Gitiles
Code Review Sign In
gerrit-public.fairphone.software / platform / external / libxml2 / 024f19966eafc5943d32f212894b1e73cf06e2ea / . / doc / python.html
blob: 44e3d0977ce3961c5a47f981fb5b07ac282fb691 [file] [log] [blame]
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]1<?xml version="1.0" encoding="ISO-8859-1"?>
2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
3<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" /><link rel="SHORTCUT ICON" href="/favicon.ico" /><style type="text/css">
Daniel Veillard373a4752002-02-21 14:46:29 +0000[diff] [blame]4TD {font-family: Verdana,Arial,Helvetica}
5BODY {font-family: Verdana,Arial,Helvetica; margin-top: 2em; margin-left: 0em; margin-right: 0em}
6H1 {font-family: Verdana,Arial,Helvetica}
7H2 {font-family: Verdana,Arial,Helvetica}
8H3 {font-family: Verdana,Arial,Helvetica}
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]9A:link, A:visited, A:active { text-decoration: underline }
Daniel Veillarde8ba84e2003-11-18 13:54:15 +0000[diff] [blame]10</style><title>Python and bindings</title></head><body bgcolor="#8b7765" text="#000000" link="#000000" vlink="#000000"><table border="0" width="100%" cellpadding="5" cellspacing="0" align="center"><tr><td width="120"><a href="http://swpat.ffii.org/"><img src="epatents.png" alt="Action against software patents" /></a></td><td width="180"><a href="http://www.gnome.org/"><img src="gnome2.png" alt="Gnome2 Logo" /></a><a href="http://www.w3.org/Status"><img src="w3c.png" alt="W3C Logo" /></a><a href="http://www.redhat.com/"><img src="redhat.gif" alt="Red Hat Logo" /></a><div align="left"><a href="http://xmlsoft.org/"><img src="Libxml2-Logo-180x168.gif" alt="Made with Libxml2 Logo" /></a></div></td><td><table border="0" width="90%" cellpadding="2" cellspacing="0" align="center" bgcolor="#000000"><tr><td><table width="100%" border="0" cellspacing="1" cellpadding="3" bgcolor="#fffacd"><tr><td align="center"><h1>The XML C parser and toolkit of Gnome</h1><h2>Python and bindings</h2></td></tr></table></td></tr></table></td></tr></table><table border="0" cellpadding="4" cellspacing="0" width="100%" align="center"><tr><td bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td valign="top" width="200" bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="1" width="100%" bgcolor="#000000"><tr><td><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>Developer Menu</b></center></td></tr><tr><td bgcolor="#fffacd"><form action="search.php" enctype="application/x-www-form-urlencoded" method="get"><input name="query" type="text" size="20" value="" /><input name="submit" type="submit" value="Search ..." /></form><ul><li><a href="index.html" style="font-weight:bold">Main Menu</a></li><li><a href="examples/index.html" style="font-weight:bold">Code Examples</a></li><li><a href="guidelines.html">XML Guidelines</a></li><li><a href="tutorial/index.html">Tutorial</a></li><li><a href="xmlreader.html">The Reader Interface</a></li><li><a href="XSLT.html">XSLT</a></li><li><a href="python.html">Python and bindings</a></li><li><a href="architecture.html">libxml2 architecture</a></li><li><a href="tree.html">The tree output</a></li><li><a href="interface.html">The SAX interface</a></li><li><a href="xmlmem.html">Memory Management</a></li><li><a href="xmlio.html">I/O Interfaces</a></li><li><a href="library.html">The parser interfaces</a></li><li><a href="entities.html">Entities or no entities</a></li><li><a href="namespaces.html">Namespaces</a></li><li><a href="upgrade.html">Upgrading 1.x code</a></li><li><a href="threads.html">Thread safety</a></li><li><a href="DOM.html">DOM Principles</a></li><li><a href="example.html">A real example</a></li><li><a href="xml.html">flat page</a>, <a href="site.xsl">stylesheet</a></li></ul></td></tr></table><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>API Indexes</b></center></td></tr><tr><td bgcolor="#fffacd"><ul><li><a href="APIchunk0.html">Alphabetic</a></li><li><a href="APIconstructors.html">Constructors</a></li><li><a href="APIfunctions.html">Functions/Types</a></li><li><a href="APIfiles.html">Modules</a></li><li><a href="APIsymbols.html">Symbols</a></li></ul></td></tr></table><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>Related links</b></center></td></tr><tr><td bgcolor="#fffacd"><ul><li><a href="http://mail.gnome.org/archives/xml/">Mail archive</a></li><li><a href="http://xmlsoft.org/XSLT/">XSLT libxslt</a></li><li><a href="http://phd.cs.unibo.it/gdome2/">DOM