In Android Webview, am I able to modify a webpage's DOM?

Question

Suppose I load a 3rd party URL through webview.

public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.main);         webview = (WebView) findViewById(R.id.webview);         webview.setWebViewClient(new HelloWebViewClient());         webview.getSettings().setJavaScriptEnabled(true);         webview.setWebChromeClient(new MyWebChromeClient());         webview.loadUrl("http://ebay.com");              } 

Is it possible for me to inject something into this WebView to replace the ebay logo with my own?

Answer 1

To expand on CommonsWare's correct answer:

WebView webview = new WebView(); webview.setWebViewClient(new WebClient()); webView.getSettings().setJavaScriptEnabled(true); webview.loadUrl("stackoverflow.com"); 

then in WebClient:

public class WebClient extends WebViewClient {     @Override     public boolean shouldOverrideUrlLoading(WebView view, String url) {         view.loadUrl(url);         return true;     }      @Override     public void onPageFinished(WebView view, String url)      {                // Obvious next step is: document.forms[0].submit()         view.loadUrl("javascript:document.forms[0].q.value='[android]'");            } } 

In a nutshell, you wait for the page to load. Then you loadUrl("javascript:[your javascript here]").

Answer 2

Not directly. You can invoke Javascript code in the context of the current Web page, via loadUrl(), much like a bookmarklet does. However, you do not have direct access to the DOM from Java code.