#RXTraits
Traits are a tool for leveraging composition and interface inheritance to build a more flexible result than can be achieved with implementation inheritance alone. RXTraits applies them to instances on a case by case basis using dynamic subclassing:
@protocol Herbivore
-(void)eatPlants;
@end
@interface HerbivoreTrait : NSObject <RXTrait, Herbivore>
@end
@implementation HerbivoreTrait
+(Protocol *)traitProtocol {
return @protocol(Herbivore);
}
-(void)eatPlants {
// with gusto
}
@end
…
Lion<Herbivore> *omnivorousLion = RXTraitApply([HerbivoreTrait class], [Lion new]);
[omnivorousLion eatPlants];
Note that unlike RXConcreteProtocol, this doesn’t apply to the class as a whole; only the instances passed to RXTraitApply have the trait applied to them.
NB: You probably can’t use super in your trait methods. This probably isn’t that big a deal.