TclXSLT(n)TclXSLT(n)______________________________________________________________________________NAME
::xslt::compile -
SYNOPSIS
package require xslt
xslt2.5
::xslt
::xslt::compile doc
ssheet method ? option value ... ? ? args ... ?
::xslt::extensionadd nsuri tcl-namespace
_________________________________________________________________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 trans‐
formation 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 parame‐
ters 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 regis‐
ter an extension. The remove is
used to unregister an extension.
See for more detail.
EXTENSIONS
The TclXSLT package allows an appli‐
cation 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 names‐
pace 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 spec‐
ified as an argument, along with a
Tcl namespace that will provide
implementations of extension ele‐
ments and functions. For example,
Everytime the ::xslt::transform com‐
mand is executed, a newly-created
XSLT engine is initialized. For
each registered extension, every
procedure in the associated Tcl
namespace is defined in the XSLT
engine as either an extension ele‐
ment or an extension function. The
procedure is defined as an extension
function if it has a variable argu‐
ment 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 pro‐
cedure.
The return result of the Tcl
procedure becomes the return
value of the extension func‐
tion. 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 Names‐
pace matches the extension to the
registered Tcl namespace (NB. the
stylesheet author is free to choose
any prefix for the extension names‐
pace). For example,
This stylesheet would result in the
following Tcl script being evalu‐
ated:
Tcl Built-In Commands Tcl TclXSLT(n)
