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Can an AngularJS controller inherit from another controller in the same module?

Posted by: admin November 2, 2017 Leave a comment

Questions:

Within a module, a controller can inherit properties from an outside controller:

var app = angular.module('angularjs-starter', []);

var ParentCtrl = function ($scope, $location) {
};

app.controller('ChildCtrl', function($scope, $injector) {
  $injector.invoke(ParentCtrl, this, {$scope: $scope});
});

Example via: Dead link: http://blog.omkarpatil.com/2013/02/controller-inheritance-in-angularjs.html

Can also a controller inside a module inherit from a sibling?

var app = angular.module('angularjs-starter', []);

app.controller('ParentCtrl ', function($scope) {
  //I'm the sibling, but want to act as parent
});

app.controller('ChildCtrl', function($scope, $injector) {
  $injector.invoke(ParentCtrl, this, {$scope: $scope}); //This does not work
});

The second code does not work since $injector.invoke requires a function as first parameter and does not find the reference to ParentCtrl.

Answers:

Yes, it can but you have to use the $controller service to instantiate the controller instead:-

var app = angular.module('angularjs-starter', []);

app.controller('ParentCtrl', function($scope) {
  // I'm the sibling, but want to act as parent
});

app.controller('ChildCtrl', function($scope, $controller) {
  $controller('ParentCtrl', {$scope: $scope}); //This works
});

Questions:
Answers:

In case you are using vm controller syntax, here is my solution:

.controller("BaseGenericCtrl", function ($scope) {

    var vm = this;
    vm.reload = reload;
    vm.items = [];

    function reload() {
        // this function will come from child controller scope - RESTDataService.getItemsA
        this.getItems();
    }
})

.controller("ChildCtrl", function ($scope, $controller, RESTDataService) {
    var vm = this;
    vm.getItems = RESTDataService.getItemsA;
    angular.extend(vm, $controller('BaseGenericCtrl', {$scope: $scope}));
})

Unfortunately, you can’t use $controller.call(vm, 'BaseGenericCtrl'...), to pass current context into closure (for reload()) function, hence only one solution is to use this inside inherited function in order to dynamically change context.

Questions:
Answers:

I think,you should use factory or service,to give accessible functions or data for both controllers.

here is similar question —> AngularJS controller inheritance

Questions:
Answers:

In response to the issue raised in this answer by gmontague, I have found a method to inherit a controller using $controller(), and still use the controller “as” syntax.

Firstly, use “as” syntax when you inherit calling $controller():

    app.controller('ParentCtrl', function(etc...) {
        this.foo = 'bar';
    });
    app.controller('ChildCtrl', function($scope, $controller, etc...) {
        var ctrl = $controller('ParentCtrl as parent', {etc: etc, ...});
        angular.extend(this, ctrl);

    });

Then, in HTML template, if the property is defined by parent, then use parent. to retrieve properties inherited from parent; if defined by child, then use child. to retrieve it.

    <div ng-controller="ChildCtrl as child">{{ parent.foo }}</div>

Questions:
Answers:

Well, I did this in another way. In my case I wanted a function that apply the same functions and properties in other controllers. I liked it, except by parameters. In this way, all yours ChildCtrls need to receive $location.

var app = angular.module('angularjs-starter', []);

function BaseCtrl ($scope, $location) {
    $scope.myProp = 'Foo';
    $scope.myMethod = function bar(){ /* do magic */ };
}

app.controller('ChildCtrl', function($scope, $location) {
    BaseCtrl.call(this, $scope, $location);

    // it works
    $scope.myMethod();
});

Questions:
Answers:

As mentioned in the accepted answer, you can “inherit” a parent controller’s modifications to $scope and other services by calling: $controller('ParentCtrl', {$scope: $scope, etc: etc}); in your child controller.

However, this fails if you are accustomed to using the controller ‘as’ syntax, for example in

<div ng-controller="ChildCtrl as child">{{ child.foo }}</div>

If foo was set in the parent controller (via this.foo = ...), the child controller will not have access to it.

