We have a device which is an appliance and we are developing a control interface app for macOS and iOS/iPadOS.
How can we set up our iOS application to grab information from a local network device while it is in the background in order to show notifications?
Communication between the Apple device and our device is via local networking and the device is designed to be used on networks without internet connections. On networks with internet connections we could forward events from the device, via a server and APNS push notifications, but that isn't valid here.
Events occur on our device and are forwarded to clients, who are subscribed to Server-Sent Events. On macOS this works well and the application can receive updates and show Notification Center notifications fine.
On iOS we are using a BGAppRefreshTaskRequest with time interval set to 1 minute, but it appears that we get scheduled only every few hours. This isn't very useful as notifications just arrive in batches rather than in a timely manner. All normal networking is closed when the app goes into the background, so we cannot keep the SSE request open.
Another idea which we haven't tried yet: Creating a new endpoint on the device which keeps the connection open until a notification arrives, then using background URLSession to poll on that endpoint. Would that work? It seems like a mis-use of the API perhaps?
Topic:
App & System Services
SubTopic:
Networking
Tags:
Notification Center
User Notifications
Background Tasks