Remove @condition from animation, head, layout, resources, styling, tt elements.

[skynavga]

At present, the @condition attribute can apply conditionalization to the grouping elements animation, head, layout, resources and styling. However, only one of each of these grouping elements are permitted, and, consequently, a false condition on any of these would, respectively, remove all out-of-line animations, all out-of-line regions, all referential styling, etc., as a whole.

I am at a loss to find any concrete use case for such conditionalization scenarios to offset the complexity of supporting @condition in these contexts. Therefore, I propose we drop @condition from these element types.

[nigelmegitt]

What about the tt element itself?

[nigelmegitt]

I think this is right, but would like to double check with the WG before approving.

[css-meeting-bot]

The Working Group just discussed Remove @condition from animation, head, layout, resources, and styling elements. ttml2#704, and agreed to the following resolutions:

• SUMMARY: WG agrees to implement this issue, noting that body element can still be conditionally excluded.

The full IRC log of that discussion

<nigel> Topic: Remove @condition from animation, head, layout, resources, and styling elements. ttml2#704
<nigel> github: https://github.com//issues/704
<nigel> Nigel: The question here is if there is any use case or requirement for conditionalising the
<nigel> .. tt element itself? I think Glenn and I agree that it is not needed. I just wanted to check if
<nigel> .. there are any other views.
<nigel> Glenn: Note that condition is still permitted on the body element, so some of the possible
<nigel> .. use cases for conditionalising tt are based on that.
<nigel> s/based on that/still possible using that.
<nigel> Nigel: Just to check, if we put condition on body does that imply that there can be more than
<nigel> .. one body element, and that one must be selected prior to validation? How would that work with an XSD validator?
<nigel> Glenn: No, there would only be one, and it could merely be excluded or included.
<nigel> Nigel: Oh I see, harsh, but that works!
<nigel> Glenn: Can I mark this as discussed and agreed?
<nigel> Nigel: I think so, yes.
<nigel> SUMMARY: WG agrees to implement this issue, noting that body element can still be conditionally excluded.
<nigel> Nigel: I will approve the pull request then.