Change NSURLConnection to NSURLSession for uploading images - image

Question

I currently upload images in the background to a server like this (the names get changed at the server to something better).
buildURL = [buildURL stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSData *imageData = UIImageJPEGRepresentation(imageToUpload, 1.0); //change Image to NSData
if (imageData != nil)
{
NSString *filenames = [NSString stringWithFormat:#"imagename"]; //set name here
NSLog(#"%#", filenames);
NSString *urlString = buildURL;
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setURL:[NSURL URLWithString:urlString]];
[request setHTTPMethod:#"POST"];
NSString *boundary = #"---------------------------14737809831466499882746641449";
NSString *contentType = [NSString stringWithFormat:#"multipart/form-data; boundary=%#",boundary];
[request addValue:contentType forHTTPHeaderField: #"Content-Type"];
NSMutableData *body = [NSMutableData data];
[body appendData:[[NSString stringWithFormat:#"\r\n--%#\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"filenames\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[filenames dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"\r\n--%#\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[#"Content-Disposition: form-data; name=\"userfile\"; filename=\".jpg\"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[#"Content-Type: application/octet-stream\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[NSData dataWithData:imageData]];
[body appendData:[[NSString stringWithFormat:#"\r\n--%#--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
// setting the body of the post to the reqeust
[request setHTTPBody:body];
// now lets make the connection to the web
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError)
{
NSString *returnString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"Returned From Image Upload : %#",returnString);
}];
}
This works fine, I can see the images finish in the background no problem. The thing is I want to change this to use NSURLSession and the delegate didSendBodyData so that I can monitor the upload.
I have found a load of information about the download but none really about upload. I have tried to do this with the request BUT the completion block NEVER happens.. I have also tried using uploadTaskWithStreamedRequest but I can not get the delegate to happen...
NSURLSessionConfiguration *sessionConfiguration = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *session = [NSURLSession sessionWithConfiguration:sessionConfiguration delegate:self delegateQueue:nil];
NSURLSessionDataTask *uploadTask = [session uploadTaskWithRequest:request fromData:imageData completionHandler:^(NSData *data, NSURLResponse *response, NSError *error)
{
NSLog(#"Image Uploaded ------------");
}];
[uploadTask resume];
I also found this StackOverflow 19985353 which seems to highlight some problems but I could really do with some example code. The image is picked from imagePicker if that helps.
I also tried both the answers here StackOverflow 19099448 but neither of them worked, again the block never executed. Is there something fundamental I am doing wrong with NSURLSession, a framework maybe! I also note I have no idea about the HTTP body which I have tried to play with but no luck.

Answer 1

Okay I did not realise that Session only works in iOS7 and above. To this end I have done a test and if iOS6 then I use NSURLConnection. The problem is I cannot get progress status from this (with the session I have an upload bar).
If anyone has any ideas about an upload progress bar using NSURLConnection then I would love to hear about it.

Answer 2

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:_urlToUpload];// create request
[request setHTTPMethod:#"POST"];// request type
[request setTimeoutInterval:60];
[request setValue:#"application/octet-stream" forHTTPHeaderField: #"Content-Type"];// content type
NSURLSessionConfiguration *sessionConfiguration = [NSURLSessionConfiguration defaultSessionConfiguration];// configuration
NSURLSession *session = [NSURLSession sessionWithConfiguration:sessionConfiguration delegate:self delegateQueue:nil];// session
NSURLSessionUploadTask *uploadTask = [session uploadTaskWithRequest:request fromFile:file completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { }
Use the delegates
#pragma mark -
#pragma mark Session Upload Delegate Methods
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didSendBodyData:(int64_t)bytesSent totalBytesSent:(int64_t)totalBytesSent totalBytesExpectedToSend:(int64_t)totalBytesExpectedToSend {
float status = (double)totalBytesSent / (double)totalBytesExpectedToSend;
[[MTFileStreamer sharedFileStreamer] setCurrentStatus:status];
}
- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite {
}
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error {
NSLog(#"%s", __PRETTY_FUNCTION__);
}
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task willPerformHTTPRedirection:(NSHTTPURLResponse *)response
newRequest:(NSURLRequest *)request completionHandler:(void (^)(NSURLRequest *))completionHandler {
NSLog(#"%s", __PRETTY_FUNCTION__);
}
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge
completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential *credential))completionHandler {
NSLog(#"%s", __PRETTY_FUNCTION__);
}
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task needNewBodyStream:(void (^)(NSInputStream *bodyStream))completionHandler {
NSLog(#"%s", __PRETTY_FUNCTION__);
}