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AngularJS access parent scope from child controller

Posted by: admin November 2, 2017 Leave a comment

Questions:

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?

Answers:

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>

Questions:
Answers:

I’ve just checked

$scope.$parent.someProperty

works for me.

and it will be

{{$parent.someProperty}}

for the view.

Questions:
Answers:

When you are using as syntax, like ParentController as parentCtrl, to define a controller then to access parent scope variable in child controller use following :

var id = $scope.parentCtrl.id;

Where parentCtrl is name of parent controller using as syntax and id is a variable defined in same controller.

Questions:
Answers:

Some times you may need to update parent properties directly within child scope. e.g. need to save a date and time of parent control after changes by a child controller. e.g Code in JSFiddle

HTML

<div ng-app>
<div ng-controller="Parent">
    event.date = {{event.date}} <br/>
    event.time = {{event.time}} <br/>
    <div ng-controller="Child">
        event.date = {{event.date}}<br/>
        event.time = {{event.time}}<br/>
        <br>
        event.date: <input ng-model='event.date'><br>
        event.time: <input ng-model='event.time'><br>
    </div>
</div>

JS

    function Parent($scope) {
       $scope.event = {
        date: '2014/01/1',
        time: '10:01 AM'
       }
    }

    function Child($scope) {

    }

Questions:
Answers:

You can also circumvent scope inheritance and store things in the “global” scope.

If you have a main controller in your application which wraps all other controllers, you can install a “hook” to the global scope:

function RootCtrl($scope) {
    $scope.root = $scope;
}

Then in any child controller, you can access the “global” scope with $scope.root. Anything you set here will be globally visible.

Example:

function RootCtrl($scope) {
  $scope.root = $scope;
}

function ChildCtrl($scope) {
  $scope.setValue = function() {
    $scope.root.someGlobalVar = 'someVal';
  }
}

function OtherChildCtrl($scope) {
}
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

<div ng-app ng-controller="RootCtrl">
  
  <p ng-controller="ChildCtrl">
    <button ng-click="setValue()">Set someGlobalVar</button>
  </p>
  
  <p ng-controller="OtherChildCtrl">
    someGlobalVar value: {{someGlobalVar}}
  </p>

</div>

Questions:
Answers:

I believe I had a similar quandary recently

function parentCtrl() {
   var pc = this; // pc stands for parent control
   pc.foobar = 'SomeVal';
}

function childCtrl($scope) {

   // now how do I get the parent control 'foobar' variable?
   // I used $scope.$parent

   var parentFoobarVariableValue = $scope.$parent.pc.foobar;

   // that did it
}

My setup was a little different, but the same thing should probably still work

Questions:
Answers:

Perhaps this is lame but you can also just point them both at some external object:

var cities = [];

function ParentCtrl() {
    var vm = this;
    vm.cities = cities;
    vm.cities[0] = 'Oakland';
}

function ChildCtrl($scope) {
    var vm = this;
    vm.cities = cities;
}

The benefit here is that edits in ChildCtrl now propogate back to the data in the parent.