[whatwg] Challenging canvas.supportsContext

Ian Hickson ian at hixie.ch
Fri Aug 2 13:26:16 PDT 2013

On Fri, 2 Aug 2013, Benoit Jacob wrote:
> 2013/7/31 Ian Hickson <ian at hixie.ch>
> > On Wed, 31 Jul 2013, Benoit Jacob wrote:
> > >
> > > Ping --- I thought that there was sufficient agreement in this 
> > > thread, around the fact that supportsContext, as currently spec'd 
> > > and currently implementable, is a feature without a valid use case, 
> > > that removing it from the spec is the right thing to do at this 
> > > point.
> >
> > It's on my list of e-mail to get to. Sorry about the delay. I'm 
> > currently about six months behind on feedback that isn't blocked on 
> > other things.
> >
> > In this particular case, I should note that we have at least one 
> > implementation, and we have no alternative solution to the problem for 
> > which the feature was added. So it's not as clear cut as it might 
> > seem.
> As discussed in this thread, the alternative solution is to call 
> getContext and check if it succeeded

That's not an alternative, that's the problem that this method was trying 
to fix in the first place.

> I was arguing that if one wants something reliable and tightly spec'd, 
> there is no alternative to doing the same amount of work; and I was also 
> arguing against the notion that something more loosely spec'd (as 
> supportsContext currently is) was useful to have.

Right -- that's why it's not clear cut. It's not just "this is bad, we 
should drop it", or "this is redundant, we should drop it", the questions 
are more subtle ones: "is this problem worth solving", "is the solution 
good enough", "will it be implemented enough to be worth it", etc. I 
haven't studied the thread in enough detail yet to make an educated 
argument one way or the other.

Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

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