title: Does AppSync Subscription Work When User is No Longer in View Controller or when App is Background
body: <p>I am reading <a href="https://github.com/aws-samples/aws-mobile-appsync-events-starter-ios/blob/master/EventsApp/EventDetails.swift" rel="nofollow noreferrer">this sample app</a>, and noticed that the call for subscriptions happens in viewDidLoad(). This raises the following question:</p>
  
  <p>1) Is the user subscribed to event comments only when he/she is in that particular view controller? In other words, if the user navigates to another scene, is the subscription no longer in effect? How can I make it so that once a user subscribes to something, he/she is subscribed to it until told to stop?</p>
  
  <p>I also have another question:</p>
  
  <p>2) Can I changed the parameters passed to a subscription during the app? For instance, if I am subscribing to multiple events, then I would pass an array of event_id as parameter. For some condition, I will add an event to the array. So each time I add an event, do I have to restart the subscription?</p>