In AngularJS, how can I call a directive inside a controller to perform a task?

I have a controller that performs some DB calls and loads content into my $scope accordingly. Everything works perfect. When the calls are complete I run some JS inside the controller in a call back to adjust the height and other attributes of my application. Unfortunately, I'm running this JS in multiple controllers.

I'd like to place the script into a directive so I can run the directive in the controllers callback and only have the JS live in one spot. Other than this being "the correct way" it will make upkeep much easier.