How to assert for each child one element is present or not

Question

<ClinicalDocument>
  <entry>
     <substaceAdministration>
        <effectiveTime></effectiveTime>
     </substaceAdministration>
  </entry>
  <entry>
     <substaceAdministration>
        <effectiveTime></effectiveTime>
     </substaceAdministration>
  </entry>
  <entry>
     <substaceAdministration>
     </substaceAdministration>
  </entry>
</ClinicalDocument>

I have to assert for each entry/substaceAdministration is effectiveTime element is present or not.

I have tried with this expression

<xsl:when test="count(ClinicalDocument/entry/substanceAdministration/effectiveTime)=1"/>

I am looking for advice on how to change my XPath expression to meet this requirement.

Answer 1

Instead of trying to count all instances of child elements, maybe you should count all instances without child elements (sorry about the formatting for this one; it's long):

<xsl:when 
test="count(ClinicalDocument/entry/substanceAdministration[not(effectiveTime)])
      = 0">
   <!-- True when all substanceAdministration elements
        have an effectiveTime child
   -->
</xsl:when>

You could also do this check on a per-substanceAdministration basis in either a for-each loop or a template using something like this:

<!-- Assuming the current node is substanceAdministration -->
<xsl:if test="count(effectiveTime) = 1">
   <!-- True when there is one and only one effectiveTime child -->
</xsl:if>

Answer 2

Your statement

test="count(ClinicalDocument/entry/substanceAdministration/effectiveTime)=1"

will only return true if there is one and only one <effectiveTime> element.

It would be easier to understand what you're trying to do with more of your xsl:template to look at. What is your context node? Are you tring to process each <entry> that has an <effectiveTime> descendant? If so, you could just use a template:

<xsl:template match="entry[descendant::effectiveTime]">...</xsl:template>