AngularJS directive controllers requiring parent directive controllers?

Question

AngularJS directive controllers requiring parent directive controllers?

I might be thinking about this completely backwards, but I'm trying to make three nested directives, lets call them: screen, component and widget. I want widget to be able to trigger some behavior in component, which in turn triggers some behavior in screen. So:

.directive('screen', function() {
    return {
        scope: true,
        controller: function() {
            this.doSomethingScreeny = function() {
                alert("screeny!");
            }
        }
    }
})

.directive('component', function() {
    return {
        scope: true,
        controller: function() {
            this.componentFunction = function() {
                WHAT.doSomethingScreeny();
            }
        }
    }
})

.directive('widget', function() {
    return {
        scope: true,
        require: "^component",
        link: function(scope, element, attrs, componentCtrl) {
            scope.widgetIt = function() {
                componentCtrl.componentFunction();
            };
        }
    }
})

<div screen>
    <div component>
        <div widget>
            <button ng-click="widgetIt()">Woo Hoo</button>
        </div>
    </div>
</div>

I can require parent components in a widget's link fn using require: "^component", but how do I further give components controller access to its containing screen?

What I need is the WHAT in component so when you click the widget's button it alerts "screeny!".

Thanks.

angularjs
angularjs-directive
angularjs-scope

Answer 1

Here are two ways you could solve your problem:

Since you are using scope: true, all scopes prototypically inherit. So if you define your methods on $scope instead of on this in the screen controller, then both component and widget will have access to function doSomethingScreeny.
Fiddle.
Define a link function on component and require: '^screen'. In the link function, save the screenCtrl to a scope property, then you can access it in the directive's controller (inject $scope).
Fiddle.

Answer 2

Most of this stuffs fails when you want to directly access properties or methods from the parent controller on controller creation. I found another solution by using dependency injection and using the $controller service.

.directive('screen', function ($controller) {
    return {
       require: '^parent',
       scope: {},
       link: function (scope, element, attr, controller) {
           $controller('MyCtrl', {
                $scope: scope,
                $element: element,
                $attr, attr, 
                controller: controller
           });
       }
    }
})

.controller('MyCtrl, function ($scope, $element, $attr, controller) {});

This method is better testable and does not pollute your scope with unwanted controllers.