How to retrieve value from extension in view controller swift - swift

Question

I want to retrieve the value from the scrollViewDidScroll function at my view controller. It gives the right value back in the console so that's nice.
My view controller:
import UIKit
extension UIPageViewController: UIScrollViewDelegate {
public override func viewDidLoad() {
super.viewDidLoad()
for subView in view.subviews {
if subView is UIScrollView {
(subView as! UIScrollView).delegate = self
}
}
}
public func scrollViewDidScroll(scrollView: UIScrollView) {
let point = scrollView.contentOffset
var percentComplete: CGFloat
percentComplete = fabs(point.x - view.frame.size.width)/view.frame.size.width
print("percentComplete: ", percentComplete)
}
}
class StepsDetailViewController: UIViewController {
var pageIndex: Int!
override func viewDidLoad()
{
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Where the view controller came from:
import UIKit
class PageControl: UIPageViewController, UIPageViewControllerDataSource {
var pageViewController: UIPageViewController!
var pageTitles: [[String]]!
override func viewDidLoad(){
super.viewDidLoad()
testC().getRecent() { result, error in
self.pageTitles = result;
self.pageViewController = self
self.pageViewController.dataSource = self
let startVC = self.viewControllerAtIndex(0) as StepsDetailViewController
dispatch_async(dispatch_get_main_queue(), {
let viewControllers = NSArray(object: startVC)
self.pageViewController.setViewControllers(viewControllers as? [UIViewController], direction: .Forward, animated: true, completion: nil)
})
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func viewControllerAtIndex(index: Int) -> StepsDetailViewController
{
if ((self.pageTitles.count == 0) || (index >= self.pageTitles.count)) {
return StepsDetailViewController()
}
let vc: StepsDetailViewController = self.storyboard?.instantiateViewControllerWithIdentifier("StepsDetailViewController") as! StepsDetailViewController
vc.pageIndex = index
return vc
}
// MARK: - Page View Controller Data Source
func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController?
{
let vc = viewController as! StepsDetailViewController
var index = vc.pageIndex as Int
if (index == 0 || index == NSNotFound)
{
return nil
}
index -= 1
return self.viewControllerAtIndex(index)
}
func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {
let vc = viewController as! StepsDetailViewController
var index = vc.pageIndex as Int
if (index == NSNotFound)
{
return nil
}
index += 1
if (index == self.pageTitles.count)
{
return nil
}
return self.viewControllerAtIndex(index)
}
func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int
{
return self.pageTitles.count
}
func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int
{
return 0
}
}
Is this possible?

Answer 1

You could do like this:
1. Replace your extension with a custom UIPageViewController
class BasePageViewController: UIPageViewController, UIScrollViewDelegate {
var percentComplete: CGFloat = 0.0 {
didSet { self.percentCompleteDidChange() }
}
func percentCompleteDidChange() {
print("percentCompleteDidChange")
}
public override func viewDidLoad() {
super.viewDidLoad()
for subView in view.subviews {
if subView is UIScrollView {
(subView as! UIScrollView).delegate = self
}
}
}
public func scrollViewDidScroll(scrollView: UIScrollView) {
let point = scrollView.contentOffset
self.percentComplete = fabs(point.x - view.frame.size.width)/view.frame.size.width
print("percentComplete: ", percentComplete)
}
}
2. PageControl is a BasePageViewController subclass
class PageControl: BasePageViewController, UIPageViewControllerDataSource {
// here you have the access to percentComplete of superclass
func printPercentComplete() {
if let percentComplete = self.percentComplete {
print(percentComplete)
}
}
override func percentCompleteDidChange() {
print("percentCompleteDidChange from child")
}
......
}

Answer 2

Define the percentComplete as a property of your custom class that inherits from UIPageViewController.
Then you can access it everywhere.