gdome2</a></li><li><a href="http://www.aleksey.com/xmlsec/">XML-DSig xmlsec</a></li><li><a href="ftp://xmlsoft.org/">FTP</a></li><li><a href="http://www.zlatkovic.com/projects/libxml/">Windows binaries</a></li><li><a href="http://garypennington.net/libxml2/">Solaris binaries</a></li><li><a href="http://www.zveno.com/open_source/libxml2xslt.html">MacOsX binaries</a></li><li><a href="http://sourceforge.net/projects/libxml2-pas/">Pascal bindings</a></li><li><a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml2">Bug Tracker</a></li></ul></td></tr></table></td></tr></table></td><td valign="top" bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="1" width="100%"><tr><td><table border="0" cellspacing="0" cellpadding="1" width="100%" bgcolor="#000000"><tr><td><table border="0" cellpadding="3" cellspacing="1" width="100%"><tr><td bgcolor="#fffacd"><p>There are a number of language bindings and wrappers available for
Daniel Veillard42766c02002-08-22 20:52:17 +0000[diff] [blame]11libxml2, the list below is not exhaustive. Please contact the <a href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a>
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]12(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in
13order to get updates to this list or to discuss the specific topic of libxml2
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]14or libxslt wrappers or bindings:</p><ul><li><a href="http://libxmlplusplus.sourceforge.net/">Libxml++</a> seems the
Daniel Veillardc14401e2002-11-20 14:28:17 +0000[diff] [blame]15 most up-to-date C++ bindings for libxml2, check the <a href="http://libxmlplusplus.sourceforge.net/reference/html/hierarchy.html">documentation</a>
16 and the <a href="http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/libxmlplusplus/libxml%2b%2b/examples/">examples</a>.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]17 <li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper
18 based on the gdome2 bindings</a> maintained by Tobias Peters.</li>
19 <li>and a third C++ wrapper by Peter Jones &lt;pjones@pmade.org&gt;
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]20 <p>Website: <a href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]21 </li>
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]22 <li><a href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]23 Sergeant</a> developed <a href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]24 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]25 application server</a>.</li>
Daniel Veillard4ac494b2003-09-18 15:08:00 +0000[diff] [blame]26 <li>If you're interested into scripting XML processing, have a look at <a href="http://xsh.sourceforge.net/">XSH</a> an XML editing shell based on
27 Libxml2 Perl bindings.</li>
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]28 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides an
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]29 earlier version of the libxml/libxslt <a href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li>
30 <li>Gopal.V and Peter Minten develop <a href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of
31 C# libxml2 bindings.</li>
32 <li>Petr Kozelka provides <a href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
33 libxml2</a> with Kylix, Delphi and other Pascal compilers.</li>
34 <li>Uwe Fechner also provides <a href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2
35 implementation for Kylix2/D5/D6 from Borland.</li>
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]36 <li>Wai-Sun "Squidster" Chia provides <a href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]37 libxml2 bindings are also available in Ruby through the <a href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module
38 maintained by Tobias Peters.</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]39 <li>Steve Ball and contributors maintains <a href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for
40 Tcl</a>.</li>
41 <li>There is support for libxml2 in the DOM module of PHP.</li>
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]42 <li><a href="http://savannah.gnu.org/projects/classpathx/">LibxmlJ</a> is
Daniel Veillard806cada2003-03-19 21:58:59 +0000[diff] [blame]43 an effort to create a 100% JAXP-compatible Java wrapper for libxml2 and
44 libxslt as part of GNU ClasspathX project.</li>
Daniel Veillard6d373a22003-11-04 10:26:43 +0000[diff] [blame]45 <li>Patrick McPhee provides Rexx bindings fof libxml2 and libxslt, look for
