In my view, I want to render:
<p>
  {{ say() }}
</p>
Where say is defined as such: 
say = function() {
  return "Hello World";
}
I can define it in my controller:
function TestCtrl($scope) {
  $scope.say = function() { ... };
}
But then it's only accessible within that controller.
If I define the function outside the Angular file structure, it renders nothing. Same if I define it in my controllers.js file, but outside a controller function scope.
Where is the proper place to put my function, so I can render it in any controller?

