Question

I have a use case that should be rather common but I can’t find an easy way to handle it with AFNetworking:

Whenever the server returns a specific status code for any request, I want to:

• remove a cached authentication token
• re-authenticate (which is a separate request)
• repeat the failed request.

I thought that this could be done via some global completion/error handler in AFHTTPClient, but I didn’t find anything useful. So, what’s the “right” way to do what I want? Override enqueueHTTPRequestOperation: in my AFHTTPClient subclass, copy the operation and wrap the original completion handler with a block that does what I want (re-authenticate, enqueue copied operation)? Or am I on the wrong track altogether?

Thanks!

EDIT: Removed reference to 401 status code, since that’s probably reserved for HTTP basic while I’m using token auth.

Answer 1

In the AFHTTPClient’s init method register for the AFNetworkingOperationDidFinishNotification which will be posted after a request finishes.

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(HTTPOperationDidFinish:) name:AFNetworkingOperationDidFinishNotification object:nil];

In the notification handler check the status code and copy the AFHTTPRequestOperation or create a new one.

- (void)HTTPOperationDidFinish:(NSNotification *)notification {
  AFHTTPRequestOperation *operation = (AFHTTPRequestOperation *)[notification object];

    if (![operation isKindOfClass:[AFHTTPRequestOperation class]]) {
        return;
    }

    if ([operation.response statusCode] == 401) {
        // enqueue a new request operation here
    }
}

EDIT:

In general you should not need to do that and just handle the authentication with this AFNetworking method:

- (void)setAuthenticationChallengeBlock:(void (^)(NSURLConnection *connection, NSURLAuthenticationChallenge *challenge))block;