ISSUE: Rules for cascaded profiles from WebCGM 2.0?

["Cruikshank, David W" <david.w.cruikshank@boeing.com>]

I'm trying to restate an issue Dieter (and Lofton) have raised in the past.  They can correct me if I have it wrong.

Question:  Does WebCGM 2.0 need to provide guidance (rules) for creating cascaded profiles?

Examples of things that could occur  in a cascaded profile:

1)  An industry profile could restrict the use of standard WebCGM APS types and attributres

This could happen, for example, in the S1000D profile where they currently restrict WebCGM APS types to grobject and restrict WebCGM APS attributes to name region and viewcontext.  Does that mean that the viewer has to handle exceptions if DOM interface calls are made to add non-allowable APS types or attributes?  Probably not.

Similarly, the industry XCF DTD might be more restrictive than the WebCGM generic DTD and have namespace extensions.  The compliant XCF instance would parse successfully against the industry DTD and would also  parse successfully against the WebCGM DTD with the namespace extensions.  This probably is not a problem.

2)  An industry profile might have a restriction on which DOM interfaces and methods are allowed to be called

Does the view software have to check that illegal calls are not made according to a profile?  Probably not.

3)  An industry profile might try to expand the DOM to set style properties

If an industry defined what it considered a function to change line type, would a viewer be required to support that industry specific type function through the DOM?  I don't think so.

4)  An industry profile might try to insert semantics into namespace elements and attributes assuming the viewer should implement the semantics

As an example S1000D currently  has an attribute "visibility" that has possible values of "visible" or "hidden".  Should the viewer have to deal with S1000D:visibility the same way it deals with the WebCGM visibility attribute.  I don't think so.  I would be up to the script writer to make the conversion between the two attributes and make the appropriate DOM calls.

Those are the four cases I can document.

thx...Dave Cruikshank

Technical Fellow - Graphics/Digital Data Interchange
Boeing Commercial Airplane
206.544.8876, fax 206.544.9590
david.w.cruikshank@boeing.com