Asynchronously send an NSDictionary to a server PHP (or other) script using JSON with a completion handler (Objective C).

SendDictionaryToScript.m

/* Created by Hersh Bhargava of H2 Micro (www.h2micro.com) */

- (void)sendDictionary:(NSDictionary *)dictionary toScript:(NSString *)scriptName completion:(void (^) (id response))completionBlock
{
    //Convert the passed dictionary into JSON.
    NSString *JSONStringfromDictionary = [self JSONfromDictionary:dictionary];
    //Set up the query string for the Server with the API Key inline.
    NSString *URLString = YOUR_URL_STRING;
    NSString *queryString = [NSString stringWithFormat:@"%@key=%@", URLString, YOUR_OPTIONAL_API_KEY];
    //Create a URLRequest using the query string.
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:[queryString stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding]]];
    request.HTTPMethod = @"POST";
    [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
    //Convert JSON string to NSData object
    NSData *dataFromJSON = [JSONStringfromDictionary dataUsingEncoding:NSUTF8StringEncoding];
    NSString *stringifiedData = [[NSString alloc]initWithData:dataFromJSON encoding:NSUTF8StringEncoding];
    request.HTTPBody = dataFromJSON;
    
    //Execute Asynchronous request with a completion handler block.
    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
        if (!connectionError) {
            NSString *receivedString = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
            NSError *deserializationError;
            id deserializedJSON = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&deserializationError];
            if (deserializationError) {
                NSLog(@"NetworkManager: Failed Deserialization: %@", deserializationError.description);
                NSLog(@"NetworkManager: Failing string from script. \"%@\": %@", scriptName, receivedString);
            } else {
                NSLog(@"NetworkManager: Succesfully deserialized JSON from script \"%@\": %@", scriptName, [self dictionaryWithoutBigKeysFromDictionary:deserializedJSON]);
            }
            //Call completion handler with deserialied server response as a parameter.
            if (completionBlock) {
                completionBlock(deserializedJSON);
            }
        } else {
            NSLog(@"NetworkManager: failed to connect to server: %@", connectionError.description);
        }
    }];
}
-(NSString *)JSONfromDictionary:(NSDictionary *)dictionary
{
    NSData *jsonData;
    @try {
        jsonData = [NSJSONSerialization dataWithJSONObject:dictionary options:NSJSONWritingPrettyPrinted error:nil];
    }
    @catch (NSException *exception) {
        NSLog(@"Failed JSON Serialization: %@", exception);
    }
    return  [[NSString alloc] initWithBytes:[jsonData bytes] length:[jsonData length] encoding:NSUTF8StringEncoding];
}