AngularJS: Controller inheritance using call (or apply)

Question

This is something I discovered when trying to make my controllers more reusable.

app.factory('BaseController', function(myService) {
  return function(variable) {
    this.variable = variable;
    this.method = function() {
      myService.doSomething(variable);
    };
  };
})

.controller("ChildController1", function($scope, BaseController) {
  BaseController.call($scope, "variable1");
})

.controller("ChildController2", function($scope, BaseController) {
  BaseController.call($scope, "variable2");
});

And now I can do something like this in my HTML (e.g inside ng-controller="ChildController1"): ng-click="method()"

The code simply works. But I don't know how it really works (what kind of pattern is it?) and would it be a good practice to do so?

Answer 1

Your solution works more or less like this:

app.factory('mixinBaseController', function(myService) {
  return function (scope, variable) {
    angular.extend(scope, {
      variable: variable;
      method: function() {
        myService.doSomething(variable);
      }
    });
  };
})

.controller("ChildController1", function($scope, mixinBaseController) {
  mixinBaseController($scope, "variable1");
})

.controller("ChildController2", function($scope, mixinBaseController) {
  mixinBaseController($scope, "variable2");
});

Can you see? By your .call($scope, ...) is just setting the context (this) to the real $scope and this way the BaseController just extends your scope with properties and functions.

This is only to demonstrate how your code works.

To achieve a more JavaScript like inheritance, please see:

• Can an AngularJS controller inherit from another controller in the same module?
• AngularJS controller inheritance
• AngularJS Inheritance Patterns
• Two Approaches to AngularJS Controller Inheritance

You should as well have a look at the "controllerAs" syntax introduced in AngularJS 1.2. I highly recommend to use controllerAs. This also should help to implement inheritance for your controllers.