How to receive offline messages with XMPP in ios

Question

I am working on a chat using XMPP Protocol. Everything is working fine using XMPP. But I'm unable to receive offline messages from agent when user comes to online. As user A is logged out and user B sends messages to user A, and when user A logs into app, it must receive all the messages that were sent by user B during offline session. How can I receive these messages?

Answer 1

With rooms you can do this easily by joining the chat asking history since the time you went offline. For one-to-one chat, you will have to implement per user offline queue at the server end. And notify server once you are online to receive the chats.