NSURLSession completion block not called

Question

var session = NSURLSession.sharedSession()
session.dataTaskWithRequest(urlRequest, 
                            completionHandler: {(data: NSData!, 
                             


        

Answer 1

Are you using playgrounds??

If you are, you should be careful to include:

 XCPSetExecutionShouldContinueIndefinitely(continueIndefinitely: true)

In order to make the playground wait for the callback