Re: [xml-dev] Concerned about the increasing reliance on XPath

["G. Ken Holman" <gkholman@CraneSoftwrights.com>]

At 2011-05-09 16:49 +0100, Stephen D Green wrote:
>I think we tend to hope that XPath expressions can be
>written such that they are immune from such implementation
>specifics

XPath cannot function in a vacuum.

>  (like we would love to do with HTML) and we rush
>into using it for standards and for writing XML Schema
>schemas and Schematron schemas hoping that these too will
>be implementation agnostic. Is that realistic? Is this the case
>of our over-relying on it? Maybe in future XPath will become
>what we need it to be but is it that yet?

As XPath syntax does not include namespace URI binding, it is the 
responsibility of the outside environment to supply such bindings, 
for two examples:

   XPath2:
     default namespace:   xpath-default-namespace="{uri}"
     prefixed namespaces: XML namespace declarations in context

   XQuery:
     default namespace:   declare default element namespace "{uri}";
     prefixed namespaces: declare namespace prefix="{uri}";
     prefixed namespaces: XML namespace declarations in context


To operate without such external fulfillment, it would be necessary 
to introduce XPath syntax to accomplish namespace bindings.

I hope this helps.

. . . . . . . . . Ken

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