Re: [xsl] Variable in XPath

[Garvin Riensche <g.riensche@xxxxxxx>]

Hi Andrew,

Thanks for your answer but it's not exactly that what I was looking for. 
Maybe I have to explain my problem a bit more. Consider again the 
following XML:

<facts>
  <class id="2" owner="1" name="A"/>
  <class id="3" owner="1" name="B"/>
<facts>

This is a simple example, there might be input with nodes containing 
more attributes.

For each attribute there has to be a variable, $id, $owner and $name in 
this case, which is set from commandline. When writing the stylesheet I 
dont't know which classes are goint to be selected. This could be all 
classes, classes selected by id, classes selected by id and name, ect. 
So there are lots of possibilities - and even more if there are more 
attributes. The stylesheet would be very large if I would use a 
<xsl:when> for every possible combination. So my idea was to use a 
default value for each variable, so that all (class) nodes are selected 
if the variable is not set.

For example:

I call saxon with $owner="1" $name="A" then $id is empty and I want the 
following test to return true:

<xsl:when test="doc('factbase.xml')/facts/class[@id eq $id and @owner eq 
$owner and @name eq $name]">

This will return false because $id is empty. My quesion is, is there a 
default value that I can put in the select of <xsl:variable name="id" 
select"?????"/> so that the test above will return true?
It would be great if that would work somehow because with lots of 
<xsl:when>s I think it would be much more complicated (considering more 
attributes).

regards,
Garvin


> On 6/27/07, Andrew Welch <andrew.j.welch@xxxxxxxxx> wrote:
> > Seems like a long-winded way of just saying you want to check if 
> > <class> exists:
> >
> > <xsl:when test="doc('factbase.xml')/facts/class">
> >
> > If you then want to do something specific if the @id eq $id then add a
> > condition inside the xsl:when.
>
> Or its probably cleaner to just add another when:
>
> <xsl:when test="doc('factbase.xml')/facts/class[@id eq $id]">
>  there is a class with a matching @id
> </xsl:when>
> <xsl:when test="doc('factbase.xml')/facts/class">
>  there are one or more class elements, but none of them a matching @id
> </xsl:when>
> <xsl:otherwise>
>  this aren't any class elements...
> </xsl:otherwise>
>
> You'd want to refactor the call to doc() into a variable too.