$interval invokes `$rootScope.$digest()` regardless of `invokeApply` param

[wmadden]

$interval() uses a $q deferred to notify its callback function each tick and the $QProvider wraps all callbacks in $rootScope.$evalAsync which executes them inside the next $digest loop.

This means that the final line of $interval has no useful effect:

if (!skipApply) $rootScope.$apply();

and the invokeApply param is very misleading since regardless of what value it holds $interval will cause a full $rootScope.$digest() with every invocation.

It might be better to have $interval and $timeout functions available on a $scope instance so that a) they get cleaned up when the scope is destroyed, b) they only cause their $scope instance to be dirty checked.

[erwinmombay]

+1, even with the skipApply option set to false the still causes digest cause of the evalAsync

[n8agrin]

We noticed this as well when trying to understand why any $interval use triggered a digest loop, making it unusable for us.