Re: [xsl] Determine if an element with descents has complete empty text content

["Dimitre Novatchev dnovatchev@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

> If there's any possibility that $context has a large number of descendant text nodes or that their content is large, then it's going to be best to avoid forming the string concatenation of those text nodes, which you can achieve with
>
> exists($context//text()[normalize-space()])
>
> Michael Kay
> Saxonica

I thought that the simpler expression below with a decent optimizer
will be as efficient as the above:

     exists($context[normalize-space()])

as it is sufficient to find the first non-empty text() descendent to
conclude that the argument to the exists() function is the $context
element.

Seems a simple short-cutting. Or is it?


Cheers,
Dimitre



On Sun, Oct 2, 2016 at 9:12 AM, Michael Kay mike@xxxxxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
>> On 2 Oct 2016, at 13:16, Eliot Kimber ekimber@xxxxxxxxxxxx <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> I've inherited some code that has this type of check to determine if an
>> element with arbitrary possible subelements has completely empty text
>> content:
>>
>> normalize-space(string-join($context//text(), '')) != ''
>>
>> In XSLT 2 I'm pretty sure there's a simpler and/or more efficient way to
>> do this.
>>
>>
>> Is there a better way to do this and if so, what is it?
>>
>
> If there's any possibility that $context has a large number of descendant text nodes or that their content is large, then it's going to be best to avoid forming the string concatenation of those text nodes, which you can achieve with
>
> exists($context//text()[normalize-space()])
>
> Michael Kay
> Saxonica
> 



-- 
Cheers,
Dimitre Novatchev
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