This expressions lets one register participants directly from a process definition.

  pdef = Ruote.define do

    registerp 'alpha', :class => 'MyParticipant', :target => 'mail'
      # register participant named 'alpha' with the given class
      # and some attributes

    registerp /^user_.+/, :class => 'MyParticipant'
    registerp :regex => '^user_.+', :class => 'MyParticipant'
      # register participant with a given regular expression

    registerp 'admin', :class => 'MyParticipant', :position => -2
      # register participant 'admin' as second to last in participant list
  end

Participant info can be given as attributes to the expression (see code above) or via the workitem.

  pdef = Ruote.define do

    registerp :participant => 'participant'
      # participant info is found in the field 'participant'

    registerp :participants => 'participants'
      # an array of participant info is found in the field 'participants'
  end

The expression ‘unregisterp’ can be used to remove participants from the participant list.