Slider's aria-disabled attribute does not update

[marcysutton]

On a material-slider with a disabled expression such as ng-disabled="color.green < 125", aria-disabled does not update to true along with the presence of the disabled attribute. It looks like updateAriaDisabled() should be routed through the $watch function, but it isn't being fired when the disabled condition is met.

A little more about the disabled attribute: it's not semantically valid on a custom element without extending a native element such as input via a Web Component. http://www.w3.org/TR/html5/disabled-elements.html
I wonder if it makes sense to only use aria-disabled for the current state since there is also disabled and ng-disabled? Attribute city.

[ajoslin]

Found the problem: slider was trying to watch the ngDisabled expression on its own scope, which is an isolate scope.

The ngDisabled expression always evaluated to false because the value is undefined.

Fix: use scope.$parent.$watch(attr.ngDisabled)