isKindOfClass method to check Swift ViewController in Objective C

Question

There's this AViewController which is written in Swift. Now in my Obj C manager class I want to check the type of the viewcontroller. But it doesn't read because Obj C read the class name as "ProjectName.AViewController". How can we have the below mentioned check?

//Swift class
class AViewController: UIViewController {
}

//Obj C - Manager class
- (void)sampleMethod:(UIViewController *)viewController {
 if ([viewController isKindOfClass:[AViewController class]]) {
  //Action
 }
}

Is `isKindOfClass:` actually failing here? The actual name of the class shouldn't matter, since you're using `[AViewController class]` to check it. the above should work. In my tests, it does. — Rob Napier, Apr 08 '15 at 13:00
@RobNapier Yes, and that is because [AViewController class] is treated as class of type AViewController, where as variable viewController is treated as class of type ProjectName.AViewController — Kumar Nitin, Apr 08 '15 at 15:28

score 2 · Answer 1 · edited May 23 '17 at 10:10

2

Add @objc(...Name...) before the class name in Swift.

Eg: Swift

//Swift class
@objc(SwiftAViewController)
class AViewController: UIViewController {
}

Eg: ObjC

//Obj C - Manager class
- (void)sampleMethod:(UIViewController *)viewController {
 if ([viewController isKindOfClass:[SwiftAViewController class]]) {
  //Action
 }
}

More details: Name of Swift class when exposed to Objective-C code does not respect the @objc renaming

edited May 23 '17 at 10:10

Community

1
1

answered Apr 08 '15 at 12:58

Kyle Howells

3,008
1
25
35

It doesn't seem to work. It says "SwiftAViewController" not found. – Kumar Nitin Apr 08 '15 at 13:03
The import part is the "@objc(...)" In the swift file. That defines the name the class will have in ObjC. – Kyle Howells Apr 08 '15 at 13:04
If you change it to `@objc(ThingIsAClass) class AViewController: UIViewController` the name it'll have in ObjC is `ThingIsAClass` not `AViewController`. – Kyle Howells Apr 08 '15 at 13:05
Xcode did create SWIFT_CLASS("SwiftAViewController") in "Project-swift.h" class, yet it doesnt read – Kumar Nitin Apr 08 '15 at 13:06
Seems to be a bug: Though I presumed they'd fixed it by now. http://stackoverflow.com/questions/26132823/name-of-swift-class-when-exposed-to-objective-c-code-does-not-respect-the-objc?lq=1 – Kyle Howells Apr 08 '15 at 13:20
@Freerunnering Joking? – Amin Negm-Awad Apr 08 '15 at 14:03

score 0 · Accepted Answer · answered Apr 08 '15 at 14:18

0

Because of the bug in swift, @Freerunnering answer will not work. As a work around, we can get the class name as string and then do the string match.

if ([NSStringFromClass([AViewController class] isEqualToString:@"ProjectName.AViewController"]) {

}

answered Apr 08 '15 at 14:18

Kumar Nitin

1,845
2
16
21

1

Can you explain a bit more about that bug? – Miknash Apr 08 '15 at 14:22
Sure, the compiler couldn't read [viewController isKindOfClass:[SwiftAViewController class]] and hence it'll not compile. I tried cleaning the project and derived data but it wasn't was much help. – Kumar Nitin Apr 08 '15 at 15:18
@NickCatib I will have to do some research on that. It looks like a bug to me. Read this http://stackoverflow.com/questions/26132823/name-of-swift-class-when-exposed-to-objective-c-code-does-not-respect-the-objc?lq=1 – Kumar Nitin Apr 08 '15 at 15:31

score -1 · Answer 3 · answered Jul 04 '17 at 14:39

let arrControllers = self.navigationController.viewControllers

                    for (indx, vc) in (arrControllers?.enumerated())! {
                        if vc is YourViewController{
                            self.navigationController.viewControllers.remove(at: indx)
                        }
                    }

score -1 · Answer 4 · answered Aug 24 '17 at 09:50

you can use below code:

for viewController in viewControllers {
                            if viewController.isKind(of: OurViewController.self){
                                print("yes it is OurViewController")
                                self.navigationController?.popToViewController(viewController, animated: true)
                            }
                        }

for more detail you can refer this answer already answered question

isKindOfClass method to check Swift ViewController in Objective C

4 Answers4