in iOS 7 cachePolicy doesn't work, it just cache the downloaded json.
//URLRequest
NSString *url = [NSString stringWithFormat:@"http://www.semhora.com/jsonparser/categories/categories_%d_test.json", _categoriesIndex];
NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:url]
cachePolicy:NSURLCacheStorageNotAllowed
timeoutInterval:60.0];
How can I disallow cache in iOS 7?