PubSub Node Presence Protocol

Occupant Use Case === Log in to Pubsub Node To log in to PubSub Node user must send presence to PubSub component with additional information about node:

<presence
    from='hag66@shakespeare.lit/pda'
    id='n13mt3l'
    to='pubsub.shakespeare.lit'>
  <pubsub xmlns='tigase:pubsub:1' node='princely_musings'/>
</presence>

Component will publish this information in node:

<message from='pubsub.shakespeare.lit' to='francisco@denmark.lit' id='foo'>
  <event xmlns='http://jabber.org/protocol/pubsub#event'>
    <items node='princely_musings'>
      <item>
        <presence xmlns='tigase:pubsub:1' node='princely_musings' jid='hag66@shakespeare.lit/pda' type='available'/>
      </item>
    </items>
  </event>
</message>
<message from='pubsub.shakespeare.lit' to='bernardo@denmark.lit' id='bar'>
  <event xmlns='http://jabber.org/protocol/pubsub#event'>
    <items node='princely_musings'>
      <item>
        <presence xmlns='tigase:pubsub:1' node='princely_musings' jid='hag66@shakespeare.lit/pda' type='available'/>
      </item>
    </items>
  </event>
</message>

And then will send notification with presences of all occupants to new occupant.