Hurtig pseudo kode for håndtering af ind- og udgående beskeder fra og til flere forskellige gateways

gateway.rb

module Gateway
  UNWIRE = 'unwire'
  FOO    = 'foo'
  BAR    = 'bar'

  class << self
    def all
      [UNWIRE, FOO, BAR]
    end

    def send_message(message)
      get(message.type).send_message message
    end

    def get(type)
      eval type.to_s.camelcase
    end
  end

  class Base
    # generic methods used by all gateways - maybe not needed
  end

  class Unwire < Base
    # custom or overridden methods for specific gateways

    class << self
      def parse_params(params)
        {
          :type => params[:type]
          'foo' => params['abc']
          'bar' => params['def']
        }
      end

      def send_message(message)
        # do the actial sending specific for this gateway
      end
    end
  end

  # ... other gateways
end

incomming_message.rb

class IncommingMessage < ActiveRecord::Base
  validates_presence_of  :msgid, :message
  validates_inclusion_of :gateway, :in => Gateway.all

  # Attributes:
  #   gateway (e.g. Gateway::UNWIRE)
  #   msgid   (tlf.nummer)
  #   body    (besked)

  class < self
    def create(params, *args)
      super Gateway.get(params[:type]).parse_params(params), *args
    end
  end
end

outgoing_message.rb

class OutgoingMessage < ActiveRecord::Base
  validates_presence_of  :sender, :recipients, :body
  validates_inclusion_of :gateway, :in => Gateway.all

  named_scope :unsend, :conditions => {:send_at => nil}
  named_scope :send,   :conditions => 'send_at IS NOT NULL'

  serialize :recipients

  # Attributes:
  #   gateway (e.g. Gateway::UNWIRE)
  #   sender
  #   recipients
  #   body
  #   send_at

  def send_message
    if valid?
      Gateway.send_message self
    else
      # handle errors
    end
  end
end

outgoing_test.rb

# sending outgoing message
OutgoingMessage.unsend.each &:send_message

unwire_controller.rb

# catching and storing incomming message
class UnwireController < ActionController::Base
  def action
    if IncommingMessage.create(params.merge(:type => Gateway::UNWIRE))
      render :text => "SUCCESS"
    else
      # handle errors
    end
  end
end