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| 14 | <title>Python and bindings</title> |
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Daniel Veillard | 8f40f1e | 2002-08-28 21:18:45 +0000 | [diff] [blame] | 19 | <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> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 20 | </td> |
| 21 | <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"> |
| 22 | <h1>The XML C library for Gnome</h1> |
| 23 | <h2>Python and bindings</h2> |
| 24 | </td></tr></table></td></tr></table></td> |
| 25 | </tr></table> |
| 26 | <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> |
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| 28 | <table width="100%" border="0" cellspacing="1" cellpadding="3"> |
| 29 | <tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>Main Menu</b></center></td></tr> |
| 30 | <tr><td bgcolor="#fffacd"><ul> |
| 31 | <li><a href="index.html">Home</a></li> |
| 32 | <li><a href="intro.html">Introduction</a></li> |
| 33 | <li><a href="FAQ.html">FAQ</a></li> |
| 34 | <li><a href="docs.html">Documentation</a></li> |
| 35 | <li><a href="bugs.html">Reporting bugs and getting help</a></li> |
| 36 | <li><a href="help.html">How to help</a></li> |
| 37 | <li><a href="downloads.html">Downloads</a></li> |
| 38 | <li><a href="news.html">News</a></li> |
| 39 | <li><a href="XMLinfo.html">XML</a></li> |
| 40 | <li><a href="XSLT.html">XSLT</a></li> |
| 41 | <li><a href="python.html">Python and bindings</a></li> |
| 42 | <li><a href="architecture.html">libxml architecture</a></li> |
| 43 | <li><a href="tree.html">The tree output</a></li> |
| 44 | <li><a href="interface.html">The SAX interface</a></li> |
| 45 | <li><a href="xmldtd.html">Validation & DTDs</a></li> |
| 46 | <li><a href="xmlmem.html">Memory Management</a></li> |
| 47 | <li><a href="encoding.html">Encodings support</a></li> |
| 48 | <li><a href="xmlio.html">I/O Interfaces</a></li> |
| 49 | <li><a href="catalog.html">Catalog support</a></li> |
| 50 | <li><a href="library.html">The parser interfaces</a></li> |
| 51 | <li><a href="entities.html">Entities or no entities</a></li> |
| 52 | <li><a href="namespaces.html">Namespaces</a></li> |
| 53 | <li><a href="upgrade.html">Upgrading 1.x code</a></li> |
| 54 | <li><a href="threads.html">Thread safety</a></li> |
| 55 | <li><a href="DOM.html">DOM Principles</a></li> |
| 56 | <li><a href="example.html">A real example</a></li> |
| 57 | <li><a href="contribs.html">Contributions</a></li> |
Daniel Veillard | fc59c09 | 2002-06-05 14:48:26 +0000 | [diff] [blame] | 58 | <li><a href="tutorial/index.html">Tutorial</a></li> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 59 | <li> |
| 60 | <a href="xml.html">flat page</a>, <a href="site.xsl">stylesheet</a> |
| 61 | </li> |
| 62 | </ul></td></tr> |
| 63 | </table> |
| 64 | <table width="100%" border="0" cellspacing="1" cellpadding="3"> |
| 65 | <tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>API Indexes</b></center></td></tr> |
Daniel Veillard | 5ede35e | 2002-10-01 11:37:35 +0000 | [diff] [blame] | 66 | <tr><td bgcolor="#fffacd"> |
Daniel Veillard | 595978c | 2002-10-09 18:46:35 +0000 | [diff] [blame] | 67 | <form action="search.php" enctype="application/x-www-form-urlencoded" method="GET"> |
Daniel Veillard | 5ede35e | 2002-10-01 11:37:35 +0000 | [diff] [blame] | 68 | <input name="query" type="TEXT" size="20" value=""><input name="submit" type="submit" value="Search ..."> |
| 69 | </form> |
| 70 | <ul> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 71 | <li><a href="APIchunk0.html">Alphabetic</a></li> |
| 72 | <li><a href="APIconstructors.html">Constructors</a></li> |
| 73 | <li><a href="APIfunctions.html">Functions/Types</a></li> |
| 74 | <li><a href="APIfiles.html">Modules</a></li> |
| 75 | <li><a href="APIsymbols.html">Symbols</a></li> |
Daniel Veillard | 5ede35e | 2002-10-01 11:37:35 +0000 | [diff] [blame] | 76 | </ul> |
| 77 | </td></tr> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 78 | </table> |
| 79 | <table width="100%" border="0" cellspacing="1" cellpadding="3"> |
| 80 | <tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>Related links</b></center></td></tr> |
| 81 | <tr><td bgcolor="#fffacd"><ul> |
