I use an alternative means for doing this with AFNetworking 2.0.
You can subclass dataTaskWithRequest:success:failure: and wrap the passed completion block with some error checking. For example, if you’re working with OAuth, you could watch for a 401 error (expiry) and refresh your access token.
- (NSURLSessionDataTask *)dataTaskWithRequest:(NSURLRequest *)urlRequest completionHandler:(void (^)(NSURLResponse *response, id responseObject, NSError *error))originalCompletionHandler{
//create a completion block that wraps the original
void (^authFailBlock)(NSURLResponse *response, id responseObject, NSError *error) = ^(NSURLResponse *response, id responseObject, NSError *error)
{
NSHTTPURLResponse* httpResponse = (NSHTTPURLResponse*)response;
if([httpResponse statusCode] == 401){
NSLog(@"401 auth error!");
//since there was an error, call you refresh method and then redo the original task
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{
//call your method for refreshing OAuth tokens. This is an example:
[self refreshAccessToken:^(id responseObject) {
NSLog(@"response was %@", responseObject);
//store your new token
//now, queue up and execute the original task
NSURLSessionDataTask *originalTask = [super dataTaskWithRequest:urlRequest completionHandler:originalCompletionHandler];
[originalTask resume];
}];
});
}else{
NSLog(@"no auth error");
originalCompletionHandler(response, responseObject, error);
}
};
NSURLSessionDataTask *task = [super dataTaskWithRequest:urlRequest completionHandler:authFailBlock];
return task;
}