从Sinatra路由访问EventMachine通道

Question

我有一个简单的Sinatra应用程序运行在EventMachine上，就像这个例子。

应用程序正在工作，现在我想允许我在Sinatra中定义的路由使用创建的EventMachine通道访问websocket。我天真地尝试了以下方法，但当然在Sinatra应用程序中，@channel变量没有定义，所以这不起作用。

require 'em-websocket'
require 'sinatra'
EventMachine.run do
  @channel = EM::Channel.new
  class App < Sinatra::Base
    get '/' do
      erb :index
    end
    post '/test' do
      @channel.push "Post request hit endpoint"
      status 200
    end
  end

  EventMachine::WebSocket.start :host => '0.0.0.0', :port => 8080 do |socket|
    socket.onopen do
      sid = @channel.subscribe { |msg| socket.send msg }
      @channel.push "Subscriber ID #{sid} connected!"
      socket.onmessage do |msg|
        @channel.push "Subscriber <#{sid}> sent message: #{msg}"
      end
      socket.onclose do
        @channel.unsubscribe(sid)
      end
    end
  end
  App.run! :port => 3000
end

我怎样才能访问我在Sinatra应用程序中打开的EventMachine通道?

Answer 1

如果其他人不知道我们在评论中谈论的是什么，这里有一个使用类实例变量的例子，我建议的方式。这可以运行，但我不知道它是否符合预期:

require 'em-websocket'
require 'sinatra'
require 'haml'
module Example
  def self.em_channel
    @em_channel ||= EM::Channel.new
  end
  EventMachine.run do
    class App < Sinatra::Base
      configure do
        enable :inline_templates
      end
      get '/' do
        haml :index
      end
      get '/test' do
        Example.em_channel.push "Test request hit endpoint"
        status 200
      end
    end

    EventMachine::WebSocket.start :host => '0.0.0.0', :port => 8080 do |socket|
      socket.onopen do
        sid = Example.em_channel.subscribe { |msg| socket.send msg }
        Example.em_channel.push "Subscriber ID #{sid} connected!"
        socket.onmessage do |msg|
          Example.em_channel.push "Subscriber <#{sid}> sent message: #{msg}"
        end
        socket.onclose do
          Example.em_channel.unsubscribe(sid)
        end
      end
    end
    App.run!
  end
end
__END__
@@ layout
%html
  = yield
@@ index
%div.title Hello world.