The issue arises when an AngularJS directive fails to recognize the controller's scope due to binding variables using "this"

In my setup, I have an angularJS controller as well as a directive that work together:

angular.module('twitterApp', [])
    .controller('AppCtrl', AppCtrl)
    .directive('enter', EnterFunc);

function AppCtrl($scope) {
    $scope.loadMoreTweets = function() {
        alert('loading more tweets!');
    }
}

function EnterFunc() {
    return function(scope, element, attrs) {
        element.bind('click', function() {
            scope.loadMoreTweets();
        });
    }
}

Additionally, there is HTML code structured like this:

  <body ng-app="twitterApp">
    <div class="container" ng-controller="AppCtrl">
      <div enter>
        Roll over to load more tweets
      </div>
    </div>
  </body>

The existing setup functions correctly by accessing the controller's scope from a directive. However, I aim to enhance the readability of the code by utilizing the "controller as" syntax in the HTML. When I modify the controller function as follows:

function AppCtrl() {
    var vm = this;
    vm.loadMoreTweets = function() {
        alert('loading more tweets!');
    }
}

At this point, the example ceases to function properly. Clicking on the directive results in the following error message:

Uncaught TypeError: scope.loadMoreTweets is not a function

I am seeking guidance on how to rectify this issue and make the directive work without reverting back to binding to $scope. For reference, here is the Plunkr link for both versions - working and "Controller As": http://plnkr.co/edit/PyIA4HVOMLn0KNJ5V2bc?p=info

Answer №1

I was able to resolve the issue by making a modification and wanted to share my solution for anyone who may encounter similar problems. Instead of calling "scope.loadMoreTweets()" within my directive, I switched to using "scope.ctrl.loadMoreTweets()". While this workaround did fix the issue, I feel frustrated that I had to use ".ctrl" to access the parent scope as using ".$parent" did not yield the desired results. If anyone has an alternative approach, please do share. It would be beneficial to have more resources available on utilizing directives with Controller's Controller As syntax.

Answer №2

After some modification, the code now allows you to specify which controller's scope you want to pass to the directive. From there, you can easily call the desired method on that specific controller's scope. Give it a try and let me know if it solves your issue.

Custom Directive:

function EnterFunc() {
  return {
        restrict: 'A',
        scope: {
            controller: '='
        },
        link: linkFunction
    }
   function linkFunction(scope, element, attrs) {
      element.bind('click', function() {
        //scope.$apply(attrs.action);
        scope.controller.loadMoreTweets();
      });
   }
}

HTML Usage:

<body ng-app="twitterApp">
<div class="container" ng-controller="AppCtrl as ctrl">
  <div enter controller="ctrl">
    Roll over to load more tweets
  </div>
</div>

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