46 <a href="http://www.interlog.com/~ptjm/software.html">RexxXML</a>.</li>
47</ul><p>The distribution includes a set of Python bindings, which are guaranteed
Daniel Veillardc0801af2002-05-28 16:28:42 +0000[diff] [blame]48to be maintained as part of the library in the future, though the Python
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]49interface have not yet reached the completeness of the C API.</p><p><a href="mailto:stephane.bidoul@softwareag.com">Stéphane Bidoul</a>
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000[diff] [blame]50maintains <a href="http://users.skynet.be/sbi/libxml-python/">a Windows port
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]51of the Python bindings</a>.</p><p>Note to people interested in building bindings, the API is formalized as
Daniel Veillard7ef0fcb2002-12-14 10:38:55 +0000[diff] [blame]52<a href="libxml2-api.xml">an XML API description file</a> which allows to
53automate a large part of the Python bindings, this includes function
Daniel Veillard7b4b2f92003-01-06 13:11:20 +0000[diff] [blame]54descriptions, enums, structures, typedefs, etc... The Python script used to
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]55build the bindings is python/generator.py in the source distribution.</p><p>To install the Python bindings there are 2 options:</p><ul><li>If you use an RPM based distribution, simply install the <a href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]56 RPM</a> (and if needed the <a href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python
57 RPM</a>).</li>
Daniel Veillard0b28e882002-07-24 23:47:05 +0000[diff] [blame]58 <li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]59 module distribution</a> corresponding to your installed version of
60 libxml2 and libxslt. Note that to install it you will need both libxml2
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]61 and libxslt installed and run "python setup.py build install" in the
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]62 module tree.</li>
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]63</ul><p>The distribution includes a set of examples and regression tests for the
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]64python bindings in the <code>python/tests</code> directory. Here are some
MST 2003 John Fleck2dffb762003-11-29 04:41:24 +0000[diff] [blame]65excerpts from those tests:</p><h3>tst.py:</h3><p>This is a basic test of the file interface and DOM navigation:</p><pre>import libxml2, sys
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]66
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]67doc = libxml2.parseFile("tst.xml")
68if doc.name != "tst.xml":
69 print "doc.name failed"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]70 sys.exit(1)
71root = doc.children
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]72if root.name != "doc":
73 print "root.name failed"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]74 sys.exit(1)
75child = root.children
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]76if child.name != "foo":
77 print "child.name failed"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]78 sys.exit(1)
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]79doc.freeDoc()</pre><p>The Python module is called libxml2; parseFile is the equivalent of
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]80xmlParseFile (most of the bindings are automatically generated, and the xml
81prefix is removed and the casing convention are kept). All node seen at the
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]82binding level share the same subset of accessors:</p><ul><li><code>name</code> : returns the node name</li>
83 <li><code>type</code> : returns a string indicating the node type</li>
84 <li><code>content</code> : returns the content of the node, it is based on
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]85 xmlNodeGetContent() and hence is recursive.</li>
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]86 <li><code>parent</code> , <code>children</code>, <code>last</code>,
Daniel Veillardaf43f632002-03-08 15:05:20 +0000[diff] [blame]87 <code>next</code>, <code>prev</code>, <code>doc</code>,
88 <code>properties</code>: pointing to the associated element in the tree,
89 those may return None in case no such link exists.</li>
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]90</ul><p>Also note the need to explicitly deallocate documents with freeDoc() .
