Given an Objective-C object and an attribute name, how can you access (read/write) it?

ios-object-attribute-access

return [self.object valueForKey: attrName];


--




    
    SEL getterSEL = NSSelectorFromString( attrName);
    
    // http://stackoverflow.com/questions/7017281/performselector-may-cause-a-leak-because-its-selector-is-unknown
    _Pragma("clang diagnostic push")
    _Pragma("clang diagnostic ignored \"-Warc-performSelector-leaks\"")
   
    
    NSLog(@"_________%d",index);
    
//    SHEMBAOSEnum_ValueType valueType = [[_list_valueType objectAtIndex:index] integerValue];
    
    id value;
    
//    if ([self.object respondsToSelector: getterSEL]) {
//        
//        NSLog(@"!!! getterSelector cannot be responded: %s", getterSEL);
//        
//        return nil;
//    }
    
    Method met = class_getInstanceMethod([self.object class], getterSEL);
    char * returntype = method_copyReturnType(met);
    
    NSLog(@"return type: %s", returntype);
    
    JXOCModel_Type_base * returnType =
    [JXOCModelFactory_Type modelFromString: [NSString stringWithCString: returntype encoding: NSASCIIStringEncoding]];
    
    free(returntype);
    
    
    switch (returnType.kind) {
        case JXOCEnum_Type_Kind_Primitive:
        
            value = [NSNumber numberWithInteger: [self.object performSelector: getterSEL]];
            
            break;
        case JXOCEnum_Type_Kind_Object:
            
         value= [self.object performSelector: getterSEL];
            break;
        default:
            break;
    }
    
    
    
    _Pragma("clang diagnostic pop")
    return value;