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PONSURLConnection Hangs under certain conditions
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  1. PONSURLConnection Hangs under certain conditions
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    copied!<p>I'm posting to a RESTful webservice and receiving a response, this works great if I'm getting back only a few records however there is a threshold where didReceiveData: stops being called (6 records) and it just hangs. (does not matter what records, just the number)</p> <p>I can't seem to figure out why. I'm getting a status message of 200 application/json in didReceiveResponse: however that's the last I hear from my connection.</p> <p>From other clients I can get the full data with any number of records so it's related to my NSURLConnection code. </p> <p>See full NSURLConnection Post class below. </p> <p>the .h</p> <pre><code>#import &lt;Foundation/Foundation.h&gt; #import "MBProgressHUD.h" @protocol PostJsonDelegate &lt;NSObject, NSURLConnectionDelegate&gt; @optional - (void) downloadFinished; - (void) downloadReceivedData; - (void) dataDownloadFailed: (NSString *) reason; @end @interface PostURLJson : NSObject { NSMutableData *receivedData; int expectedLength; MBProgressHUD *HUD; } @property (strong, nonatomic) NSMutableData *receivedData; @property (weak) id &lt;PostJsonDelegate&gt; delegate; @property (assign, nonatomic) int expectedLength; + (id)initWithURL:(NSString *)url dictionary:(NSDictionary *)dictionary withDelegate:(id &lt;PostJsonDelegate&gt;)delegate; @end </code></pre> <p>the .m</p> <pre><code>#import "PostURLJson.h" #define SAFE_PERFORM_WITH_ARG(THE_OBJECT, THE_SELECTOR, THE_ARG) (([THE_OBJECT respondsToSelector:THE_SELECTOR]) ? [THE_OBJECT performSelector:THE_SELECTOR withObject:THE_ARG] : nil) @implementation PostURLJson @synthesize delegate; @synthesize receivedData; @synthesize expectedLength; + (id)initWithURL:(NSString *)url dictionary:(NSDictionary *)dictionary withDelegate:(id &lt;PostJsonDelegate&gt;)delegate { if (!url) { NSLog(@"Error. No URL"); return nil; } PostURLJson *postJson = [[self alloc] init]; postJson.delegate = delegate; [postJson loadWithURL:url dictionary:dictionary]; return postJson; } - (void)loadWithURL:(NSString *)url dictionary:(NSDictionary *)dictionary { [self setExpectedLength:0]; receivedData = [[NSMutableData alloc] init]; NSError* error; NSDictionary *tmp = [[NSDictionary alloc] initWithDictionary:dictionary]; NSData *postdata = [NSJSONSerialization dataWithJSONObject:tmp options:0 error:&amp;error]; NSString *someString = [[NSString alloc] initWithData:postdata encoding:NSASCIIStringEncoding]; NSLog(@"%@",someString); NSString *postLength = [NSString stringWithFormat:@"%d", [postdata length]]; NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init]; [request setURL:[NSURL URLWithString:url]]; [request setHTTPMethod:@"POST"]; [request setTimeoutInterval:10.0f]; [request setValue:postLength forHTTPHeaderField:@"Content-Length"]; [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"]; [request setHTTPBody:postdata]; NSURLConnection *connection = [NSURLConnection connectionWithRequest:request delegate:self]; [connection start]; [self setLoadingModeEnabled:YES]; } - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response { NSHTTPURLResponse * httpResponse = (NSHTTPURLResponse *) response; int errorCode = httpResponse.statusCode; NSString *fileMIMEType = [[httpResponse MIMEType] lowercaseString]; NSLog(@"%d",errorCode); NSLog(@"%@",fileMIMEType); [receivedData setLength:0]; // Check for bad connection expectedLength = [response expectedContentLength]; if (expectedLength == NSURLResponseUnknownLength) { NSString *reason = [NSString stringWithFormat:@"Invalid URL"]; SAFE_PERFORM_WITH_ARG(delegate, @selector(dataDownloadFailed:), reason); [connection cancel]; return; } } - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data { [receivedData appendData:data]; SAFE_PERFORM_WITH_ARG(delegate, @selector(downloadReceivedData), nil); } - (void)connectionDidFinishLoading:(NSURLConnection *)connection { SAFE_PERFORM_WITH_ARG(delegate, @selector(downloadFinished), nil); [self setLoadingModeEnabled:NO]; } - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error { NSLog(@"Something went wrong..."); HUD.labelText = @"Something went wrong..."; [self performSelector:@selector(didFailHideHud) withObject:nil afterDelay:2]; } - (void)setLoadingModeEnabled:(BOOL)isLoading { //when network action, toggle network indicator and activity indicator if (isLoading) { [UIApplication sharedApplication].networkActivityIndicatorVisible = YES; UIWindow *window = [UIApplication sharedApplication].keyWindow; HUD = [[MBProgressHUD alloc] initWithWindow:window]; [window addSubview:HUD]; HUD.labelText = @"Loading"; [HUD show:YES]; } else { [UIApplication sharedApplication].networkActivityIndicatorVisible = NO; [HUD hide:YES]; [HUD removeFromSuperview]; } } -(void)didFailHideHud { [HUD hide:YES]; [HUD removeFromSuperview]; } @end </code></pre> <p><strong>Edit</strong> Server was not giving back a valid length after a certain size triggering NSURLResponseUnknownLength which I had mistakenly not logged so I was not getting my "Invalid URL" message in the console. </p> <pre><code>if (expectedLength == NSURLResponseUnknownLength) { NSString *reason = [NSString stringWithFormat:@"Invalid URL"]; SAFE_PERFORM_WITH_ARG(delegate, @selector(dataDownloadFailed:), reason); [connection cancel]; return; } </code></pre>
 

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