AngularJS - Communication Between Controllers

This is an example of how to use a custom service to facilitate communicate between multiple controllers using $rootscope as an event bus.

HTML

<script src="http://code.angularjs.org/angular-1.0.0rc9.js"></script>
<div ng-controller="ControllerZero">
    <input ng-model="message" >
    <button ng-click="handleClick(message);">LOG</button>
</div>

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

<div ng-controller="ControllerTwo">
    <span ng-show="Controller.test()"></span>
</div>

JavaScript

var myModule = angular.module('myModule', []);

function ControllerZero($scope) { 
    $scope.handleClick = function(msg) {
        
    };          
}

function ControllerOne($scope) {
    
}

function ControllerTwo($scope) {
    var controller = $scope.Controller = {
        test: function() {
           alert( 'Я - сообщение, которое должно быть выведено только один раз, при инициализации' );
        }
    };
}

//ControllerZero.$inject = ['$scope', 'mySharedService'];        
        
//ControllerOne.$inject = ['$scope', 'mySharedService'];

//ControllerTwo.$inject = ['$scope', 'mySharedService'];