Programming Jabber

Reversing a user registration

The opposite of registering a user is unregistering a user. This is not the same as removing that user altogether. When the <remove/> tag, described in Section 6.2.11, is used in a jabber:iq:register-qualified IQ-set during a user session, the user is unregistered. That is, all the information held in the user’s spool file is removed. But the spool file itself is not removed until the Jabber server is shut down. This means that even if you <remove/> a user, the username will still exist until the server is cycled, causing an error if the same username is used in a new registration attempt:

RECV: <iq type='error'>
        <query xmlns='jabber:iq:register'>
          <username>dj</username>
          <password>secret</password>
        </query>
        <error code='409'>Username Not Available</error>
      </iq>

This may well be fixed in a later release of the Jabber server.