[whatwg] Challenging canvas.supportsContext

[Dean Jackson]

On 25/06/2013, at 5:54 PM, Simon Pieters <simonp at opera.com> wrote:

> On Mon, 24 Jun 2013 23:31:59 +0200, Dean Jackson <dino at apple.com> wrote:
> 
>> Also, the presence of window.WebGLRenderingContext doesn't necessarily indicate
>> that WebGL is supported. On iOS for example, that object is available in Safari
>> but calling getContext('webgl') fails. The supportsContext method would allow
>> authors to easily detect this case.
> 
> Since supportsContext is not supported in Safari on iOS, authors cannot use it to detect this case at all.

I think you missed the point. I know it's not there, which is why we suggested adding it :)

> We could say in the spec that if a UA knows it cannot create a specific context, it must hide the corresponding interface object. This does basically the same thing as supportsContext, except that it would also work for pages that already do feature detection based on the interface object.

Showing or hiding interface objects is not something I want to do. Others on this thread said the same thing.

Dean