How to add window message event Listener - Android WebView

Issue

How to add an event listener to handle window message event in a WebView. I have tried this,

webView.evaluateJavascript("window.addEventListener('message', function (e) { Android.logData('HELLO')});", null);

But it is not working. Is there any way to achieve this?

Solution

After exploring I didn't find any way to get data from the website running in WebView to the app without adding any code to in the website. And finally, I decided to make the necessary changes on my website as well. And this is how I did it:

In App

Created a class

private class JsObject {
    @JavascriptInterface
    public void shareData(String data) {
        Log.v(LOG_TAG, data);
    }
}

Add an instance of the new class as Javascript Interface to the WebView with a name

ssWebView.addJavascriptInterface(new JsObject(), "Android");

This instance will be added to the window object of the WebView as Android(name, the second argument of the above function)

In Website

In the website to share data

window.Android && window.Android.shareData("This is the data from website");

Answered By - Ajay Sivan