WebSockets in Ruby

WebSockets in Ruby can be implemented using various libraries and frameworks. One popular library is `faye-websocket`, which provides a simple API for working with WebSockets in Ruby.

To get started, you'll need to install the `faye-websocket` gem:

gem install faye-websocket

Once installed, you can use the library to create a WebSocket server or client. Here's an example of how to create a WebSocket server using `faye-websocket`:

require 'faye/websocket'
require 'eventmachine'

EM.run {
  class MyWebSocketServer
    def initialize
      @clients = []
    end

    def call(env)
      if Faye::WebSocket.websocket?(env)
        ws = Faye::WebSocket.new(env)

        ws.on :open do |event|
          @clients << ws
        end

        ws.on :message do |event|
          @clients.each { |client| client.send(event.data) }
        end

        ws.on :close do |event|
          @clients.delete(ws)
          ws = nil
        end

        # Return async Rack response
        ws.rack_response
      else
        # Handle non-WebSocket requests
        [200, { 'Content-Type' => 'text/plain' }, ['Hello']]
      end
    end
  end

  # Start the WebSocket server
  App = MyWebSocketServer.new
  Rack::Handler::Thin.run(App, Port: 8080)
}

In this example, we create a WebSocket server using the `faye-websocket` library and the `EventMachine` event loop. The server listens on port 8080 and broadcasts any received messages to all connected clients.

You can also create WebSocket clients using `faye-websocket`. Here's an example of how to create a WebSocket client:

require 'faye/websocket'
require 'eventmachine'

EM.run {
  ws = Faye::WebSocket::Client.new('ws://localhost:8080')

  ws.on :open do |event|
    puts 'Connected to server'
    ws.send('Hello server!')
  end

  ws.on :message do |event|
    puts "Received message: #{event.data}"
  end

  ws.on :close do |event|
    puts 'Disconnected from server'
    EM.stop
  end
}

In this example, we create a WebSocket client using the `faye-websocket` library and the `EventMachine` event loop. The client connects to a WebSocket server running at `ws://localhost:8080`, sends a message, and prints any received messages.

These examples should give you a basic understanding of how to use WebSockets in Ruby using the `faye-websocket` library. However, there are also other libraries available, such as `websocket-eventmachine-server` and `em-websocket`, which you can explore based on your specific requirements.