ruby-on-rails - 如何终止服务器对可操作 channel 的订阅？

Question

有没有办法从服务器端( Controller )终止对任何特定消费者的特定 channel 的订阅，以便可以调用我的 CoffeeScript 文件中的断开连接回调？

Answer 1

http://api.rubyonrails.org/classes/ActionCable/Channel/Base.html#class-ActionCable::Channel::Base-label-Rejecting+subscription+requests

class ChatChannel < ApplicationCable::Channel
  def subscribed
    @room = Chat::Room[params[:room_number]]
    reject unless current_user.can_access?(@room)
  end
end

在调用reject之前，您还可以告知订阅者拒绝的原因:

class ChatChannel < ApplicationCable::Channel
  def subscribed

    if params["answerer"]

      answerer = params["answerer"]

      answerer_user = User.find_by email: answerer

      if answerer_user

        stream_from "chat_#{answerer_user}_channel"    

      else

        connection.transmit identifier: params, error: "The user #{answerer} not found."

  # http://api.rubyonrails.org/classes/ActionCable/Channel/Base.html#class-ActionCable::Channel::Base-label-Rejecting+subscription+requests

        reject

      end

    else

        connection.transmit identifier: params, error: "No params specified."

  # http://api.rubyonrails.org/classes/ActionCable/Channel/Base.html#class-ActionCable::Channel::Base-label-Rejecting+subscription+requests

        reject

    end     

  end
end