未初始化的常量 > ActionCable::Server::Configuration::ApplicationCable

Posted 2023-02-15

【中文标题】未初始化的常量 > ActionCable::Server::Configuration::ApplicationCable

【英文标题】：uninitialized constant > ActionCable::Server::Configuration::ApplicationCable

【发布时间】：2016-03-27 13:07:18

【问题描述】：

当我运行服务器时，它的抛出错误显示在下面的日志中。我用谷歌搜索了很多，但没有找到背后的原因。有人请给它一些亮光。

宝石文件

source 'https://rubygems.org'

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '>= 5.0.0.beta1', '< 5.1'
# Use sqlite3 as the database for Active Record
gem 'sqlite3'

gem 'active_model_serializers', '~> 0.10.0.rc1'

group :development, :test do
  gem 'byebug'
end
gem 'puma'
group :development do
  gem 'spring'
end

日志：

/home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/configuration.rb:15:in
`initialize': uninitialized constant
ActionCable::Server::Configuration::ApplicationCable (NameError)    from
/home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/base.rb:16:in `new'  from
/home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/base.rb:16:in `block in <class:Base>'    from
/home/pd/.rvm/gems/ruby-2.2.4/gems/activesupport-5.0.0.beta1/lib/active_support/core_ext/module/attribute_accessors.rb:72:in
`block in mattr_reader'     from
/home/pd/.rvm/gems/ruby-2.2.4/gems/activesupport-5.0.0.beta1/lib/active_support/core_ext/module/attribute_accessors.rb:55:in
`each'  from
/home/pd/.rvm/gems/ruby-2.2.4/gems/activesupport-5.0.0.beta1/lib/active_support/core_ext/module/attribute_accessors.rb:55:in
`mattr_reader'  from
/home/pd/.rvm/gems/ruby-2.2.4/gems/activesupport-5.0.0.beta1/lib/active_support/core_ext/module/attribute_accessors.rb:208:in
`mattr_accessor'    from
/home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/base.rb:16:in `<class:Base>'     from
/home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/base.rb:12:in `<module:Server>'  from
/home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/base.rb:7:in
`<module:ActionCable>'  from
/home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/server/base.rb:6:in
`<top (required)>'  from
/home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable.rb:43:in
`server'    from
/home/pd/.rvm/gems/ruby-2.2.4/gems/actioncable-5.0.0.beta1/lib/action_cable/process/logging.rb:10:in
`<top (required)>'  from /home/pd/Documents/EventsApp/config.ru:7:in
`block in <main>'   from
/home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/builder.rb:55:in
`instance_eval'     from
/home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/builder.rb:55:in
`initialize'    from /home/pd/Documents/EventsApp/config.ru:in `new'
    from /home/pd/Documents/EventsApp/config.ru:in `<main>'     from
/home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/builder.rb:49:in
`eval'  from
/home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/builder.rb:49:in
`new_from_string'   from
/home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/builder.rb:40:in
`parse_file'    from
/home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/server.rb:318:in
`build_app_and_options_from_config'     from
/home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/server.rb:218:in
`app'   from
/home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/server.rb:56:in
`app'   from
/home/pd/.rvm/gems/ruby-2.2.4/gems/rack-2.0.0.alpha/lib/rack/server.rb:353:in
`wrapped_app'   from
/home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/server.rb:134:in
`log_to_stdout'     from
/home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/server.rb:74:in
`start'     from
/home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/commands_tasks.rb:90:in
`block in server'   from
/home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/commands_tasks.rb:85:in
`tap'   from
/home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/commands_tasks.rb:85:in
`server'    from
/home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands/commands_tasks.rb:49:in
`run_command!'  from
/home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/command.rb:20:in
`run'   from
/home/pd/.rvm/gems/ruby-2.2.4/gems/railties-5.0.0.beta1/lib/rails/commands.rb:19:in
`<top (required)>'  from /home/pd/Documents/EventsApp/bin/rails:9:in
`require'   from /home/pd/Documents/EventsApp/bin/rails:9:in `<top
(required)>'    from
/home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/lib/spring/client/rails.rb:28:in
`load'  from
/home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/lib/spring/client/rails.rb:28:in
`call'  from
/home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/lib/spring/client/command.rb:7:in
`call'  from
/home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/lib/spring/client.rb:28:in
`run'   from
/home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/bin/spring:51:in `<top
(required)>'    from
/home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/lib/spring/binstub.rb:11:in
`load'  from
/home/pd/.rvm/gems/ruby-2.2.4/gems/spring-1.6.0/lib/spring/binstub.rb:11:in
`<top (required)>'  from /home/pd/Documents/EventsApp/bin/spring:13:in
`require'   from /home/pd/Documents/EventsApp/bin/spring:13:in `<top
(required)>'    from bin/rails:3:in `load'  from bin/rails:3:in `<main>'

【问题讨论】：

我在尝试使用路由 'mount ActionCable.server => '/cable'' 挂载它时遇到了这个问题

@MacTeo 看看我下面的回答，应该能解决你的问题。

【参考方案1】：

该错误与您的项目中没有正确的 ActionCable 文件有关。你需要像这样的app/channels/application_cable/channel.rb

module ApplicationCable
  class Channel < ActionCable::Channel::Base
  end
end

和app/channels/application_cable/connection.rb

module ApplicationCable
  class Connection < ActionCable::Connection::Base
  end
end

【讨论】：

这也解决了我的问题。我将 4.x.x 项目升级到 5.x.x 以使用动作电缆，这是在遵循新 5.x.x 项目的早期教程时缺少的项目之一。

【参考方案2】：

如果您从以前的版本升级（当 actioncable 不在捆绑包中时），请检查 config/application.rb 是否包含

require "action_cable/engine"

【参考方案3】：

我在尝试将 ActionCable 与 Rails 4.2.5 一起使用时遇到了同样的问题，解决方案是将以下内容添加到 config/application.rb：

config.autoload_paths += %W(#config.root/app/channels)

这是 ActionCable gem：

gem 'actioncable', github: 'rails/actioncable', branch: 'archive'

【参考方案4】：

根据昨天的DHH's video tutorial，Spring 和 ActionCable 依赖之间存在问题，因此在 Rails 5 的最终版本之前，您需要使用 --skip-spring 选项重新创建您的项目。

【讨论】：

感谢您的回复，但这不起作用。同样的错误。

只是一个健全的检查：你是否在从 Gemfile 中删除 bundle 后运行它？ :-)

从 gemfile 中删除 Spring 不起作用，但是在新的 rails 应用程序中 --skip-spring 之后它工作正常。

这不是正确的答案，因为 spring 与这个问题无关。错误是由于缺少ApplicationCable 模块而引发的。弹簧问题是与赛璐珞不可重新加载有关的完全不同的问题（因此不适用于弹簧）。 --skip-spring 接缝处理空白项目的原因是 b/c 我在下面建议的文件已经存在。 -1

@PardeepDhingra 看看我下面的回答，应该可以解决你的问题。

【参考方案5】：

我还通过添加以下内容来解决 Heroku 部署的问题：

require "action_cable/engine"

在config/application.rb