javascript中任意objective-c对象的访问方法及属性

我想访问返回到JavaScript主机的ObjuleC对象的属性和调用方法,作为被暴露对象的属性( [windowScriptObject setValue:self forKey:@"a"] ):

- (id) valueForUndefinedKey:(NSString*) key {
  if ( [key isEqualToString:@"b"] ) {
    MyObject* obj = [ [ MyObject alloc ] init ];
    return obj;
  }
  return Nil;
}

在javascript中,我希望能够执行以下操作:

// a is already exposed Objective-C object
var b = a.b; // reference to myObject
var c = a.b.c; // myObject.c
var d = a.b.d(); // [ myObject d ]