| 82 | <li><a href="http://mail.gnome.org/archives/xml/">Mail archive</a></li> |
| 83 | <li><a href="http://xmlsoft.org/XSLT/">XSLT libxslt</a></li> |
| 84 | <li><a href="http://phd.cs.unibo.it/gdome2/">DOM gdome2</a></li> |
Daniel Veillard | 2d347fa | 2002-03-17 10:34:11 +0000 | [diff] [blame] | 85 | <li><a href="http://www.aleksey.com/xmlsec/">XML-DSig xmlsec</a></li> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 86 | <li><a href="ftp://xmlsoft.org/">FTP</a></li> |
| 87 | <li><a href="http://www.fh-frankfurt.de/~igor/projects/libxml/">Windows binaries</a></li> |
| 88 | <li><a href="http://garypennington.net/libxml2/">Solaris binaries</a></li> |
Daniel Veillard | cb7543b | 2002-09-09 10:54:06 +0000 | [diff] [blame] | 89 | <li><a href="http://www.zveno.com/open_source/libxml2xslt.html">MacOsX binaries</a></li> |
Daniel Veillard | e6d8e20 | 2002-05-02 06:11:10 +0000 | [diff] [blame] | 90 | <li><a href="http://sourceforge.net/projects/libxml2-pas/">Pascal bindings</a></li> |
Daniel Veillard | 2d347fa | 2002-03-17 10:34:11 +0000 | [diff] [blame] | 91 | <li><a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml&product=libxml2">Bug Tracker</a></li> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 92 | </ul></td></tr> |
| 93 | </table> |
| 94 | </td></tr></table></td> |
| 95 | <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"> |
Daniel Veillard | 42766c0 | 2002-08-22 20:52:17 +0000 | [diff] [blame] | 96 | <p>There are a number of language bindings and wrappers available for |
| 97 | libxml2, 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 Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 98 | (<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in |
| 99 | order to get updates to this list or to discuss the specific topic of libxml2 |
| 100 | or libxslt wrappers or bindings:</p> |
| 101 | <ul> |
| 102 | <li> |
Daniel Veillard | c14401e | 2002-11-20 14:28:17 +0000 | [diff] [blame] | 103 | <a href="http://libxmlplusplus.sourceforge.net/">Libxml++</a> seems the |
| 104 | most up-to-date C++ bindings for libxml2, check the <a href="http://libxmlplusplus.sourceforge.net/reference/html/hierarchy.html">documentation</a> |
| 105 | and the <a href="http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/libxmlplusplus/libxml%2b%2b/examples/">examples</a>.</li> |
Daniel Veillard | 0b28e88 | 2002-07-24 23:47:05 +0000 | [diff] [blame] | 106 | <li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper |
| 107 | based on the gdome2 bindings</a> maintained by Tobias Peters.</li> |
| 108 | <li>and a third C++ wrapper by Peter Jones <pjones@pmade.org> |
Daniel Veillard | 9b6fd30 | 2002-05-13 12:06:47 +0000 | [diff] [blame] | 109 | <p>Website: <a href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a> |
| 110 | </p> |
Daniel Veillard | 0b28e88 | 2002-07-24 23:47:05 +0000 | [diff] [blame] | 111 | </li> |
| 112 | <li> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 113 | <a href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 114 | Sergeant</a> developed <a href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for |
Daniel Veillard | af43f63 | 2002-03-08 15:05:20 +0000 | [diff] [blame] | 115 | libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML |
Daniel Veillard | 0b28e88 | 2002-07-24 23:47:05 +0000 | [diff] [blame] | 116 | application server</a>.</li> |
| 117 | <li> |
Daniel Veillard | 2147367 | 2002-06-17 07:29:22 +0000 | [diff] [blame] | 118 | <a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides an |
Daniel Veillard | 0b28e88 | 2002-07-24 23:47:05 +0000 | [diff] [blame] | 119 | earlier version of the libxml/libxslt <a href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li> |
| 120 | <li>Gopal.V and Peter Minten develop <a href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of |
| 121 | C# libxml2 bindings.</li> |
| 122 | <li>Petr Kozelka provides <a href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue |
| 123 | libxml2</a> with Kylix, Delphi and other Pascal compilers.</li> |
| 124 | <li>Uwe Fechner also provides <a href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2 |
| 125 | implementation for Kylix2/D5/D6 from Borland.</li> |
| 126 | <li>Wai-Sun "Squidster" Chia provides <a href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 127 | libxml2 bindings are also available in Ruby through the <a href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module |
