Question

Is that possible to make a UIToolbarButton pass an object to its target by using some exoteric method (as it seems not to be possible using regular button use)?

I mean something like

UIBarButtonItem *Button = [[UIBarButtonItem alloc] initWithImage:buttonImage
  style:UIBarButtonItemStylePlain target:self action:@selector(doSomething:) **withObject:usingThis**];

I know I can trigger a method that will launch the full method with the object, but for the sake of elegance I was trying to minimize the code… I suspect it is not possible, but as you guys out there are insanely good you may come with an transcendental answer… who knows…

Answer 1

You would have to extend the UIBarButtonItem class.

Here is an example creating RCBarButtonItem class. I’ve used initWithTitle for ease, I’m sure you could change it…

The UIBarButtonItem Subclass

#import <UIKit/UIKit.h>

@interface RCBarButtonItem : UIBarButtonItem {
    id anObject;
}

@property (nonatomic, retain) id anObject;

- (id)initWithTitle:(NSString *)title style:(UIBarButtonItemStyle)style target:(id)target action:(SEL)action withObject:(id)obj;

@end

@implementation RCBarButtonItem

@synthesize anObject;

-(void)dealloc {
    [anObject release];
    [super dealloc];
}

- (id)initWithTitle:(NSString *)title style:(UIBarButtonItemStyle)style target:(id)target action:(SEL)action withObject:(id)obj {
    if (self = [super initWithTitle:title style:style target:target action:action]) {
        self.anObject = obj;
    }
    return self;
}

@end

Then this could then be implemented like so:

#import "RootViewController.h"
#import "RCBarButtonItem.h"

@implementation RootViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    RCBarButtonItem *button = [[RCBarButtonItem alloc] initWithTitle:@"Hello"
                                                               style:UIBarButtonItemStylePlain 
                                                              target:self
                                                              action:@selector(doSomething:)
                                                          withObject:@"Bye"];
    self.navigationItem.rightBarButtonItem = button;

}

- (void)doSomething:(id)sender {
    NSLog(@"%@", [(RCBarButtonItem *)sender anObject]);
}