WKNavigationDelegate is an essential protocol in the WebKit framework, which is used for managing web content in iOS applications. This delegate provides methods to track the progress of web content loading, handle navigation actions, and manage errors. Understanding and implementing WKNavigationDelegate can significantly enhance the user experience by providing more control over web content interactions.

In this article, we will explore how to implement WKNavigationDelegate in a Swift-based iOS application. We will cover the fundamental methods provided by the protocol and demonstrate how to use them effectively.

Examples:

1. Setting Up WKWebView and WKNavigationDelegate:

   First, we need to set up a WKWebView and assign its navigation delegate.

   import UIKit
   import WebKit
   
   class ViewController: UIViewController, WKNavigationDelegate {
      var webView: WKWebView!
   
      override func viewDidLoad() {
          super.viewDidLoad()
   
          // Initialize WKWebView
          webView = WKWebView(frame: self.view.frame)
          webView.navigationDelegate = self
          self.view.addSubview(webView)
   
          // Load a URL
          if let url = URL(string: "https://www.apple.com") {
              let request = URLRequest(url: url)
              webView.load(request)
          }
      }
   
      // WKNavigationDelegate methods will be implemented here
   }

2. Implementing WKNavigationDelegate Methods:

   Here are some key methods of WKNavigationDelegate that you can implement to manage web navigation:

   • webView(_:didStartProvisionalNavigation:): Called when the web view begins to load content.
   • webView(_:didFinish:): Called when the web view finishes loading content.
   • webView(_:didFailProvisionalNavigation:withError:): Called when an error occurs during content loading.

   extension ViewController {
      func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
          print("Started to load")
      }
   
      func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
          print("Finished loading")
      }
   
      func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) {
          print("Failed to load with error: \(error.localizedDescription)")
      }
   }

3. Handling Navigation Actions:

   You can also decide whether to allow or cancel a navigation action using the webView(_:decidePolicyFor:decisionHandler:) method.

   extension ViewController {
      func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
          if let url = navigationAction.request.url {
              print("Navigating to URL: \(url)")
              // Allow the navigation
              decisionHandler(.allow)
          } else {
              // Cancel the navigation
              decisionHandler(.cancel)
          }
      }
   }

By implementing these methods, you can gain better control over the web content loading process and handle various navigation events effectively.