MSXSL Scripts for XSLT
The <msxsl:script> element contains user-defined functions and variables that can be called from within XPath expressions in the XSLT stylesheet. The <msxsl:script> is a top-level element, that is, it must be a child element of <xsl:stylesheet> or <xsl:transform>.
The <msxsl:script> element must be in the namespace urn:schemas-microsoft-com:xslt (see example below).
Scripting language and namespace
The scripting language used within the block is specified in the <msxsl:script> element's language attribute and the namespace to be used for function calls from XPath expressions is identified with the implements-prefix attribute (see below).
<msxsl:script language="scripting-language" implements-prefix="user-namespace-prefix">
function-1 or variable-1
...
function-n or variable-n
</msxsl:script>
The <msxsl:script> element interacts with the Windows Scripting Runtime, so only languages that are installed on your machine may be used within the <msxsl:script> element. The .NET Framework 2.0 platform or higher must be installed for MSXSL scripts to be used. Consequently, the .NET scripting languages can be used within the <msxsl:script> element.
The language attribute accepts the same values as the language attribute on the HTML <script> element. If the language attribute is not specified, then Microsoft JScript is assumed as the default.
The implements-prefix attribute takes a value that is a prefix of a declared in-scope namespace. This namespace typically will be a user namespace that has been reserved for a function library. All functions and variables defined within the <msxsl:script> element will be in the namespace identified by the prefix specified in the implements-prefix attribute. When a function is called from within an XPath expression, the fully qualified function name must be in the same namespace as the function definition.
Example
Here is an example of a complete XSLT stylesheet that uses a function defined within a <msxsl:script> element.
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:fn="http://www.w3.org/2005/xpath-functions"
xmlns:msxsl="urn:schemas-microsoft-com:xslt"
xmlns:user="http://mycompany.com/mynamespace">
<msxsl:script language="VBScript" implements-prefix="user">
<![CDATA[
' Input: A currency value: the wholesale price
' Returns: The retail price: the input value plus 20% margin,
' rounded to the nearest cent
dim a as integer = 13
Function AddMargin(WholesalePrice) as integer
AddMargin = WholesalePrice * 1.2 + a
End Function
]]>
</msxsl:script>
<xsl:template match="/">
<html>
<body>
<p>
<b>Total Retail Price =
$<xsl:value-of select="user:AddMargin(50)"/>
</b>
<br/>
<b>Total Wholesale Price =
$<xsl:value-of select="50"/>
</b>
</p>
</body>
</html>
</xsl:template>
</xsl:stylesheet>
Datatypes
The values of parameters passed into and out of the script block are limited to XPath datatypes. This restriction does not apply to data passed among functions and variables within the script block.
Assemblies
An assembly can be imported into the script by using the msxsl:assembly element. The assembly is identified via a name or a URI. The assembly is imported when the stylesheet is compiled. Here is a simple representation of how the msxsl:assembly element is to be used.
<msxsl:script>
<msxsl:assembly name="myAssembly.assemblyName" />
<msxsl:assembly href="pathToAssembly" />
...
</msxsl:script>
The assembly name can be a full name, such as:
"system.Math, Version=3.1.4500.1 Culture=neutral PublicKeyToken=a46b3f648229c514"
or a short name, such as "myAssembly.Draw".
Namespaces
Namespaces can be declared with the msxsl:using element. This enables assembly classes to be written in the script without their namespaces, thus saving you some tedious typing. Here is how the msxsl:using element is used so as to declare namespaces.
<msxsl:script>
<msxsl:using namespace="myAssemblyNS.NamespaceName" />
...
</msxsl:script>
The value of the namespace attribute is the name of the namespace.