AFNetworking 2.0 Get JSON from code 400 in failure

Question

I'm using AFHTTPRequestOperationManager for a POST request. Now I'm deliberately entering incorrect information to handle a 400 error code. Now, the web service actually returns a JSON with a message explaining to the user what they've done wrong. I would very much like to get this JSON to display the message in a UIAlertView. However, the failure block of:

[operationManager POST:ServerURL parameters:parameters success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@"Success: Status Code: %d", operation.response.statusCode);
}
 failure:^(AFHTTPRequestOperation *operation, NSError *error) {
     NSLog(@"Failed: Status Code: %d", operation.response.statusCode);
 }];

doesn't pass down a responseObject like the one in the success block. So does anyone know how I can access the JSON returned by the Web Service with the 400 error? The NSError *error simply gives me Request failed: bad request (400) and not the JSON returned.

Any help would be appreciated,
Mike

Answer 1

I also faced same problem in AFNetworking, as instead of using

- (NSURLSessionDataTask *)POST:(NSString *)URLString
                parameters:(id)parameters
                  progress:(void (^)(NSProgress * _Nonnull))uploadProgress
                   success:(void (^)(NSURLSessionDataTask * _Nonnull, id _Nullable))success
                   failure:(void (^)(NSURLSessionDataTask * _Nullable, NSError * _Nonnull))failure

Please try to use that one :-

- (NSURLSessionDataTask *)POST:(NSString *)URLString
                parameters:(id)parameters
 constructingBodyWithBlock:(void (^)(id <AFMultipartFormData> formData))block
                  progress:(nullable void (^)(NSProgress * _Nonnull))uploadProgress
                   success:(void (^)(NSURLSessionDataTask *task, id responseObject))success
                   failure:(void (^)(NSURLSessionDataTask *task, NSError *error))failure

thanks,

Answer 2

You can do either of these solutions

1) Set the acceptableStatusCodes to accept your 400 statusCode, and you handle in the success block

manager.responseSerializer.acceptableStatusCodes = [NSIndexSet indexSetWithIndex:400];

2) Create a custom ResponseSerializer, like this JSONResponseSerializerWithData, to insert the responseObject into the NSError userInfo, and handle in the failure block

Pro tip: AFNetworking is opensource, just take a look at AFHTTPRequestOperation for methods

setCompletionBlockWithSuccess:failure:

responseObject

error

Answer 3

Looking at the code for - responseObject, it appears that an HTTP error prevents it from being populated. You can grab the responseData directly and parse it yourself, but I would say this is either a bug or a good enhancement request. (It looks like - responseObject probably should be checking self.responseSerializationError, not self.error, when deciding if it should try to build a response object.)

Answer 4

Following code worded for me:

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    manager.responseSerializer = [AFJSONResponseSerializer serializer];
    manager.requestSerializer = [AFJSONRequestSerializer serializer];

    [manager.requestSerializer setValue:@"parse-application-id-removed" forHTTPHeaderField:@"X-Parse-Application-Id"];
    [manager.requestSerializer setValue:@"parse-rest-api-key-removed" forHTTPHeaderField:@"X-Parse-REST-API-Key"];
    [manager.requestSerializer setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
    manager.securityPolicy.allowInvalidCertificates = YES;

    NSString *URLString = [NSString stringWithFormat:@"%@/%@", BASE_URL,methodName];



    [manager POST:URLString parameters:requestDict success:^(AFHTTPRequestOperation *operation, id responseObject)
    {
        NSLog(@"JSON: %@", responseObject);

        [myDelegate StopIndicator];
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Error: %@", error);
        [myDelegate StopIndicator];
    }];