Question

Is there any way the application perform a certain function depending on the open page in webview? Eg detecting some javascript in it?

Answer 1

This part of the Android docs will likely be helpful: http://developer.android.com/guide/webapps/webview.html#UsingJavaScript

You can call javascript on the WebView by using loadUrl(). For example:

webView.loadUrl("javascript: someJavascriptMethod(true, 1, 8, 'some string');");

The page can also pass data back up to Java code by using a Javascript Interface. Create a public class with public methods. Then, create an instance of that class and install it with webView.addJavascriptInterface()

For example

 public class JsObject {
    @JavascriptInterface
    public String toString(String value) { // This method can be called from Javascript }
 }
 webView.addJavascriptInterface(new JsObject(), "injectedObject");
 webView.loadData("", "text/html", null);
 webView.loadUrl("javascript:alert(injectedObject.aJavaMethod('some value'))");

If you need to see if a certain javascript method is available or if you need to read from the DOM, you can use loadUrl to call some javascript that can do those look ups for you. Then you can use a javascript interface to call a Java method with some sort of response.