AngularJS - Communication Between Controllers & Directive

This is an example of how to use a custom service to facilitate communicate between multiple controllers using $rootscope as an event bus. I added in a directive just for fun.

HTML

<script src="http://code.angularjs.org/angular-1.0.0rc9.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<div ng-controller="ControllerZero">
    <input ng-model="message" >
    <button ng-click="handleClick(message);">BROADCAST 1</button>
</div>

<div ng-controller="ControllerOne">
    <input ng-model="message" >
    <button ng-click="handleClick(message);">BROADCAST 2</button>
</div>

<div ng-controller="ControllerTwo">
    <input ng-model="message" >
</div>

<my-component></my-component>

JavaScript

var myModule = angular.module('myModule', []);
myModule.factory('mySharedService', function($rootScope) {
    var sharedService = {};

    sharedService.message = '';

    sharedService.prepForBroadcast = function(msg) {
        this.message = msg;
        this.broadcastItem();
    };

    sharedService.broadcastItem = function() {
        $rootScope.$broadcast('handleBroadcast');
    };

    return sharedService;
});

myModule.directive('myComponent', function(mySharedService) {
    return {
        restrict: 'E',
        controller: function($scope, $element, $attrs, mySharedService) {
            $scope.$on('handleBroadcast', function() {
                $scope.message = 'Directive: ' + mySharedService.message;
                // $scope.$digest();
            });
            $scope.handleClick = function(msg) {
                mySharedService.prepForBroadcast(msg);
            };
        },
        link: function($scope, $element, $attrs) {
            $('.test2').on('click', function(){
                alert('clicked on test2');
                $scope.handleClick('test2');
            });
        },
        replace: true,
        template: '<div><input ng-model="message"> <button ng-click="handleClick(message)">BROADCAST 3</button> <button class="test2">test2</button></div>'
    };
});

function ControllerZero($scope, sharedService) {
    /*
    $scope.handleClick = function(msg) {
        sharedService.prepForBroadcast(msg);
    };
    */
    $scope.$on('handleBroadcast', function() {
        alert('Ctrl0 has recognized handleBroadcast');
        $scope.message = sharedService.message;
    });
}

function ControllerOne($scope, sharedService) {
    /*
    $scope.handleClick = function(msg) {
        sharedService.prepForBroadcast(msg);
    };
    */
    $scope.$on('handleBroadcast', function() {
        $scope.message = 'ONE: ' + sharedService.message;
    });
}

function ControllerTwo($scope, sharedService) {
    $scope.$on('handleBroadcast', function() {
  ...