http://mydoc.example.org/schemas/"> |
| 888 | <elem1>...</elem1> |
| 889 | <elem2>...</elem2> |
| 890 | </mydoc></pre> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 891 | |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 892 | <p>Concerning the namespace value, this has to be an URL, but the URL doesn't |
Daniel Veillard | ec30341 | 2000-03-24 13:41:54 +0000 | [diff] [blame] | 893 | have to point to any existing resource on the Web. It will bind all the |
| 894 | element and atributes with that URL. I suggest to use an URL within a domain |
| 895 | you control, and that the URL should contain some kind of version information |
| 896 | if possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is |
Daniel Veillard | 361d845 | 2000-04-03 19:48:13 +0000 | [diff] [blame] | 897 | a good namespace scheme.</p> |
Daniel Veillard | ec30341 | 2000-03-24 13:41:54 +0000 | [diff] [blame] | 898 | |
| 899 | <p>Then when you load a file, make sure that a namespace carrying the |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 900 | version-independent prefix is installed on the root element of your document, |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 901 | and if the version information don't match something you know, warn the user |
| 902 | and be liberal in what you accept as the input. Also do *not* try to base |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 903 | namespace checking on the prefix value. <foo:text> may be exactly the |
| 904 | same as <bar:text> in another document. What really matter is the URI |
| 905 | associated with the element or the attribute, not the prefix string (which is |
| 906 | just a shortcut for the full URI). In libxml element and attributes have a |
Daniel Veillard | ec30341 | 2000-03-24 13:41:54 +0000 | [diff] [blame] | 907 | <code>ns</code> field pointing to an xmlNs structure detailing the namespace |
| 908 | prefix and it's URI.</p> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 909 | |
| 910 | <p>@@Interfaces@@</p> |
| 911 | |
| 912 | <p>@@Examples@@</p> |
| 913 | |
| 914 | <p>Usually people object using namespace in the case of validation, I object |
| 915 | this and will make sure that using namespaces won't break validity checking, |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 916 | so even is you plan to use or currently are using validation I strongly |
| 917 | suggest adding namespaces to your document. A default namespace scheme |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 918 | <code>xmlns="http://...."</code> should not break validity even on less |
Daniel Veillard | 88f00ae | 2000-03-02 00:15:55 +0000 | [diff] [blame] | 919 | flexible parsers. Now using namespace to mix and differentiate content coming |
| 920 | from multiple DTDs will certainly break current validation schemes. I will try |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 921 | to provide ways to do this, but this may not be portable or standardized.</p> |
| 922 | |
Daniel Veillard | 2f4dfc4 | 1999-09-24 14:03:48 +0000 | [diff] [blame] | 923 | <h2><a name="Validation">Validation, or are you afraid of DTDs ?</a></h2> |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 924 | |
| 925 | <p>Well what is validation and what is a DTD ?</p> |
| 926 | |
| 927 | <p>Validation is the process of checking a document against a set of |
| 928 | construction rules, a <strong>DTD</strong> (Document Type Definition) is such |
| 929 | a set of rules.</p> |
| 930 | |
| 931 | <p>The validation process and building DTDs are the two most difficult parts |
| 932 | of XML life cycle. Briefly a DTD defines all the possibles element to be |
| 933 | found within your document, what is the formal shape of your document tree (by |
| 934 | defining the allowed content of an element, either text, a regular expression |
Daniel Veillard | 306be99 | 2000-07-03 12:38:45 +0000 | [diff] [blame] | 935 | for the allowed list of children, or mixed content i.e. both text and |
| 936 | children). The DTD also defines the allowed attributes for all elements and |
| 937 | the types of the attributes. For more detailed informations, I suggest to read |
| 938 | the related parts of the XML specification, the examples found under |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 939 | gnome-xml/test/valid/dtd and the large amount of books available on XML. The |
| 940 | dia example in gnome-xml/test/valid should be both simple and complete enough |
| 941 | to allow you to build your own.</p> |
| 942 | |
| 943 | <p>A word of warning, building a good DTD which will fit your needs of your |
| 944 | application in the long-term is far from trivial, however the extra level of |
| 945 | quality it can insure is well worth the price for some sets of applications or |
| 946 | if you already have already a DTD defined for your application field.</p> |
| 947 | |
| 948 | <p>The validation is not completely finished but in a (very IMHO) usable |
| 949 | state. Until a real validation interface is defined the way to do it is to |
| 950 | define and set the <strong>xmlDoValidityCheckingDefaultValue</strong> external |
| 951 | variable to 1, this will of course be changed at some point:</p> |
