Dynamically allow ion-items dragging

canDrag.js

angular.module('canDragDirective', [ionic])

.directive('isPurchased', function($timeout, $ionicListDelegate) {
    return {
      restrict: 'A',
      link: function($scope, $element) {
        $timeout(function() {
          var elm = $element[0];
          ionic.on('touch', function() {
            // Simple way to check if the item is already purchased
            if (elm.classList.contains('purchased')) {
              // if it is, disable the drag
              $ionicListDelegate.canSwipeItems(false);
            } else {
              // if not, allow the drag
              $ionicListDelegate.canSwipeItems(true);
            }
            //console.log($ionicListDelegate.canSwipeItems());
          }, elm);
        });
      }
    };
  })