| 128 | maintained by Tobias Peters.</li> |
Daniel Veillard | 0b28e88 | 2002-07-24 23:47:05 +0000 | [diff] [blame] | 129 | <li>Steve Ball and contributors maintains <a href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for |
| 130 | Tcl</a>.</li> |
| 131 | <li>There is support for libxml2 in the DOM module of PHP.</li> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 132 | </ul> |
Daniel Veillard | c0801af | 2002-05-28 16:28:42 +0000 | [diff] [blame] | 133 | <p>The distribution includes a set of Python bindings, which are guaranteed |
| 134 | to be maintained as part of the library in the future, though the Python |
Daniel Veillard | 0b79dfe | 2002-02-23 13:02:31 +0000 | [diff] [blame] | 135 | interface have not yet reached the maturity of the C API.</p> |
Daniel Veillard | 7ef0fcb | 2002-12-14 10:38:55 +0000 | [diff] [blame] | 136 | <p>Note to people interested in building bindings, the API is formalized as |
| 137 | <a href="libxml2-api.xml">an XML API description file</a> which allows to |
| 138 | automate a large part of the Python bindings, this includes function |
| 139 | descriptions, enums, structures, typedefs, etc... The Python script used |
| 140 | to build the bindings is python/generator.py in the source distribution.</p> |
Daniel Veillard | af43f63 | 2002-03-08 15:05:20 +0000 | [diff] [blame] | 141 | <p>To install the Python bindings there are 2 options:</p> |
Daniel Veillard | 0b79dfe | 2002-02-23 13:02:31 +0000 | [diff] [blame] | 142 | <ul> |
Daniel Veillard | af43f63 | 2002-03-08 15:05:20 +0000 | [diff] [blame] | 143 | <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 |
| 144 | RPM</a> (and if needed the <a href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python |
| 145 | RPM</a>).</li> |
Daniel Veillard | 0b28e88 | 2002-07-24 23:47:05 +0000 | [diff] [blame] | 146 | <li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python |
Daniel Veillard | af43f63 | 2002-03-08 15:05:20 +0000 | [diff] [blame] | 147 | module distribution</a> corresponding to your installed version of |
| 148 | libxml2 and libxslt. Note that to install it you will need both libxml2 |
| 149 | and libxslt installed and run "python setup.py build install" in the |
| 150 | module tree.</li> |
Daniel Veillard | 0b79dfe | 2002-02-23 13:02:31 +0000 | [diff] [blame] | 151 | </ul> |
Daniel Veillard | af43f63 | 2002-03-08 15:05:20 +0000 | [diff] [blame] | 152 | <p>The distribution includes a set of examples and regression tests for the |
| 153 | python bindings in the <code>python/tests</code> directory. Here are some |
Daniel Veillard | 0b28e88 | 2002-07-24 23:47:05 +0000 | [diff] [blame] | 154 | excerpts from those tests:</p> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 155 | <h3>tst.py:</h3> |
| 156 | <p>This is a basic test of the file interface and DOM navigation:</p> |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 157 | <pre>import libxml2 |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 158 | |
| 159 | doc = libxml2.parseFile("tst.xml") |
| 160 | if doc.name != "tst.xml": |
| 161 | print "doc.name failed" |
| 162 | sys.exit(1) |
| 163 | root = doc.children |
| 164 | if root.name != "doc": |
| 165 | print "root.name failed" |
| 166 | sys.exit(1) |
| 167 | child = root.children |
| 168 | if child.name != "foo": |
| 169 | print "child.name failed" |
| 170 | sys.exit(1) |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 171 | doc.freeDoc()</pre> |
Daniel Veillard | 0b28e88 | 2002-07-24 23:47:05 +0000 | [diff] [blame] | 172 | <p>The Python module is called libxml2; parseFile is the equivalent of |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 173 | xmlParseFile (most of the bindings are automatically generated, and the xml |
| 174 | prefix is removed and the casing convention are kept). All node seen at the |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 175 | binding level share the same subset of accessors:</p> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 176 | <ul> |
| 177 | <li> |
Daniel Veillard | af43f63 | 2002-03-08 15:05:20 +0000 | [diff] [blame] | 178 | <code>name</code> : returns the node name</li> |
