ios7 - How to get and set private instance variable/ property from outside a class Objective C? -

i have class myconfig property/ variable nsstring * url. private, don't want able set url outside of myconfig class. example, don't want following allowed:

myconfig * myconfig = [[myconfig alloc] init]; myconfig.url = @"some url";// want forbid 

my goals:

• forbit setting of variable/ property via dot notation
• use automatically generated/ standard getter (myconfig.url) , setter ([myconfig seturl]) - don't want write getters , setters myself

what have: myconfig.h

@interface myconfig : nsobject @property (readonly) nsstring * url; @end 

problem: standard getter not working!

myconfig * myconfig = [[myconfig alloc] init]; [myconfig seturl];// instance method "-seturl:" not found (return default type "id") 

this shouldn't case according this right?

is there better way achieve goal?

you try creating public property getter such have , create private version in implementation file such below.

myconfig.h

// public interface world can see @interface myconfig : nsobject  @property (readonly) nsstring *url; // readonly getter generated not setter  @end 

myconfig.m

#import "myconfig.h"  // private interface implementation can see @interface myconfig() // class extension @property (nonatomic, strong) nsstring *url; // private getter , setter @end  @implentation myconfig  // rest of code...    @end 

the way have implemented using class extensions, syntax declare class extension same 1 creating category empty name. , quite important part don't have define implementation block, implementation extension , code in has implemented in main implementation block.

using class extension method (not possible categories) can have property readonly access public facing , readwrite access privately. declare property readonly in header file , redeclare readwrite in class extension.