Refresh UIPageViewController - reorder pages and add new pages

Question

I have a UIPageViewController which I am providing page data for using an implementation of UIPageControllerDelegate and UIPageControllerData

Answer 1

I found a workaround to force UIPageViewController to forget about cached view controllers of neighboring pages that are currently not displayed:

pageViewController.dataSource = nil;
pageViewController.dataSource = self;

I do this everytime I change the set of pages. Of course this doesn't affect the currently displayed page.

With this workaround I avoid the caching bug and can still use animated:YES in setViewControllers:direction:animated:completion:.

Answer 2

Swift 4 Version for reload of data of pageviewcontroller, to @theory's version.

func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
    if !completed { return }
    DispatchQueue.main.async() {
        self.dataSource = nil
        self.dataSource = self
    }
}

Answer 3

Here's my complete implementation of @ortwin-gentz's answer in the didFinish delegate method in Swift 2, which works perfectly for me:

func pageViewController(
    pageViewController: UIPageViewController,
    didFinishAnimating finished: Bool,
    previousViewControllers: [UIViewController],
    transitionCompleted completed: Bool
) {
    if !completed { return }
    dispatch_async(dispatch_get_main_queue()) {
        pageViewController.dataSource = nil
        pageViewController.dataSource = self
    }
}

Answer 4

You need to call setViewControllers:direction:animated:completion:.

Also, in iOS 6, watch out if you're using UIPageViewControllerTransitionStyleScroll style, as there is a major caching bug if animated: is YES (see my discussion here: UIPageViewController navigates to wrong page with Scroll transition style).