<div ng-controller="AlertDemoCtrl">
 <alert ng-repeat="alert in alerts" type="alert.type" close="closeAlert($index)">{{alert.msg}}</alert>
 <button class='btn' ng-click="addAlert()">Add Alert</button>
</div>

function AlertDemoCtrl($scope) {
 $scope.alerts = [
  { type: 'error', msg: 'Oh snap! Change a few things up and try submitting again.' }, 
  { type: 'success', msg: 'Well done! You successfully read this important alert message.' }
 ];

 $scope.addAlert = function() {
  $scope.alerts.push({msg: "Another alert!"});
 };

 $scope.closeAlert = function(index) {
  $scope.alerts.splice(index, 1);
 };
}

'use strict';
/* services.js */
// don't forget to declare this service module as a dependency in your main app constructor!
var appServices = angular.module('appApp.services', []);
appServices.factory('alertService', function($rootScope) {
  var alertService = {};
  // create an array of alerts available globally
  $rootScope.alerts = [];
  alertService.add = function(type, msg) {
   $rootScope.alerts.push({'type': type, 'msg': msg});
  };
  alertService.closeAlert = function(index) {
   $rootScope.alerts.splice(index, 1);
  };
  return alertService;
 });

<div>
 <alert ng-repeat="alert in alerts" type="alert.type" close="closeAlert($index)">{{ alert.msg }}</alert>
</div>

function RootCtrl($rootScope, $location, alertService) {
 $rootScope.changeView = function(view) {
  $location.path(view);
 }
 // root binding for alertService
 $rootScope.closeAlert = alertService.closeAlert; 
}
RootCtrl.$inject = ['$scope', '$location', 'alertService'];

function ArbitraryCtrl($scope, alertService) {
 alertService.add("warning", "This is a warning.");
 alertService.add("error", "This is an error!");
}