Objective C : Given a Class id, can I check if this class implements a certain protocol? Or has a certain selector?
NSString *className; //assume this existsClass class = NSClassFromString(className);if ([class conformsToProtocol:@protocol(SomeProtocol)]) { id instance = [[class alloc] init]; [instance create];}
Class klass = NSClassFromString(classname);if ([klass instancesRespondToSelector:@selector(create)]) { [[klass alloc] create];}May I, however, point out just how many awful Objective-C rules you're breaking by doing the above? For example, you should never be calling methods on an allocated-but-not-initialized instance. The Xcode Static Analyzer will give you all sorts of warnings about memory leaks.
A better option would be this:
[[[klass alloc] init] create];But you seem to imply that you don't want to call init.
You could consider a class method: [klass create], which would return a non-owned instance of klass. Then you'd just check [klass respondsToSelector:@selector(create)] before calling it.