zenaton_workflow.rb

class SequentialWorkflow < Zenaton::Interfaces::Workflow
  include Zenaton::Traits::Zenatonable

  def handle
    a = TaskA.new.execute # Let's store the return value from the task

    if a > 0 # And use that value to determine which task to run next
      TaskB.new.execute
    else
      TaskC.new.execute
    end

    TaskD.new.execute # This gets execute in either cases
  end
end