Angularjs Update Directive After A Call To Service Method

I'm trying to create resusable alert service, which I would call anywhere in my application with just: alertService.showAlert('warning', 'something went wrong!'); For example afte

Solution 1:

Here is a pattern that I used once before

var srv = angular.module('srv', []);
srv.factory('alertService', ['$timeout', function($timeout){
    var alertListeners = [];

    this.register = function (listener) {
        alertListeners.push(listener);
    };

    this.notifyAll = function (data) {
        for (// each listener in array) {var listenerObject = alertListeners[i];
            try { // do not allow exceptions in individual listeners to corrupt other listener processing
                listenerObject.notify(data);
            } catch(e) {
                    console.log(e);
            }   
        }
    };
 }]).
 directive('myAlerts', ['alertService', function(alertService){

     var alertDirectiveObserver = function($scope, alertService) {

         this.notify = function(data) {
            /*
             * TO DO - use data to show alert
             */
         };

         alertService.register(this);
     };


   return {
     restrict: 'A',
     template: '<div ng-class="alertClass" ng-show="alertNeeded">{{alertMessage}}</div>',
     controller: ['$scope', 'alertService', alertDirectiveObserver],
     link: function(scope){  
     }
    }
}]).
controller('alertShowingController', ['$scope', 'alertService',   function($scope, alertService){
    alertService.notifyAll({'warning', 'Warning alert!!!'})   
 ]);

Of course you should also cleanup by registering a function to delete objects on scope destroy.

eg

element.on('$destroy', function() {
    alertService.unregister(// some listener id);
});

Solution 2:

Your code has two different meanings for alertService. Inside the factory definition, it refers to the factory itself. Everywhere else, it refers to the object returned by the factory. The easiest way to move forward would be to add a few missing methods to the object returned by the factory:

return {
    showAlert: function(cssClass, msg){
        alertService.setAlertNeeded();
        alertService.setAlertClass(cssClass);
        alertService.setAlertMessage(msg);
    },

    alertClass: function() { return alertService.alertClass; },     
    alertMessage: function() { return alertService.alertMessage; },
    alertNeeded: function() { return alertService.alertNeeded; }
};

Then, change your directive's template so that it calls these functions on each digest cycle:

directive('myAlerts', ['alertService', function(alertService){
        return {
            restrict: 'A',
            template: '<div ng-class="alertClass()"' +
                      '     ng-show="alertNeeded()">' +
                      '  {{alertMessage()}}' +
                      '</div>',
            link: function(scope){                   
                scope.alertNeeded = alertService.alertNeeded;
                scope.alertMessage = alertService.alertMessage;
                scope.alertClass = alertService.alertClass;
            }
        }
}])

Then you should see your warning message. Try it in a fiddle.