Access class methods from an instance in Objective-C - objective-c

Question

Given the following class,
#interface MyBaseClass : NSObject
-(void)printName
+(NSString*)printableName
#end
how can I call the class method +printableName from within the instance method -printName without explicitly referring to MyBaseClass? [[self class] printableName] doesn't compile.
The idea is that subclasses will override +printableName so -printName should polymorphically invoke the appropriate +printableName for its class.

Answer 1

Declare MyBaseClass as
#interface MyBaseClass : NSObject
and your [[self class] name] should compile.
This compiles for me:
#interface MyBaseClass : NSObject
-(void)printName;
+(NSString*)printableName;
#end
#implementation MyBaseClass
-(void)printName
{
[[self class] printableName];
}
+(NSString*)printableName {
return #"hello";
}
#end

Answer 2

Have you tried [object_getClass(this) printableName]?
(But you realize, of course, that you could also just create a version of
-(NSString*)printableName2 {
return [MyBaseClass printableName];
}
in each of your classes and call [self printableName2]?)

Answer 3

From what you are describing, it should work. As you didn't offer your implementation, we won't be able to tell, what is wrong.
Based on this question, I wrote an example code for polymorphism in Objective-C.
It contains inheritance-based polymorphism, but also polymorphism based on formal and informal protocols. May you want check your code against it.
here an excerpt:
#import <Foundation/Foundation.h>
/*
* 1.: Polymorphism via subclassing
*/
#interface MyBaseClass : NSObject
-(void)printName;
+(NSString*)printableName;
#end
#implementation MyBaseClass
+(NSString *)printableName
{
return NSStringFromClass(self);
}
-(void)printName
{
NSLog(#"%#", [[self class] printableName]);
}
#end
#interface MySubBaseClass : MyBaseClass
#end
#implementation MySubBaseClass
#end
//...
int main (int argc, const char * argv[])
{
/*
* 1.: Polymorphism via subclassing. As seen in any Class-aware OO-language
*/
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
MyBaseClass *myBaseObject = [[MyBaseClass alloc] init];
[myBaseObject printName];
[myBaseObject release];
MySubBaseClass *mySubBaseObject = [[MySubBaseClass alloc] init];
[mySubBaseObject printName];
[mySubBaseObject release];
//...
[pool drain];
return 0;
}