Target namespace in WSDL

Both WSDL and XML Schema have the notion of a target namespace. In XML
Schema this property can be absent, denoting constructs that are not
affiliated with a particular namespace. This was necessary because XML
Schema describes XML instances, and elements in an XML instance may be
unqualified ( not affiliated with a namespace ). 

The question I would like to pose is 'Does it makes sense to allow the
target namespace property of WSDL components to be absent?'. And I will
argue that it does not. WSDL does not describe XML instances, it
describes messages, portTypes, bindings and services. I think it makes
sense to mandate that these contructs always be affiliated with a
namespace.

To this end, I propose that we mandate the 'targetNamespace' AII on the
definitions EII. And that we modify the spec to say that the value of
the AII must be a non-zero length URI.

Changes to spec

Section 3.1

Add a bullet between current bullets 2 and 3;

* A target namespace attribute information item amongst its [attributes]
as described below


Section 3.1.1

Add a third bullet

* A type of anyURI in the http://www.w3.org/2001/XMLSchema namespace

Add prose

The value of the targetNamespace attribute information item MUST NOT be
the empty string.



Gudge