Question

I want to check if there is a string which is equal to one of the attributes. For instances:

<rules>
        <mother cat="pp">
            <daughter cat="pr"/>
            <daughter cat="np"/>
        </mother>
        <mother cat="wp">
            <daughter cat="rp"/>
            <daughter cat="vp"/>
        </mother>
        <mother cat="cn">
            <daughter cat="jj"/>
            <daughter cat="cn"/>
        </mother>
        <mother cat="np">
            <daughter cat="jj"/>
            <daughter cat="np"/>
        </mother>
    </rules>

I just need to test if “pp” is equal to one of the mothers’ cat attribute.
For this example yes it is. But it should be false for “pr”.

Thank You.

Answer 1

Use the following expression:

/*/mother[@cat='pp']

This expression returns the mother element having an attribute named cat whose value is equal to pp.

In an xsl:if test expression, this will return true if such a node exists; false, otherwise. For example:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:template match="/">
        <xsl:if test="/*/mother[@cat='pp']">NODE EXISTS</xsl:if>
    </xsl:template>
</xsl:stylesheet>

This stylesheet prints NODE EXISTS only when such a node is present in the source.

Find this element’s position using the following expression:

count(/*/mother[@cat='pp']/preceding-sibling::*)+1