There are some specific scenarios specially when you manipulate the DOM with ng-repeat directive. Lets imagine we have a code that prints a list of element using an ng-repeat. In your controller you have a code to instantiate a bootstrap tooltip for all the elements that are going to be rendered when the ng-repeat is compiled by AngularJs. As a best practice it is better to place this type of code in a directive, for this example purpose, we are going to keep it simple and leave it in the controller.

This page concerns on how to pass parameters on angular-translate.