CODEWITHSUNDEEP
iosnsurlsession
Simankov
Simankov

Reputation: 91

Why we are using ephemeralSessionConfiguration here?

- (void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler
{
    if (self.photoDatabaseContext) {
        NSURLSessionConfiguration *sessionConfig = [NSURLSessionConfiguration ephemeralSessionConfiguration];
        sessionConfig.allowsCellularAccess = NO;
        sessionConfig.timeoutIntervalForRequest = BACKGROUND_FLICKR_FETCH_TIMEOUT;
        NSURLSession *session = [NSURLSession sessionWithConfiguration:sessionConfig];
        NSURLRequest *request = [[NSURLRequest alloc] initWithURL:[FlickrFetcher URLforRecentGeoreferencedPhotos]];
        NSURLSessionDownloadTask *task = [session downloadTaskWithRequest:request
                                                        completionHandler:^(NSURL *localFile, NSURLResponse *response, NSError *error) {
                                                            if (error) {
                                                                NSLog(@"Flickr background fetch failed: %@", error.localizedDescription);
                                                                completionHandler(UIBackgroundFetchResultNoData);
                                                            } else {
                                                                [self loadFlickrPhotosFromLocalURL:localFile
                                                                                       intoContext:self.photoDatabaseContext
                                                                               andThenExecuteBlock:^{
                                                                                   completionHandler(UIBackgroundFetchResultNewData);
                                                                               }
                                                                 ];
                                                            }
                                                        }];
        [task resume];
    } else {
        completionHandler(UIBackgroundFetchResultNoData);
    }
}

It seems logical that there must be backgroundSessionConfigurationWithIdentifier instead of ephemeralSessionConfiguration because it is loading in the background. But Paul Hegarty from Stanford iOS course said that second is better. Why? He said something about discrete fetching, but I didn't understand.

Upvotes: 0

Views: 1613

Answers (1)

Joyal Clifford
Joyal Clifford

Reputation: 1212

ephemeralSessionConfiguration: Similar to the default configuration, except that all session-related data is stored in memory. Think of this as a “private” session. backgroundSessionConfiguration: Lets the session perform upload or download tasks in the background. Transfers continue even when the app itself is suspended or terminated. more info :https://www.raywenderlich.com/110458/nsurlsession-tutorial-getting-started

Upvotes: 1

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