Re: [cgmo-webcgm] ISSUE: what does 'get..' return?

[Lofton Henderson <lofton@rockynet.com>]

At 11:54 AM 4/27/2005 -0400, Benoit Bezaire wrote:
> Wednesday, April 27, 2005, 10:09:58
> AM, Lofton wrote:
>
> LH> Hi WebCGM TC,
>
> LH> I'm working on the DOM test case for ApsAttr 'viewcontext', and
> think that
> LH> we ought to clarify something about the 'get...' methods. 
> Specifically I'm
> LH> working with getAppStructureAttr, section 5.7.6 (but this probably
> applies
> LH> somewhere else as well).
>
> LH> Let's consider the case of 'viewcontext' first.  Section
> 3.2.2.2 says
> LH> "Initial value: none", which is reasonable.  If I
> getAppStructureAttr on an
> LH> APS where there is no explicit 'viewcontext' ApsAttr, then the
> answer
> LH> should be "undefined" (see side-issue about
> "undefined" below).  This is
> LH> the way DOM2 works, so we should stick with that unless we have a
> LH> compelling reason to deviate.
> I've been doing a bit more research on this... All DOM Level 1, 2
> and
> 3 are very clear about the getAttribute() method (similar to
> getAppStructureAttr), they all state that the return value is a
> DOMString or an empty string if the attribute is not specified or
> doesn't have a default (i.e., DTD) value.

Right.  The only issue is whether or not the WebCGM-specific
"Initial value" concept is equivalent to "default (i.e.,
DTD)" value.  We agree that it is NOT.


> Could you send us a pointer to the
> DOM 'undefined' concept?

Sorry, I was sloppy and synthesized the "undefined" from here,
the conceptual description of Interface Attr in DOM2 Core (p.51). 
What it actually says is "does not exist" (see 3rd pgph):
[1]
http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113/DOM2-Core.pdf

Indeed, if I had looked further on p.54, getAttribute method, return
value should be empty string as you said: "...value as a string, or
the empty string if that attribute does not have a specified or default
value."  So my side-issue goes away, thanks.

-Lofton.