I was asked on Twitter about how to have the server tell the app that there was new data for the app to display.
As I said in the original post, the exact method to use will depend on the application but here are the main techniques to consider.
If the app is still running and the server has some new data for the app to display the server can tell the app directly. Either by telling the app to get it or sending it directly.
- Via a push notification (raw or toast)
- Via a socket connection - like with SignalR ;)
Having the app just check if there is new data on a predetermined periodic basis isn't the best we can do.
- If we've told the server we want some data and the server is indicating that it will be some time before the data is ready, the server should be able to provide an indication of how long it will be before the data is ready (based on typical load time, current queue size, etc.) The app can check back after that time. And, of course be given a new time if it isn't ready by then.
Of course if the server is taking it's time to generate (or prepare) the data the app needs then it's possible that the app might not still be running when the data is ready. In this instance the server may want to tell the user that there is data to view when they re-launch the app.
- The obvious option here is with push notifications (toast and tile)
Of course a better alternative to any of the above would be to have the data ready when the the user/app wants it. This could be done either by preparing the data in advance so it's ready when needed or by being able to prepare it very quickly.