AFNetworking + Pause/ Resume downloading big files

Question

I need to download large .zip files (up to 800 MB) with my iPad app. I want to resume the download again if it is canceled or if the app is in the background.

operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
operation.outputStream = [NSOutputStream outputStreamToFileAtPath:filePath append:YES];

[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject){

// unzip the .zip


}failure:^(AFHTTPRequestOperation *operation, NSError *error){

//Handle the error

}];


[operation setDownloadProgressBlock:^(NSInteger bytesWritten, long long totalBytesWritten,long long totalBytesExpectedToWrite) {

//update the progressView

}];

[operation setShouldExecuteAsBackgroundTaskWithExpirationHandler:^{

// What I have to do here?

}];

[operation start];
[operation waitUntilFinished];


-(void)applicationWillResignActive:(UIApplication *)application{

// What I have to do here?

}

Thanks for your help.

Solution

You can use AFDownloadRequestOperation to do this.

    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"....zip"]];
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *path = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"....zip"];
    AFDownloadRequestOperation *operation = [[AFDownloadRequestOperation alloc] initWithRequest:request targetPath:path shouldResume:YES];
    [operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
        NSLog(@"Successfully downloaded file to %@", path);
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Error: %@", error);
    }];
    [operation setProgressiveDownloadProgressBlock:^(NSInteger bytesRead, long long totalBytesRead, long long totalBytesExpected, long long totalBytesReadForFile, long long totalBytesExpectedToReadForFile) {
        NSLog(@"Operation%i: bytesRead: %d", 1, bytesRead);
        NSLog(@"Operation%i: totalBytesRead: %lld", 1, totalBytesRead);
        NSLog(@"Operation%i: totalBytesExpected: %lld", 1, totalBytesExpected);
        NSLog(@"Operation%i: totalBytesReadForFile: %lld", 1, totalBytesReadForFile);
        NSLog(@"Operation%i: totalBytesExpectedToReadForFile: %lld", 1, totalBytesExpectedToReadForFile);
    }];
    [operations addObject:operation];

After you restart your app, and generate the request having a same url, it will resume downloading. "shouldResume:YES" works

Comments

[Tudor]

Is there a non ARC alternative?

[Praveen Sharma]

Do you know if this works with URL redirection? I have presigned urls which then redirect to the actual file to download. The downloads don't seem to be resuming using these URLs.

[mrgrieves]

Just make sure that you specify the same targetPath every time. Also it can't be directory; if you specify a directory, it'll use the URL to name the file.

[Adam Lockhart]

@Tudorizer Just set a compiler flag for the file under build phases, -fobjc-arc. See the AFNetworking on github for details.

[mkc842]

Thanks.. could you elaborate on [operations addObject:operation] ?

[lenhhoxung]

AFDownloadRequestOperation not found in the latest AFNetworking git hub

[Siriss]

what is 'operations'?

[Hamid Zandi]

how is in AFN 3.0 ? answer is in AFN 2.0 :(