How do I avoid using deprecated methods conditionally when also targeting for an older OS version?

Question

I have an application designed for iPhone OS 2.0 and I am adding some new 3.x functionality to it. My idea is to maintain compatibility with older versions.

I have managed so far, to test for deprecated functions using "if respondToSelector...". This is just fine for calls inside a method but how to deal with method name changes? For example, the OS 2.x method

-imagePickerController:didFinishPickingImage:editingInfo:

changed in OS 3.x to

-imagePickerController:didFinishPickingMediaWithInfo:

How can I test for the OS version and direct the application to the proper method in this case?

thanks for any help.

Answer 1

OK.

After a second read, I found, that I did not get your problem completely. If you implement both methods, either one will be performed at runtime. If it is a 2.x the -imagePickerController:didFinishPickingImage:editingInfo: will be performed, if it is 3.x the other one will be called

This is the crap I have written prematurely and where the comments are related to:

you may use

#ifdef __IPHONE_3_0
// iPhone 3.0 specific stuff
#else
// iPhone 2.2 specific stuff
#endif

see also this post:

http://stackoverflow.com/questions/146986/what-defines-are-setup-by-xcode-when-compiling-for-iphone

Answer 2

You can use NSObject's -respondsToSelector method to dynamically determine if the method exists, then call it. You might also want to use -performSelector:withObject: to call the methods, so you don't get compiler warnings.