How to Get Class Name of Parent Viewcontroller in Swift

How to get class name of parent ViewController in Swift?

Here's one approach:

if let parentVC = parent as? SomeViewController {
    // parentVC is someViewController
} else if let parentVC = parent as? AnotherViewController {
    // parentVC is anotherViewController
}

This will conditionally assign and unwrap parent (the parent view controller) to its appropriate type. Within the condition blocks, parentVC will be the correct class.

That said, this is a code smell - child view controllers should typically have no idea who their parent view controllers are. Whatever problem you're solving, you should probably solve it with tell, don't ask and delegation instead.

Get class name of Parent View controller in iPhone Navigation push

This should do it:

NSUInteger numberOfViewControllersOnStack = [self.navigationController.viewControllers count];
UIViewController *parentViewController = self.navigationController.viewControllers[numberOfViewControllersOnStack - 2];
Class parentVCClass = [parentViewController class];
NSString *className = NSStringFromClass(parentVCClass);

Get the parentViewController instance

The fact that it's difficult to get a reference to a view's associated controller should be a hint that it's bad practice. You would be better off passing the parent view controller into the view's initialiser and storing it as a weak reference.

class TheView: UIView {
    weak var parentViewController: MyViewController?

    init(parentViewController: MyViewController) {
        self.parentViewController = parentViewController
    }
}

// in MyViewController...
let view = TheView(parentViewController: self)

How to send values to a parent view controller in Swift

It is not a good idea to cast the parent view controller, even when you are sure which class represents. I'll do it with a protocol:

In the child controller add a protocol like:

protocol ChildNameDelegate {
    func dataChanged(str: String)
}

class ChildClass {

    weak var delegate: ChildNameDelegate?

    func whereTheChangesAreMade(data: String) {
        delegate?.dataChanged(data)
    }
}

And in the parent:

class ParentClass: ChildNameDelegate {

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        guard let segueId = segue.identifier else { return }

        switch segueId {
        case "childSegue":
            let destVC = segue.destinationViewController as! ChildClass
            destVC.delegate = self
            break
        default:
            break
        }
    }

    // Child Delegate
    func dataChanged(str: String) {
        // Do whatever you need with the data
    }
}

finding out superview's class name

I ended up setting a property, which does not answer the original question (sorry). There really should be a way though, even if I had done it by evaluating the frame of the super view.

Get child class from parent

You can use a function like this:

func getRawClassName(object: AnyClass) -> String {
    let name = NSStringFromClass(object)
    let components = name.componentsSeparatedByString(".")
    return components.last ?? "Unknown"
}

which takes an instance of a class and obtain the type name using NSStringFromClass.

But the type name includes the namespace, so to get rid of that it's split into an array, using the dot as separator - the actual class name is the last item of the returned array.

You can use it as follows:

class Parent {
    class func sayHello() {
        println("hi \(getRawClassName(self))")
    }
}

and that will print the name of the actual inherited class

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