Re: unrecognized actiontype in maction

On 29/05/2012 11:13, David Carlisle wrote:
> On 28/05/2012 17:17, Andrii Zui wrote:
>> Hello everyone!
>>
>> While working on my summer project with MathML maction, there was
>> discovered an uncertainty in the REC. In section 3.7.1.1
>> <http://www.w3.org/TR/MathML3/chapter3.html#id.3.7.1.1> it says:
>>
>> By default, MathML applications that do not recognize the specified
>> actiontype should render the selected sub-expression as defined
>> below.
>>
>>
>> and then it goes on to describe the actiontype attribute and the
>> effect of the selection attribute.
>>
>> The question is, how to deal with the selection attribute when we get
>> an unrecognized actiontype? Should the selection attribute on maction
>> be considered by default?
>>
>> -- Andrii Zui
>
> I think that is fairly unambiguous that "the selected sub-expression as
> defined below" means "the child specified by the selection attribute"
> so yes, my reading is that the selection attribute should always be
> used, and if it refers to a missing child then that is an error.
>
> David
> [personal response not checked with WG] 
There are four predefined action types: "toggle", "statusline", 
"tooltip", "input". For the first one, the expected behavior with 
respect to the "selection" attribute is clearly defined. However, for 
the three others this attribute does not seem to make sense. Firefox 
always took into account the selection attribute whatever the specified 
action type, but Andrii changed this and now this attribute is ignored 
for all but toggle. So the real question is: what to do when the 
actiontype is not among those defined in the spec, or not specified at 
all? Andrii is preparing a patch to do this:

- If the actiontype is not specified, is is an error: display an 
"invalid markup" message (as Firefox does e.g. when an msup has only one 
child)
- If the actiontype is unknown, take into account the selection 
attribute (that may help people to implement via javascript custom 
actiontype like "menu" described in MathML 1)

Does that make sense?

Received on Tuesday, 29 May 2012 09:29:39 UTC