rails_streamer.rb

  class Streamer
    def initialize(records, &block)
      @block = nil
      @records = records
      @record_block = block
    end

    def write(bytes)
      @block.call bytes
      bytes.bytesize
    end

    def each(&block)
      @block = block
      stream = Psych::JSON::Stream.new self

      @records.each do |record|
        stream << @record_block.call(record)
      end
    end
  end

  def events
    do_not_cache

    self.response_body = Streamer.new(subscribed_events) do |event|
      event.to_json
    end
  end

gem 'psych'