em-eventsource with the basic example of sinatra

source.rb

require "em-eventsource"

EM.run do
  source = EventMachine::EventSource.new("http://localhost:4567/stream", {}, {'Accept' => 'text/event-stream'})

  source.open do
    puts "opened"
  end

  source.error do |error|
    puts "error #{error}"
  end

  source.message do |message|
    puts "new message #{message}"
  end
  source.start # Start listening
end