XML Use another variable if first one is empty-CodePudding

I am brand new to xml and xsl. I have a question relating to xsl:value-of select

Is there a way to insert a type of "isnull", meaning that if one value is empty it should hide that tag and use another one?

Example of the code:

      <ExternalIdentifier>
        <!-- Id number -->
        <TypeCode>IdentityDocumentId </TypeCode>
        <Id>
          <xsl:value-of select="idy_nbr"/>
        </Id>
      </ExternalIdentifier>

I need to change it to something like this (but it should hide the IdentityDocumentId tag if there is no value and use the Passport Number tag instead :

  <ExternalIdentifier>
    <!-- Id number -->
    <TypeCode>IdentityDocumentId </TypeCode>
    <Id>
      <xsl:value-of select="idy_nbr"/>
    </Id>
    <TypeCode>Passport Number</TypeCode>
    <Id>
      <xsl:value-of select="ppo_nbr"/>
    </Id>
  </ExternalIdentifier>

Thank you.

CodePudding user response：

This is what template rules are for:

<xsl:apply-templates select="idy_nbr, "pro_nbr"/>

<xsl:template match="idy_nbr">
   <TypeCode>IdentityDocumentId</TypeCode>
   <Id>
       <xsl:value-of select="idy_nbr"/>
   </Id>
</xsl:template>

<xsl:template match="pro_nbr">
   <TypeCode>Passport Number</TypeCode>
   <Id>
       <xsl:value-of select="pro_nbr"/>
   </Id>
</xsl:template>

CodePudding user response：

I suppose you want something like:

<ExternalIdentifier>
    <xsl:choose>
        <xsl:when test="string(idy_nbr)">
            <TypeCode>IdentityDocumentId</TypeCode>
            <Id>
                <xsl:value-of select="idy_nbr"/>
            </Id>
        </xsl:when>
        <xsl:otherwise>
            <TypeCode>Passport Number</TypeCode>
            <Id>
                <xsl:value-of select="ppo_nbr"/>
            </Id>
        </xsl:otherwise>
    </xsl:choose>
</ExternalIdentifier>

Untested because no input example was provided.