WKURLSessionRefreshBackgroundTask

Ok, i'm glad that im not the only one 😉

So i'm waiting for Beta 4....

Seeing the same thing as well, can't get a background URLSession to work at all with the handleBackgroundTask methods.

Has anyone gotten any further along with this thing? I just tested the sample app with Beta 4 and the same problems seem to exist. I did notice this not in the last two watchOS 3 beta release notes:

"The determination of whether a WatchKit app implements handleBackgroundTasks: in its WKExtensionDelegate is made at launch time and never updated. If your WatchKit app sets [WKExtension sharedExtension].delegate after being launched, it will not properly be checked.

Yes, just tried again with the same result 😟 Seems we have to wait for Beta 5 ?

Still doesn't work in Beta 5 either (on device or in Simulator) - bug report 26972292

Agreed. Any chance you could add the bug to http://www.openradar.me so we can dupe? (At this point, I'm not really sure how to articulate it.)

Tested with Beta 6 - still not working.

But as above, checking in the cache folder, I can see the download going but when it completes, it never gets moved out of the cache folder and the handle delegate doesn't get called.

I've even moved everything out into the ExtensionDelegate class and made sure that that is the only delegate (removed the delegate change from the MainInterfaceController) but no joy.

I just tried with xcode beta 6,with iOS 10 beta 6 and watch os beta 6. It seems that nothing changed

.I can schedule a normal background refesh ,then using the urlsession to fetch some data ,but he system never gives me a WKURLSessionRefreshBackgroundTask callback in handle function.

It's real annoying .I think this kind of background task api is real great but just wonder why it does not work even with apple's sample code.

I've watched all the WWDC 2016 videos and some techniques are described a litte bit different there (and I think the sample code is just wrong). I am now able to download content in the background and get a WKURLSessionRefreshBackgroundTask. Some other things are my own findings so I don't know if they are right...

So this is what I am doing now:

1. Create a NSURLSessionConfiguration with Identifier [[NSUUID UUID] UUIDString]]

2. Create a NSURLSession with Delegate self and delegateQueue nil
3. Remember the NSURLSession

4. Store the Task when getting a WKURLSessionRefreshBackgroundTask to complete it after processing the download (especially this is wrong in the sample code)

5. NSURLSessionDownloadDelegate -> didFinishDownloadingToURL to process the download

6. NSURLSessionDelegate -> URLSessionDidFinishEventsForBackgroundURLSession to finally complete the task (4) and release the reference to the NSURLSession (3)

This is only working on the device for me not on the simulator. On the simulator I never get the WKURLSessionRefreshBackgroundTask.

On the device it takes some time to get the WKURLSessionRefreshBackgroundTask because the amount of tasks per hour is limited. You can get more tasks if your Watch App is in the Dock together with only few other apps. You can also include and activate a complication to get more tasks per hour.

You should also invalidateAndCancel an old NSURLSession if you no longer need the scheduled download(s).

Please correct me if I am wrong.

I'm using a similar strategy to you, and everything you've listed matches my findings. Thanks for providing a neat list.

Any chance of sharing the code in your handling of background tasks? A bit hard with samples not working and simulator not acting as it should :-/

- Christer

[NSURLSession sessionWithConfiguration:backgroundConfiguration delegate:self delegateQueue:nil];

One other very important thing: HTTP is not working by default. You can set NSAllowsArbitraryLoads to true but the best way is to use HTTPS.