AFNetworking 2.0 Get JSON from code 400 in failure block - ios

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

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 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

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 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];
}];