Daniel Veillard | 0b28e88 | 2002-07-24 23:47:05 +0000 | [diff] [blame] | 179 | <li> |
Daniel Veillard | c0801af | 2002-05-28 16:28:42 +0000 | [diff] [blame] | 180 | <code>type</code> : returns a string indicating the node type</li> |
Daniel Veillard | 0b28e88 | 2002-07-24 23:47:05 +0000 | [diff] [blame] | 181 | <li> |
Daniel Veillard | af43f63 | 2002-03-08 15:05:20 +0000 | [diff] [blame] | 182 | <code>content</code> : returns the content of the node, it is based on |
| 183 | xmlNodeGetContent() and hence is recursive.</li> |
Daniel Veillard | 0b28e88 | 2002-07-24 23:47:05 +0000 | [diff] [blame] | 184 | <li> |
Daniel Veillard | af43f63 | 2002-03-08 15:05:20 +0000 | [diff] [blame] | 185 | <code>parent</code> , <code>children</code>, <code>last</code>, |
| 186 | <code>next</code>, <code>prev</code>, <code>doc</code>, |
| 187 | <code>properties</code>: pointing to the associated element in the tree, |
| 188 | those may return None in case no such link exists.</li> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 189 | </ul> |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 190 | <p>Also note the need to explicitly deallocate documents with freeDoc() . |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 191 | Reference counting for libxml2 trees would need quite a lot of work to |
| 192 | function properly, and rather than risk memory leaks if not implemented |
| 193 | correctly it sounds safer to have an explicit function to free a tree. The |
| 194 | wrapper python objects like doc, root or child are them automatically garbage |
| 195 | collected.</p> |
| 196 | <h3>validate.py:</h3> |
| 197 | <p>This test check the validation interfaces and redirection of error |
| 198 | messages:</p> |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 199 | <pre>import libxml2 |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 200 | |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 201 | #deactivate error messages from the validation |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 202 | def noerr(ctx, str): |
| 203 | pass |
| 204 | |
| 205 | libxml2.registerErrorHandler(noerr, None) |
| 206 | |
| 207 | ctxt = libxml2.createFileParserCtxt("invalid.xml") |
| 208 | ctxt.validate(1) |
| 209 | ctxt.parseDocument() |
| 210 | doc = ctxt.doc() |
| 211 | valid = ctxt.isValid() |
| 212 | doc.freeDoc() |
| 213 | if valid != 0: |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 214 | print "validity check failed"</pre> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 215 | <p>The first thing to notice is the call to registerErrorHandler(), it |
| 216 | defines a new error handler global to the library. It is used to avoid seeing |
| 217 | the error messages when trying to validate the invalid document.</p> |
| 218 | <p>The main interest of that test is the creation of a parser context with |
| 219 | createFileParserCtxt() and how the behaviour can be changed before calling |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 220 | parseDocument() . Similarly the informations resulting from the parsing phase |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 221 | are also available using context methods.</p> |
| 222 | <p>Contexts like nodes are defined as class and the libxml2 wrappers maps the |
| 223 | C function interfaces in terms of objects method as much as possible. The |
| 224 | best to get a complete view of what methods are supported is to look at the |
| 225 | libxml2.py module containing all the wrappers.</p> |
| 226 | <h3>push.py:</h3> |
| 227 | <p>This test show how to activate the push parser interface:</p> |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 228 | <pre>import libxml2 |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 229 | |
| 230 | ctxt = libxml2.createPushParser(None, "<foo", 4, "test.xml") |
| 231 | ctxt.parseChunk("/>", 2, 1) |
| 232 | doc = ctxt.doc() |
| 233 | |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 234 | doc.freeDoc()</pre> |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 235 | <p>The context is created with a special call based on the |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 236 | xmlCreatePushParser() from the C library. The first argument is an optional |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 237 | SAX callback object, then the initial set of data, the length and the name of |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 238 | the resource in case URI-References need to be computed by the parser.</p> |
