JavaScript alert not working in Android WebView

Question

In my application I am using WebView and in that I am using JavaScript alert( ) method but its not working, no pop-up appears.

in my manifest file I have added

<uses-permission android:name="android.permission.INTERNET"></uses-permission>

and in activity file I have added

mWebView = (WebView) findViewById(R.id.webview);
mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.loadUrl("file:///android_asset/demo.html");

In layout xml file I have added

<WebView 
    android:id="@+id/webview"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
/>

Any clue how to enable full JavaScript in WebView?

---

Update

Thanks mark
the alert() method in the html file are working now :) .

Now there are two issues in WebView :
1: I am using a <textarea> in the html file that i am loading in WebView , and trying to write in Hindi language font in it, but when i try to write Hindi text it displays as symbols ( rectangle symbols like [] ) .

when i do the same in firefox browser on desktop it works fine. any clue how to give support for multiple language in textarea in WebView ?

2: When I am clicking submit and trying to open the value of text in alert() method in another java script it doesn't work , does it mean even after using WebChromeClient its applicable only for current loaded html page and not javascripts called from that page ?

Answer 1

As others indicated, setting the WebChromeClient is needed to get alert() to work. It's sufficient to just set the default WebChromeClient():

mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.setWebChromeClient(new WebChromeClient());

Thanks for all the comments below. Including John Smith's who indicated that you needed to enable JavaScript.