Any success with Sinatra working together with EventMachine WebSockets?

Question

I have been using Sinatra for sometime now and I would like to add some realtime features to my web-app by pushing the data via websockets.

I have successfully used the gem 'em-websocket' on its own, but have not been able to write one ruby file that has a sinatra web server AND a web-socket server.

I've tried spinning the run! or start! methods off in separate threads with no success.

Has anyone gotten this to work?

I want to have them in the same file as I can then share variables between the two servers.

Thanks!

Answer 1

Did not try it, but should not be too hard:

require 'em-websocket'
require 'sinatra/base'
require 'thin'

EM.run do
  class App < Sinatra::Base
    # Sinatra code here
  end

  EM::Websocket.start(:host => '0.0.0.0', :port => 3001) do
    # Websocket code here
  end

  # You could also use Rainbows! instead of Thin.
  # Any EM based Rack handler should do.
  Thin.start App, '0.0.0.0', 3000
end

Also, Cramp has a websocket implementation that works directly with Thin/Rainbows! you might be able to extract, so you won't even need to run the server on another port.

Answer 2

Thanks Konstantin... that worked! I had to tweak your code slightly. I added comments where I changed it.

-poul

require 'rubygems'      # <-- Added this require
require 'em-websocket'
require 'sinatra/base'
require 'thin'

EventMachine.run do     # <-- Changed EM to EventMachine
  class App < Sinatra::Base
      get '/' do
          return "foo"
      end
  end

  EventMachine::WebSocket.start(:host => '0.0.0.0', :port => 8080) do |ws| # <-- Added |ws|
      # Websocket code here
      ws.onopen {
          ws.send "connected!!!!"
      }

      ws.onmessage { |msg|
          puts "got message #{msg}"
      }

      ws.onclose   {
          ws.send "WebSocket closed"
      }

  end

  # You could also use Rainbows! instead of Thin.
  # Any EM based Rack handler should do.
  App.run!({:port => 3000})    # <-- Changed this line from Thin.start to App.run!
end