require "em-eventsource"
EM.run do
  source = EventMachine::EventSource.new("https://example.com/streaming")
  source.message do |message|
    puts "new message #{message}"
  end
  source.start # Start listening
end

source.on "eventname" do |message|
  puts "eventname #{message}"
end

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

source.open do
  puts "opened"
end

source.close

# Can be:
# - EM::EventSource::CLOSED
# - EM::EventSource::CONNECTING
# - EM::EventSource::OPEN
source.ready_state

source.retry = 5 # in seconds (default 3)

source.last_event_id

source.use EM::Middleware::JSONResponse

source.inactivity_timeout = 120 # in seconds (default: 60).