There have been a few instances where I have had to filter the incoming XML to look for a value from a different node in the XML. For the example in this article I had the parent node id but I wanted to know the name of that parent node.
This excellent article gave me a starting point for the principle of searching for values in different nodes using an XSLT template. This worked spendedly in one map I was working where I was trying to sum up all values in the current list of node items.
<xsl:template name="OutputSum">
<xsl:param name="param1" />
<xsl:element name="TransactionAmount">
<xsl:variable name="var:vTranAmt"
select="sum(//ExpenseItem[ReportEntryID=$param1]/TransactionAdjustmentAmount" />
<xsl:value-of select="$var:vTranAmt" />
</xsl:element>
</xsl:template>
However, when I tried to use the same principle to select the name value of a parent node for which I only knew the ID, it just wouldn’t work. I kept gettiing blank values no matter what I tried.
The source schema was from the MS Dynamics CRM v4 web services using the RetrieveMultiple method and is much more complex than one I normally use. After a lot of headscratching I noticed that it was the namespaces that were causing the problems. When I right clicked the map, selected validate and viewed the .xsl that Visual Studio was generating I noticed in my other mappings that BizTalk was adding some bizarre namespaces to the nodes, e.g. s6:RetrieveMultipleResult/s4:BusinessEntities . Eventually I got it to work using these namespaces.
<xsl:template name="ParentCompanyCode">
<xsl:param name="param1" />
<xsl:element name="Code">
<xsl:value-of select="//s4:BusinessEntity[s6:new_geographyid=$param1]/s6:new_name" />
</xsl:element>
</xsl:template>
Unfortunately I can’t explain exactly why this was required, but my advise is that if you can’t work out why custom xsl isn’t working then create something similar using functoids and have a look through the xsl that it generates via the Validate map functionality.