Swift version: 5.2
By default a WKWebView
can navigate to any links the user selects, but it’s common to want to restrict that. It only takes three steps to accomplish this:
WKNavigationDelegate
.navigationDelegate
.decidePolicyFor
method to decide whether each URL should be allowed or denied.Let’s try it out now. First, make your view controller conform to WKNavigationDelegate
.
Second, set your view controller to be the navigationDelegate
property of your web view. This might be done in viewDidLoad()
, but you can also change the delegate dynamically. Either way, you need to use this code:
yourWebView.navigationDelegate = self
Finally, implement the decidePolicyFor
method. This is the only part that takes any work: you need to pull out the host of the URL that was requested, run any checks you want to make sure it’s OK, then call the decisionHandler()
closure with either .allow
to allow the URL or .cancel
to deny access.
Here’s an example to get you started:
func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
if let host = navigationAction.request.url?.host {
if host.contains("hackingwithswift.com") {
decisionHandler(.allow)
return
}
}
decisionHandler(.cancel)
}
That code will allow navigation only to URLs that contain “hackingwithswift.com”.
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This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
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