As mentioned in comments you can assign the result of $controller directly to the scope:

var app = angular.module('angularjs-starter', []);
app.controller('ParentCtrl ', function(etc...) {
    this.foo = 'bar';
});
app.controller('ChildCtrl', function($scope, $controller, etc...) {
    var inst = $controller('ParentCtrl', {etc: etc, ...});

    // Perform extensions to inst
    inst.baz = inst.foo + " extended";

    // Attach to the scope
    $scope.child = inst;
});

Note: You then must remove the ‘as’ part from ng-controller=, because you are specifying the instance name in the code, and no longer the template.

Questions:
Answers:

For those wondering, you can extend component controllers in the same fashion, using the method in the accepted answer.

Use the following approach:

Parent component (to extend from):

/**
 * Module definition and dependencies
 */
angular.module('App.Parent', [])

/**
 * Component
 */
.component('parent', {
  templateUrl: 'parent.html',
  controller: 'ParentCtrl',
})

/**
 * Controller
 */
.controller('ParentCtrl', function($parentDep) {

  //Get controller
  const $ctrl = this;

  /**
   * On init
   */
  this.$onInit = function() {

    //Do stuff
    this.something = true;
  };
});

Child component (the one extending):

/**
 * Module definition and dependencies
 */
angular.module('App.Child', [])

/**
 * Component
 */
.component('child', {
  templateUrl: 'child.html',
  controller: 'ChildCtrl',
})

/**
 * Controller
 */
.controller('ChildCtrl', function($controller) {

  //Get controllers
  const $ctrl = this;
  const $base = $controller('ParentCtrl', {});
  //NOTE: no need to pass $parentDep in here, it is resolved automatically
  //if it's a global service/dependency

  //Extend
  angular.extend($ctrl, $base);

  /**
   * On init
   */
  this.$onInit = function() {

    //Call parent init
    $base.$onInit.call(this);

    //Do other stuff
    this.somethingElse = true;
  };
});

The trick is to use named controllers, instead of defining them in the component definition.

Questions:
Answers:

I was using the “Controller as” syntax with vm = this and wanted to inherit a controller. I had issues if my parent controller had a function that modified a variable.

Using IProblemFactory’s and Salman Abbas’s answers, I did the following to have access to parent variables:

(function () {
  'use strict';
  angular
      .module('MyApp',[])
      .controller('AbstractController', AbstractController)
      .controller('ChildController', ChildController);

  function AbstractController(child) {
    var vm = child;
    vm.foo = 0;
    
    vm.addToFoo = function() {
      vm.foo+=1;
    }
  };
  
  function ChildController($controller) {
    var vm = this;
    angular.extend(vm, $controller('AbstractController', {child: vm}));
  };
})();
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-controller="ChildController as childCtrl" layout="column" ng-cloak="" ng-app="MyApp">
  <button type="button" ng-click="childCtrl.addToFoo()">
    add
  </button>
  <span>
      -- {{childCtrl.foo}} --
  </span>
</div>

Questions:
Answers:

You can use a simple JavaScript inheritence mechanism. Also don’t forget pass a needly angular services to invoke of .call method.

//simple function (js class)
function baseCtrl($http, $scope, $location, $rootScope, $routeParams, $log, $timeout, $window, modalService) {//any serrvices and your 2

   this.id = $routeParams.id;
   $scope.id = this.id;

   this.someFunc = function(){
      $http.get("url?id="+this.id)
      .then(success function(response){
        ....
       } ) 

   }
...
}

angular
        .module('app')
        .controller('childCtrl', childCtrl);

//angular controller function
function childCtrl($http, $scope, $location, $rootScope, $routeParams, $log, $timeout, $window, modalService) {      
   var ctrl = this;
   baseCtrl.call(this, $http, $scope, $location, $rootScope,  $routeParams, $log, $timeout, $window, modalService);

   var idCopy = ctrl.id;
   if($scope.id == ctrl.id){//just for sample
      ctrl.someFunc();
   }
}

//also you can copy prototype of the base controller
childCtrl.prototype = Object.create(baseCtrl.prototype);