Applying Conditional Logic using XSL - xslt

Question

I have an XML document where I get several addresses for a member as address type PRIMARY, MAILING etc. however I only want to read the address as PRIMARY, MAILING when memberId is '0'. Please see the sample xml below.
<core>
<address>
<postalZipCode>90017</postalZipCode>
<updateSource>xxxxxx</updateSource>
<city>LOS ANGELES</city>
<stateProvince>CA</stateProvince>
<type>MAILING</type>
<line1>818 WEST SEVENTH STREET</line1>
</address>
<address>
<postalZipCode>95014</postalZipCode>
<updateSource>xxxxxx</updateSource>
<city>CUPERTINO</city>
<stateProvince>CA</stateProvince>
<type>PRIMARY</type>
<line1>1234 XYZ STREET</line1>
</address>
<memberId>0</memberId>
</core>
The XSL condition I am trying to evaluate in my XSLT file is as below -
<xsl:template match="core">
<xsl:when test="memberId[.='0'] and address/type[.='PRIMARY']">
<fo:table-row>
<fo:table-cell xsl:use-attribute-sets="data">
<fo:block>Line 1</fo:block>
</fo:table-cell>
</fo:table-row>
But this condition check is not working and address is not rendered in the generated document .
Could the experts here please suggest how do I go about such conditional check ?

Answer 1

First, you can't have <xsl:when> as a child of anything other than <xsl:choose>. I suspect in this case you probably meant to use <xsl:if>.
Secondly, your template matches core, not the primary address element- Not sure if this is intentional or not though.
Thirdly, your template doesn't actually output anything from the source document anyway, unless there's some missing from what you've included here.
As a rule it's generally advisable to write templates with predicates that fit your conditions, rather than explicit conditional logic within a template. I think what you probably want to do is:
<xsl:template match="core[memberId='0']/address[type='PRIMARY']">
<fo:etc..
</xsl:template>