Route-Dependent CSS Page Transitions in AngularJS - angularjs

Question

I am new to AngularJS and would like to implement route dependent page transitions. For example, I would like the page to slide left, slide right or fade depending on the route.
My 'Plunker' below achieves this by listening to the $routeChangeSuccess event and then applying a transition style specific CSS class to the entering and leaving view (inspired by http://phillippuleo.com/articles/scalable-approach-page-transitions-angularjs):
http://plnkr.co/edit/ee4CHfb8kZC1WxtDM9wr?p=preview
However, the call to $scope.$apply() in the event listener makes AngularJS issue an error message '$digest already in progress'. But if I don't call $scope.$apply() the CSS class of the leaving view is not updated and the animation does not work correctly.
What is going on here?

Answer 1

I looked in your plunker. The problem is with the way you use classes to animate your views.
When the $routeChangeSuccess event is fired, ngView had already removed the class before you get the chance of changing the direction. You override it by applying the new class so quickly so it would not be noticed but then you get the digest in progress error.
My solution (plunker):
I came up with a directive:
app.directive('animClass',function($route){
return {
link: function(scope, elm, attrs){
var enterClass = $route.current.animate;
elm.addClass(enterClass);
scope.$on('$destroy',function(){
elm.removeClass(enterClass);
elm.addClass($route.current.animate);
})
}
}
});
Declare an animate option for each route:
app.config(function($routeProvider) {
$routeProvider.
when("/page1", {
templateUrl: "page1.html",
controller: "Page1Ctrl",
animate: "slideLeft"
}).
when("/page2", {
templateUrl: "page2.html",
controller: "Page2Ctrl",
animate: "slideRight"
}).
otherwise({
redirectTo: "/page1"
});
});
And just add it to ngView like so:
<div ng-view ng-controller="ViewCtrl" anim-class class="view"></div>
css:
.view {
width: 100%;
padding-left: 1em;
position:absolute;
top: 0;
left: 0;
}
.slideLeft.ng-enter, .slideLeft.ng-leave, .slideRight.ng-enter, .slideRight.ng-leave {
-webkit-transition:all 1s;
transition:all 1s;
}
.slideLeft.ng-enter {
left:100%;
}
.slideLeft.ng-enter.ng-enter-active {
left:0;
}
.slideLeft.ng-leave.ng-leave-active {
left:-100%;
}
.slideRight.ng-enter {
left:-100%;
}
.slideRight.ng-enter.ng-enter-active {
left:0;
}
.slideRight.ng-leave.ng-leave-active {
left:100%;
}

Answer 2

Currently my approach to this is to check whether angular is already within a digest cycle or not by using this snippet:
if (!($scope.$$phase)) $scope.$apply();
That's not very pretty, but unfortunately it's the only approach I've discovered so far for exactly the problem you're describing.