Redis Pubsub Subscriber Class

gistfile1.txt

# Public: Subscriber class for digesting conn messages
#
# channel - Channel to subscribe to
# block   - Block for digesting message (opt)
#
# Examples
#
#   # With a block!
#   Subscriber.new("test").start
#   #=> "Subscribed to #test"
#   #=> "#test: Hello World"
#
#   # With a block!
#   r = Subscriber.new("test") do |channel, msg|
#     puts "Block Msg from ##{channel}: #{msg}"
#   end
#   r.start
#   #=> "Subscribed to #test"
#   #=> "Msg from #test: Hello World"
class Subscriber

  def conn
    @conn ||= RDB.conn
  end

  def initialize(channel, &block)
    @channel = channel
    @block   = block if block_given?
  end

  def start
    conn.subscribe(@channel) do |on|
      on.subscribe do |channel, subscriptions|
        puts "Subscribed to ##{channel}"
      end

      on.message do |channel, message|
        if message == "exit"
          conn.unsubscribe
        else
          unless @block && @block[channel, message]
            puts "##{channel}: #{message}"
          end
        end
      end

      on.unsubscribe do |channel, subscriptions|
        puts "Unsubscribed from ##{channel}"
      end
    end
  end
end