Re: Preload/Unload

Klaus Hofrichter (hofrichter@fokus.gmd.de)
Fri, 16 Jan 1998 17:21:38 +0100

Folks,

here is a followup to Emmanuel

> 1. Regarding the provision of use that embarassed Andreas, I'm just asking
> how the content attribute of an Ingredient could be Null.

The intention was to refernence objects which have no content, such as
Rectangle.

> 2. How the Null value shall be interpreted ? Should it be considered as a
> specific value or as no value at all ? In other words, is it equivalent to
> "void" ? In the specific case of Ingredient class content attribute, the
> default value is "none". Should we considered that the default value (no
> value) is equivalent to Null or shall an MHEG engine consider that no value
> is different from Null ? I must admit that this is not completely clear in
> my mind.

I can not see a difference in "none" and "null".

> Anyway, I haven't participated to the meeting where MHEG-5 IS was discussed
> and consequently have no clear idea about the intention that was behind
> this provision of use for Preload/Unload actions.

The idea was to invoce the preparation behavior for initiallyActive
False objects by Preload. The content of InitiallyActive false objects
is not loaded (at least: it is not required) when the Group prepares. I
think that the existence of objects which have no content (but need to
have the preparation behavior) was overseen.

- Klaus

-- 
GMD FOKUS    German National Research Center for Information Technology
Klaus Hofrichter    Kaiserin-Augusta-Allee 31  D-10589 Berlin   Germany
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