manager.rb

class Manager < ActiveRecord::Base
  belongs_to :demo
  
  serialize :state
  serialize :cache
  
  def after_initialize
    @observers = []
  end
  
  def kind
    read_attribute(:kind) or write_attribute(:kind, "example")
  end
  
  def before_update
    logger.info "setting state to #{state.to_yaml}"
    write_attribute(:state, state)
    logger.info "setting state to #{cache.to_yaml}"
    write_attribute(:cache, cache)
  end
  
  def object
    @object ||= new_object
  end
  
  def state
    object.state
  end
  
  def cache
    object.cache
  end
  
  def completed?(command)
    case command
    when :rollout
      object.position == object.tasks.length
    when :rollback
      object.position == 0
    end
  end
  
  def rollout
    object.rollout!
  end

  def rollback
    object.rollback!
  end
  
  def add_observer( obj )
    @observers << obj
    object.add_observer( obj )
  end
  
  def observed_by?( obj )
    @observers.include? obj
  end
  
  def task_count
    object.tasks.length
  end
  
  def method_missing(meth, *args)
    if object.respond_to?(meth)
      object.send(meth, *args)
    else
      super(meth, *args)
    end
  end
  
  private
  
  def new_object
    require File.join(RAILS_ROOT, 'lib', 'outback', "#{kind}.rb")
    
    @object = Outback.const_get(kind.classify).create
    
    if s = read_attribute(:state)
      logger.info "Going to update state with #{s.to_yaml}"
      @object.restore_state(s)
    end
    
    if c = read_attribute(:cache)
      logger.info "Going to update cache with #{c.to_yaml}"
      @object.cache = c
    end
          
    @object
  end
end