Make two Directives have the same $Scope at Angular

Question

I have a directive that generates a button, and when I click this button a counter increases 1. This directive is inserted in two places in my index.html. I wish that when I clicked on one of the buttons, the two would be changed...

Just follow my code:

index.html:

<div ng-app='demo'>
    <button-directive></button-directive>
    <button-directive></button-directive>
</div>

app js.:

var demo = angular.module('demo', []);
demo.directive('buttonDirective', function($parse) {
    return {
        restrict: 'E',
        template: '<button ng-controller="MyCtrl" ng-click="increment()">{{count}}</button>',
    }
});

demo.controller('MyCtrl', ['$scope', function($scope){
    $scope.count = 0;
    $scope.increment = function(){
        $scope.count = $scope.count + 1;
    };
}]);

Here is a fiddle: http://jsfiddle.net/dfalbel/1kyq5e15/

Answer 1

I’m not very experienced with Angularjs, but as far as I know the default behavior of a directive is to share the controller’s Scope (otherwise we need to create an isolated Scope).

You are creating a new controller for each directive.

I would do so:

<div ng-app='demo' ng-controller="MyCtrl">
    <button-directive></button-directive>
    <button-directive></button-directive>
</div>

js:

var demo = angular.module('demo', []);
demo.directive('buttonDirective', function($parse) {    
    return {
        restrict: 'E',
        template: '<button ng-click="increment()">{{count}}</button>',
    }
});

demo.controller('MyCtrl', ['$scope', function($scope){
    $scope.count = 0;
    $scope.increment = function(){
        $scope.count = $scope.count + 1;
    };
}]);

https://jsfiddle.net/rvnypx1c/3/

But note that the directive became very specific. For it to be more generic and can be reused, we could do something like this:

<div ng-app='demo' ng-controller="MyCtrl">
    <button-directive ng-click="increment()" counter="{{count}}"></button-directive>
    <button-directive ng-click="increment()" counter="{{count}}"></button-directive>
    <button-directive ng-click="increment1()" counter="{{count1}}"></button-directive>
</div>

js:

var demo = angular.module('demo', []);
demo.directive('buttonDirective', function($parse) {

    return {
        restrict: 'E',        
        scope: {
            counter: '@'
        },
        template: '<button>{{counter}}</button>',
    }
});

demo.controller('MyCtrl', ['$scope', function($scope){
    $scope.count = 0;
    $scope.increment = function(){
        $scope.count = $scope.count + 1;
    };

    $scope.count1 = 0;
    $scope.increment1 = function(){
        $scope.count1 = $scope.count1 + 1;
    };
}]);

https://jsfiddle.net/rvnypx1c/5/

Answer 2

You can use the function $broadcast of $rootScope to transmit the events you wish to.

Code:

demo.controller('MyCtrl', ['$scope', '$rootScope', function ($scope, $rootScope) {
  $scope.count = 0;
  $scope.increment = function ($broadcast) {
    $scope.count++;
    $broadcast('evento', $scope.count);
  }
}