Question

I’m trying to run a singleton in my iPhone App’.

When I try to implement and to request it from the first class to the singleton’s class, it’s running but after, when I try to use it from an other class, it doesn’t working…

Here’s the call to the singleton in the first and second classes:

NSLog([ [MySingleton sharedMySingleton] getAuth]);

Her’s the Singleton’s class :

#import "MySingleton.h"

@implementation MySingleton

static MySingleton* _sharedMySingleton = nil;
@synthesize myToken;

+(MySingleton*)sharedMySingleton
{
    @synchronized([MySingleton class])
    {
        if (!_sharedMySingleton)
            [[self alloc] init];
        return _sharedMySingleton;
    }
    return nil;
}

+(id)alloc
{
    @synchronized([MySingleton class])
    {
        NSAssert(_sharedMySingleton == nil, @"Attempted to allocate a second instance of a singleton.");
        _sharedMySingleton = [super alloc];
        return _sharedMySingleton;
    }

    return nil;
}

-(id)init {
    self = [super init];
    if (self != nil) {
        myToken = [[NSString alloc] initWithString:@""];
    }

    return self;
}

-(void)setAuth:(NSString*) token {
    myToken=token;
}


-(NSString*)getAuth {
    return myToken;
}

- (id)copyWithZone:(NSZone *)zone {
    return self;
}
- (id)retain {
    return self;
}
- (unsigned)retainCount {
    return UINT_MAX; //denotes an object that cannot be released
}
- (void)release {
    // never release
}
- (id)autorelease {
    return self;
}
- (void)dealloc {
    // Should never be called, but just here for clarity really.
    [myToken release];
    [super dealloc];
}


@end

I imported correctly the singleton’s class in the second class 😉

That’s it!

thanks for your help 😀

Answer 1

Implemet the rest of the methods also as given here and try.

Edit:

Are u retaining the myToken string variable?

-(void)setAuth:(NSString*) token {
    if( token != myToken )
    {
       [myToken release];
       myToken=[token copy];
    }
}

Replace the setAuth method like this..