Re: Is EventData really optional for LinkCondition that may have one ?

Andreas Kraft (kraft@fokus.gmd.de)
Thu, 22 Jan 1998 15:34:49 +0100 (MET)

Emmanuel,

first, I agree with Guido that a Link which triggers on an event but has no
defined event data fires on every event of this type.

On Tue, 20 Jan 1998, Emmanuel BEUQUE wrote:
> BTW, if this is possible, I don't think any clarification needed but
> perhaps a note could prevent any confusion when reading the standard. In
> fact, when reading the standard, it seems not obvious to me whether the
> EventData attribute is optional because some EventType cannot have an
> EventData or the EventData is optional even for other EventTypes.

I think the text in section 13.1.2, part 4 is ok. But we need a clarification
in 5.6 ("Overview of the MHEG-5 Classes", Link) where this "feature" is not
mentioned.
What do you think?

> If the EventData is always optional, I understand the need of the
> GetLastEventData action of Recommandation 18 from WG12. In the example
> given above, it is very interesting in my opinion to be able to define only
> one link and to get the index of the item selected in a variable because
> sometimes, you can not expect how many items your ListGroup may contain.

Right, this is one of the useful puposes of the "GetLastEventData" action.

> I only missed the first discussions of the MUG (I know I could check the
> archives) but I have never seen anything discussed about this
> GetLastEventData action to be added. Could it be possible to know in which
> area this issue needs further discussion, as stated in the WG12
> recommandations ?

Right, there was no discussions on the MUG concerning this event. As this
resolution states it is a recommendation from the MHEG ISO meeting in
Stockholm this summer. There were some discussions and it came up that this
actions might be a good solution. I can not remember what the actual subject
of the discussion was, can anybody of the participants help me with that?

Best regards,

Andreas

--
  o  _     Andreas Kraft
 (\_|_)      GMD FOKUS, kraft@fokus.gmd.de, +49 30 3463-7232
 T> ] [        The sky is the limit