base_participant.rb

class BaseParticipant
  include Ruote::LocalParticipant

  def consume( workitem )
    @workitem = workitem
    begin
      _, method, *args = workitem.fields['command'].split('/')
      if arg
        send( method, *args )
      else
        send( method )
      end
    rescue => e
      @workitem.fields['error'] = e
      reply_to_engine( @workitem )
    end
  end

  def done( message )
    @workitem.fields['report'].push message
   reply_to_engine( @workitem )
  end

  def failed( message )
    @workitem.fields['report'].push message
    @workitem.fields['error'] = true
    reply_to_engine( @workitem )
  end
end

base_participant_spec.rb

require 'spec_helper'

describe BaseParticipant do
  subject { BaseParticipant }
  before do
    @base = subject.new
  end

  def workitem(opts = {})
    items = {
      'report' => []
    }.merge(opts)
    Ruote::Workitem.new('fields' => items)
  end

  it "should check dispatch to a method from a path" do
    item = workitem('command' => '/test_one')
    @base.should_receive(:test_one)
    @base.consume(item)
  end

  it "should recieve the method with an argument" do
    item = workitem('command' => '/test_two/foo')
    @base.should_receive(:test_two).with('foo')
    @base.consume(item)
  end

  it "should recieve the method with multiple arguments" do
    item = workitem('command' => '/test_three/foo/bar')
    @base.should_receive(:test_three).with('foo', 'bar')
    @base.consume(item)
  end

  it "should reply to the engine when it's done" do
    item = workitem('command' => '/foo')
    @base.stub!(:foo)
    @base.should_receive(:reply_to_engine).with(item)

    @base.consume(item)
    @base.done("foo")
    item.fields['report'].should include('foo')
  end

  it "should register a fail" do
    item = workitem('command' => '/foo')
    @base.stub!(:foo)
    @base.should_receive(:reply_to_engine).with(item)

    @base.consume(item)
    @base.fail('you fail')
    item.fields['report'].should include('you fail')
    item.fields['error'].should be_true
  end

  it 'should send an error back to the engine when an action raises' do
    item = workitem('command' => '/die')

    def @base.die
      raise "dead"
    end

    @base.should_receive(:reply_to_engine).with(item)

    @base.consume item

    item.fields['error'].should be_present
  end

end

gistfile2.rb

Ruote.process_defition :name => 'Hello world' do
  cursor :break_if => "${f:error}" do
    foo :command => '/verify/something'
    bar :command => '/report'
  end
end

participants.rb

class Foo < BaseParticipant
  def verify( something )
    # Do something
    done "It worked"
  end
end

class Bar < BaseParticipant
  def report
    # Oh well
    failed "No way I'm doing this"
  end
end