WebView ↔ Native app communication is easier than you think.

Even without relying on the utilities provided by Capacitor, you can easily pass data back and forth between your web app and its native counterpart:

➡️In JavaScript / TypeScript you can register global functions on the window object. The native code can call these via executeJavaScript() on the WebView.

➡️In the other direction, the native code can register a JavaScript interface on the

WebView:

webView.addJavascriptInterface(new Object() {
  @JavascriptInterface
  public void onSessionId(String value) {
    SaveUrlHandler.instance.setSessionId(value);
  }

  @JavascriptInterface
  public void closeApp() {
    MainActivity.this.finish();
  }
}, "Android");

which the JavaScript / TypeScript code can call whenever it wants:

handleBackButton() {
if (this.location.isCurrentPathEqualTo('/')) {
  if ((window as any)['Android']) {
    (window as any)['Android'].closeApp();
  }
...
}