Re: [xsl] XPATH 1.0: Selecting an element attribute starting from a self:: attribute

["Martin Honnen martin.honnen@xxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Malecki, Piotr piotr.malecki@xxxxxxxxxxxxxxxx wrote:

> <library>
>
>              <catalog>
>
>                          <book id="_1" name="Book1"/>
>
>                          <book id="_2" name="Book2"/>
>
>                          <book id="_3" name="Book3"/>
>
>              </catalog>
>
>              <customer>
>
>                          <borrowed bookId="_1"/>
>
>                          <borrowed bookId="_2"/>
>
>              </customer>
>
> </library>
>
> In an appplication (Windows WPF / XAML), my execution context is e.g.
> the element "borrowed" (e.g. <borrowed bookId="_1"/>).
>
> I have to find the name of the book which is referenced as bookId.
>
> So my XPATH expression is like:
>
> "//book[@id=self::*/@bookId]/@name"
>
> Read as: give all books whose id equals to the bookId of the current node.


The context node inside of the predicate
  [@id = self::*/@bookId]
is the "book" element so both
  @id
as well as
  self::*
are evaluated with the "book" element as the context node and
  self::*
simply selects that "book" element.