Question

I am probably overlooking something small, but I cant seem to figure it out.

I am attempting to pass an instance of a custom class to an instance of another custom class.
NOTE: I am using ARC*

The second custom class is set up:

#import "OneArtsDay.h"

@interface SocialButton : UIButton {    
    OneArtsDay *artsDay;
}

@property (nonatomic) OneArtsDay *artsDay;

- (void)setArtsDay:(OneArtsDay *)day;

@end

and

#import "SocialButton.h"

@implementation SocialButton
@synthesize artsDay;

- (void)setArtsDay:(OneArtsDay *)day {
  if (day ==nil) {
    NSLog(@"Error, cannot set artsDay");
  }
  else {
  artsDay = day;
  }
}

@end

Now, when I call these commands in code:

    SocialButton *social = [[SocialButton alloc] init];
    OneArtsDay *day = [[OneArtsDay alloc] init];
    //Do things with day here//
    [social setArtsDay:day];

I am still given an error when I try to access the property OneArtsDay *artsDay. What am I missing?

Answer 1

The property should be declared strong. Here’s how I code the same thing:

#import "OneArtsDay.h"

@interface SocialButton : UIButton

// property decl gives me the file var and the public getter/setter decls
// strong tells ARC to retain the value upon assignment (and release the old one)
@property (nonatomic, strong) OneArtsDay *artsDay;

@end


#import "SocialButton.h"

@implementation SocialButton

// _underscore alias let's me name stack vars and prams the same name as my property
// without ambiguity/compiler warnings

@synthesize artsDay=_artsDay;

- (void)setArtsDay:(OneArtsDay *)artsDay {
    if (artsDay==nil) {
        NSLog(@"Error, cannot set artsDay");
    } else {
        _artsDay = artsDay;
    }
}

@end