add remove childviewcontroller ios

import UIKit
import PureLayout

extension UIViewController {
    func addChildController(_ controller: UIViewController, containerView: UIView) {
        addChild(controller)
        // When your custom container calls the addChild(_:) method, it automatically calls the willMove(toParent:) method of the view controller to be added as a child before adding it.
        containerView.addSubview(controller.view)
        controller.view.translatesAutoresizingMaskIntoConstraints = false
        controller.view.autoPinToSuperviewEdges()
        controller.didMove(toParent: self)
    }

    func removeAsChild() {
        willMove(toParent: nil)
        view.removeFromSuperview()
        removeFromParent()
        // The removeFromParent() method automatically calls the didMove(toParent:) method of the child view controller after it removes the child.
    }

    func tryRemovingFirstChild() {
        guard let child = children.first else { return }

        child.removeAsChild()
    }
}