iOS Swift: UIPageViewController - Turning page programmatically

Question

I have a UIPageViewController, which works fine when we swipe left or right to turn pages.

class ViewController: UIViewController, UIPageViewControllerDataSou         


        

Answer 1

The Swift 3 version of SuitedSloth's answer (with a small tweak to the animated parameter as I needed it to be animated by default, but still taking a parameter in the function) in case anyone needs it:

extension UIPageViewController {

    func goToNextPage(animated: Bool = true) {
        guard let currentViewController = self.viewControllers?.first else { return }
        guard let nextViewController = dataSource?.pageViewController(self, viewControllerAfter: currentViewController) else { return }
        setViewControllers([nextViewController], direction: .forward, animated: animated, completion: nil)
    }

    func goToPreviousPage(animated: Bool = true) {
        guard let currentViewController = self.viewControllers?.first else { return }
        guard let previousViewController = dataSource?.pageViewController(self, viewControllerBefore: currentViewController) else { return }
        setViewControllers([previousViewController], direction: .reverse, animated: animated, completion: nil)
    }

}