backgroundTask not receiving BGTaskScheduler in Swift / SwiftUI - swift

Question

I want to execute something in the background the check data every one hour.
For this, I am following the Apple Documentation video.
Here is the App Delegate code
import SwiftUI
import UserNotifications
import BackgroundTasks
#main
struct notificationtestApp: App {
var body: some Scene {
WindowGroup {
ContentView()
.onAppear(perform: {
AppCheckData()
})
}.backgroundTask(.appRefresh("notifyuser")) {
print("In Background Task")
//Check data
}
}
}
func AppCheckData() {
var startDate = Date()
let calendar = Calendar.autoupdatingCurrent
var checkTime = calendar.date(byAdding: .minute, value: 2, to: startDate)!
print(checkTime)
let notifyrequest = BGAppRefreshTaskRequest(identifier: "notifyuser")
notifyrequest.earliestBeginDate = checkTime
try? BGTaskScheduler.shared.submit(notifyrequest)
print("Done Scheduling")
}
For testing purposes, I changed addition of time to 2 minutes.
According to this code, it should print out the date after adding 2 minutes to the current date, then print out a confirmation that the BGTaskScheduler had been submitted. From there, after 2 minutes, it should print out the "In background task" in the console.
However, my app is not receiving the scheduled background task. I am not sure what I am missing here, is it the limits that Apple creates, or something else.
Please help

Answer 1

A BGAppRefreshTaskRequest is a request, and it is scheduled with earliestBeginDate. You are not requesting a specific time to run. You are indicating the earliest time it makes sense to run so that the OS doesn't call this unnecessarily.
As the docs note (emphasis mine):
The system decides the best time to launch your background task, and provides your app up to 30 seconds of background runtime.
In order to test your background operations, see Starting and Terminating Tasks During Development. IMO it is quite awkward, but it does work.
I want to execute something in the background the check data every one hour.
You will need to send a push notification in that case. This is not possible with BGTaskScheduler. As a rule, however, you should avoid this kind of polling and rather send the push notification only when there is new information. The point of BGAppRefreshTask is to periodically update your app's information at some point soon before the user is anticipated to need it so the user doesn't have to wait. It is not to facilitate polling.
There is no mechanism in iOS to allow you to do something at specific time intervals, without the user's intervention, except silent push notifications (and there are limits on those). This is by design. If you do not have a system for sending push notifications, then this is impossible, and you will need to redesign to not require it.