You want:

//tab[@page=$param]/preceding::tab[1]/@page
//tab[@page=$param]/following::tab[1]/@page

Michael Kay
Software AG
home: Michael.H.Kay@xxxxxxxxxxxx
work: Michael.Kay@xxxxxxxxxxxxxx 

> -----Original Message-----
> From: owner-xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> [mailto:owner-xsl-list@xxxxxxxxxxxxxxxxxxxxxx]On Behalf Of Peet, Mike
> Sent: 25 April 2002 20:49
> To: 'xsl-list@xxxxxxxxxxxxxxxxxxxxxx'
> Subject:  Complex XPath Help
> 
> 
> Okay, it's probably not *that* complicated, but I'm having 
> some trouble with
> this one.  I think I'm missing something fundamental.  Sorry 
> for the long
> message.  For those of you that have the patience to look at 
> this, your help
> is greatly appreciated.
> 
> <xml>
>    <tab-groups>
>       <tab-group id="100" name="group1">
>          <tabs>
>             <tab desc="Page 1" page="page1.asp"/>
>             <tab desc="Page 2" page="page2.asp"/>
>          </tabs>
>       </tab-group>
>       <tab-group id="104" name="group2">
>          <tabs>
>             <tab desc="Page x" page="pagex.asp"/>
>             <tab desc="Page y" page="pagey.asp"/>
>          </tabs>
>          <tab-group id="145" name="group3">
>             <tabs>
>                <tab desc="Page A" page="pageA.asp"/>
>                <tab desc="Page B" page="pageB.asp"/>
>             </tabs>
>          </tab-group>
>          <tab-group id="167" name="group3">
>             <tabs>
>                <tab desc="Page A" page="pageA.asp"/>
>                <tab desc="Page B" page="pageB.asp"/>
>             </tabs>
>          </tab-group>
>       </tab-group>
>    </tab-groups>
> </xml>
> 
> With the above XML document, if I pass a "page" into the XSLT as a
> parameter, and I want to know what the previous and next 
> pages are, how
> would that be done?  Note that the tab-groups may be nested.
> 
> The desired behaviour is that the previous page would be 
> simply the page
> attribute of the preceding <tab> element (in document order, 
> regardless of
> group), and next would be the page attribute of the following 
> <tab> element
> (in document order, regardless of group).  The special cases 
> of first and
> last pages can return nothing.
> 
> One way that I can think of is an intermediate transform to 
> get a document
> containing just the <tab> elements with no nesting, and using the
> preceding-sibling and following-sibling axes off the current 
> tab, like this:
> 
> <xml>
>    <tabs>
>       <tab group-id="100" desc="Page 1" page="page1.asp"/>
>       <tab group-id="100" desc="Page 2" page="page2.asp"/>
>       <tab group-id="104" desc="Page x" page="pagex.asp"/>
>       <tab group-id="104" desc="Page y" page="pagey.asp"/>
>       <tab group-id="145" desc="Page A" page="pageA.asp"/>
>       <tab group-id="145" desc="Page B" page="pageB.asp"/>
>       <tab group-id="167" desc="Page A" page="pageA.asp"/>
>       <tab group-id="167" desc="Page B" page="pageB.asp"/>
>    </tabs>
> </xml>
> 
> But this seems to defeat the purpose of a having a nice structured XML
> document in the first place.  I would like to be able to 
> accomplish this
> without another transform, but I cannot seem to come up with 
> the correct
> XPath.. :(
> 
> Well, back to the XSL; thanks in advance!
> 
> Michael Peet
> Software Engineer
> Choice One Communications
> 100 Chestnut Street, Suite 600
> Rochester, NY 14604
> mpeet@xxxxxxxxxxxxxxxx
> (585) 530-2773
> 
>  XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list
> 

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list