bug: setWebViewClient is not working

[astrocreep]

Bug Report

Capacitor Version

   Capacitor Doctor   

Latest Dependencies:

  @capacitor/cli: 3.4.0
  @capacitor/core: 3.4.0
  @capacitor/android: 3.4.0
  @capacitor/ios: 3.4.0

Installed Dependencies:

  @capacitor/ios: not installed
  @capacitor/core: 3.4.0
  @capacitor/cli: 3.4.0
  @capacitor/android: 3.4.0

[success] Android looking great! 👌

Platform(s)

Android

Current Behavior

I need to use a custom WebViewClient. I coded a new one, extending BridgeWebViewClient and set it via customn Plugin using the this.bridge.setWebVielClient(new MyCustomWebViewClient(this.bridge)); method. The custom WebViewClient isn't used by Capacitor.

Expected Behavior

My custom WebViewClient should be used instead the default one.

Code Reproduction

package com.example;

import com.getcapacitor.Plugin;
import com.getcapacitor.PluginCall;
import com.getcapacitor.PluginMethod;
import com.getcapacitor.annotation.CapacitorPlugin;

@CapacitorPlugin(name = "CustomWebViewClient")
public class CustomWebViewClient extends Plugin {

    @PluginMethod
    public void init(PluginCall call)
    {
        this.bridge.setWebViewClient(new MyCustomWebViewClient(this.bridge));

        call.resolve();
    }
}

Other Technical Details

npm --version output: 8.1.3

node --version output: v17.1.0

Additional Context

The reason for this issue is the setWebViewClient setter in Bridge.java. The new WebViewClient is only assigned to the Bridge but never set in the WebView itself. I added this to get it working here locally (needs to run in the main thread. Calling this from a plugin fails, because we are in the PluginThread):

    public void setWebViewClient(BridgeWebViewClient client) {
        this.webViewClient = client;

        Handler mainHandler = new Handler(this.getContext().getMainLooper());
        WebView webView = this.webView;
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                webView.setWebViewClient(client);
            }
        });
    }

[Ionitron]

This issue may need more information before it can be addressed. In particular, it will need a reliable Code Reproduction that demonstrates the issue.

Please see the Contributing Guide for how to create a Code Reproduction.

Thanks!
Ionitron 💙

[astrocreep]

https://github.com/astrocreep/capacitor-setWebViewClient

After starting this one on Android. You should see a log message:
D/APP: NEW WEB VIEW CLIENT CREATED
So the new CustomWebViewClient is created. Then an image is loaded in the index.html. I would expect that load process to be intercepted by the new client, but nothing happens. If you modify Bridge.java like I did in the initial bug report, the new client is used correctly and you can see this message:

D/APP: should override? http://localhost/logo.png
D/Capacitor: Handling local request: http://localhost/logo.png

Without the fix, you only see the second line...

[jcesarmobile]

So this was thought in a way that the WebViewClient was set by the users on the bridge initialization, so it would use the users client from the beginning, instead of swapping it after initialization, in that case your code modification is not needed. But with the Capacitor 3 refactor maybe things work in a different order and that doesn't work as expected, will look into it.

If done after the initialization, it should be done like this by the user/plugin:

bridge.getWebView().setWebViewClient(new BridgeWebViewClient(bridge) {
    @Override
    public void onReceivedSslError(WebView view, final SslErrorHandler handler, SslError error) {
        handler.proceed();
    }
});

Or at least that's what I answered on an issue long ago #2751 (comment)

[astrocreep]

Can you provide an example how to setup a custom WebViewClient without a plugin? I'n my linked example I tried this:

package com.example.app;
import android.os.Bundle;
import com.getcapacitor.BridgeActivity;

public class MainActivity extends BridgeActivity {
    @Override
    public void onStart() {
        super.onStart();

        this.bridge.setWebViewClient(new CustomWebViewClient(this.bridge));
    }
}

No plugin, just a minimal MainActivity. The WebView is already set up here and the client isn't changeable. Where else could I hook in?

[jcesarmobile]

It's working from plugins but not from MainActivity.java

As workaround you can use this.bridge.getWebView().setWebViewClient(new CustomWebViewClient(this.bridge)); to set the WebViewClient on the WebView directly as setting it to the bridge has no effect after bridge initialization.

[astrocreep]

Yes, this is what I'm doing now and it's working

Handler mainHandler = new Handler(this.getContext().getMainLooper());
WebView webView = this.bridge.getWebView();
mainHandler.post(new Runnable() {
    @Override
    public void run() {
        webView.setWebViewClient(client);
    }
});

But having a setter that does nothing once the initialization is complete still bothers me. Imho this is not a good design choice. If there is stuff that needs to be set up before init, better have an settings object or whatever.

[jcesarmobile]

This is marked as a bug, see the type: bug label on it.

[ionitron-bot]

Thanks for the issue! This issue is being locked to prevent comments that are not relevant to the original issue. If this is still an issue with the latest version of Capacitor, please create a new issue and ensure the template is fully filled out.