gistfile1.rb

#+++ pubsub_presence_controller.rb
class Pubsub_presenceController < Babylon::Base::Controller  
  @@nodes = []
  def nodes
    Babylon.logger.debug { "NODES" }

    @from = Babylon.config["jid"]
    @to = Babylon.config["pubsub_jid"]
    @id = "nodereq"

    @@nodes = @stanza.nodes.map {|i| i.node}

    # collects the node request response, and for each node, asks for a list of subscribers
    @@nodes.each do |n|
      render_evaluate_and_send(:file => "subscription_request.xml.builder", :locals => {:node => n})
    end
  end

#+++ subscription_request.xml.builder

xml.iq(:type => 'get', :from => @from, :to => @to, :id => @id) do
  xml.pubsub(:xmlns => 'http://jabber.org/protocol/pubsub#owner') do
    xml.subscriptions(:node => @node)
  end
end

#+++ renders
#
#<iq type="get" from="presence.pubsub.localhost" to="pubsub.localhost" id="nodereq">
#  <pubsub xmlns="http://jabber.org/protocol/pubsub#owner">
#    <subscriptions node=""/>
#  </pubsub>
#</iq>