Swift 3: Preload SecondViewController's WKWebView ahead of click - ios

Question

I need some help.
I want to preload my webView in Second View Controller after the webView in the First View Controller is done.
I believe I need to use a notification center post/observe to call my loadWebView-function in my Second View Controller but don't know how. Any suggestions is appreciated.
FirstViewController.swift
import UIKit;
import WebKit;
class FirstViewController: UIViewController, WKNavigationDelegate {
let webView:WKWebView = WKWebView(frame: CGRectMake(0, 0, UIScreen.main.bounds.width, UIScreen.main.bounds.height))
func webView(_ webView: WKWebView,
didFinish navigation: WKNavigation!) {
print("loaded!")
webView.isHidden = false
}
override func viewDidLoad() {
super.viewDidLoad()
let url = URL(string: "https://www.google.com")
webView.navigationDelegate = self
webView.load(URLRequest(url: url!))
webView.isHidden = true
self.view.addSubview(webView)
}
}
SecondViewController.swift
import UIKit
import WebKit
class SecondViewController: UIViewController, WKNavigationDelegate {
let webView:WKWebView = WKWebView(frame: CGRectMake(0, 0, UIScreen.main.bounds.width, UIScreen.main.bounds.height))
func webView(_ webView: WKWebView,
didFinish navigation: WKNavigation!) {
print("loaded!")
webView.isHidden = false
}
override func viewDidLoad() {
super.viewDidLoad()
}
func loadWebView() {
let url = URL(string: "https://www.amazon.com")
webView.navigationDelegate = self
webView.load(URLRequest(url: url!))
webView.isHidden = true
self.view.addSubview(webView)
}
}

Answer 1

In First VC :
func webView(_ webView: WKWebView,
didFinish navigation: WKNavigation!) {
//Post notification
NotificationCenter.default.post(name: NSNotification.Name(rawValue: "WebViewFinishedLoading"), object: nil)
}
In Second VC:
override func viewDidLoad() {
super.viewDidLoad()
// Add observer for your notification
NotificationCenter.default.addObserver(self, selector: #selector(loadWebView), name: NSNotification.Name(rawValue: "WebViewFinishedLoading"), object: nil)
}
//Remove observer in deinit
deinit {
NotificationCenter.default.removeObserver(self)
}