NSURLConnection and NSURLConnectionDelegate work on different thread - iphone

Question

as descripted in the title, I did some NSURLConnection like this. But I found that the delegate method couldn't get run. Anyone knows how to deal with it ?
edit:
my delegate works on the main thread, while NSURLConnection works on an operation queue. Now the case is :NSURLConnection works fine, but delegate won't run.
edit 2:
I used the class method [NSURLConnection connectionWithRequest: delegate:]
here is on my main queue
NSOperationQueue *queuePhoto = [[NSOperationQueue alloc] init];
NSInvocationOperation *invocationOperationPhotos = [[NSInvocationOperation alloc] initWithTarget:self selector:#selector(transferToServerAddimages:) object:arrayOfASection];
// [invocationOperationPhotos addObserver:self forKeyPath:#"isExecuting" options:0 context:invocationOperationPhotos];
// [invocationOperationPhotos addObserver:self forKeyPath:#"isCancelled" options:0 context:invocationOperationPhotos];
// [[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(<#selector#>) name:#"isExecuting" object:nil];
[invocationOperationPhotos setQueuePriority:NSOperationQueuePriorityHigh];
[queuePhoto addOperation:invocationOperationPhotos];
[mutableArrayPhotoQueue addObject:queuePhoto];
[invocationOperationPhotos release];
[queuePhoto release];
here is my NSURLConnnection:
- (void) transferToServerAddimages:(NSArray *) arrayToAdd
{
NSLog(#"[NSOperationQueue currentQueue]: %#", [NSOperationQueue currentQueue]);
NSString *murphoAppPrefix = [[AppDelegate sharedAppDelegate] murphoAppPrefix];
// setting up the request object now
NSString *urlString = [murphoAppPrefix stringByAppendingString:#"addPhotos.php"];
NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
[request setURL:[NSURL URLWithString:urlString]];
[request setHTTPMethod:#"POST"];
/*
add some header info now
we always need a boundary when we post a file
also we need to set the content type
*/
// set header value , some random text that will never occur in the body
NSString *boundary = #"---------------------------14737809831466499882746641449";
NSString *contentType = [NSString stringWithFormat:#"multipart/form-data; boundary=%#",boundary];
[request addValue:contentType forHTTPHeaderField: #"Content-Type"];
/*
now lets create the body of the post
*/
NSMutableData *body = [NSMutableData data];
// email part
[body appendData:[[NSString stringWithFormat:#"\r\n--%#\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"email\"\r\n\r\n%#", self.trip.whoCreate.email] dataUsingEncoding:NSUTF8StringEncoding]];
// password part
[body appendData:[[NSString stringWithFormat:#"\r\n--%#\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"password\"\r\n\r\n%#", self.trip.whoCreate.psw] dataUsingEncoding:NSUTF8StringEncoding]];
// image part
NSInteger subCount=0;
for (NSDictionary *aDict in arrayToAdd) {
// belonging part
[body appendData:[[NSString stringWithFormat:#"\r\n--%#\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"r_whichShortTrip%d\"\r\n\r\n%#", subCount, [aDict objectForKey:#"r_whichShortTrip"]] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"\r\n--%#\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"uniqueId%d\"\r\n\r\n%#", subCount, [aDict objectForKey:#"uniqueId"]] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"\r\n--%#\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"createdTime%d\"\r\n\r\n%#", subCount, [aDict objectForKey:#"createdTime"]] dataUsingEncoding:NSUTF8StringEncoding]];
UIImage *imageFile = [aDict objectForKey:#"image"];
NSData *imageData = UIImageJPEGRepresentation(imageFile, 1.0);
NSString *imageName = [[URLConnect createUUID] stringByAppendingString:#".jpg"];
[body appendData:[[NSString stringWithFormat:#"\r\n--%#\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:
#"Content-Disposition: form-data; name=\"image%d\"; filename=%#\r\n", subCount, imageName] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:#"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[NSData dataWithData:imageData]];
[body appendData:[#"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
UIImage *thumbnail = [aDict objectForKey:#"thumbnail"];
NSData *thumbnailData = [NSData dataWithData:UIImageJPEGRepresentation(thumbnail, 1)];
NSString *thumbnailName = [[URLConnect createUUID] stringByAppendingString:#".jpg"];
[body appendData:[[NSString stringWithFormat:#"\r\n--%#\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:
#"Content-Disposition: form-data; name=\"thumbnail%d\"; filename=%#\r\n", subCount++, thumbnailName] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:#"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[NSData dataWithData:thumbnailData]];
[body appendData:[#"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
}
[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
[NSURLConnection connectionWithRequest:request delegate:self];
}
here is my delegate:
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
[[[AppDelegate sharedAppDelegate] mArrayOfFailedConnection] addObject:connection];
[connection cancel];
connection = nil;
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
NSLog(#"response: %#", response);
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSLog(#"connection: %#", connection);
}

Answer 1

Actually when you set selector for operation as "transferToServerAddimages" that means when this function would executed completely your operation would be finished, also since NSUrlConnection calls its delegates on that same thread, on which it was started, so its probable that thread (OperationQueue) was finished before response arrived. If you indeed want to use NSOperationQueue then a better function to use is "sendAsynchronousRequest:queue:completionHandler:" of NSUrlConnection.

Answer 2

What's the delegate, the NSOperation? One possibility is your operation is calling -[connectionWithRequest:delegate:] and exit, which causes it to finish and be deleted. Put an NSLog in the operation's dealloc to see if its running.
Assuming all the operation does is NSURLConnection transations, you don't need to wrap the transaction in an NSOperation to get concurrency, since those transations are asynchronous already. But if you really want to use NSOperation (for coordination purposes etc), make it a "concurrent" one and put it on the main queue. Those kind are trickier but there are examples around.