app/views/shared/profile_actions/xmpp_chat.html.erb
<% label_name = profile.person? ? _('Open chat') : _('Join chat room') %>
<% display = profile.person? ? profile.friends.include?(user) : profile.members.include?(user) %>
<% if display %>
<li>
<%= button(:comments, label_name , {}, :class => 'open-conversation', 'data-jid' => profile.jid) %>
</li>
<% end %>