Accessing current scope's controller instance alias from within directives?

[gsklee]

Say I've got:

<div ng-controller="NavCtrl as nav">
    <button app-hmm>Turn Red</button>
    <p ng-class="{
        'red': nav.active
    }"></p>
</div>

directive('appHmm', function(
){
    return {
        link: function(scope, element, attrs) {
            foo();
            bar();

            /*
            // I'd like to set `nav.active = true` here without hard-coding `nav`
            */
        }
    };
})

Is there a way to do it currently? If not, perhaps add a way to retrieve the current scope's controller instance alias from within directives?

[gsklee]

Right now I need to do this after the v1.2 isolate scope change which is kinda crappy:

directive('appHmm', function(
    Nav
){
    return function(scope, element, attrs) {
        foo();
        bar();

        Nav.active = Nav.active ? false : true;
        scope.$apply();
    };
}).

factory('Nav', function(
){
    return {
        'active': false
    };
}).

controller('MainCtrl', function(
){
    this.Nav = Nav;
});

[CWSpear]

The good ol' fashioned way with an isolate scope, passing in the variable you want to to go back and forth, e.g. scope: { state : '=' } in the directive, adding state="nav.active" on the button and then toggling scope.state in the directive.

Working example plnkr: http://plnkr.co/edit/csOPju9atijfFPATIPbH?p=preview

[gsklee]

I know this method but I don't know if I like it. I'm interested to know if it's a design decision that the current scope's controller instance is not being passed in, or is it simply an oversight.

[CWSpear]

I believe it's not only a design decision but a _feature_. The "way" to make directives re-usable and controller-independent.

Directives have their own controllers that can be passed in between other directives via require to communicate between each other. And there is also Angular's pub/sub abilities where you could

$rootScope.$broadcast('eventName', varName);

in the directive and

$scope.$on('eventName', function (event, varName) { ... });

in the controller.

[vojtajina]

A directive can get a controller:

module.directive('appHmm', function() {
  return {
    controller: function Ctrl() {},
    link: function(scope, elm, attrs, ctrl) {
      assert(ctrl instanceof Ctrl);
    }
  };
});

You can also get hold or other directive's controllers using require, see http://docs.angularjs.org/guide/directive.

I don't see any issue. Closing. Thanks @CWSpear !