Re: key() question?

Hi Steven,

> I have some keys declared for easy access to the attributes declared for
> a specific element, and to retrieve the contentModels in which an 
> element is referred to:
>
> <xsl:key name="attlistbyname" match="/dtd/attlist" use="@ename"/>
> <xsl:key name="contentmodelbychildren" match="//contentModel" 
> use="descendant::element/@name"/>

[A // beginning a pattern (match attribute) is always superfluous --
you're matching "any contentModel element that is a descendant of the
root node" when you may as well match "any contentModel element" since
all elements must be descendants of the root node by definition.]

> My question is how I can easily locate <contentModel> elements which
> don't have an <element> counterpart bearing an attribute 'name' with
> the contentModel/@ename as its value.

If you're looking at a contentModel element, then you can find all the
element elements that have the same name as that contentModel element
using your contentmodelbychildren key with the value of the ename
attribute on the contentModel element:

  key('contentmodelbychildren', @ename)

If there are no element elements returned by the key, then the element
is never referred to from within a content model.

So you can collect all the contentModel elements that don't return any
nodes when their ename attribute is passed to the
'cotentmodelbychildren' key:

  /dtd/contentModel[not(key('contentmodelbychildren', @ename))]
  
Cheers,

Jeni

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


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