XSLT Functions

Stroom has a number of built in custom XSLT functions that can be called from within the XSLTFilter pipeline element. These functions provide additional capabilities and access to data held in Stroom.

Using Stroom XSLT Functions

To use a Stroom custom XSLT function you need to add the xmlns:stroom="stroom" namespace declaration to the XSLT document. The convention is to use the namespace prefix stroom to make it clear that function calls are to a Stroom built-in function, but any prefix can be used.

<xsl:stylesheet
  version="2.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:stroom="stroom"
  xmlns="event-logging:3"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  ...>

The following is an example of calling the hash custom XSLT function to produce a hash of the username value.

  <xsl:template match="/record">
    <HashedUser>
      <xsl:value-of select="stroom:hash(data[@name='username']/@value, 'SHA-256')"/>
    </HashedUser>
  </xsl:template>

Return Values

XSLT functions can return the following data types:

• Boolean - True/false.
• Date - A date value (xs:date).
• Date-Time - A date and time value (xs:datetime).
• Decimal - A decimal or floating point value (xs:decimal).
• Integer - A number with no decimal part (xs:integer).
• String - A simple string value (xs:string).
• Sequence - Any sequence of nodes or atomic values, e.g. a single node, a list of nodes or a list of strings.

Functions

The following table lists all the Stroom XSLT functions.