• Chapter 1: Getting Started with Stylus Studio®
• Chapter 2: Editing and Querying XML
• Chapter 3: Converting Non-XML Files to XML
• Chapter 4: Working with XSLT
  • Getting Started with XSLT
  • Tutorial: Understanding How Templates Work
  • Working with Stylesheets
  • Creating Stylesheets That Generate HTML
  • Specifying Extension Functions in Stylesheets
  • Working with Templates
  • Using Third-Party XSLT Processors
  • Validating Result Documents
  • Post-processing Result Documents
  • Generating Formatting Objects
  • Generating Scalable Vector Graphics
  • Generating Java Code for XSLT
  • XSLT Instructions Quick Reference
    • xsl:apply-imports
    • xsl:apply-templates
    • xsl:attribute
    • xsl:attribute-set
    • xsl:call-template
    • xsl:character-map
    • xsl:choose
    • xsl:comment
    • xsl:copy
    • xsl:copy-of
    • xsl:decimal-format
    • xsl:element
    • xsl:fallback
    • xsl:for-each
    • xsl:for-each-group
    • xsl:function
      • Format
      • Description
      • Example
    • xsl:if
    • xsl:import
    • xsl:import-schema
    • xsl:include
    • xsl:key
    • xsl:message
    • xsl:namespace-alias
    • xsl:number
    • xsl:otherwise
    • xsl:output
    • xsl:output-character
    • xsl:param
    • xsl:preserve-space
    • xsl:processing-instruction
    • xsl:sequence
    • xsl:sort
    • xsl:strip-space
    • xsl:stylesheet
    • xsl:template
    • xsl:text
    • xsl:transform
    • xsl:value-of
    • xsl:variable
    • xsl:when
    • xsl:with-param
• Chapter 5: Creating XSLT Using the XSLT Mapper
• Chapter 6: Debugging Stylesheets
• Chapter 7: Defining XML Schemas
• Chapter 8: Defining Document Type Definitions
• Chapter 9: Writing XPath Expressions
• Chapter 10: Working with XQuery in Stylus Studio
• Chapter 11: Composing Web Service Calls
• Chapter 12: Accessing Relational Data as XML
• Chapter 13: Building XML Pipelines
• Chapter 14: Publishing XML Data
• Chapter 15: Integrating with Third-Party File Systems
• Chapter 16: Extending Stylus Studio
• Chapter 17: The Stylus Studio Java API
• Chapter 18: Stylus Studio GUI Reference

Home > Online Product Documentation > Table of Contents > xsl:function

xsl:function

Allows the creation of user-defined stylesheet function that can be called from any XPath expression within the stylesheet in which the function is defined. This instruction is supported in XSLT 2.0 only.

Format

<xsl:function name="Qname" as="sequence type" [override="yes" | "no"]>
               
function_body
               
</xsl:function>
               

            

Description

The value of the name attribute, Qname, is a qualified name and takes the form prefix :name. The prefix is required in order to avoid possible conflicts with any functions in the default function namespace. The prefix cannot refer to a reserved namespace.

The function_body contains zero or more <hyperlink>xsl:param elements that specify the formal arguments of the function. These xsl:param elements are followed by a sequence constructor that defnes the value to be returned by the function. The xsl:param elements within an xsl:function element must be empty; they cannot have a select attribute because they must be specified.

An xsl:function declaration can only appear as a top-level element in a stylesheet.

Example

Here is an example from the W3C XSLT Working Draft of a simple function that reverses the order of the words in a sentence.

<xsl:transform 
               
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
               
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
               
  xmlns:str="http://example.com/namespace"
               
  version="2.0"
               
  exclude-result-prefixes="str">
               
 
               
<xsl:function name="str:reverse" as="xs:string">
               
  <xsl:param name="sentence" as="xs:string"/>
               
  <xsl:sequence  
               
     select="if (contains($sentence, ' '))
               
             then concat(str:reverse(substring-after($sentence, ' ')),
               
                         ' ',
               
                         substring-before($sentence, ' '))
               
             else $sentence"/>
               
</xsl:function>
               
 
               
<xsl:template match="/">
               
<output>
               
  <xsl:value-of select="str:reverse('DOG BITES MAN')"/>
               
</output>
               
</xsl:template>
               
 
               
</xsl:transform>