AFNetworking POST to REST webservice

Question

Brief backstory, our previous developer used ASIHTTPRequest to make POST requests and retrieve data from our webservice. For reasons unknown this portion of our app stopped

Answer 1

These are the essential (stripping out conditions I've made for my own use) lines that ended up satisfying my request to the web service. Thanks for the suggestions @8vius and @mattt !

- (IBAction)loginButtonPressed {        
    NSURL *baseURL = [NSURL URLWithString:@"https://www.example.com/api/class"];

    //build normal NSMutableURLRequest objects
    //make sure to setHTTPMethod to "POST". 
    //from https://github.com/AFNetworking/AFNetworking
    AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:baseURL];
    [httpClient defaultValueForHeader:@"Accept"];

    NSDictionary *params = [NSDictionary dictionaryWithObjectsAndKeys:
                            [usernameTextField text], kUsernameField, 
                            [passwordTextField text], kPasswordField, 
                            nil];

    NSMutableURLRequest *request = [httpClient requestWithMethod:@"POST" 
          path:@"https://www.example.com/api/class/function" parameters:params];

    //Add your request object to an AFHTTPRequestOperation
    AFHTTPRequestOperation *operation = [[[AFHTTPRequestOperation alloc] 
                                      initWithRequest:request] autorelease];

    //"Why don't I get JSON / XML / Property List in my HTTP client callbacks?"
    //see: https://github.com/AFNetworking/AFNetworking/wiki/AFNetworking-FAQ
    //mattt's suggestion http://stackoverflow.com/a/9931815/1004227 -
    //-still didn't prevent me from receiving plist data
    //[httpClient registerHTTPOperationClass:
    //         [AFPropertyListParameterEncoding class]];

    [httpClient registerHTTPOperationClass:[AFHTTPRequestOperation class]];

    [operation setCompletionBlockWithSuccess:
      ^(AFHTTPRequestOperation *operation, 
      id responseObject) {
        NSString *response = [operation responseString];
        NSLog(@"response: [%@]",response);
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"error: %@", [operation error]);
    }];

    //call start on your request operation
    [operation start];
    [httpClient release];
}

Answer 2

Use AFHTTPClient -postPath:parameters:success:failure:, passing your parameters (nested dictionaries/arrays are fine). If you're expecting a plist back, be sure to have the client register AFPropertyListRequestOperation.

In any case, setValue:forHTTPHeaderField: is not what you want here. HTTP headers are for specifying information about the request itself; data is part of the request body. AFHTTPClient automatically converts parameters into either a query string for GET requests or an HTTP body for POST, et al.