| 952 | |
| 953 | <p>extern int xmlDoValidityCheckingDefaultValue;</p> |
| 954 | |
| 955 | <p>...</p> |
| 956 | |
| 957 | <p>xmlDoValidityCheckingDefaultValue = 1;</p> |
| 958 | |
| 959 | <p></p> |
| 960 | |
| 961 | <p>To handle external entities, use the function |
| 962 | <strong>xmlSetExternalEntityLoader</strong>(xmlExternalEntityLoader f); to |
| 963 | link in you HTTP/FTP/Entities database library to the standard libxml |
| 964 | core.</p> |
| 965 | |
| 966 | <p>@@interfaces@@</p> |
| 967 | |
Daniel Veillard | 3500838 | 1999-10-25 13:15:52 +0000 | [diff] [blame] | 968 | <h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 969 | |
| 970 | <p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document Object |
Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 971 | Model</em> this is an API for accessing XML or HTML structured documents. |
| 972 | Native support for DOM in Gnome is on the way (module gnome-dom), and it will |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 973 | be based on gnome-xml. This will be a far cleaner interface to manipulate XML |
Daniel Veillard | c08a2c6 | 1999-09-08 21:35:25 +0000 | [diff] [blame] | 974 | files within Gnome since it won't expose the internal structure. DOM defines a |
Daniel Veillard | 25940b7 | 1998-10-29 05:51:30 +0000 | [diff] [blame] | 975 | set of IDL (or Java) interfaces allowing to traverse and manipulate a |
| 976 | document. The DOM library will allow accessing and modifying "live" documents |
| 977 | presents on other programs like this:</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 978 | |
| 979 | <p><img src="DOM.gif" alt=" DOM.gif "></p> |
| 980 | |
| 981 | <p>This should help greatly doing things like modifying a gnumeric spreadsheet |
Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 982 | embedded in a GWP document for example.</p> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 983 | |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 984 | <p>The current DOM implementation on top of libxml is the <a |
| 985 | href="http://cvs.gnome.org/lxr/source/gdome/">gdome Gnome module</a>, this is |
| 986 | a full DOM interface, thanks to <a href="mailto:raph@levien.com">Raph |
| 987 | Levien</a>.</p> |
| 988 | |
| 989 | <p>The gnome-dom module in the Gnome CVS base is obsolete</p> |
| 990 | |
Daniel Veillard | 3500838 | 1999-10-25 13:15:52 +0000 | [diff] [blame] | 991 | <h2><a name="Example"></a><a name="real">A real example</a></h2> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 992 | |
| 993 | <p>Here is a real size example, where the actual content of the application |
| 994 | data is not kept in the DOM tree but uses internal structures. It is based on |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 995 | a proposal to keep a database of jobs related to Gnome, with an XML based |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 996 | storage structure. Here is an <a href="gjobs.xml">XML encoded jobs |
| 997 | base</a>:</p> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 998 | <pre><?xml version="1.0"?> |
| 999 | <gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"> |
| 1000 | <gjob:Jobs> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1001 | |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1002 | <gjob:Job> |
| 1003 | <gjob:Project ID="3"/> |
| 1004 | <gjob:Application>GBackup</gjob:Application> |
| 1005 | <gjob:Category>Development</gjob:Category> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1006 | |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1007 | <gjob:Update> |
| 1008 | <gjob:Status>Open</gjob:Status> |
| 1009 | <gjob:Modified>Mon, 07 Jun 1999 20:27:45 -0400 MET DST</gjob:Modified> |
| 1010 | <gjob:Salary>USD 0.00</gjob:Salary> |
| 1011 | </gjob:Update> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1012 | |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1013 | <gjob:Developers> |
| 1014 | <gjob:Developer> |
| 1015 | </gjob:Developer> |
| 1016 | </gjob:Developers> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1017 | |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1018 | <gjob:Contact> |
| 1019 | <gjob:Person>Nathan Clemons</gjob:Person> |
| 1020 | <gjob:Email>nathan@windsofstorm.net</gjob:Email> |
| 1021 | <gjob:Company> |
| 1022 | </gjob:Company> |
| 1023 | <gjob:Organisation> |
| 1024 | </gjob:Organisation> |
| 1025 | <gjob:Webpage> |
| 1026 | </gjob:Webpage> |
| 1027 | <gjob:Snailmail> |
| 1028 | </gjob:Snailmail> |
| 1029 | <gjob:Phone> |
| 1030 | </gjob:Phone> |
| 1031 | </gjob:Contact> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1032 | |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1033 | <gjob:Requirements> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1034 | The program should be released as free software, under the GPL. |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1035 | </gjob:Requirements> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1036 | |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1037 | <gjob:Skills> |
