Re: [uiml] Summary of issues raised by Takashi Endo and suggested UIML 4.0 changes

["Jim Helms" <jhelms@gmail.com>]

Robbie, thanks for you input!  Additional comments below.

On 12/3/07, Robbie Schaefer <robbie@c-lab.de> wrote:
> > Suggested change: add an attribute to <variable> called "id-ref" that
> > is used to reference a variable after it is declared.
>
> We had thought of this when designing DISL and the current sulution in the
> UIML-DTD is that we have an additional attribute for the variable which
> specifies wether it is used as a declaration or as a reference: reference
> (true|false) "true".
>
> However if all agree that id-ref is the more proper/consitent solution
> (since it is used in other UIML-elements in the same fashion) I could go
> through the relevant parts in the spec and change the examples and
> explanations.
>
> The point in favor of the "reference"-Attribute is that it is implicitly set
> true, so that only once, for the declaration, a variable needs to state the
> reference attribute, which IMHO adds to the readability of the
> UIML-document.
>
> Anyway, I am open to both options.

That is a good point.  I like the way DISL handles this, but we have
two considerations: 1) UIML sets a precedent with the <property>
element that establishes "name" as the way to reference an existing id
without conflicting; and 2) the additional reference attribute still
leaves us with the issue of having conflicting id's.  The DISL
approach is very good for readability, but I think the problem Mr.
Endo had was related to limitations of the DOM specification that only
allows you to look up single elements by id.  One way to solve this
and use the DISL scheme would be to use a different attribute as the
name of the variable and have an id attribute that's sole purpose is
to uniquely identify the element within the document.

Whatever we decide, I believe we should choose a consistent scheme to
handle this for <property>, <variable>, and <param>.  Thus using id in
the declaration and name for the references may serve for this version
of the specification with further improvements to come in the next
version.

Just my thoughts :)
Jim