Fix ERR_UNKNOWN_URL_SCHEME on Android WebView for tel

I am building a hybrid mobile app with Visual Studio Tools for Apache Cordova that is able to make phone calls, send text message or emails, view a location on a map, etc. These are all handled with external applications (for instance use Gmail to send an email or Maps to pinpoint a location). They are placed in an anchor tag in HTML, such as <a href="tel:12345678">, <a href="sms:12345678">, <a href="mailto:name@domain.com"> or <a href="geo:...">. These work fine except that when you execute one of these actions and the system opens another app you see for a short time a webview with an error: “Web page not available”. Then the external app opens, you take the action and then go back to the app. At that point you again see this webview with the error as shown below.

ERR_UNKNOWN_URL_SCHEME when sending a text message

solution is:

@Override
    public boolean shouldOverrideUrlLoading(WebView webview, String url)
    {
     if (url.startsWith("tel:") || url.startsWith("sms:") || url.startsWith("smsto:") || url.startsWith("mms:") || url.startsWith("mmsto:"))
       { 
         Intent intent = new Intent(Intent.ACTION_VIEW,Uri.parse(url)); 
         startActivity(intent); 
         return true;
       }
    return false;
   }