$broadcast working asynchronously, need to be synchronous

Question

I have a controller which has a number of $rootScope.$broadcast which update the contents of a directive.

The first $rootScope.$broadcast is clearing all the contents/data whilst the other populates it.

app.controller('MyController', function($scope, header) {

    $rootScope.$broadcast('clear');
    $rootScope.$broadcast('title', header.title);
    $rootScope.$broadcast('total', header.total);

});

Note: header is resolved from my $stateProvider e.g:

.state('index', {
        url: '/index',
        templateUrl: 'home.html',
        controller: 'MyController',
        resolve: {
            header:  function() {
                return {
                    title : 'Welcome to Home',
                    total : 6
                };
            }
        }
    })

directive:

app.directive('myDirective', function() {
    return {
        restrict: 'A',
        replace: true,
        scope: {},
        link: function(scope, element, attrs) {
            scope.$on("clear", function(event, val) {
                scope.Title = '';
                scope.Total = 0;
            });               
            scope.$on("title", function(event, title) {
                scope.Title = title;
            });
            scope.$on("total", function(event, total) {
                scope.Total = total;
            });
        },
        template:
            '<section>' +
                '<p>{{Title}} - {{Total}}</p>' +                        
            '</section>'
    }
});

The problem I am having is that on page load, the $broadcast of title and total appear to be being called before clear has completed.

---

UPDATE:

Plunker: http://plnkr.co/edit/o7wEFyIGh0284ZAc9VnS?p=preview

Whenever on the home.html, the directive will hide - correct. Whenever on the cart.html, the directive will show - correct.

To see issue, click on Cart... Click the button to increment counter.. Then go back to home, then back to Cart... the counter will not reset to 0

Answer 1

As mentioned in my comment above, the problem was that scope.Total within 'clear' was/is not accessible in other .on casts. So, a global variable has been declared and updated within each broadcast:

app.directive('myDirective', function() {
  return {
    restrict: 'A',
    replace: true,
    scope: {},
    link: function(scope, element, attrs) {

      var localTotal = null;

      scope.$on("clear", function(event) {
        scope.Title = '';
        scope.Total = 0;
        localTotal = scope.Total;
      });
      scope.$on("showDirective", function(event, show) {
        scope.showDirective = show;
      });
      scope.$on("total", function(event, total) {
        if (localTotal !== 0) {
          console.log("in IF");
          scope.Total = total;
        }
        else {
          scope.Total = localTotal;
        }
      });
      scope.$on("title", function(event, title) {
        scope.Title = title;
      });
    },
    template: '<section>' +
      '<p ng-if="showDirective">{{Title}} - {{Total}}</p>' +
      '</section>'
  }
});

See Plunker: http://plnkr.co/edit/2Xx99RzvQtaD9ntiod0d?p=preview

Answer 2

You should use service for synchronization like this:

app.controller('MyController', function($scope, header, myDirectiveManager) {
  myDirectiveManager.getPromise().then(function(directive){
    directive.clear();
    directive.setTitle(header.title);
    directive.setTotal(header.total);
 });

});

service

app.service('myDirectiveManager',function($q){
   var deferred = $q.defer();
   this.getDeffer = function(){
     return deferred;
   };
   this.getPromise = function(){
      return deferred.promise;
   }
});

directive

app.directive('myDirective', function() {
return {
    restrict: 'A',
    replace: true,
    scope: {},
    controller: function($scope, myDirectiveManager) {
        var fasade = {
           clear: function(event, val) {
            scope.Title = '';
            scope.Total = 0;
           },
           setTitle: function(event, title) {
            scope.Title = title;
           },
           setTotal: function(event, total) {
            scope.Total = total;
           }

        };
        myDirectiveManager.getDeffer().resolve(fasade);
    },
    template:
        '<section>' +
            '<p>{{Title}} - {{Total}}</p>' +                        
        '</section>'
    }
  });