Objective-C how to call a method after self is initialized inside the object file?

Question

Is there any way to know when a custom object is finished with being initialized from inside the object's file? Or let me rephrase the question, why can't I call any method inside this method?

- (id)initWithCoder:(NSCoder *)coder {
    //NSLog(@"initWithCoder inside CustomObject (subclass of UIView)");
    self = [super initWithCoder:coder];
    if (self) {
        //... initialization here


        [self visibleEmptyButton]; //why does this method never get called?


    }
    return self;
}

EDIT:

-(void)viewDidLoad{



    NSLog(@"viewDidLoad inside CustomObject(subclass of UIView) is called"); //It never gets called
    [self viewDidLoad];
    //initialization here...


}

My guess is that you're initiating the view from a storyboard/xib. If so, the button probably doesn't exist yet. Try moving the method call to viewDidLoad instead... — T. Benjamin Larsen, Jan 14 '13 at 14:01
see http://stackoverflow.com/questions/3741946/when-does-initwithcoder-get-called — Girish, Jan 14 '13 at 14:02
@nick That is right that I am using xib to initialize this view. I tried it too, but the method never gets called... — GourmetFan, Jan 14 '13 at 14:03
viewDidLoad is not a UIViewMethod. It's a UIViewController method. — T. Benjamin Larsen, Jan 14 '13 at 14:14
If initWithCoder was called at all (and not any other init method) then [self visibleEmptyButton]; should be called in most cases (99+ %) — Hermann Klecker, Jan 14 '13 at 14:30
Calling `[self viewDidLoad];` within `viewDidLoad` will cause some ... stackoverflow (tätä) :) Simply call `[super viewDidLoad];` instead. — Hermann Klecker, Jan 14 '13 at 14:31
@Herman No, it is possible, because UIView has no such method, only UIViewController. So I am going to custom a UIViewController, then own this custom UIView. — GourmetFan, Jan 14 '13 at 14:33
Yes, it is possible to call [self viewDidLoad] within viewDidLoad. It will just cause some sort of endless loop. Not really endless because it consumes some fractio of the call stack on every call. Give it a try. — Hermann Klecker, Jan 14 '13 at 14:46
@Herman I have tried, but the method never gets called. I will try other solution. — GourmetFan, Jan 15 '13 at 09:08

score 1 · Accepted Answer · answered Jan 14 '13 at 14:05

1

(If the class you are init-ing is a subclass of UIViewController) Changing and setting things in the screen should be done after the view is loaded. Try doing it in this method:

- (void)viewDidLoad {
    [super viewDidLoad];

    [self visibleEmptyButton];
    //Do the additional view altering here
}

If this method doesn't exist yet you can just add it to the .m file (no need to add it to the .h file).

answered Jan 14 '13 at 14:05

Manuel

10,153
5
41
60

In that case you could create a UIViewController instance and make that the owner of you UIView. That Controller will then get the above mentioned call. – Manuel Jan 14 '13 at 14:15

T. Benjamin Larsen · Answer 2 · 2013-01-14T14:30:02.783

0

In lieu of you're edit you could simply move the call to the UIViewController:

- (void)viewDidLoad {
    [super viewDidLoad];
    [TheInstanceOfYourViewClass visibleEmptyButton];
}

Also, to avoid making a whole bunch of small subview related methods public it often makes sense to create one method to handle the initial visual states.

edited Jan 14 '13 at 14:30

answered Jan 14 '13 at 14:15

T. Benjamin Larsen

6,373
4
22
32

Objective-C how to call a method after self is initialized inside the object file?

2 Answers2