User presence not receiving xmpp ios

问题

I have added user to my roster using this rest api http://192.168.1.39:9090/plugins/restapi/v1/users/hello/roster Header

Authorization:FBeGHvBFSa7JsLL3
Content-Type:application/xml

Body

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<rosterItem>
    <jid>vinod@192.168.1.39</jid>
    <nickname>vinod</nickname>
    <subscriptionType>3</subscriptionType>
</rosterItem>

user successfully added to roster but user presence not receiving in my iOS application.

please help me for this , what i missing in my code or other things

来源：https://stackoverflow.com/questions/37831308/user-presence-not-receiving-xmpp-ios