Re: [xsl] variable question

[Jeni Tennison <jeni@xxxxxxxxxxxxxxxx>]

Hi Geert,

> Is it allowed to use a function-call at the end of a path
> expression? That must be new in XPath 2. It wasn't allowed in 1.0,
> which was a pity in some occasions as it would have prevented the
> need of the node-set function...

Yes, in XPath 2.0 *any* step in a path can be *any* kind of expression
-- these are known as "general steps", as opposed to "axis steps",
which are the normal kind we know and love.

Function calls are particularly useful, as in:

  $documents/key('mykey', $myvalue)

It's also really helpful to be able to use unions in steps, as in:

  table/(thead | tfoot)/tr

There's one restriction, though, in that general steps must return
nodes (rather than atomic values). This restriction is lifted only for
last step in a path, which can return atomic values instead (though
it's not permitted for it to return atomic values in some cases and
nodes in other cases).

In other words, you can do things like:

  keyword/lower-case(.)

but you can't do:

  keyword/lower-case(.)/substring-before(., '-')
  
Cheers,

Jeni

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