AFNetworking 2.0 AFHTTPSessionManager: how to get status code and response JSON in failure block?

When switched to AFNetworking 2.0 the AFHTTPClient has been replaced by AFHTTPRequestOperationManager / AFHTTPSessionManager (as mentioned in the migration guide). The very first issue I came across when using the AFHTTPSessionManager is how to retrieve the body of the response in the failure block?

Here's an example:

[self.sessionManager POST:[endpoint absoluteString] parameters:params success:^(NSURLSessionDataTask *task, id responseObject) {
    // How to get the status code?
} failure:^(NSURLSessionDataTask *task, NSError *error) {
    // How to get the status code? response?
}];

In the success block I would like to retrieve response's status code. In the failure block I would like to retrieve both response's status code and the content (which is JSON in this case that describes the server-side error).

The NSURLSessionDataTask has a response property of type NSURLResponse, which has not statusCode field. Currently I'm able to retrieve statusCode like this:

[self.sessionManager POST:[endpoint absoluteString] parameters:params success:^(NSURLSessionDataTask *task, id responseObject) {
    // How to get the status code?
} failure:^(NSURLSessionDataTask *task, NSError *error) {
    NSHTTPURLResponse *response = (NSHTTPURLResponse *)task.response;
    DDLogError(@"Response statusCode: %i", response.statusCode);

}];

But this looks ugly to me. And still can't figure about the response's body.

Any suggestions?

You can access the “data” object directly from AFNetworking by using the “AFNetworkingOperationFailingURLResponseDataErrorKey” key so there is no need for subclassing the AFJSONResponseSerializer. You can the serialize the data into a readable dictionary. Here is some sample code to get JSON Data :

 NSData *errorData = error.userInfo[AFNetworkingOperationFailingURLResponseDataErrorKey];
 NSDictionary *serializedData = [NSJSONSerialization JSONObjectWithData: errorData options:kNilOptions error:nil];

Here is the code to Get Status code in the Failure block:

  NSHTTPURLResponse* r = (NSHTTPURLResponse*)task.response;
  NSLog( @"success: %d", r.statusCode ); 

After of read and research for several days, It worked for me:

1) You have to build your own subclass of AFJSONResponseSerializer

File : JSONResponseSerializerWithData.h:

#import "AFURLResponseSerialization.h"

/// NSError userInfo key that will contain response data
static NSString * const JSONResponseSerializerWithDataKey = @"JSONResponseSerializerWithDataKey";

@interface JSONResponseSerializerWithData : AFJSONResponseSerializer
@end

File: JSONResponseSerializerWithData.m

#import "JSONResponseSerializerWithData.h"

@implementation JSONResponseSerializerWithData

- (id)responseObjectForResponse:(NSURLResponse *)response
                           data:(NSData *)data
                          error:(NSError *__autoreleasing *)error
{
    id JSONObject = [super responseObjectForResponse:response data:data error:error];
    if (*error != nil) {
        NSMutableDictionary *userInfo = [(*error).userInfo mutableCopy];
        if (data == nil) {
//          // NOTE: You might want to convert data to a string here too, up to you.
//          userInfo[JSONResponseSerializerWithDataKey] = @"";
            userInfo[JSONResponseSerializerWithDataKey] = [NSData data];
        } else {
//          // NOTE: You might want to convert data to a string here too, up to you.
//          userInfo[JSONResponseSerializerWithDataKey] = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
            userInfo[JSONResponseSerializerWithDataKey] = data;
        }
        NSError *newError = [NSError errorWithDomain:(*error).domain code:(*error).code userInfo:userInfo];
        (*error) = newError;
    }

    return (JSONObject);
}

2) Setup your own JSONResponseSerializer in your AFHTTPSessionManager

+ (instancetype)sharedManager
{
    static CustomSharedManager *manager = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        manager = [[CustomSharedManager alloc] initWithBaseURL:<# your base URL #>];

        // *** Use our custom response serializer ***
        manager.responseSerializer = [JSONResponseSerializerWithData serializer];
    });

    return (manager);
}

Source: http://blog.gregfiumara.com/archives/239

You can get the status code like this, read the failure block...

 NSURLSessionDataTask *op = [[IAClient sharedClient] POST:path parameters:paramsDict constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
    } success:^(NSURLSessionDataTask *task, id responseObject) {
        DLog(@"\n============= Entity Saved Success ===\n%@",responseObject);

        completionBlock(responseObject, nil);
    } failure:^(NSURLSessionDataTask *task, NSError *error) {
        DLog(@"\n============== ERROR ====\n%@",error.userInfo);
        NSHTTPURLResponse *response = (NSHTTPURLResponse *)task.response;
        int statuscode = response.statusCode;}