Publish Subscribe service using AngularJS
<p>I am using this code to create a factory for publishing and subscribing messages between controllers , directives and services .</p>

<pre><code>angular.module('app', []);

angular.module('app').controller('TheCtrl', function($scope, NotifyingService) {
    $scope.notifications = 0;

    $scope.notify = function() {
        NotifyingService.publish();
    };

    // ... stuff ...
    NotifyingService.subscribe($scope, function somethingChanged() {
        // Handle notification
        $scope.notifications++;
    });
});

angular.module('app').factory('NotifyingService', function($rootScope) {
    return {
        subscribe: function(scope, callback) {
            var handler = $rootScope.$on('notifying-service-event', callback);
            scope.$on('$destroy', handler);
        },

        publish: function() {
            $rootScope.$emit('notifying-service-event');
        }
    };
});
</code></pre>

<p>It is working fine but I want to pass data while I am publishing to someone whos subscribing that ,how do I do that.
Suppose I want to publish a value of 4 , How do I perform that?</p>