Re: [xsl] Testing for Missing or Empty Tags

[Wendell Piez <wapiez@xxxxxxxxxxxxxxxx>]

Maybe Rechell wants

<xsl:if test="not(Tag[normalize-space() or *]">...</xsl:if>

or the same leaving out the "or *" if she already knows there will never be 
an element inside the Tag element, or doesn't care if there is.

string(Tag), alas, checks to see whether the first Tag element child has a 
string value (not the empty string). This may or may not be useful 
depending on the data (do Tag elements appear clustered or are they always 
alone?). It also doesn't address the empty string issue, and will test true 
on <Tag>    </Tag> (which is not always wanted).

Whenever this question comes up, it turns out the answer depends on what 
the OP means by "empty" elements. If Rechell wants to assure that there is 
present a Tag child that includes some kind of text not whitespace, 
not(Tag[normalize-space()] will do that: it checks whether there does (not) 
exist a Tag element child with a non-empty string value. But David has 
already pointed out that this will fail on <Tag><some/></Tag>. Only Rechell 
can say whether that case should be in or out.... :->

Cheers,
Wendell

At 10:30 AM 1/8/2004, David wrote:
> XSLT has no access to the tags in the document.
>
> the test <xsl:if test="not(Tag)" would test if there are any Tag element
> node children of the current node,
>
>
> <xsl:if test="not(Tag[1]) or Tag ='' ">
>
> is the same as
>
>
> <xsl:if test="not(Tag) or Tag ='' ">
>
> and tests if there is no Tag element or if some empty Tag element has
> empty string value, so it would be true on
>
> <x><Tag><y/></Tag></x>


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Wendell Piez                            mailto:wapiez@xxxxxxxxxxxxxxxx
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