In apple documentation
setAnimationRepeatAutoreverses: Sets whether the animation of property changes within an animation block automatically reverses repeatedly. Use of this method is discouraged in iOS 4.0 and later. You should use the block-based animation methods instead. They mentioned like this... But my app supports from 3.0 or later. Do i need to use two separate codes( one for 3.0 and blocks above 4.0). How to accomplish this?
You can keep using your existing code. It will continue to work; they would just prefer you to use newer APIs if you can (which, as you've said, you can't yet.)
The "old" animations are just discouraged not deceprated, this is Apples version of telling you: "If you use block based animations you'll unlikely write spaghetti code and mess things up really bad."
It's just a friendly nudge into the right direction, as "blocks" were not available with the older compilers in the older SDKs programmers got used to the begin->commit style (like old opengl with glbegin, glend) but that's unneccessarily spaghettiish if you want to chain multiple animations.
