iphone - passing an object on an UIToolbarButton action - iphone

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]);
}

Answer 2

What I've done in this situation is create an NSDictionary property called, say, buttonArguments:
self. buttonArguments = [[NSDictionary alloc] initWithObjectsAndKeys: usingThis, Button, ... , nil];
Then in your doSomething: method, look up the object based on the sender parameter.

Answer 3

I prefer using categories:
UIBarButtonItem+BarButtonItem.h
#interface UIBarButtonItem (BarButtonItem)
#property (strong, nonatomic) NSDictionary *userInfo;
#end
UIBarButtonItem+BarButtonItem.m
static void *kUserInfo = &kUserInfo;
#implementation UIBarButtonItem (BarButtonItem)
- (NSDictionary *)userInfo {
return objc_getAssociatedObject(self, kUserInfo);
}
- (void)setUserInfo:(NSDictionary *)userInfo {
objc_setAssociatedObject(self, kUserInfo, userInfo,
OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
#end