activeresource_participants.rb

class ActiveResourceParticipant
 include OpenWFE::LocalParticipant

 def initialize (options, &block)

   @options = options

   # some defaults
   @options[:site] ||= 'http://127.0.0.1:3000'
   @options[:method] ||= :get

   @block = block

   #[ :resource_name ].each do |n|
   #  raise "missing option :#{optname}" unless @options[n]
   #end
 end

 #
 # This method is called each time the participant receives a workitem. It
 # calls the requested ActiveResource method, calls the response handling code
 # if present and then immediatly replies to the engine.
 #
 def consume (workitem)

   # use block to determine the method's arguments if given
   args = if @block
     call_block(@block, workitem)
   elsif a = param[:args] || param[:arguments]
     Array(a)
   else
     [] # no arguments
   end

   # create new subclass of ActiveResource::Base
   active_resource_class = Class.new(ActiveResource::Base)
   active_resource_class.site = param[:site]
   active_resource_class.element_name = param[:resource_name]

   # Do we work on a single or on a set of resources? If resource_id is nil or
   # negative, it's a set of resources.

   resource_id = param[:resource_id]

   active_resource = if (!resource_id) || (resource_id.to_i < 0)
     # set of resources
     active_resource_class
   else
     # specific resource
     active_resource_class.new(:id => resource_id)
   end

   response = active_resource.send(param[:method], *args)

   # we got our response, but what to do with it?
   if h = param[:response_handling]
     h.call(response, workitem)
   end

   # reply to the engine
   reply_to_engine(workitem)
 end

 protected

   def param (key)
     workitem.params[key] || @options[key]
   end
end