Adding alert() support to a WebView - Android

MainActivity.java

/* 
Retrieved from https://web.archive.org/web/20160516165158/http://lexandera.com/2009/01/adding-alert-support-to-a-webview/
*/

// ...
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;

public class MainActivity extends AppCompatActivity {
  
  private WebView webViewSpacetrace;
  @Override
  protected  void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    
    browser=(WebView) findViewById(R.id.yourBrowserViewId);
    browser.setWebChromeClient(new WebChromeClient());
    browser.setWebViewClient(new WebViewClient());
    final WebView browser = (WebView)findViewById(R.id.browser);  
    /* JavaScript must be enabled if you want it to work, obviously */   
    browser.getSettings().setJavaScriptEnabled(true);  
    
    final Context myApp = this;  
    
    /* WebChromeClient must be set BEFORE calling loadUrl! */  
    browser.setWebChromeClient(new WebChromeClient() {  
      @Override  
      public boolean onJsAlert(WebView view, String url, String message, final android.webkit.JsResult result)   
      {  
        new AlertDialog.Builder(myApp)  
        .setTitle("")  
        .setMessage(message)  
        .setPositiveButton(android.R.string.ok,  
        new AlertDialog.OnClickListener()   
        {  
          public void onClick(DialogInterface dialog, int which)   
          {  
            result.confirm();  
          }  
        })  
        .setCancelable(false)  
        .create()  
        .show();  
        
        return true;  
      };  
    });  
    
    /* load a web page which uses the alert() function */  
    browser.loadUrl("http://lexandera.com/files/jsexamples/alert.html");
    
  }
}