Refresh $scope variables from a service - angularjs

Question

What is the proper method of refreshing data that is retrieved from a service? I am retrieving a test array from my dataService that I'd like to be automatically updated in my view when my save() method is called. I have commented the line that is supposed to update my $scope variable but yet nothing changes. Should I be wrapping it in $apply()?
The data that is placed into the array that dataService.getActivities() returns is from a cookie (which may or not be relevant).
app.controller("activityCtrl", ["$scope", "dataService", function ($scope, dataService) {
$scope.newActivity = "";
$scope.activities = dataService.getActivities();
$scope.save = function (activity) {
try{
if (activity != "") {
dataService.saveActivity(activity);
$scope.newActivity = "";
$scope.activities = dataService.getActivities(); //HERE
}
} catch (e) {
alert(e);
}
}
}
Here is my view, the array lives in a ng-repeat
<div class="col-xs-12" ng-controller="activityCtrl">
<div class="row text-center">
<form novalidate>
<input type="text" placeholder="Activity name" ng-model="newActivity" />
<input type="submit" value="Add activity" ng-click="save(newActivity)" />
</form>
</div>
<div class="row" ng-controller="activityCtrl">
<div class="col-xs-2"> </div>
<div class="col-xs-6 text-left">
<div class="row" ng-repeat="activity in activities">
<div class="btn btn-default" ng-class="{ active : activity.active }" ng-click="activate(activity)">{{ activity.name }}</div>
</div>
</div>
<div class="col-xs-4 text-left">
sdfas
</div>
</div>
</div>
dataService code:
app.service("dataService", function () {
this.getActivities = function () {
if (docCookies.hasItem("activities")) {
var activities = JSON.parse(docCookies.getItem("activities"));
if (activities.constructor != Array) {
activities = [activities];
}
activities.sort(
function (a, b) {
if (a.name > b.name) { return 1; }
if (b.name < a.name) { return -1; }
return 0;
});
return activities;
}
return [];
}
this.saveActivity = function (activity) {
if (!docCookies.hasItem("activities")) {
docCookies.setItem("activities", [JSON.stringify({ "name": activity, "active": true })], Infinity);
} else {
var activities = this.getActivities();
for (var i = 0; i < activities.length; i++) {
if (activities[i].name == activity) {
throw "Activity already exists";
}
}
activities.push({ "name": activity, "active": false });
docCookies.setItem("activities", JSON.stringify(activities), Infinity);
}
};
});

Answer 1

Zac, your answer should work for you. As another option, I like to broadcast an event whenever my service is updated. In the last line of your saveActivity() function in your service, try broadcasting an event on the rootScope. Inject the $rootScope into your service. Add the following to your save method:
$rootScope.$broadcast('activitiesUpdated');
Then in your controller, inject the $rootScope and add an event handler:
$rootScope.$on('activitiesUpdated', function(event, args){
//Update $scope variable here
});

Answer 2

The answer was to look at the cookie value with a call to $watch instead of the method that returns an object. Added this in my activityCtrl
$scope.$watch(function () {
return docCookies.getItem("activities");
}, function (oldVal, newVal) {
$scope.activities = dataService.getActivities();
});