IPHONE SDK : NSURLConnection asynchronous / wait completion bug ? - iphone

Question

I am trying to use NSURLConnection in asynchronous mode and wait for completion.
During the wait, I use NSRUNLOOP to handle events. Its works in most cases (3G and WIFI)
but the application hangup randomly in GSM DATA and EDGE environment.
My code:
(void) connectionDidFinishLoading:(NSURLConnection *)connection
{
_requestCompleted = TRUE;
CFRunLoopStop(CFRunLoopGetCurrent());
}
(void) connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
_response = (NSHTTPURLResponse *)response;
[ _response retain];
}
(void) connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
/* Append the new data to the received data. */
[_receivedData appendData:data];
}
(void) connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
_requestError = error;
NSLog(#"request error - cause : %#", [_requestError localizedDescription ]);
_requestCompleted = TRUE;
[_requestError retain];
CFRunLoopStop(CFRunLoopGetCurrent());
}
(NSString*)downloadFileFromURL:(NSString*)url
{
NSURLRequest *request = nil;
NSString *contents = nil;
NSData *response = nil;
int tries;
NSURLConnection *URLConnection = nil;
int i = 0;
NSDate* dateLimit;
[_mutex lock];
NSLog(#"url = %#", url);
NSString *requestWithEscaping = [ url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding ];
request = [NSURLRequest requestWithURL:[NSURL URLWithString:requestWithEscaping]
cachePolicy: NSURLRequestReloadIgnoringLocalCacheData
timeoutInterval:30];
for (tries = 0; tries < HTTP_REQUESTS_TRIES && response == nil ; tries ++) {
[_receivedData setLength:0];
_requestCompleted = FALSE;
_requestError = nil;
_requestTimeout = FALSE;
if (URLConnection == nil)
URLConnection = [ NSURLConnection connectionWithRequest:request delegate:self];
else {
[URLConnection cancel ];
[URLConnection start];
}
if (URLConnection == nil) {
NSLog(#"No connection ! maybe mistake in Request Format ?");
continue;
}
for (i = 0; ; i++) {
dateLimit = [[NSDate date] addTimeInterval:INTERVALL_LOOP];
[ [NSRunLoop currentRunLoop] runUntilDate:dateLimit];
if (_requestCompleted == TRUE)
break;
if (i > (int)(HTTP_TIMEOUT_FIRE * (1 / INTERVALL_LOOP))) {
_requestTimeout = TRUE;
break;
}
}
if (_requestTimeout) {
[ URLConnection cancel];
NSLog(#"request timeout");
continue;
}
if (_requestError) {
NSLog(#"request error");
continue;
}
NSLog(#"Request success");
break;
}
if (_requestTimeout) {
_lastErrorType = ServicesRequestManager_error_Network;
[ _lastErrorString setString:#"Délai de connexion depassé"];
[ _mutex unlock];
return nil;
}
if (_requestError) {
NSLog(#"ERROR Cannot get %# - cause : %#",url, [ _requestError localizedDescription ]);
_lastErrorType = ServicesRequestManager_error_Network;
[_lastErrorString setString:#"Impossible de se connecter" ];
[ _mutex unlock];
return nil;
}
if ([ _response statusCode] != 200 ) {
NSLog(#"ERROR Download file %# HTTP response - code : %d", url, [ _response statusCode]);
[_lastErrorString setString:[ NSString stringWithFormat:#"Error http code : %d", [_response statusCode]]];
_lastErrorType = ServicesRequestManager_error_Service;
[_lastErrorString setString:#"Le service n'est pas disponible actuellement" ];
[ _mutex unlock];
return nil;
}
contents = [[NSString alloc] initWithData:_receivedData encoding:NSUTF8StringEncoding];
[ _mutex unlock];
return contents;
}

Answer 1

NSURLConnection is already asynchronous. Simply implement the delegate methods. If you want to update the UI on the MainThread (e.g. a progress bar), you can do so in didReceiveData.

Answer 2

I use NSNotificationor that puspose. In DidFinishLoading method post a notification,
[[NSNotificationCenter defaultCenter] postNotificationName:#"Name" object:someObject];
and handle this notification in anyclass by
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(handleMethod:) notificationName:#"Name" object:nil];
and implement
-(void)handleMethod:(NSNotification *)ntf