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]91Reference counting for libxml2 trees would need quite a lot of work to
92function properly, and rather than risk memory leaks if not implemented
93correctly it sounds safer to have an explicit function to free a tree. The
94wrapper python objects like doc, root or child are them automatically garbage
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]95collected.</p><h3>validate.py:</h3><p>This test check the validation interfaces and redirection of error
96messages:</p><pre>import libxml2
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]97
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]98#deactivate error messages from the validation
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]99def noerr(ctx, str):
100 pass
101
102libxml2.registerErrorHandler(noerr, None)
103
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]104ctxt = libxml2.createFileParserCtxt("invalid.xml")
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]105ctxt.validate(1)
106ctxt.parseDocument()
107doc = ctxt.doc()
108valid = ctxt.isValid()
109doc.freeDoc()
110if valid != 0:
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]111 print "validity check failed"</pre><p>The first thing to notice is the call to registerErrorHandler(), it
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]112defines a new error handler global to the library. It is used to avoid seeing
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]113the error messages when trying to validate the invalid document.</p><p>The main interest of that test is the creation of a parser context with
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]114createFileParserCtxt() and how the behaviour can be changed before calling
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]115parseDocument() . Similarly the informations resulting from the parsing phase
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]116are also available using context methods.</p><p>Contexts like nodes are defined as class and the libxml2 wrappers maps the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]117C function interfaces in terms of objects method as much as possible. The
118best to get a complete view of what methods are supported is to look at the
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]119libxml2.py module containing all the wrappers.</p><h3>push.py:</h3><p>This test show how to activate the push parser interface:</p><pre>import libxml2
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]120
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]121ctxt = libxml2.createPushParser(None, "&lt;foo", 4, "test.xml")
122ctxt.parseChunk("/&gt;", 2, 1)
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]123doc = ctxt.doc()
124
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]125doc.freeDoc()</pre><p>The context is created with a special call based on the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]126xmlCreatePushParser() from the C library. The first argument is an optional
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]127SAX callback object, then the initial set of data, the length and the name of
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]128the resource in case URI-References need to be computed by the parser.</p><p>Then the data are pushed using the parseChunk() method, the last call
129setting the third argument terminate to 1.</p><h3>pushSAX.py:</h3><p>this test show the use of the event based parsing interfaces. In this case
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]130the parser does not build a document, but provides callback information as
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]131the parser makes progresses analyzing the data being provided:</p><pre>import libxml2
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]132log = ""
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]133
134class callback:
135 def startDocument(self):
136 global log
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]137 log = log + "startDocument:"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]138
139 def endDocument(self):
140 global log
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]141 log = log + "endDocument:"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]142
143 def startElement(self, tag, attrs):
144 global log
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]145 log = log + "startElement %s %s:" % (tag, attrs)
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]146
147 def endElement(self, tag):
148 global log
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]149 log = log + "endElement %s:" % (tag)
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]150
151 def characters(self, data):
152 global log
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]153 log = log + "characters: %s:" % (data)
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]154
155 def warning(self, msg):
156 global log
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]157 log = log + "warning: %s:" % (msg)
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]158
159 def error(self, msg):
160 global log
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]161 log = log + "error: %s:" % (msg)
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]162
163 def fatalError(self, msg):
164 global log
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]165 log = log + "fatalError: %s:" % (msg)
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]166
167handler = callback()
168
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]169ctxt = libxml2.createPushParser(handler, "&lt;foo", 4, "test.xml")
170chunk = " url='tst'&gt;b"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]171ctxt.parseChunk(chunk, len(chunk), 0)
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]172chunk = "ar&lt;/foo&gt;"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]173ctxt.parseChunk(chunk, len(chunk), 1)
174
