[Bug] WebView.Navigated event not fired when no internet available on iOS.

[aaRopi]

Description

WebView.Navigated NOT fired on iOS when no internet connection is available.

Steps to Reproduce

1. Hook into WebView.Navigating and WebView.Navigated events.
2. Run app on iOS without internet connection.
3. Handler for WebView.Navigated is never called.

Expected Behavior

On iOS, when loading a url in the WebView, if there is no internet connection available, the WebView should fire a Navigated event with WebNavigationResult.Failure.

Since this is observed behavior on Android, I expected iOS to behave the same way.

Actual Behavior

The Navigated event is never fired for this error case.

Basic Information

• Version with issue: 4.8.0.1364
• Platform Target Frameworks:
  • iOS: 13, 14

Workaround

No suitable workaround found yet. I know where the bug is and how it can be fixed.

1. iOS WkWebView requires a delegate WkNavigationDelegate to handle various callbacks from the WkWebView.

2. The WkNavigationDelegate has 2 methods to handle errors:

• DidFailNavigation(WKWebView webView, WKNavigation navigation, NSError error)
• DidFailProvisionalNavigation(WKWebView webView, WKNavigation navigation, NSError error)

3. Only one of them has been implemented as can be seen here: WkWebViewRenderer source code

4. For now the solution would be to implement the other method. The implementation can be copied from DidFailNavigation

[pcdus]

It's the same thing when requesting a invalid url:

• on Android, this will fire a Navigated event with WebNavigationResult.Failure
• on iOS, nothing happens: we only have a white empty View

Do you prefer I create a new issue, or is it possible to fix this in the same time?

[aaRopi]

Hi @Goldstrike ,

Thank you for the additional info. I have a PR that is open fixing the issue I have outlined. Here: #12327

I don't know if the PR fixes your issue as well.

[pcdus]

Hi @aaRopi ,
So if I want to use your code, what do I have to do?

• add the WkWebViewRenderer.cs class in my "Renderers" iOS folder
• add you implementation you've given

Is it correct? Is there something else to do?

[aaRopi]

Hi @Goldstrike ,

Unfortunately, that will not work. This is because the current code references a lot of code that is internal to Xamarin.Forms. I could not find a way to fix my issue from outside, without duplicating a lot of the code that already exists. Thus, making a PR was the easier solution for me.

[pcdus]

@samhouts @jsuarezruiz
What's new about this PR? Is there another way to fix the original issue?

[pcdus]

I've created a new bug for the other cases: #12732