What event fires when a WebKit WebApp is "terminated"

Question

I am in the process of developing a Web App for iOS and am using the DOMApplicationCache. I know that Web Apps can not run in the background, but I still would like to simulate a resume of the app when the user switches to another app and returns to the web app later.

In order to do this I at least need to record when the Web App terminates/unloads. But the window.unload does not seem to fire.

Does anybody have an idea how to catch the termination of a WebApp running?

PS: on a related question, where does the console.log go when apple-mobile-web-app-capable is yes?

Tripedal

Answer 1

You can use the "pageshow" event to detect when the app has resumed. This event will fire when user returns to your app from a different safari tab. It will also fire when user clicks the home button and then comes back to the app by clicking on safari button

     <script>
    window.addEventListener("pageshow", function(){
        alert("page shown");
    }, false);
  </script>

I have tested this on the iOS simulator and its working as I described above.

Willson

Answer 2

I have an answer. It's not what we were hoping for.

The technical definition of unload from http://www.w3.org/TR/DOM-Level-2-Events/events.html is:

The unload event occurs when the DOM implementation removes a document from a window or frame. This event is valid for BODY and FRAMESET elements.

I also got a reply from some in the know at Apple: "Unfortunately, I haven't been able to find an event that fires when the Home button is clicked! I think the most appropriate event for this might be the pagehide event. This event actually does fire in Safari on iOS when you switch to the "tabs" view to open a new page, but not when you click the home screen icon :-("

Lotty

thanks for taking the time to respond. So the only way to determine if a webapp has been "resumed" is to compare a heartbeat stored locally? – Tripedal

just in case anyone doesn't understand, this is the "heartbeat" Jamgold is referring to. I only comment to help others in their quest ;) #4941157 – Molest

Awesome! The pagehide event is queued even when the home and lock buttons are pressed in 4.3.4, but it isn't until you reopen Safari (or unlock the device) that it gets executed. I don't think it gets any better than this. It's good enough for me. – Concordant