TclXSLT(n) TclXSLT(n)
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NAME
::xslt::compile -
SYNOPSIS
package require xslt
xslt2.5
::xslt
::xslt::compile doc
ssheet method ? option value ... ? ? args ... ?
::xslt::extensionadd nsuri tcl-namespace
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DESCRIPTION
TclXSLT is a wrapper for the that allows an application to perform XSL transformations (XSLT). The package also provides a binding to the
XSLT extension mechanism so that XSLT extension may be implemented using Tcl scripts.
Transformation only works with documents created by TclDOM/libxml2.
The TclXSLT package makes extensive use of Tcl objects. Compiled XSL stylesheets are stored as the internal representation of a Tcl
object. Source and result documents are accessed via TclDOM's C interface as Tcl objects. This allows the application to cache parsed XML
documents and compiled XSL stylesheets for better runtime performance.
PACKAGES AND NAMESPACES
The TclXSLT package defines the package and also a Tcl namespace using that name.
COMMANDS
::xslt::compile
The ::xslt::compile command pre-compiles a stylesheet document. It returns a compiled stylesheet object and also defines a Tcl command to
access the stylesheet. This Tcl command may be used to transform XML documents.
NB. It is advisable to use the -baseuri option when parsing the source and stylesheet documents to allow external resources to be
resolved.
Stylesheet Command
The stylesheet command created by ::xslt::compile command accesses a compiled stylesheet.
Following is an example of how to use the stylesheet transform method.
Command Methods
The following command methods may be used:
cget option
Returns the value of an option. See below for the list of valid options.
configure optionvalue
Sets the value of an option. Available options are as follows:
transform source ? name value?
Performs an XSL transformation on the given source document. Stylesheet parameters may be specified as name-value pairs.
The return result is the DOM token for the result document.
Stylesheet Parameters
Any number of name-value pairs may be specified as arguments to the stylesheet transform method. These are passed as values for
parameters in the stylesheet. interprets the values as XPath expressions, where the context node is the root node for the source
document. To pass a value as a string it must be XPath-quoted, for example
set library "Gnome libxslt"
$ssheet transform $source_doc library '$library' author "'Daniel Veillard'" node {/*/Element[3]}
::xslt::extension
The ::xslt::extension command is used to manage extensions of the library. The add is used to register an extension. The remove is used
to unregister an extension. See for more detail.
EXTENSIONS
The TclXSLT package allows an application to bind Tcl scripts to the extension mechanism of . This means that Tcl scripts may provide the
implementation of an XSLT extension element or function. The binding is achieved to associating a Tcl namespace with an XML namespace.
Implementing An Extension
The Tcl application uses the ::xslt::extension add command to register an extension. An XML Namespace for the extension is specified as an
argument, along with a Tcl namespace that will provide implementations of extension elements and functions. For example,
Everytime the ::xslt::transform command is executed, a newly-created XSLT engine is initialized. For each registered extension, every pro-
cedure in the associated Tcl namespace is defined in the XSLT engine as either an extension element or an extension function. The proce-
dure is defined as an extension function if it has a variable argument list, otherwise it is defined as an extension element. The proce-
dure name is used as the local part of the extension name. For example,
"myfunc" is defined as an extension function and "myelement" is defined as an extension element.
Extension Functions
The arguments to an extension function are converted to a string value and then passed as parameters to the Tcl procedure.
The return result of the Tcl procedure becomes the return value of the extension function. The type of the result is preserved
where possible, otherwise it is converted to a string value.
Extension Elements
Extension elements have not been implemented in TclXSLT v1.1.
Using An Extension
To invoke an extension in an XSL stylesheet, use the normal XSLT extension mechanism. The XML Namespace matches the extension to the reg-
istered Tcl namespace (NB. the stylesheet author is free to choose any prefix for the extension namespace). For example,
This stylesheet would result in the following Tcl script being evaluated:
Tcl Built-In Commands Tcl TclXSLT(n)