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diff --git a/gnu/xml/transform/package.html b/gnu/xml/transform/package.html new file mode 100644 index 000000000..d4355966c --- /dev/null +++ b/gnu/xml/transform/package.html @@ -0,0 +1,77 @@ +<html> +<body> + +<h1>GNU JAXP XSL transformer</h1> + +<div> +This package contains a Java XSL transformer compliant with the JAXP +specification. It depends on the GNU DOM and XPath implementations, and +will generate GNU DOM nodes unless a specific target from another +implementation was given. It understands DOM, SAX, and stream sources +and result sinks and supports these JAXP features. +</div> + +<div> +To use this transformer, set the system property +<code>javax.xml.transform.TransformerFactory</code> to the value +<code>gnu.xml.transform.TransformerFactoryImpl</code>. You can then +instantiate <a href='TransformerFactory.html'>TransformerFactory</a> +and transformers in the ordinary manner. Reuse of stylesheets is +supported using the JAXP <a href='Templates.html'>Templates</a> +mechanism. +</div> + +<h3>Architecture</h3> + +<div> +When given a stylesheet source, this implementation compiles it internally +into a Stylesheet object, which is a container for templates and state. +Each stylesheet instruction is represented by a subclass of TemplateNode, +which is arranged in a directed graph: each TemplateNode has a reference +to its first child and the next node. +</div> + +<div> +The transformation process consists of identifying the Template that matches +the root of the source context, and calling <code>apply</code> on its +corresponding TemplateNode. This in turn processes its children and next +TemplateNode, depending on the semantics of each node type. +</div> + +<div> +Template nodes may reference XPath expressions or patterns. These are fully +compiled to objects of type <a href='../xpath/Expr.html'>Expr</a> at the +time the stylesheet is compiled. +</div> + +<h3>Conformance</h3> + +<div> +This implementation is feature complete, but the XSLT specification is +large and there are still many bugs that need to be ironed out. It has +been tested against the OASIS XSLT TC test suite, comprising unit tests +from the Xalan project and Microsoft. Conformance to these unit tests +is approximately 70% at the current time, although normal usage of the +transformer should involve relatively few surprises (the test suite is +designed to test very complex and obscure functionality). +</div> + +<h3>Known bugs</h3> + +<ul> +<li>When reusing stylesheets using the JAXP Templates mechanism, XSL +<code>apply-imports</code> instructions will not work.</li> +<li>XPath filter expressions do not always work as expected (this is a +problem with the GNU XPath implementation rather than the transformer). +This can result in problems with the <code>position()</code> function, +as well as <code>select</code> expressions and numbering.</li> +</ul> + +<div> +Obviously we'd like to improve conformance and fix these bugs. If you're +interested in working on any of these issues please +<a href='mailto:classpathx-xml@gnu.org'>contact us</a>. +</div> + +</body> +</html> |