Runtime class creation in iPhone

I need to split my job with my partner for designing game stages, and we badly need to use plist. So, say I have 20 different types of classes from which I need to dynamically instantiate objects in runtime. A particular class will be selected from plist inp开发者_StackOverflow社区ut and an object of the class will be created on the fly.

The first thing that went through my mind was switch() and that was a bit dated I guess.

So I searched Stack Overflow and realized that iOS had NSClassFromString and objc_getclass.

• Create a class at runtime - Why do NSClassFromString AND objc_getclass return nil ?
• NSClassFromString returns nil

After few tries, I can tell NSClassFromString is really nice since I can just say what class I want upfront in plist and bam! there we go. Setting object properties is done with KeyValue dictionary after that and it's all done like a magic.

My question is, how can I call class methods (those that start with +) if you're to create objects this way? I've looked up documents and there is NSSelectorFromString(). But isn't it for an instance rather than a class?

NSClassFromString returns the class object not an instance of the class. Eg:

Class dateClass = NSClassFromString(@"NSDate"); //get the class object

NSDate *dateInstance = [dateClass date]; //call a class method on the class object

You can call performSelector: on a class.

For example you can call:

[NSClassFromString(@"UIViewController") performSelector:NSSelectorFromString(@"setToolbarItems:")]