ng-optimizely.js

angular.module('ng-optimizely', ['ng'])
.provider('optimizely', function() {
    var key;
    var activationEventName = '$viewContentLoaded';
    this.setKey = function(val) {
        key = val;
    };
    this.setActivationEventName = function(val) {
        activationEventName = val;
    };
    this.$get = ['$rootScope', '$window', '$timeout', '$q'
, function($rootScope, $window, $timeout, $q) {
    var service = $window.optimizely = $window.optimizely || [];

    service.loadProject = function() {
      var deferred = $q.defer();

      if (document.getElementById('optimizely-js')) {
        deferred.reject(new Error({message: 'Optimizely already activated'}));

      } else if (key == void 0) {
        deferred.reject(new Error({message: 'Key not provided'}));

      } else {
        var script = document.createElement('script');
        script.type = 'text/javascript';
        script.id = 'optimizely-js';
        script.async = true;
        script.src = 'https://cdn.optimizely.com/js/' + key + '.js';
        script.onload = script.onreadystatechange = function () {
          deferred.resolve($window.optimizely);
        };
        script.onerror = script.onreadystatechange = function (error) {
          deferred.reject(error);
        };

        var first = document.getElementsByTagName('script')[0];
        first.parentNode.insertBefore(script, first);

        deferred.promise.then(function() {
          if (!activationEventName) {
            $window.optimizely.push(['activate']);
          } else {
            $rootScope.$on(activationEventName, function() {
              $timeout(function() {
                $window.optimizely.push(['activate']);
              });
            });
          }
        });
      }

      return deferred.promise;
    };

    return service;
}]});