I'm creating an onboarding app for New Patients of a physical therapy clinic. The new patient will answer questions on each view controller within the UIPageViewController and tap a button to go to the next question.
I followed a tutorial and set up my UIPageViewController PageVC along with 3 view controllers. PageVC currently changes pages by swiping, but I want to be able to navigate backward and forward through view controllers using two buttons that are subviews of PageVC itself. How do I accomplish this?
I like using UIPageViewController and want to understand it a bit more. If there is a more effective method besides using UIPageViewController to accomplish this same task I'm happy to consider it.
class PageVC: UIPageViewController, UIPageViewControllerDataSource {
private(set) lazy var orderedViewControllers: [UIViewController] = {
return [self.VCInstance(name: "BodyChart"),
self.VCInstance(name: "Symptoms"),
self.VCInstance(name: "HadSurgery")]
}()
private func VCInstance(name: String) -> UIViewController {
return UIStoryboard(name: "Main", bundle: nil) .
instantiateViewController(withIdentifier: name)
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
guard let viewControllerIndex = orderedViewControllers.index(of: viewController) else {
return nil
}
let previousIndex = viewControllerIndex - 1
guard previousIndex >= 0 else {
return nil
}
guard orderedViewControllers.count > previousIndex else {
return nil
}
return orderedViewControllers[previousIndex]
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
guard let viewControllerIndex = orderedViewControllers.index(of: viewController) else {
return nil
}
let nextIndex = viewControllerIndex + 1
let orderedViewControllersCount = orderedViewControllers.count
guard orderedViewControllersCount != nextIndex else {
return nil
}
guard orderedViewControllersCount > nextIndex else {
return nil
}
return orderedViewControllers[nextIndex]
}
override func viewDidLoad() {
super.viewDidLoad()
dataSource = self
if let firstViewController = orderedViewControllers.first {
setViewControllers([firstViewController], direction: .forward, animated: true, completion: nil)
}
}
}
