Cocoa - Return information from NSOperation

Question

I have an IPhone app that uses webservices to get data from a server. I\'m putting each call to the webservice in a NSOperation subclass so that it can be threaded. My questio

Answer 1

I've personally done this in two ways. Both worked quite well.

First Way

You can have a function that returns the "output", and you call that function after the operation has finished. You can observe the key isFinished on the NSOperation object, or use -[NSOperationQueue waitUntilAllOperationsAreFinished] to determine when the operation is finished.

Second Way

You can use a delegate or target/action from the NSOperation. Just make sure that when you call the delegate function, or trigger the target/action, you do so on the main thread by using -[NSObject performSelectorOnMainThread:withObject:waitUntilDone:]