Pull notifications - iOS

[nghiacc]

Purpose: With current mobile platform's push notifications, all notification messages must go through the platform service (Apple Push Notification service - APNs for iOS or Firebase Cloud Messaging - FCM) and centrally managed via a remote push notification server. This represents a challenge for a decentralised application like Stamp.

While no perfect technologies are yet available to offer a decentralised notification delivery, Stamp will initially adopt a pull notification technique which leverage background tasks to query the server periodically and update the user if there are new messages available for them.

With iOS, there will be a limitation related on how the platform manages the background tasks. The platform prioritise the front applications a lot more than any background tasks, therefore a scheduled background task may not be invoked until the device is less used. This leads to unreliable frequencies on which a background task is triggered, hence results in intermittent notification service. At the initial stage, the pull notification service will mainly serve for the engaging with users, inform them about new messages so that they can open the app and check for new content periodically. When Stamp gets more usage, a more sophisticated technique maybe developed to replace or enhance the pull notification via background task.

A/C:

• The notification must be able to notify users at least once a day given normal usage
• There is no significant battery drain to device
• There is no significant impact to device performance
• There should be a message to inform users about the expected intermittent service and the decrease in performance/battery (if noticeable)