A quick and dirty fix / fun with hopper for coins app

NSURLSession+DHCDirtyCoinsFix.m

@interface NSURLSession (DHCDirtyCoinsFix)

//lazy way to keep compiler happy
+(void)setLoading:(BOOL)isLoading;
-(UIButton *)updateButton;
- (void)_updateTimerPaused:(BOOL)on;

@end

@implementation NSURLSession (DHCDirtyCoinsFix)

//lazy way to keep compiler happy
+(void)setLoading:(BOOL)isLoading {
}
-(UIButton *)updateButton{
    return nil;
}

- (void)_updateTimerPaused:(BOOL)on{
}

static NSURLSessionDownloadTask * (*OriginalDownloadedTaskWithRequestCompletionHandler)(id, SEL, NSURLRequest *, void (^completionHandler)(NSURL *location, NSURLResponse *response, NSError *error));

+ (void)load
{
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        
        Class class = [NSURLSession sharedSession].class;
        
        SEL originalSelector = @selector(downloadTaskWithRequest:completionHandler:);
        
        IMP replacement = imp_implementationWithBlock(^NSURLSessionDownloadTask *(id _self, NSURLRequest *request, void (^completionHandler)(NSURL *location, NSURLResponse *response, NSError *error)){
            
            void (^fixedCompletionHandlerBlock)(NSURL *location, NSURLResponse *response, NSError *error) = ^(NSURL *location, NSURLResponse *response, NSError *error) {
                
                // This is basically the part that needs to implemented
                // if there's an error a nil data value can be passed to the +JSONObjectWithData:options:error:
                //which throws the relevant exception
                
                if (error) {
                    dispatch_async(dispatch_get_main_queue(), ^{
                        //This is the terrible part, how does one reference
                        //the self that would have been referenced in the original creation of the completionHandler?

                        //BTCValueViewController instance (hopefully) set loading 0
                        if ([[(UINavigationController *)[[[[UIApplication sharedApplication] delegate] window] rootViewController] viewControllers][0] respondsToSelector:@selector(setLoading:)]) {
                            [[(UINavigationController *)[[[[UIApplication sharedApplication] delegate] window] rootViewController] viewControllers][0] setLoading:0];
                            
                            //BTCValueViewController display unobtrusive error message
                            [[[(UINavigationController *)[[[[UIApplication sharedApplication] delegate] window] rootViewController] viewControllers][0] updateButton] setTitle:@"There was a problem updating" forState:UIControlStateNormal];
                        }
                    });
                    return;
                }
                completionHandler(location,response,error);
            };
            
            return OriginalDownloadedTaskWithRequestCompletionHandler(_self, _cmd, request, fixedCompletionHandlerBlock);
        });
        
        
        
        IMP *store = (IMP *)&OriginalDownloadedTaskWithRequestCompletionHandler;
        
        IMP originalImp = NULL;
        Method method = class_getInstanceMethod(class, originalSelector);
        if (method) {
            const char *type = method_getTypeEncoding(method);
            originalImp = class_replaceMethod(class, originalSelector, replacement, type);
            if (!originalImp) {
                originalImp = method_getImplementation(method);
            }
        }
        if (originalImp && store) { *store = originalImp; }
    });
}

@end