ngAnimate + $$RAFProvider : crashes when browser doesn't support requestAnimationFrame or is prefixed with 'moz'

[atomrc]

The RAFProvider is adding a supported property to indicate whether the browser supports or not the requestAnimationFrame (see

angular.js/src/ng/raf.js

Line 18 in 04d7317

raf.supported = !!requestAnimationFrame;

) but the ngAnimate doesn't check this property before using it (see https://github.com/angular/angular.js/blob/master/src/ngAnimate/animate.js#L261).

I would be happy to make a pull request on this but my question is :
is it best to add a fallback on a timeout directly in the RAFProvider or to check for the supportedproperty every time it is used ?

I think just adding the mozRequestAnimationFrame would be a good start.

[matsko]

Yes let's add mozRequestAnimationFrame. All browsers that support CSS animations/transitions also support RAF, therefore, there is no reason to fallback to timeout anymore.

I didn't think that Firefox still needed it. I guess the error showed up on an older version of FF.

[matsko]

Can you verify that adding mozRequestAnimationFrame and mozCancelAnimationFrame fixes the issue?

[atomrc]

Yes indeed the error occurs in an old version of FF (20).
The fact is that if the browser doesn't support RAF (I am thinking of IE8 for example) the code will simply crash.
What is weird is that there is the property supported (false if the browser doesn't support rAF) but it is never checked wherever the rAF service is used.

[mgol]

@matsko

All browsers that support CSS animations/transitions also support RAF

That's not true. Opera has had transitions since 10.5 (which is really old) and even the latest Presto-based version, 12.16 doesn't have rAF. Opera Presto is still popular in some countries like Russia.

[matsko]

Right. Yes. My mistake on this. I'm putting together a patch that uses the $timeout code with a low value: $timeout(callback, 1000 / 60); and updating the tests to support it.

[mgol]

@matsko If you're putting the timeout in, maybe the moz-prefixed version doesn't matter anymore? Hardly anyone uses old Fx versions so it's mostly so that they work, not necessarily in the most performant way.

Angular 2.0 is a rewrite anyway so the $timeout fallback will live in Angular 1.x forever.

[tbosch]

I agree with @mzgol, e.g. Android 2.3 browsers don't support rAF but do support CSS transitions/animations.

[mgol]

@tbosch Not only 2.3. :) No Android Browser version supports requestAnimationFrame, only Chrome mobile does: http://caniuse.com/requestanimationframe

[dcherman]

Why are we adding this? Per the browser support policy at https://docs.angularjs.org/misc/faq#what-browsers-does-angular-work-with-, only the latest versions of Firefox are supported; it's a hard sell to consider 20 as a new version.