i am using Afnetworking 2.0 library with NSURLSession.
i found in AFURLSessionManager they configure Session with default session , so if i need to download images in background then i have to set Session with Background configuration.
So , I have to change AFNetworking library for that or is there any other way for that in AFNetworking 2.0.
From Using NSURLSession:
The NSURLSession class supports background transfers while your app is suspended. Background transfers are provided only by sessions created using a background session configuration object (as returned by a call to backgroundSessionConfiguration:).
You must configure your AFHTTPSessionManager to use the background session configuration if you want to do this:
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration backgroundSessionConfiguration:#"com.myApp.backgroundDownloadSession"]
AFHTTPSessionManager *backgroundManager = [[AFHTTPSessionManager alloc] initWithSessionConfiguration:configuration];
AFNetworking will set itself as the delegate. From the NSURLSession docs:
[T]he delegate will be retained until after the delegate has been sent the URLSession:didBecomeInvalidWithError: message
As a result, your manager will stick around as long as this session does.
Two side notes:
You should probably use use a separate AFHTTPSessionManager for background transfers (large downloads, etc.) You don't want literally all requests to be assigned a background URL session.
In case you want to retrieve the response without AFNetworking, note what the background session identifier is ('com.myApp.backgroundDownloadSession' in my sample code):
An identifier for the new session configuration that is unique for your app. Your app can retrieve the download or the upload response later by creating a new background session with the same identifier.
Related
I am experiencing some weird behaviour when using an uploadTask for a URLSessionConfiguration.background.
My custom delegate is implementing all of the delegate methods that belong to URLSessionDelegate, URLSessionTaskDelegate, and URLSessionDataDelegate. All of them has a print statement indicating that the method has been called.
I am trying to upload five images to a server, each of them has their own session with an id matching the image id.
The problem is that when uploading using a very slow connection "edge", the upload progress will reset before reaching 100% This happens whenever didFinishCollectingMetrics is called as you can see here: Data
This does not happen all the time when using a slow connection but only some of the time.
Anyone got any ideas as to what is happening here?
Edge networking is notoriously unreliable, and frequent upload failures are not atypical. The way you solve this is by replacing whole-file-based uploads with some form of chunked uploads so that you can continue the upload where you left off, but that requires server support.
Increase time-out of NSURLSession for request and resource:
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
[configuration setTimeoutIntervalForRequest:120];
[configuration setTimeoutIntervalForResource:240];
NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration];
Use session to upload your image
I want to upload a file to a server using NSURLSession.
Cases Are:
1. It should resume uploading a file to the server from where it stopped because of app crash.
2. It should handle background upload as well.
Try AFNetworking Library to upload image asynchronously.You can find a brief example in this thread.
You should use background NSURLSession. If your app crashed or user left the app while upload was in progress, with a background NSURLSession the upload would continue seamlessly in the background. When the upload is done, your app will be notified of this via the delegate (and if your app wasn't alive at the time the download finished, it will be started in a background mode, at which point you can do whatever cleanup you need).
So create NSURLSessionConfiguration with backgroundSessionConfigurationWithIdentifier, and then instantiate a NSURLSession with that configuration.
There are a few caveats:
You cannot use completion handler pattern. You have to use delegate-based implementation.
You have to implement handleEventsForBackgroundURLSession in the app delegate, capturing the completionHandler it passes you and also instantiate the background session again. Likewise, in your NSURLSession delegate methods, you have to implement URLSessionDidFinishEventsForBackgroundURLSession, which will call the saved completion handler.
For more information, see Background Task Considerations in URL Session Programming Guide, see a section of the same name (but different text) in the NSURLSession class reference, or see the WWDC 2013 What's New in Foundation Networking, where Apple first introduced us to background sessions.
Using NSUrlSession with a background configuration let's me download files even if the app gets terminated by iOS. Being curious, I tried to add an upload task and noticed that it won't continue, even not if the app is only suspended.
Apple talks about "Downloading in the background" but they don't explicitly state that uploading would not be possible.
Can somebody confirm that uploads and background session configuration don't work together?
They DO work together.
What you need to do is the following:
Have a NSURLSessionConfiguration with background configuration
NSURLSessionConfiguration *conf = [NSURLSessionConfiguration backgroundSessionConfiguration:#"backgroundSession"];
Setup a NSURLSession (#property NSURLSession *urlSession)
Obtain the path to the file (fullPath)
Create the NSURLRequest (request)
Create a NSURLSessionTask
NSURLSessionTask*task = [self.urlSession uploadTaskWithRequest:request fromFile:fullPath];
[task resume];
And the task will run in background. You can get the status from NSURLSession delegate methods.
Cheers
I am using below code to create background session for huge uploads,
NSURLSessionConfiguration *config = [NSURLSessionConfiguration backgroundSessionConfigurationWithIdentifier:identifier];
NSURLSession *session = [NSURLSession sessionWithConfiguration:config delegate:delegate delegateQueue:nil];
and save the identifier to re-associate with the session later. But once app goes to background and terminated by OS then, upon relaunch I am not receiving any callbacks from that session even if I use same identifier to create session. It always creates new session that has no ongoing upload task.
The previous task can't finish this early as I have GBs to upload.
Am I missing anything here ? any additional setting etc.
Save the delegate as well in order to receive the call backs! The instance of the delegate is not retained after the App kill.
Make your delegate comply to NSCoding protocol and do the archiving and unarchiving!
Cheers:)
I have a question about AFNetworking 2 and background downloads/uploads thanks to the new iOS7 NSURLSession background requests
Is this automatically handled by my AFHTTPRequestOperationManager ? Does it automatically set my requests'session to background mode?
I saw that the AFURLSessionManager Has a setDidFinishEventsForBackgroundURLSessionBlock Method but I wonder if everything is automatic?
If my app is killed or suspended, will requests keep on going? How can I get a callback when my app is relaunched?
Thanks a lot for your help!
AFHTTPRequestOperationManager uses the old NSURLConnection so that doesn't facilitate background downloading.
AFURLSessionManager uses NSURLSession under the hood so that does. I think you still need to configure the NSURLSession appropriately.
"The NSURLSession class supports background transfers while your app is suspended. Background transfers are provided only by sessions created using a background session configuration object (as returned by a call to backgroundSessionConfiguration:)."
Suggested reading:URL Loading System