Websocket Rails 5 actioncable未定义的方法'fetch'；零级：零级

我正在将Rails 5与

actioncable

一起使用，当我尝试发送任何抛出

actioncable

的东西时，我得到了什么？ 我想把这个项目推给赫罗库

NoMethodError in MessagesController#create

undefined method `fetch' for nil:NilClass
Extracted source (around line #37):

#35       # Also makes sure proper dependencies are required.
#36       def pubsub_adapter
*37         adapter = (cable.fetch('adapter') { 'redis' })
#38         path_to_adapter = "action_cable/subscription_adapter/#{adapter}"
#39         begin
#40           require path_to_adapter

Extracted source (around line #50):

#48       # Adapter used for all streams/broadcasting.
#49       def pubsub
*50         @pubsub ||= config.pubsub_adapter.new(self)
#51       end
#52 
#53       # All the identifiers applied to the connection class associated with this server.

Extracted source (around line #42):

#40           def broadcast(message)
#41             server.logger.info "[ActionCable] Broadcasting to #{broadcasting}: #{message}"
*42             server.pubsub.broadcast broadcasting, ActiveSupport::JSON.encode(message)
#43           end
#44         end
#45     end


Rails.root: /media/adham/Data/code/rails5test

Application Trace
app/controllers/messages_controller.rb:6:in `create'
app/middleware/chat_action_cable.rb:10:in `call'

---

这里有一个承诺：

正在从读取并更改ActionCable的配置文件

config/redis/cable.yml

到

config/cable.yml

---

…解决了这个问题。此更新允许ActionCable后端不可知。

调用

cable.fetch

时，听起来好像

cable

是

nil

。是这样吗？有人能解释为什么会这样吗？在Rails 5.0.0.Beta2中，我也遇到了同样的情况，他们将配置文件更改为更加模糊的ActionCable后端，而不是默认为Redis。