WKWebView: Use same delegate code (WKNavigationDelegate) in multiple view controllers - ios

Question

I have an application with 5 navigation tabs, each one with a different View Controller that has a WKWebView inside it. I would like to somehow use the same delegate code to prevent copy and pasting in each one.
How do I reuse the "decidePolicyFor" code in different View Controllers?
class DashboardViewController: UIViewController, WKUIDelegate, WKNavigationDelegate {
var webView: WKWebView!
override func loadView() {
let webConfiguration = WebViewUtils.getWKWebViewConfiguration()
webView = WKWebView(frame: .zero, configuration: webConfiguration)
webView.uiDelegate = self
webView.navigationDelegate = self
view = webView
}
override func viewDidLoad() {
super.viewDidLoad()
webView.load(Constants.DASHBOARD)
}
func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: #escaping (WKNavigationActionPolicy) -> Void) {
if navigationAction.request.url?.scheme == "tel" {
UIApplication.shared.open(navigationAction.request.url!, options: convertToUIApplicationOpenExternalURLOptionsKeyDictionary([:]), completionHandler: nil)
decisionHandler(.cancel)
}
else {
decisionHandler(.allow)
}
}
}

Answer 1

You can implement this by dependency injection like this:
class NavigationBehavior: NSObject, WKNavigationDelegate {
func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: #escaping (WKNavigationActionPolicy) -> Void) {
if let url = navigationAction.request.url, url.scheme == "tel" {
UIApplication.shared.open(url, options: [:], completionHandler: nil)
decisionHandler(.cancel)
} else {
decisionHandler(.allow)
}
}
}
class DashboardViewController: UIViewController, WKUIDelegate {
lazy var webView: WKWebView = {
let webConfiguration = WKWebViewConfiguration()
return WKWebView(frame: .zero, configuration: webConfiguration)
}()
let navigationDelegate: WKNavigationDelegate
init(navigationDelegate: WKNavigationDelegate) {
self.navigationDelegate = navigationDelegate
super.init(nibName: nil, bundle: nil)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func loadView() {
webView.uiDelegate = self
webView.navigationDelegate = navigationDelegate
view = webView
}
override func viewDidLoad() {
super.viewDidLoad()
webView.load(Constants.DASHBOARD)
}
}
let delegate = NavigationBehavior()
let vc1 = DashboardViewController(navigationDelegate: delegate)
let vc2 = ProfileViewController(navigationDelegate: delegate)

Answer 2

You can extract the navigation delegate code in an object like this:
class MyWebViewNavigationDelegate: NSObject, WKNavigationDelegate {
func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: #escaping (WKNavigationActionPolicy) -> Void) {
if navigationAction.request.url?.scheme == "tel" {
UIApplication.shared.open(navigationAction.request.url!, options: [:], completionHandler: nil)
decisionHandler(.cancel)
} else {
decisionHandler(.allow)
}
}
}
and then use instances of this object throughout the app:
class DashboardViewController: UIViewController, WKUIDelegate, WKNavigationDelegate {
var webView: WKWebView!
let webViewNavigationDelegate = MyWebViewNavigationDelegate()
override func loadView() {
let webConfiguration = WebViewUtils.getWKWebViewConfiguration()
webView = WKWebView(frame: .zero, configuration: webConfiguration)
webView.uiDelegate = self
webView.navigationDelegate = webViewNavigationDelegate
view = webView
}
override func viewDidLoad() {
super.viewDidLoad()
webView.load(Constants.DASHBOARD)
}
}