Dynamic view slide animation

Hey guys, I’m trying to set the animation dynamically.

I was hoping that this would work : <ion-nav-view animation="{{nextAnimationVariable}}"> but unfortunately, it seems that the code in double braces is not being parsed.

I modified a pen by ionic to illustrate my issue : http://codepen.io/anon/pen/zkiBL, in this I have tried to bind the animation attribute to a variable (just like I mentioned above) which in is defined in MainCtrl

Any suggestions on how to do this?