AngularJS access parent scope from child controller

zpydee picture zpydee · Jan 30, 2014 · Viewed 494.4k times · Source

I've set up my controllers using data-ng-controller="xyzController as vm"

I have a scenario with parent / child nested controllers. I have no problem accessing parent properties in the nested html by using $parent.vm.property, but I cannot figure out how to access the parent property from within my child controller.

I've tried injecting $scope and then using $scope.$parent.vm.property, but this isn't working?

Can anyone offer advice?

Answer

Dieterg picture Dieterg · Jan 30, 2014

If your HTML is like below you could do something like this:

<div ng-controller="ParentCtrl">
    <div ng-controller="ChildCtrl">
    </div>
</div>

Then you can access the parent scope as follows

function ParentCtrl($scope) {
    $scope.cities = ["NY", "Amsterdam", "Barcelona"];
}

function ChildCtrl($scope) {
    $scope.parentcities = $scope.$parent.cities;
}

If you want to access a parent controller from your view you have to do something like this:

<div ng-controller="xyzController as vm">
   {{$parent.property}}
</div>

See jsFiddle: http://jsfiddle.net/2r728/

Update

Actually since you defined cities in the parent controller your child controller will inherit all scope variables. So theoritically you don't have to call $parent. The above example can also be written as follows:

function ParentCtrl($scope) {
    $scope.cities = ["NY","Amsterdam","Barcelona"];
}

function ChildCtrl($scope) {
    $scope.parentCities = $scope.cities;
}

The AngularJS docs use this approach, here you can read more about the $scope.

Another update

I think this is a better answer to the original poster.

HTML

<div ng-app ng-controller="ParentCtrl as pc">
    <div ng-controller="ChildCtrl as cc">
        <pre>{{cc.parentCities | json}}</pre>
        <pre>{{pc.cities | json}}</pre>
    </div>
</div>

JS

function ParentCtrl() {
    var vm = this;
    vm.cities = ["NY", "Amsterdam", "Barcelona"];
}

function ChildCtrl() {
    var vm = this;
    ParentCtrl.apply(vm, arguments); // Inherit parent control

    vm.parentCities = vm.cities;
}

If you use the controller as method you can also access the parent scope as follows

function ChildCtrl($scope) {
    var vm = this;
    vm.parentCities = $scope.pc.cities; // note pc is a reference to the "ParentCtrl as pc"
}

As you can see there are many different ways in accessing $scopes.

Updated fiddle

function ParentCtrl() {
    var vm = this;
    vm.cities = ["NY", "Amsterdam", "Barcelona"];
}
    
function ChildCtrl($scope) {
    var vm = this;
    ParentCtrl.apply(vm, arguments);
    
    vm.parentCitiesByScope = $scope.pc.cities;
    vm.parentCities = vm.cities;
}
    
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.20/angular.min.js"></script>
<div ng-app ng-controller="ParentCtrl as pc">
  <div ng-controller="ChildCtrl as cc">
    <pre>{{cc.parentCities | json}}</pre>
    <pre>{{cc.parentCitiesByScope | json }}</pre>
    <pre>{{pc.cities | json}}</pre>
  </div>
</div>