AFNetworking 2.0 responseObject handling

Question

I have a question. Maybe 2 questions.

First one relates to this piece of code:

-(void)isLoggedIn {
NSString *urlString = [NSString stringWithFormat:@"%@%@%@", kBaseURL, kAPI, kUserIsLogged];
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
manager.responseSerializer = [AFJSONResponseSerializer serializerWithReadingOptions:NSJSONReadingAllowFragments];
[manager GET:urlString parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@"JSON: %@", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"Error: %@", error);
}];
}

I would like that this method is not a void, i would like it to be returning a BOOL or something that I can use like: User is logged in > Ok do something somewhere in the app; User is not logged in > Ok prompt the user to a screen where he can introduce his credentials and log in.

Second question is related to this piece of code:

-(void)detail {
NSString *urlString = [NSString stringWithFormat:@"%@%@%@", kBaseURL, kAPI, kUser];
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
manager.responseSerializer = [AFJSONResponseSerializer serializerWithReadingOptions:NSJSONReadingAllowFragments];
[manager GET:urlString parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@"JSON: %@", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"Error: %@", error);
}];
}

I would like that this method returns me a NSArray with the parsed JSON, which i can use wherever i want to.

This methods are contained into a Model called NetworkModel (NSObject subclass). I'm just wondering why i should do everything inside the blocks. I should have pieces interacting with network all over the place, and not organized in one unique place/class. Is there a way to do that. I don't want to have 5 lines of requests every ViewController. I want to define methods i can call from any ViewController (obviously importing the header files where needed).

Any suggestions? Thank you in advice!

Answer 1

You can do this with 2 approaches, one change your methods in order to use blocks or use a semaphore to wait for the async request:

With semaphore (THE UGLY WAY)

-(BOOL)isLoggedIn {

__block BOOL isLoggedIn;
 dispatch_semaphore_t waiter = dispatch_semaphore_create(0);

NSString *urlString = [NSString stringWithFormat:@"%@%@%@", kBaseURL, kAPI, kUserIsLogged];
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
manager.responseSerializer = [AFJSONResponseSerializer serializerWithReadingOptions:NSJSONReadingAllowFragments];
[manager GET:urlString parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@"JSON: %@", responseObject);
    isLoggedIn = YES;
    dispatch_semaphore_signal(waiter);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"Error: %@", error);
    isLoggedIn = NO;
    dispatch_semaphore_signal(waiter);

}];

dispatch_group_wait(waiter, DISPATCH_TIME_FOREVER);
return isLoggedIn;
}

The Right Way to do it

-(void)isLoggedIn:(void(^)(BOOL isLoggedIn))completionBlock {
NSString *urlString = [NSString stringWithFormat:@"%@%@%@", kBaseURL, kAPI, kUserIsLogged];
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
manager.responseSerializer = [AFJSONResponseSerializer serializerWithReadingOptions:NSJSONReadingAllowFragments];
[manager GET:urlString parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@"JSON: %@", responseObject);
    completionBlock(YES);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"Error: %@", error);
    completionBlock(NO);
}];
}

For your second question, you can set a block variable on your networking class that will be called when the request is completed or it fails.

Anyway I think you are not quite familiar with blocks (because of your second question) and I think after a few blocks you will start to like them and you will see that the code is not complicated if you have small snippets of code that perform request & parsing, also you will see that it's soooo easy to debug them and find the problems, I mean, this was also my case when I started to work with blocks.

Using a block variable

@interface YourNetworkClass:NSObject {
void(^resultHandlerBlock)(NSArray *results); //this block has as param a NSArray, you can change it to whatever you want
}

-(void)setResultHandlerBlock:(void(^)(NSArray *array))handlerBlock;

@implementation YourNetworkClass

-(void)setResultHandlerBlock:(void(^)(NSArray *array))handlerBlock {
resultHandlerBlock = block;
}

-(void)anotherMethodThatDoesNetworkOperationsAndReturnsAnArray {
 ....
 resultHandlerBlock(arrayOfResults);
}


@interface AViewControllerThatUseNetwork: UIViewController {
}

@implementation AViewControllerThatUseNetwork 

-(void)initNetworkClass {
  YourNetworkClass *networkClass = [[YourNetworkClass alloc] init]; //or other init methods
  [networkClass setResultHandlerBlock:^(NSArray *results) {
   //do whatever you want with the array
}];
}