Migrating from UIWebView to WKWebView - ios

Question

I'm migrating from UIWebView to WKWebView, how can I rewrite these function for WKWebView?
func webViewDidStartLoad(webView: UIWebView){}
func webViewDidFinishLoad(webView: UIWebView){}
and
func webView(webView: UIWebView, shouldStartLoadWithRequest request: NSURLRequest, navigationType: UIWebViewNavigationType) -> Bool {
print("webview asking for permission to start loading")
if navigationType == .LinkActivated && !(request.URL?.absoluteString.hasPrefix("http://www.myWebSite.com/exemlpe"))!{
UIApplication.sharedApplication().openURL(request.URL!)
print(request.URL?.absoluteString)
return false
}
print(request.URL?.absoluteString)
lastUrl = (request.URL?.absoluteString)!
return true
}
func webView(webView: UIWebView, didFailLoadWithError error: NSError?) {
print("webview did fail load with error: \(error)")
let testHTML = NSBundle.mainBundle().pathForResource("back-error-bottom", ofType: "jpg")
let baseUrl = NSURL(fileURLWithPath: testHTML!)
let htmlString:String! = "myErrorinHTML"
self.webView.loadHTMLString(htmlString, baseURL: baseUrl)
}

Answer 1

UIWebView => WKWebView Equivalent
UIWebViewDelegate => WKNavigationDelegate
delegate => navigationDelegate
didFailLoadWithError => didFailNavigation
webViewDidFinishLoad => didFinishNavigation
webViewDidStartLoad => didStartProvisionalNavigation
shouldStartLoadWithRequest => decidePolicyForNavigationAction
About shouldStartLoadWithRequest you can write:
func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: #escaping (WKNavigationActionPolicy) -> Void) {
print("webView:\(webView) decidePolicyForNavigationAction:\(navigationAction) decisionHandler:\(decisionHandler)")
switch navigationAction.navigationType {
case .linkActivated:
if navigationAction.targetFrame == nil {
self.webView?.loadRequest(navigationAction.request)
}
if let url = navigationAction.request.url, !url.absoluteString.hasPrefix("http://www.myWebSite.com/example") {
UIApplication.shared.open(url)
print(url.absoluteString)
decisionHandler(.cancel)
return
}
default:
break
}
if let url = navigationAction.request.url {
print(url.absoluteString)
}
decisionHandler(.allow)
}
And for the didFailLoadWithError:
func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
print("webView:\(webView) didFailNavigation:\(navigation) withError:\(error)")
let testHTML = Bundle.main.path(forResource: "back-error-bottom", ofType: "jpg")
let baseUrl = URL(fileURLWithPath: testHTML!)
let htmlString = "myErrorInHTML"
self.webView.loadHTMLString(htmlString, baseURL: baseUrl)
}

Answer 2

Here is the Objective-C methods for the migration:
shouldStartLoadWithRequest -> decidePolicyForNavigationAction
Remember to call the decisionHandler:
- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
if (navigationAction.navigationType == WKNavigationTypeLinkActivated) {
}
NSString *url = [navigationAction.request.URL query];
decisionHandler(WKNavigationActionPolicyAllow);
}
webViewDidStartLoad -> didStartProvisionalNavigation
- (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation {
}
webViewDidFinishLoad -> didFinishNavigation
- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation {
}
didFailLoadWithError -> didFailNavigation
- (void)webView:(WKWebView *)webView didFailNavigation:(WKNavigation *)navigation withError:(NSError *)error {
}

Answer 3

Migrating UIWebView to WKWebView, Swift 4:
Equivalent of shouldStartLoadWithRequest:
func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: #escaping (WKNavigationActionPolicy) -> Void) {
var action: WKNavigationActionPolicy?
defer {
decisionHandler(action ?? .allow)
}
guard let url = navigationAction.request.url else { return }
print(url)
if navigationAction.navigationType == .linkActivated, url.absoluteString.hasPrefix("http://www.example.com/open-in-safari") {
action = .cancel // Stop in WebView
UIApplication.shared.openURL(url) // Open in Safari
}
}
Equivalent of webViewDidStartLoad:
func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
print(String(describing: webView.url))
}
Equivalent of didFailLoadWithError:
func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
let nserror = error as NSError
if nserror.code != NSURLErrorCancelled {
webView.loadHTMLString("404 - Page Not Found", baseURL: URL(string: "http://www.example.com/"))
}
}
Equivalent of webViewDidFinishLoad:
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
print(String(describing: webView.url))
}