| 1038 | </gjob:Skills> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1039 | |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1040 | <gjob:Details> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1041 | A GNOME based system that will allow a superuser to configure |
| 1042 | compressed and uncompressed files and/or file systems to be backed |
| 1043 | up with a supported media in the system. This should be able to |
| 1044 | perform via find commands generating a list of files that are passed |
| 1045 | to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine |
| 1046 | or via operations performed on the filesystem itself. Email |
| 1047 | notification and GUI status display very important. |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1048 | </gjob:Details> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1049 | |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1050 | </gjob:Job> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1051 | |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1052 | </gjob:Jobs> |
| 1053 | </gjob:Helping></pre> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 1054 | |
| 1055 | <p>While loading the XML file into an internal DOM tree is a matter of calling |
| 1056 | only a couple of functions, browsing the tree to gather the informations and |
| 1057 | generate the internals structures is harder, and more error prone.</p> |
| 1058 | |
| 1059 | <p>The suggested principle is to be tolerant with respect to the input |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 1060 | structure. For example, the ordering of the attributes is not significant, |
| 1061 | Cthe XML specification is clear about it. It's also usually a good idea to not |
Daniel Veillard | 306be99 | 2000-07-03 12:38:45 +0000 | [diff] [blame] | 1062 | be dependent of the orders of the children of a given node, unless it really |
Daniel Veillard | f13e1ed | 2000-03-06 07:41:49 +0000 | [diff] [blame] | 1063 | makes things harder. Here is some code to parse the informations for a |
| 1064 | person:</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 1065 | <pre>/* |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1066 | * A person record |
| 1067 | */ |
| 1068 | typedef struct person { |
| 1069 | char *name; |
| 1070 | char *email; |
| 1071 | char *company; |
| 1072 | char *organisation; |
| 1073 | char *smail; |
| 1074 | char *webPage; |
| 1075 | char *phone; |
| 1076 | } person, *personPtr; |
| 1077 | |
| 1078 | /* |
| 1079 | * And the code needed to parse it |
| 1080 | */ |
| 1081 | personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) { |
| 1082 | personPtr ret = NULL; |
| 1083 | |
| 1084 | DEBUG("parsePerson\n"); |
| 1085 | /* |
| 1086 | * allocate the struct |
| 1087 | */ |
| 1088 | ret = (personPtr) malloc(sizeof(person)); |
| 1089 | if (ret == NULL) { |
| 1090 | fprintf(stderr,"out of memory\n"); |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 1091 | return(NULL); |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1092 | } |
| 1093 | memset(ret, 0, sizeof(person)); |
| 1094 | |
| 1095 | /* We don't care what the top level element name is */ |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1096 | cur = cur->xmlChildrenNode; |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1097 | while (cur != NULL) { |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1098 | if ((!strcmp(cur->name, "Person")) && (cur->ns == ns)) |
| 1099 | ret->name = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1); |
| 1100 | if ((!strcmp(cur->name, "Email")) && (cur->ns == ns)) |
| 1101 | ret->email = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1); |
| 1102 | cur = cur->next; |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1103 | } |
| 1104 | |
| 1105 | return(ret); |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 1106 | }</pre> |
| 1107 | |
| 1108 | <p>Here is a couple of things to notice:</p> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1109 | <ul> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 1110 | <li>Usually a recursive parsing style is the more convenient one, XML data |
| 1111 | being by nature subject to repetitive constructs and usualy exibit highly |
| 1112 | stuctured patterns.</li> |
| 1113 | <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>, i.e. |
| 1114 | the pointer to the global XML document and the namespace reserved to the |
| 1115 | application. Document wide information are needed for example to decode |
| 1116 | entities and it's a good coding practice to define a namespace for your |
| 1117 | application set of data and test that the element and attributes you're |
| 1118 | analyzing actually pertains to your application space. This is done by a |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1119 | simple equality test (cur->ns == ns).</li> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 1120 | <li>To retrieve text and attributes value, it is suggested to use the |
| 1121 | function <em>xmlNodeListGetString</em> to gather all the text and entity |
| 1122 | reference nodes generated by the DOM output and produce an single text |
| 1123 | string.</li> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1124 | </ul> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 1125 | |
