Re: Escher could have drawn it (Re: XML Schema and Entities)

[Jeni Tennison <mail@jenitennison.com>]

Eric van der Vlist wrote:
> Dylan Walsh wrote:
>> Aside from the fact that only global elements have global scope,
>> what are the operations that are only achievable on global
>> elements? I've taken a quick look at the structures recommendation
>> and the primer, and I have not found a list of these. The primer
>> does mention limitations of global elements, that they cannot
>> contain references or have cardinality constraints.
>
> No, I was thinking about the global scope and its consequences.
>
> You can't reference local elements and that means for instance that you
> can't include or import local elements into others schemas.
>
> This has also an impact on your design style since you might be
> using global complex types and element groups to workaround this and
> I am not sure everyone is aware of this issue ;=) ...

Another place where this impacts is on substitution groups - the head
of a substitution group has to be a global element (otherwise the
other elements can't refer to it). Also, as far as I can work out, in
most cases the members of the substitution group will be global as
well (the exception being if you're using the head element within a
type that you later restrict by substituting the head element for the
more specialised element).

Cheers,

Jeni

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