Upload image in a share extension results in NSURLErrorDomain Code=-997

Question

I try to implement an extension with which the user can share an image on App.net.

After a lot of trial and error I'm finally out of ideas.

I have a framework to create the request. The request is a POST request with Content-Disposition: form-data. Therefore I think I have to use a sessionDataTask to upload the image.

The delegate of the session is a singleton in the same framework. Some delegate methods are called.

But didReceiveData is never called. In stead I get the following error in didCompleteWithError before any upload has started:

Error Domain=NSURLErrorDomain Code=-997 "Lost connection to background transfer service" UserInfo=0x7b29dc80 {NSErrorFailingURLKey=https://alpha-api.app.net/stream/0/files, NSErrorFailingURLStringKey=https://alpha-api.app.net/stream/0/files, NSLocalizedDescription=Lost connection to background transfer service}

Here is the code in the share extension:

let imageUploadRequest = RequestFactory.imageUploadRequest(imageToShare, accessToken: accessToken!)

let sessionId = "de.dasdom.jupp.image.backgroundsession"

let config = NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier(sessionId)

config.sharedContainerIdentifier = "group.de.dasdom.Jupp"

let session = NSURLSession(configuration: config, delegate: PostService.sharedService, delegateQueue: NSOperationQueue.mainQueue())

let sessionTask = session.dataTaskWithRequest(imageUploadRequest)
sessionTask.resume()

self.extensionContext!.completeRequestReturningItems(nil, completionHandler: nil)

This also gives the same error in the host app.

I have set up an App Group in the share extension and the host app.

The upload does work but I need the response from the upload to compose the post for App.net. When I use a normal NSURLSession, everything works.

Any help would be strongly appreciate.

Answer 1

I think data tasks are cancelled when the extension returns. You might have better luck with an NSURLSessionUploadTask, which MUST be file-backed for background upload requests.