| 1126 | <p>Here is another piece of code used to parse another level of the |
| 1127 | structure:</p> |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1128 | <pre>#include <libxml/tree.h> |
Daniel Veillard | 361d845 | 2000-04-03 19:48:13 +0000 | [diff] [blame] | 1129 | /* |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1130 | * a Description for a Job |
| 1131 | */ |
| 1132 | typedef struct job { |
| 1133 | char *projectID; |
| 1134 | char *application; |
| 1135 | char *category; |
| 1136 | personPtr contact; |
| 1137 | int nbDevelopers; |
| 1138 | personPtr developers[100]; /* using dynamic alloc is left as an exercise */ |
| 1139 | } job, *jobPtr; |
| 1140 | |
| 1141 | /* |
| 1142 | * And the code needed to parse it |
| 1143 | */ |
| 1144 | jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) { |
| 1145 | jobPtr ret = NULL; |
| 1146 | |
| 1147 | DEBUG("parseJob\n"); |
| 1148 | /* |
| 1149 | * allocate the struct |
| 1150 | */ |
| 1151 | ret = (jobPtr) malloc(sizeof(job)); |
| 1152 | if (ret == NULL) { |
| 1153 | fprintf(stderr,"out of memory\n"); |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 1154 | return(NULL); |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1155 | } |
| 1156 | memset(ret, 0, sizeof(job)); |
| 1157 | |
| 1158 | /* We don't care what the top level element name is */ |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1159 | cur = cur->xmlChildrenNode; |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1160 | while (cur != NULL) { |
| 1161 | |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1162 | if ((!strcmp(cur->name, "Project")) && (cur->ns == ns)) { |
| 1163 | ret->projectID = xmlGetProp(cur, "ID"); |
| 1164 | if (ret->projectID == NULL) { |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 1165 | fprintf(stderr, "Project has no ID\n"); |
| 1166 | } |
| 1167 | } |
Daniel Veillard | 60979bd | 2000-07-10 12:17:33 +0000 | [diff] [blame] | 1168 | if ((!strcmp(cur->name, "Application")) && (cur->ns == ns)) |
| 1169 | ret->application = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1); |
| 1170 | if ((!strcmp(cur->name, "Category")) && (cur->ns == ns)) |
| 1171 | ret->category = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1); |
| 1172 | if ((!strcmp(cur->name, "Contact")) && (cur->ns == ns)) |
| 1173 | ret->contact = parsePerson(doc, ns, cur); |
| 1174 | cur = cur->next; |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1175 | } |
| 1176 | |
| 1177 | return(ret); |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 1178 | }</pre> |
Daniel Veillard | 14fff06 | 1999-06-22 21:49:07 +0000 | [diff] [blame] | 1179 | |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 1180 | <p>One can notice that once used to it, writing this kind of code is quite |
| 1181 | simple, but boring. Ultimately, it could be possble to write stubbers taking |
| 1182 | either C data structure definitions, a set of XML examples or an XML DTD and |
| 1183 | produce the code needed to import and export the content between C data and |
| 1184 | XML storage. This is left as an exercise to the reader :-)</p> |
| 1185 | |
Daniel Veillard | 6f0adb5 | 2000-07-03 11:41:26 +0000 | [diff] [blame] | 1186 | <p>Feel free to use <a href="example/gjobread.c">the code for the full C |
| 1187 | parsing example</a> as a template, it is also available with Makefile in the |
| 1188 | Gnome CVS base under gnome-xml/example</p> |
Daniel Veillard | b05deb7 | 1999-08-10 19:04:08 +0000 | [diff] [blame] | 1189 | |
Daniel Veillard | c310d56 | 2000-06-23 18:32:15 +0000 | [diff] [blame] | 1190 | <h2><a name="Contributi">Contributions</a></h2> |
| 1191 | <ul> |
| 1192 | <li><a href="mailto:ari@btigate.com">Ari Johnson</a> provides a C++ wrapper |
| 1193 | for libxml: |
| 1194 | <p>Website: <a |
| 1195 | href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p> |
| 1196 | <p>Download: <a |
| 1197 | href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p> |
| 1198 | </li> |
| 1199 | <li><a href="mailto:doolin@cs.utk.edu">David Doolin</a> provides a |
| 1200 | precompiled Windows version |
| 1201 | <p><a |
| 1202 | href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p> |
| 1203 | </li> |
Daniel Veillard | 3f6f7f6 | 2000-06-30 17:58:25 +0000 | [diff] [blame] | 1204 | <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> provided <a |
| 1205 | href="libxml-doc.el">an emacs module</a> to lookup libxml functions |
| 1206 | documentation</li> |
Daniel Veillard | c310d56 | 2000-06-23 18:32:15 +0000 | [diff] [blame] | 1207 | <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a |
| 1208 | href="http://xmlsoft.org/messages/0488.html">man pages</a> (not yet |
| 1209 | integrated in the distribution)</li> |
| 1210 | </ul> |
| 1211 | |
Daniel Veillard | c8eab3a | 1999-09-04 18:27:23 +0000 | [diff] [blame] | 1212 | <p></p> |
| 1213 | |
| 1214 | <p><a href="mailto:Daniel.Veillard@w3.org">Daniel Veillard</a></p> |
| 1215 | |
Daniel Veillard | 94e9060 | 2000-07-17 14:38:19 +0000 | [diff] [blame] | 1216 | <p>$Id: xml.html,v 1.42 2000/07/14 12:12:59 veillard Exp $</p> |
Daniel Veillard | ccb0963 | 1998-10-27 06:21:04 +0000 | [diff] [blame] | 1217 | </body> |
| 1218 | </html> |