CODEWITHSUNDEEP
iphoneobjective-c
Raptor
Raptor

Reputation: 54248

Accessing Properties in Static Library in iOS App

I have a objective-C static library ( iOS SDK 6 ):

Implementation file ( .m )

#import "MyClass.h"

@implementation MyClass
static id _instance;
static NSString *version;

- (id)init {
    if(_instance == nil) {
        _instance = [super init];
        version = @"1.0";
    }
    return _instance;
}

- (NSString *)getVersion {
    return version;
}

+ (MyClass *)sharedInstance {
    return _instance;
}

@end

When I access the class in other iPhone App project (imported the library), I cannot get the version string. 

#import "ViewController.h"
#import <MyClass/MyClass.h>

@interface ViewController ()
@end
@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    MyClass *cls = [MyClass sharedInstance];
    NSLog(@"Loaded. Version: %@", [cls getVersion]);
}
@end

What did I miss? No error is reported, but version is (null)

Upvotes: 0

Views: 157

Answers (1)

zrzka
zrzka

Reputation: 21259

There's lot of mistakes ...

  • init is not called at all
  • etc.

... you seem try to use singleton pattern. So, do this ...

+ (MyClass *)sharedInstance {
  static MyClass *instance = nil;
  static dispatch_once_t onceToken;
  dispatch_once(&onceToken, ^{
    instance = [[[self class] alloc] init];
  });
  return instance;
}

... and change your init to ...

- (id)init {
  self = [super init];
  if ( !self ) {
    return nil;
  }

  _version = @"1.0";
  return self;
}

... and call [[MyClass sharedInstance] getVersion] to get your version.

P.S. Read ObjC guide and don't use get prefix. Should be just version.

Upvotes: 3

Related Questions