iOS Tutorial Background Fetch (Downloads)

I'm checking it. If you have a local Mac then you can monitor the logs and you will see that the OS mostly doesn't allow any app to start in the background. I'm still monitoring it to see if it will eventually run.

 

What you posted is not relevant. You need to wait...

 

After testing it for 24 hours I can say that it works properly.

I've created a simple app that counts the number of times FetchDownload is called:

Code:

'app start
If File.Exists(File.DirDocuments, "1.txt") = False Then
       File.WriteString(File.DirDocuments, "1.txt", 0)
   End If

Sub Application_Active
   Page1.Title = "Value: " & File.ReadString(File.DirDocuments, "1.txt")
  
End Sub

Private Sub Application_FetchDownload
   Log("FetchDownload")
   File.WriteString(File.DirDocuments, "1.txt", File.ReadString(File.DirDocuments, "1.txt") + 1)
   Dim no As NativeObject = App
   no = no.GetField("delegate")
   no.RunMethod("completeFetch:", Array(0))
End Sub

Monitoring the system logs shows that many apps try to start in the background and the OS gives a score to each one. Only Apple knows how the score is calculated. I assumed that the app should be used from time to time so I started every couple of hours.
The first FetchDownload event happened after about 12 hours. It was raised another 11 times in the following 12 hours.

System logs:


Don't use iReleaseLogger with fetch download as it can cause the process to fail to start.
Don't show a notification. Maybe the OS doesn't like.

It is probably not relevant however I used an app that also implements push notifications.