AFNetworking: Get JSON Value From Http Response - ios

Question

I am primarily an android developer and really new to IOS. I am using AFNetworking 1.0 since I am working with an existing source and I am sending a standard http Post request and returning the data like so:
//Sending the post request and getting the result
AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:[NSURL URLWithString:#"http://testsite.org/mobile_app"]];
[httpClient setParameterEncoding:AFFormURLParameterEncoding];
NSMutableURLRequest *request = [httpClient requestWithMethod:#"POST"
path:#"http://testsite.org/mobile_app/studentregister.php"
parameters:#{#"username":username, #"displayname":displayname, #"password":password, #"passwordc":passwordc, #"email":email, #"teacherCode":teacherCode}];
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
[httpClient registerHTTPOperationClass:[AFHTTPRequestOperation class]];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
// Print the response body in text
NSLog(#"Response: %#", [[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding]);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Error: %#", error);
}];
[operation start];
the response should contain the JSON data which looks like this according to burp suit:
{"userCharLimit":"Your username must be between 5 and 25 characters in length"}
{"displaynameCharLim":"Your displayname must be between 5 and 25 characters in length"}
{"passLimit":"Your password must be between 8 and 50 characters in length"}
{"emailInvalid":"Not a valid email address"}
{"teacherCodeLength":"Your teacher code is not 5 to 12 characters"}.
How can I get those JSON values? I have seen a lot of AFNetworking 2.0 JSON examples and sending JSON Post request but I can seem to find much for version 1.0 let alone getting the values form a standard post request.
Any ideas or resources?

Answer 1

All you should need is to change your code to register a AFJSONRequestOperation instead of AFHTTPRequestOperation.
[httpClient registerHTTPOperationClass:[AFJSONRequestOperation class]];
Then you can use this method on AFHTTPClent to create the operation which will actually be of type AFJSONRequestOperation.
AFHTTPRequestOperation *operation = [httpClient HTTPRequestOperationWithRequest:request success:nil failure:nil];
[httpClient enqueueOperation:operation];