targetnamespace - what is it?!?!

hi there,

i'm reading up on schema - but am probably missing something obvious RE
targetnamespace

i know there can only be one...

is it that the elements which are defined in the schema which have no
prefix are somehow now part of the namespace - would it need to upload the
definitions?

it says
targetnamespace - 'namespace to which all global schema components belong'

but what the point of that - there is already a default namespace
xmlns="http://....."

and anyway - what is a 'global schema component'?

thanks for ANY help?

kev bailey

kevin bailey

gabriel wrote:

> targetNamespace = "THIS" says that "this schema describes elements that
> belong to THIS namespace". So it sorts of defines a namespace. Then it can
> get more complicated of course, for instance several schemas can define
> parts of the same namespace. Let's say one schema describes a "car"
> element in namespace "asdflj234lk234/namespaces/vehicels", and another
> schema defines a "truck" element in the same namespace.
>
> The xmlns= "THIS" says that all elements and attributes that are NOT
> prefixed belong to THIS namespace.
>
> A global comonent (element) is defined at the "top level" of a schema
> document. The "car" element is the at the top level, and then I might
> define that it has wheels elements within the car element. The wheels
> elements are not global then, they are local.
> Global elements can be used several times, in different places and levels
> (not top level again though).
>
> a bit more advanced:
> However, I COULD define a wheel element on the toplevel as well, and thus
> make it global. They would not be WITHIN the car element then. I could
> then say that a car has wheels by defining an element within the car that
> _references_ the global wheel elements with the ref attribute.
> If and instance was checked against this schema, it would conform if
> 1) it had a car element with wheels in it
> 2) it had a wheel only
>
> This is because there is no in XSDL way to define a root element. All
> global elements CAN be the root! (Personally I think that sucks
>
>

thanks loads for the reply - after reading it a couple of times it has
certainly helped to clear some of the mist!!

am i right in thinking that the targetnamespace is useful when a schema is
made up from several xsd files all linked together via
import/include/redefine - it means then that another part of the schema can
reference an element by using its namespace?

kev bailey


> /Gabriel - new to XML as well
>
>
>
> "kevin bailey" <> skrev i meddelandet
> news:bd9vea$77r$1$...
>> hi there,
>>
>> i'm reading up on schema - but am probably missing something obvious RE
>> targetnamespace
>>
>> i know there can only be one...
>>
>> is it that the elements which are defined in the schema which have no
>> prefix are somehow now part of the namespace - would it need to upload
>> the definitions?
>>
>> it says
>> targetnamespace - 'namespace to which all global schema components
>> belong'
>>
>> but what the point of that - there is already a default namespace
>> xmlns="http://....."
>>
>> and anyway - what is a 'global schema component'?
>>
>> thanks for ANY help?
>>
>> kev bailey