javascript - TypeError : App. 电缆未定义

Question

我在计算机上运行 ActionCable 时遇到问题。

在 asset/javascripts/channels 中我有两个文件:

索引.咖啡

#= require action_cable
#= require_self
#= require_tree .

@App = {}
App.cable = ActionCable.createConsumer()

和question.coffee

App.question = App.cable.subscriptions.create "QuestionChannel",
  connected: ->
    # Called when the subscription is ready for use on the server

  disconnected: ->
    # Called when the subscription has been terminated by the server

  received: (data) ->
    # Called when there's incoming data on the websocket for this channel

  follow: ->
    @perform 'follow'

  unfollow: ->
    @perform 'unfollow'

我的 application.js 文件如下所示:

// This is a manifest file that'll be compiled into application.js, which will include all the files
// listed below.
//
// Any JavaScript/Coffee file within this directory, lib/assets/javascripts, vendor/assets/javascripts,
// or vendor/assets/javascripts of plugins, if any, can be referenced here using a relative path.
//
// It's not advisable to add code directly here, but if you do, it'll appear at the bottom of the
// compiled file.
//
// Read Sprockets README (https://github.com/sstephenson/sprockets#sprockets-directives) for details
// about supported directives.
//
//= require jquery
//= require jquery_ujs
//= require bootstrap-sprockets
//= require icheck
//= require homer/scripts
//= require Chart
//= require excanvas
//= require channels
//= require_tree .

当我启动 Cable 服务器和 Rails 服务器并在 Firefox 控制台中访问 localhost:3000 时，我看到两个错误:

SyntaxError: An invalid or illegal string was specified


this.webSocket = new WebSocket(this.consumer.url);

和

TypeError: App.cable is undefined


App.question = App.cable.subscriptions.create("QuestionChannel", {

我使用的是 Rails 5 beta 3。我该如何解决这个问题？

Answer 1

ActionCable.createConsumer 需要一个参数 - Action Cable 服务器的地址。

@App = {}
App.cable = ActionCable.createConsumer("ws://cable.example.com")

如果您错过此参数，则 this.customer.url 未定义。