Set text in the textfield does not work in Obj-C - objective-c

Question

I would like to set an text in the text field in another class and get it from another class. This is something what I want, but it does not work. Can you please help me. Thank you!
aaa.h
#import <Cocoa/Cocoa.h>
#interface aaa : NSImageView {
IBOutlet NSTextField *message;
}
#property (nonatomic, retain) IBOutlet NSTextField *message;
#end
aaa.m
#import "aaa.h"
#import "bbb.h"
#implementation aaa
#synthesize message;
- (void)awakeFromNib {
// [message setStringValue:#"ok, this works!"]; //but i don't want it from here
[self hello];
}
#end
bbb.h
#import <Foundation/Foundation.h>
#interface NSObject (bbb)
- (void)hello;
#end
bbb.m
#import "bbb.h"
#import "aaa.h"
#implementation NSObject (bbb)
- (void)hello {
aaa *obj = [[[aaa alloc] init] autorelease];
[obj.message setStringValue:#"This doesn't work :("]; // set text here, dont work.
NSLog(#"TEST: %#", [obj.message stringValue]);
}
#end

Answer 1

You are using category, so first thing it is used for extending the functionality of existing class. So you cannot set textfield value inside category. But else you can add some functonality after extracting the value. So you have to pass the value inside the category first. Try like this below:
- (void)awakeFromNib {
NSString *resultString=[self hello:#"This doesn't work :("];
[message setStringValue:resultString];
}
#end
#interface NSObject (bbb)
- (NSString*)hello:(NSString*)yourString;
#end
#implementation NSObject (bbb)
- (NSString*)hello:(NSString*)yourString {
return yourString;
}
#end