W3C home > Mailing lists > Public > w3c-sgml-wg@w3.org > May 1997

RE: SD5 - Namespaces - New Version 2

From: Arjun Ray <aray@q2.net>
Date: Fri, 23 May 1997 15:39:03 -0400 (EDT)
To: w3c-sgml-wg@w3.org
Message-ID: <Pine.LNX.3.95.970523150635.21944A-100000@q2.net>

On Fri, 23 May 1997, Andrew Layman wrote:

> 	2. "Can I use an attribute from one namespace to qualify a GI
> from another namespace?"
> 	I see the namespace as qualifying the GI, so I don't understand
> what it means to "use an attribute . . . to qualify a GI."  This must be
> a misunderstanding on one of our parts.

Sorry, my fault for overloading "qualify". Assuming ':' is the name
component separator, I was basically asking about a construction like

   ... <X:FOO Y:BAR="baz"> ...

where within the same start-tag, an attribute is drawn from some other
namespace than the element. Is this kosher?

> 	3. "If I can't, then does the namespace of the GI fix the
> namespace for its attributes? Could you clarify this, please?"
> [...]  This says nothing
> about whether various attributes or subelements are valid, merely that,
> within a tag, the namespace of the GI is to be used as the namespace for
> unqualified attributes, and within an element, the namespace of the GI
> is to be used as the namespace for unqualified sub-elements.

OK, I take this to mean that in <X:FOO BAR="baz"> BAR comes from the X
namespace. (Aside: one problem with the *term* "namespace" is the usual
connotation of uniqueness within it: yet in DTDs, element names and
attribute names are allowed to "clash". Is this a problem?) 

> 	4.	". . . what happens with colons in attribute names? Will
> there be an extra well-formedness/validation constraint involved?" 
> 	I do intend that attributes come from some namespace, and that
> means that they, too, will need qualification.  So, yes, colons would be
> needed in attribute names. I don't see how this affects the issue of
> well-formedness. (Maybe I am missing some insight.)  

Again, basically, can <X:FOO Y:BAR="baz"> be considered a well-formed
start-tag if attributes from "foreign" namespaces are verboten One way to 
look at this is to ask "Is it part of the XML parser's job to detect
namespaces and report an appropriate parse event to the application?" Or
is the detection of qualified names a job for something downstream? 

Received on Friday, 23 May 1997 15:37:12 UTC

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