Re: [xsl] Recursion Examples

[Jeni Tennison <mail at jenitennison dot com>]

Hi Larry,

> I wasn't certain if xsl:attribute could take something that fancy
> otherwise, as I've not done that particular trick before. As I said,
> I wasn't 100% certain on the syntax, it may not be necessary. :-)

It's a real kindness not to guess syntax when you're replying to
people's questions, and often one to try out your solution before you
post it.  If you'd have tried yours:

>> <xsl:template match="module">
>>     <ul>
>>         <li>
>>             <xsl:value-of select="name" />
>>             <xsl:apply-templates>
>>                 <xsl:attribute name="select">
>>                     <xsl:text>../module[@parentid='</xsl:text><xsl:value-of
>> select="id" /><xsl:text>']</xsl:text>
>>                 </xsl:attribute>
>>             </xsl:apply-templates>
>>         </li>
>>     </ul>
>> </xsl:template>

you should have found that the XSLT processor objects to you using an
xsl:attribute element within an xsl:apply-templates.  xsl:attribute is
for adding attributes to elements *in the result tree*, not to XSLT
elements.  You can never use xsl:attribute to add an attribute to an
XSLT instruction.

I can see what you're trying to do here though - you're trying to
construct an XPath that uses, within the predicate, the id of the
*current* module element (i.e. the one you're matching in the
template) rather than the id of the *context* module
element (i.e. the one that you're searching for).

There are two ways of doing that.  The simple one is to create a
variable to hold the id of the current module element, and then use
that variable value:

   <xsl:variable name="id" select="id" />
   <xsl:apply-templates select="../module[@parentid = $id]" />

The second is to use the current() function to get the current node
(the module element that you're matching in the template), and get its
id from there:

   <xsl:apply-templates
         select="../module[@parentid = current()/id]" />

I hope that helps clear things up for you,

Jeni

---
Jeni Tennison
http://www.jenitennison.com/



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