Re: [MathML3-last-call] PMML @title attribute

Christoph,
 
There has been a lot of discussion about how to deal with attributes from other markup languages when mixed with MathML in a compound document format.  
 
In terms of providing tooltip functionality within MathML in isolation, there is already support via <maction actiontype="tooltip">...</maction> which has been in MathML a long time, and that MathML 3 now elevates to normative status. Consequently, there isn't much appetite for introducing another mechanism via a title attribute.
 
Of course, I think you are primarily interested in the situation in a coupound document format, namely XHTML+MathML+SVG.  In that situation, there is more of a case for allowing attributes from the containing document markup language to be used on MathML elements. In 6.4 Combining MathML and Other Formats, the last call draft states that attributes from non-MathML namespaces are permitted when defining compound document formats.  There have been several last call comments about compound document formats, and we will be revising the language of 6.4 shortly to make it clearer that so long as the CDF specifies the expected behavior, it is allowed (or even encouraged) to specify that attributes from non-MathML namespaces on MathML element when natural and reasonable.
 
However, in the particular case of the XHTML title attribute, it isn't in any namespace, and so even lax rules permitting attributes from other namespaces in compound documents wouldn't help.  The only way to handle it would be to add a MathML attribute also called title, and say it does the same thing as the XHTML title attribute.  Since that would again lead to redundant mechanisms for tooltips in MathML itself, the Math WG doesn't want to take that step.
 
Finally, I expect there is an element of pragmatism in your question, since as you note, using the title attribute works in Firefox today, and <maction actiontype='tooltip'> does not.  It sort of does, in that it only displays the base expression, and not the tooltip message child. Of course, <maction> does work in IE+MathPlayer, but @title doesn't.  There are various JavaScript + CSS workarounds, and so on, but admittedly the current state of implementation leaves a lot to be desired.  
 
--Robert
 
------------------ Original Message -----------------
Dear all,

  has a @title attribute for presentational MathML elements ever been
specified?  Firefox supports it (and currently displays it as a mouse-over
tooltip), and we are using it in our applications.  However, I don't see it
specified in the MathML 3 WD.  Are we interested in such an attribute?

Cheers,

Christoph

-- 
Christoph Lange, Jacobs Univ. Bremen, http://kwarc.info/clange, Skype duke4701


 
Dr. Robert Miner
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