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:)
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
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 have a requirement to make an web-service call up on tapping actionable buttons from the Remote notification.
On the Remote notification, we have two buttons "Details" and "Fetch". "Fetch" is a background action (Activation Mode = UIUserNotificationActivationModeBackground) and will send some data with out launching the app.
On tapping "Fetch", i made a web-service call to send some details which i got from remote notification.
I have used NSURLSession to send those data to server.
NSURLSessionConfiguration *sessionConfiguration = [NSURLSessionConfiguration backgroundSessionConfigurationWithIdentifier:#"com.applewatch.sample"];
self.session = [NSURLSession sessionWithConfiguration:sessionConfiguration delegate:self delegateQueue:nil];
NSURLSessionUploadTask *dataTask = [self.session uploadTaskWithRequest:mutableURLRequest fromData:nil];
[dataTask resume];
This works fine when the app is in active state but not in the suspended mode. What i meant to say here is, Once we get the Remote notification and if act after 1 hour on the notification, the service request is not going through.
I suspect, the service request is not going through because the app is in suspended mode/termination mode.
Could some help me how to make service calls in the background.
Note: I have not enabled "Background Fetch" options in info.plist.
Let me know if need to enable and implement the service calls in the UIApplication delegate
application:performFetchWithCompletionHandler:
I'm not being able to recall or find again where I read this information before, but try using
- uploadTaskWithRequest:fromFile:
I believe it's the only upload method that will work in background
When I force my device to go in sleep mode by pressing the power button, my background task stops by calling the delegate method didCompleteWithError with the error :
The operation couldn’t be completed. Operation not permitted
How can I configure my NSURLSession to continue the download even in sleep mode?
Is it even possible? If not, what options do I have? I need to download a file of 300Mb, so with a low connection the application will go in sleep mode before the end of the download.
Here is the creation of my session :
static NSURLSession *backgroundSession;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
backgroundSession = [NSURLSession sessionWithConfiguration:
[NSURLSessionConfiguration backgroundSessionConfiguration:
#"com.myapp.mytask"] delegate:self.
myDelegate delegateQueue:self.myQueue];
});
NSURLSessionDownloadTask *task = [backgroundSession downloadTaskWithRequest:
self.urlRequest];
[task resume];
The problem is that the Data Protection Capability is activated. With that enabled all files are stored with NSFileProtectionComplete by default, even the temporary file used to download by the NSURLSession:
The default level of protection is complete protection, in which files
are encrypted and inaccessible when the device is locked. You can
programmatically set the level of protection for files created by your
app, as described in “Protecting Data Using On-Disk Encryption” in iOS
App Programming Guide.
With NSFileProtectionComplete activated on that file you cannot access it when the device is locked.
I'm not sure if the temporary download file can be configured to not use data protection, it seems like that is not exposed by NSURLSession.
Source: App Distribution Guide
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.