CODEWITHSUNDEEP
xsltxpath-2.0
topskip
topskip

Reputation: 17335

Is there only text between two processing instructions?

This is my XML file:

<root>
    <?pistart ?>
    <elt>
    <?pistop ?>
    </elt>
</root>

Now (using XPath 2.0) I'd like to know if there is only text between the processing instruction pistart and the next processing instruction pistop. The answer above would be 'no, there is an start element tag'.

A pistart can never occur after another pistart without a corresponding pistop. Thus this is not possible (if it helps to solve my problem): 

<root>
    <?pistart ?>
    <elt>
    <?pistart ?>
    <?pistop ?>
    </elt>
    <?pistop ?>
</root>

Upvotes: 1

Views: 186

Answers (3)

Dimitre Novatchev
Dimitre Novatchev

Reputation: 243459

Use this XPath 1.0 expression(which, of course, is also an XPath 2.0 one)

Assuming the pistart is the context item:

boolean(following::node()[not(self::text())][1][self::processing-instruction('pistop')])

Upvotes: 1

Michael Kay
Michael Kay

Reputation: 163262

Perhaps (assuming the pistart is the context item):

exists(following-sibling::node()[1][self::text()]
/following-sibling::node()[1][self::processing-instruction(pistop))

Upvotes: 1

Martin Honnen
Martin Honnen

Reputation: 167401

Based on the suggestion in my comment, I think

<xsl:template match="/">
    <xsl:for-each-group select="/root//node()"
        group-starting-with="processing-instruction('pistart')">
        <xsl:if test="self::processing-instruction('pistart')">
            <xsl:variable name="end" select="current-group()[self::processing-instruction('pistop')]"/>
            <xsl:value-of
                select="
                every $group-member in current-group()[position() gt 1 and . &lt;&lt; $end]
                satisfies $group-member instance of text()"
            />
        </xsl:if>
    </xsl:for-each-group>
</xsl:template>

will do to output true for any group of pi pairs satisfying the condition and false for those not satisfying it.

It might be easier to nest an additional for-each-group group-ending-with="processing-instruction('pistop')" to grab the nodes to check.

Upvotes: 1

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