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]175reference = "startDocument:startElement foo {'url': 'tst'}:" + \
176 "characters: bar:endElement foo:endDocument:"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]177if log != reference:
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]178 print "Error got: %s" % log
179 print "Expected: %s" % reference</pre><p>The key object in that test is the handler, it provides a number of entry
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]180points which can be called by the parser as it makes progresses to indicate
181the information set obtained. The full set of callback is larger than what
182the callback class in that specific example implements (see the SAX
183definition for a complete list). The wrapper will only call those supplied by
184the object when activated. The startElement receives the names of the element
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]185and a dictionary containing the attributes carried by this element.</p><p>Also note that the reference string generated from the callback shows a
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]186single character call even though the string "bar" is passed to the parser
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]187from 2 different call to parseChunk()</p><h3>xpath.py:</h3><p>This is a basic test of XPath wrappers support</p><pre>import libxml2
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]188
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]189doc = libxml2.parseFile("tst.xml")
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]190ctxt = doc.xpathNewContext()
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]191res = ctxt.xpathEval("//*")
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]192if len(res) != 2:
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]193 print "xpath query: wrong node set size"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]194 sys.exit(1)
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]195if res[0].name != "doc" or res[1].name != "foo":
196 print "xpath query: wrong node set value"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]197 sys.exit(1)
198doc.freeDoc()
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]199ctxt.xpathFreeContext()</pre><p>This test parses a file, then create an XPath context to evaluate XPath
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]200expression on it. The xpathEval() method execute an XPath query and returns
201the result mapped in a Python way. String and numbers are natively converted,
202and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]203the document, the XPath context need to be freed explicitly, also not that
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]204the result of the XPath query may point back to the document tree and hence
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]205the document must be freed after the result of the query is used.</p><h3>xpathext.py:</h3><p>This test shows how to extend the XPath engine with functions written in
206python:</p><pre>import libxml2
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]207
208def foo(ctx, x):
209 return x + 1
210
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]211doc = libxml2.parseFile("tst.xml")
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]212ctxt = doc.xpathNewContext()
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]213libxml2.registerXPathFunction(ctxt._o, "foo", None, foo)
214res = ctxt.xpathEval("foo(1)")
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]215if res != 2:
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]216 print "xpath extension failure"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]217doc.freeDoc()
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]218ctxt.xpathFreeContext()</pre><p>Note how the extension function is registered with the context (but that
219part is not yet finalized, this may change slightly in the future).</p><h3>tstxpath.py:</h3><p>This test is similar to the previous one but shows how the extension
220function can access the XPath evaluation context:</p><pre>def foo(ctx, x):
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]221 global called
222
223 #
224 # test that access to the XPath evaluation contexts
225 #
226 pctxt = libxml2.xpathParserContext(_obj=ctx)
227 ctxt = pctxt.context()
228 called = ctxt.function()
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]229 return x + 1</pre><p>All the interfaces around the XPath parser(or rather evaluation) context
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]230are not finalized, but it should be sufficient to do contextual work at the
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]231evaluation point.</p><h3>Memory debugging:</h3><p>last but not least, all tests starts with the following prologue:</p><pre>#memory debug specific
232libxml2.debugMemory(1)</pre><p>and ends with the following epilogue:</p><pre>#memory debug specific
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]233libxml2.cleanupParser()
234if libxml2.debugMemory(1) == 0:
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]235 print "OK"
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]236else:
Daniel Veillard024f1992003-12-10 16:43:49 +0000[diff] [blame^]237 print "Memory leak %d bytes" % (libxml2.debugMemory(1))
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]238 libxml2.dumpMemory()</pre><p>Those activate the memory debugging interface of libxml2 where all
Daniel Veillard63d83142002-05-20 06:51:05 +0000[diff] [blame]239allocated block in the library are tracked. The prologue then cleans up the
Daniel Veillard6dbcaf82002-02-20 14:37:47 +0000[diff] [blame]240library state and checks that all allocated memory has been freed. If not it
Daniel Veillard1177ca42003-04-26 22:29:54 +0000[diff] [blame]241calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p><p><a href="bugs.html">Daniel Veillard</a></p></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></body></html>