Yet another stupid namespace question...

Dean Roddey droddey at
Wed Jul 7 01:45:39 BST 1999

Ok, so I'm looking forward to implementing Schema support in XML4C/J, and
maybe I'm missing something, but I want to make sure.

Ok, lets say we have an element declaration, in Schema terms in this case so
it defines both the URI and the name of the element being declared.

Now, I see an element in the document content that I need to scan and
process the attributes of. But, lets say that one of the attributes of the
element, one that defines the default namespace of that element, is
defaulted in in the element declaration's attribute list.

I have to look up the element declaration in order to validate the
attributes and/or fault in defaulted and fixed attributes. However, since we
are now in the new Schema world, I have to know the full {uri}name form of
the name in order to look it up, because its no longer a lexical lookup in
the Schema world.

But, I cannot look up the element declaration until I know the URI that
applies to the element name. If the element name has no prefix, then it
falls under the default namespace (which can be set by one of its own
attributes.) But, since I cannot know the name of the element until I can
resolve the URI it belongs to, I cannot know whether there is a defaulted or
fixed attribute of that element which might set the default namespace
(because I cannot look up the element declaration.)

So, am I missing something or is this a Catch-22? Does this mean that Schema
cannot allow defaulting or fixing of namespace attributes because of the new
need to to logical lookup of element declarations, instead of lexical?

Dean Roddey
The CIDLib Class Libraries
Charmed Quark Software
droddey at

"100% Substance Free. Less Content, more cost. Just the way you like it"

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