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| author | Daniel Veillard <veillard@src.gnome.org> | 2001-07-06 16:33:55 +0000 |
|---|---|---|
| committer | Daniel Veillard <veillard@src.gnome.org> | 2001-07-06 16:33:55 +0000 |
| commit | ce69a281a62c2fbd4680a535b956d34ea2a5f018 (patch) | |
| tree | f455e57f88374b84018742073f4f13cb9b6290ac | |
| parent | bdffe03d8d210d8389839433b0f687715a05c555 (diff) | |
| download | libxslt-ce69a281a62c2fbd4680a535b956d34ea2a5f018.tar.gz | |
Cleanup and added a entry for the shutdown function.
Daniel
| -rw-r--r-- | doc/extensions.html | 44 |
1 files changed, 32 insertions, 12 deletions
diff --git a/doc/extensions.html b/doc/extensions.html index a866acc9..121fdf85 100644 --- a/doc/extensions.html +++ b/doc/extensions.html @@ -1,3 +1,5 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" + "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <title>Writing extensions for XSLT C library for Gnome</title> @@ -38,6 +40,7 @@ href="http://mail.gnome.org/archives/xslt/">http://mail.gnome.org/archives/xslt/ <li><a href="#Registerin2">Registering an extension element</a></li> <li><a href="#Implementi1">Implementing an extension element</a></li> <li><a href="#Example">Example for extension elements</a></li> + <li><a href="#shutdown">The shutdown of a module</a></li> <li><a href="#Future">Future work</a></li> </ul> @@ -49,7 +52,7 @@ XSLT library for use with <a href="http://xmlsoft.org/XSLT/">libxslt</a>, the href="http://www.gnome.org/">Gnome</a> project.</p> <p>Before starting reading this document it is highly recommended to get -familiar with <a href="internals.html">the libxslt internals</a>. </p> +familiar with <a href="internals.html">the libxslt internals</a>.</p> <p>Note: this documentation is by definition incomplete and I am not good at spelling, grammar, so patches and suggestions are <a @@ -72,7 +75,7 @@ have a resource there for this to work).</p> <p>libxslt provides a few extensions itself, either in libxslt namespace "http://xmlsoft.org/XSLT/" or in other namepsace for well known extensions -provided by other XSLT processors like Saxon, Xalan or XT. </p> +provided by other XSLT processors like Saxon, Xalan or XT.</p> <h2><a name="Keep">Extension modules</a></h2> @@ -80,7 +83,7 @@ provided by other XSLT processors like Saxon, Xalan or XT. </p> coming from a given source are using the same namespace name defining in practice a group of extensions providing elements, functions or both. From libxslt point of view those are considered as an "extension module", and most -of the APIs work at a module point of view. </p> +of the APIs work at a module point of view.</p> <p>Registration of new functions or elements are bound to the activation of the module, this is currently done by declaring the namespace as an extension @@ -113,17 +116,12 @@ with the application and to call a registration function:</p> <p>which also defines the type for the initialization and shutdown functions</p> -<ul> - <li><br> - </li> - <li></li> -</ul> <h2><a name="libxml">Loading a module</a></h2> <p>Once the module URI has been registered and if the XSLT processor detects that a given stylesheet need the functionalities of an extended module, this -one is initialized. </p> +one is initialized.</p> <p>The xsltExtInitFunction type defines the interface for an initialization function:</p> @@ -296,8 +294,8 @@ xsltExtFunctionTest(xmlXPathParserContextPtr ctxt, int nargs) xsltTransformFunction function);</pre> <p>It is similar to the mechanism used to register an extension function, -except that the signature of an extension element implementation is different. -</p> +except that the signature of an extension element implementation is +different.</p> <p>The registration is bound to a single transformation instance referred by ctxt, name is the UTF8 encoded name for the NCName of the element, and URI is @@ -335,7 +333,7 @@ value is <code>NULL</code> by default (it could be added and associated to the instruction in <code>inst->_private</code>).</p> <p>The same functions are available from a function implementing an extension -element as in an extension function, including +element as in an extension function, including <code>xsltGetExtData()</code>.</p> <p>The goal of extension element being usually to enrich the generated output, @@ -397,6 +395,28 @@ xsltExtElementTest(xsltTransformContextPtr ctxt, xmlNodePtr node, xmlAddChild(ctxt->insert, comment); }</pre> +<h2><a name="shutdown">The shutdown of a module</a></h2> + +<p>When the XSLT processor ends a transformation, the shutdown function (if it +exists) of all the modules initialized are called.The xsltExtShutdownFunction +type defines the interface for a shutdown function:</p> +<pre>/** + * xsltExtShutdownFunction: + * @ctxt: an XSLT transformation context + * @URI: the namespace URI for the extension + * @data: the data associated to this module + * + * A function called at shutdown time of an XSLT extension module + */ +typedef void (*xsltExtShutdownFunction) (xsltTransformContextPtr ctxt, + const xmlChar *URI, + void *data);</pre> + +<p>this is really similar to a module initialization function except a third +argument is passed, it's the value that was returned by the initialization +function. This allow to deallocate resources from the module for example close +the connection to the database to keep the same example.</p> + <h2><a name="Future">Future work</a></h2> <p>Well some of the pieces missing:</p> |