retain property points to wrong address

Question

I have singleton class with ivar named formatter. There is some code:

@interface SettingsController : NSObject {

    NSDateFormatter *formatter;  
}

@property (nonatomic,retain,readwrite)  NSDateFormatter *formatter;




@implementation SettingsController

@synthesize formatter,;

SYNTHESIZE_SINGLETON_FOR_CLASS(SettingsController);

-(id)init
{
 if ( (self = [super init]) )
  {
        ...
        self.formatter = [[[NSDateFormatter alloc] init] autorelease];
        ...
  }

Problem is that sometime when I try to get this formatter that how:

[[SettingsController sharedSettingsController] formatter]

The value is missed. There NSDate,NSString or even my own class instance at address that formatter points.

I've try use [[NSDateFormatter alloc] init] but only [[[NSDateFormatter alloc] init] retain] make problem disappear.

How could it be, when I use @property (nonatomic,retain,readwrite) and never reset this ivar to another value?

EDITE: After I made subclass for NSDateFormatter, I've clearly and easy seen the release that make fall app. Thanks a lot to progrmr!

Something must be sending release to the formatter you allocated but I don't see where from the code you posted. If you really want to find out, make a subclass of NSDateFormatter and use that in place of NSDateFormatter, override release in the subclass (be sure to call super release), then set a breakpoint in that release function to see all the places it is called from. — progrmr

Rudy Velthuis Rudy Velthuis · Accepted Answer · 2011-08-30T15:50:49

You write about class SettingsController, but are using class SyncProgress. Which is it?

If you properly @synthesized the @property, what you did in the init method you show should be correct, assuming you don't release the property -- or at least the same object, from whatever reference to it you may have -- later on, either in the same method or elsewhere. In other words, don't release an autoreleased item.

FWIW, the article that describes the macro says that you should declare

+ (SettingsController *) sharedSettingsController;

I can't see you doing that, so did you?

And you are using class SyncProgress, not SettingsController. Assuming you declared that as singleton too, you should do the same for SyncProgress:

+ (SyncProgress *) sharedSyncProgress;

What is the init method for SyncProgress? Do you set the formatter there too, and does it even have one? Or are you just looking at the wrong class?

retain property points to wrong address

1 Answers