How can I load content offline in a web view?

To load content offline in a web view, you can use the WKWebView class in iOS. By default, WKWebView has limited behavior, so you may need to configure it explicitly to handle offline content. Here are some steps you can follow:

1. Cache the Content: Ensure that the content you want to load offline is cached. You can use the URLCache class to cache responses from the web view.

2. Load Cached Content: When the device is offline, you can load the cached content from the local storage instead of making a network request.

3. Configure WKWebView: Set up the WKWebView to handle offline scenarios by checking the network status and loading the cached content when necessary.

Here is a basic example of how you might set this up:

import WebKit

class OfflineWebView: UIViewController, WKNavigationDelegate {
    var webView: WKWebView!

    override func viewDidLoad() {
        super.viewDidLoad()
        
        let webConfiguration = WKWebViewConfiguration()
        webView = WKWebView(frame: .zero, configuration: webConfiguration)
        webView.navigationDelegate = self
        view.addSubview(webView)
        
        // Load the initial content
        if let url = URL(string: "https://example.com") {
            let request = URLRequest(url: url)
            webView.load(request)
        }
    }

    // WKNavigationDelegate method to handle offline loading
    func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
        if let cachedResponse = URLCache.shared.cachedResponse(for: webView.urlRequest) {
            webView.load(cachedResponse.data, mimeType: cachedResponse.response.mimeType!, characterEncodingName: cachedResponse.response.textEncodingName!, baseURL: cachedResponse.response.url!)
        }
    }
}

In this example, the webView(_:didFail:navigation:withError:) method is used to load cached content if the network request fails.

For more detailed information on configuring WKWebView and handling offline content, you can refer to the session Get started with Writing Tools at WWDC 2024, which discusses the behavior and configuration of WKWebView.