Close SocketIO Connection

[bwernsman]

-close socketIO connection when the user leaves the app
-check to make sure the connection is closed when the app dies (killed by the OS)

[georgeaf99]

@bwernsman I think its fine if the server closes the connection after 50 seconds. You can see @xuset commit here: DelegateIt/OrderAPI@d35ca2f.

You could just recreate the socket.io connection every time the app switches to the foreground state. This would ensure that we avoid the bug in the Swift socket.io library.

This method makes it much easier for us to guarantee correctness; however, we could still close the connection when the app goes into the background state if desired.

[xuset]

I think the app should definitely close the connection when it goes in the background state. We don't want a bunch of lingering unused connections.

On top of that, my commit (DelegateIt/OrderAPI@d35ca2f) probably won't fix this issue because the bug resides in the swift socketio client not properly handling closed connections. The hope is that doing the reconnect on wake up will cleanup any invalid state.

[georgeaf99]

I agree that the app should close the socket.io connection when it goes into the background state. We should separate our two goals: eliminate lingering connections and avoid the Swift socket.io bug. Lingering connections are solved by attempting to kill the connection when the app goes into background and setting the socket.io timeout to 50s. If we are always able to execute code when our app is stopped then this would avoid the bug too. However, I don't know if we want to rely on the OS always being nice and calling the our on kill or suspend handler. If we always regenerate the connection when the app foregrounds then we guarantee that we avoid the bug.

[xuset]

We definitely should not rely on the OS playing nice so the connection should be disconnected then reconnected on resume to ensure everything gets cleaned up.