| 239 | <p>Then the data are pushed using the parseChunk() method, the last call |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 240 | setting the third argument terminate to 1.</p> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 241 | <h3>pushSAX.py:</h3> |
| 242 | <p>this test show the use of the event based parsing interfaces. In this case |
| 243 | the parser does not build a document, but provides callback information as |
| 244 | the parser makes progresses analyzing the data being provided:</p> |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 245 | <pre>import libxml2 |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 246 | log = "" |
| 247 | |
| 248 | class callback: |
| 249 | def startDocument(self): |
| 250 | global log |
| 251 | log = log + "startDocument:" |
| 252 | |
| 253 | def endDocument(self): |
| 254 | global log |
| 255 | log = log + "endDocument:" |
| 256 | |
| 257 | def startElement(self, tag, attrs): |
| 258 | global log |
| 259 | log = log + "startElement %s %s:" % (tag, attrs) |
| 260 | |
| 261 | def endElement(self, tag): |
| 262 | global log |
| 263 | log = log + "endElement %s:" % (tag) |
| 264 | |
| 265 | def characters(self, data): |
| 266 | global log |
| 267 | log = log + "characters: %s:" % (data) |
| 268 | |
| 269 | def warning(self, msg): |
| 270 | global log |
| 271 | log = log + "warning: %s:" % (msg) |
| 272 | |
| 273 | def error(self, msg): |
| 274 | global log |
| 275 | log = log + "error: %s:" % (msg) |
| 276 | |
| 277 | def fatalError(self, msg): |
| 278 | global log |
| 279 | log = log + "fatalError: %s:" % (msg) |
| 280 | |
| 281 | handler = callback() |
| 282 | |
| 283 | ctxt = libxml2.createPushParser(handler, "<foo", 4, "test.xml") |
| 284 | chunk = " url='tst'>b" |
| 285 | ctxt.parseChunk(chunk, len(chunk), 0) |
| 286 | chunk = "ar</foo>" |
| 287 | ctxt.parseChunk(chunk, len(chunk), 1) |
| 288 | |
Daniel Veillard | fcbfa2d | 2002-02-21 17:54:27 +0000 | [diff] [blame] | 289 | reference = "startDocument:startElement foo {'url': 'tst'}:" + \ |
| 290 | "characters: bar:endElement foo:endDocument:" |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 291 | if log != reference: |
| 292 | print "Error got: %s" % log |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 293 | print "Expected: %s" % reference</pre> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 294 | <p>The key object in that test is the handler, it provides a number of entry |
| 295 | points which can be called by the parser as it makes progresses to indicate |
| 296 | the information set obtained. The full set of callback is larger than what |
| 297 | the callback class in that specific example implements (see the SAX |
| 298 | definition for a complete list). The wrapper will only call those supplied by |
| 299 | the object when activated. The startElement receives the names of the element |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 300 | and a dictionary containing the attributes carried by this element.</p> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 301 | <p>Also note that the reference string generated from the callback shows a |
| 302 | single character call even though the string "bar" is passed to the parser |
| 303 | from 2 different call to parseChunk()</p> |
| 304 | <h3>xpath.py:</h3> |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 305 | <p>This is a basic test of XPath wrappers support</p> |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 306 | <pre>import libxml2 |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 307 | |
| 308 | doc = libxml2.parseFile("tst.xml") |
| 309 | ctxt = doc.xpathNewContext() |
| 310 | res = ctxt.xpathEval("//*") |
| 311 | if len(res) != 2: |
| 312 | print "xpath query: wrong node set size" |
| 313 | sys.exit(1) |
| 314 | if res[0].name != "doc" or res[1].name != "foo": |
| 315 | print "xpath query: wrong node set value" |
| 316 | sys.exit(1) |
