Mapping complex conditions in BizTalk with XSLT

Recently I found myself in a situation where I needed to evaluate a set of complex conditions that I could not use the Business Rules Engine for. The BizTalk mapper was able to achieve the conditionality by chaining a series of about 21 functoids together but this became very unmanageable especially since I was combining false statements to see if both were false, then returning a true to an “And” functoid (&) which evaluated another branch as true and passed a result to the node in the destination schema, you get the idea.

An easier way is to plug in XSLT. There are disadvantages to doing this, the main one being its maintainability and transparency but when faced with the daunting set of functoids described above, it looked a decent option.

The XSLT function that I used was the <xsl:choose> statement, inside the statement was a set of conditions which, if true, would return a value/values to the destination schema. In the last part of the statement was the <xsl:otherwise> condition which could set values if the conditions presented were not valid and you had a default you wanted to present in that event.

<xsl:variable name="var:vAnnuity" select="count(/*[local-name()='InternalSupport' and namespace-uri()='http://internal_support']/*[local-name()='LoanPartItems' and namespace-uri()='' and Method='Annuity'])" />

<xsl:variable name="var:vLinear" select="count(/*[local-name()='InternalSupport' and namespace-uri()='http://internal_support']/*[local-name()='LoanPartItems' and namespace-uri()='' and Method='Linear'])" />

<xsl:variable name="var:vTotalCount" select="count(/*[local-name()='InternalSupport' and namespace-uri()='http://internal_support']/*[local-name()='PartItems' and namespace-uri()=''])" />

<xsl:variable name="var:vHasValidEndowment" select="count(/*[local-name()='InternalSupport' and namespace-uri()='http://internal_support']/*[local-name()='LoanPartItems' and namespace-uri()='' and isValid ='true'])" />

<xsl:variable name="var:vHasValidId" select="count(/*[local-name()='InternalSupport' and namespace-uri()='http://internal_support']/*[local-name()='Ready' and HasValidId ='true'])" />

<xsl:element name="LeningSoort">

    <xsl:choose>

        <xsl:when test="$var:vAnnuity = $var:vTotalCount">

            <xsl:value-of select="1" />

        </xsl:when>

        <xsl:when test="$var:vLinear = $var:vTotalCount">

            <xsl:value-of select="2" />

        </xsl:when>

        <xsl:when test="($var:vHasValidEndowment = $var:vTotalCount) and ($var:vHasValidId = $var:vTotalCount)">

            <xsl:value-of select="3" />

        </xsl:when>

        <xsl:otherwise>

            <xsl:value-of select="4" />

        </xsl:otherwise>

    </xsl:choose>

</xsl:element>

Of course each specific case requires different XSLT, but this should provide a framework of how to do this within a functoid.

To set up the XSLT:

• Create XSLT similar to the one above which meets your needs
• Drop a scripting functoid on your map
• Connect the output parameter to the node you want to create
• Note: do no include any input parameters, the XSLT is setup already to look them up
• Open the scripting functoid’s, click the (…) inside “Configure Functoid Script”
• Under “Script type” choose “Inline XSLT”
• Paste your XSLT snippet in the text box