title: WhatsApp like group chat in android using xmpp and asmack
body: <p>I am developing a clone of WhatsApp for which i need to implement group chat like in WhatsApp. i am using Openfire as a server and Asmack on android end. Now i have implemented group chat following this <a href="http://www.igniterealtime.org/builds/smack/docs/latest/documentation/extensions/muc.html">guide</a> but this is no way like WhatsApp. Users don't persist in the room and leave the room as soon as they go offline. There's no mechanism for offline messaging like in 1-1 chat.So basically my question is how can i implement group chat using asmack that has following features:</p>
  
  <ul>
  <li>groups can persist user no matter if they are online or not.</li>
  <li>deliver offline messages to a group member(when he comes online).</li>
  </ul>
  
  <p>Do i need to customize the server side or the client side? Any idea how WhatsApp like group chat can be done with asmack and Openfire will be highly appreciated.</p>