| 317 | doc.freeDoc() |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 318 | ctxt.xpathFreeContext()</pre> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 319 | <p>This test parses a file, then create an XPath context to evaluate XPath |
| 320 | expression on it. The xpathEval() method execute an XPath query and returns |
| 321 | the result mapped in a Python way. String and numbers are natively converted, |
| 322 | and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 323 | the document, the XPath context need to be freed explicitly, also not that |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 324 | the result of the XPath query may point back to the document tree and hence |
| 325 | the document must be freed after the result of the query is used.</p> |
| 326 | <h3>xpathext.py:</h3> |
| 327 | <p>This test shows how to extend the XPath engine with functions written in |
| 328 | python:</p> |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 329 | <pre>import libxml2 |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 330 | |
| 331 | def foo(ctx, x): |
| 332 | return x + 1 |
| 333 | |
| 334 | doc = libxml2.parseFile("tst.xml") |
| 335 | ctxt = doc.xpathNewContext() |
| 336 | libxml2.registerXPathFunction(ctxt._o, "foo", None, foo) |
| 337 | res = ctxt.xpathEval("foo(1)") |
| 338 | if res != 2: |
| 339 | print "xpath extension failure" |
| 340 | doc.freeDoc() |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 341 | ctxt.xpathFreeContext()</pre> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 342 | <p>Note how the extension function is registered with the context (but that |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 343 | part is not yet finalized, this may change slightly in the future).</p> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 344 | <h3>tstxpath.py:</h3> |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 345 | <p>This test is similar to the previous one but shows how the extension |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 346 | function can access the XPath evaluation context:</p> |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 347 | <pre>def foo(ctx, x): |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 348 | global called |
| 349 | |
| 350 | # |
| 351 | # test that access to the XPath evaluation contexts |
| 352 | # |
| 353 | pctxt = libxml2.xpathParserContext(_obj=ctx) |
| 354 | ctxt = pctxt.context() |
| 355 | called = ctxt.function() |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 356 | return x + 1</pre> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 357 | <p>All the interfaces around the XPath parser(or rather evaluation) context |
| 358 | are not finalized, but it should be sufficient to do contextual work at the |
| 359 | evaluation point.</p> |
| 360 | <h3>Memory debugging:</h3> |
| 361 | <p>last but not least, all tests starts with the following prologue:</p> |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 362 | <pre>#memory debug specific |
Daniel Veillard | af43f63 | 2002-03-08 15:05:20 +0000 | [diff] [blame] | 363 | libxml2.debugMemory(1)</pre> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 364 | <p>and ends with the following epilogue:</p> |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 365 | <pre>#memory debug specific |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 366 | libxml2.cleanupParser() |
| 367 | if libxml2.debugMemory(1) == 0: |
| 368 | print "OK" |
| 369 | else: |
| 370 | print "Memory leak %d bytes" % (libxml2.debugMemory(1)) |
Daniel Veillard | 9eb146b | 2002-02-21 16:04:51 +0000 | [diff] [blame] | 371 | libxml2.dumpMemory()</pre> |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 372 | <p>Those activate the memory debugging interface of libxml2 where all |
Daniel Veillard | 63d8314 | 2002-05-20 06:51:05 +0000 | [diff] [blame] | 373 | allocated block in the library are tracked. The prologue then cleans up the |
Daniel Veillard | 6dbcaf8 | 2002-02-20 14:37:47 +0000 | [diff] [blame] | 374 | library state and checks that all allocated memory has been freed. If not it |
| 375 | calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p> |
| 376 | <p><a href="bugs.html">Daniel Veillard</a></p> |
| 377 | </td></tr></table></td></tr></table></td></tr></table></td> |
| 378 | </tr></table></td></tr></table> |
| 379 | </body> |
| 380 | </html> |