为什么rails找不到我的扫地机？答案

【问题标题】：Why rails can't find my sweepers?为什么rails找不到我的扫地机？
【发布时间】：2012-04-25 21:50:20
【问题描述】：

我的控制器上有：

class FormulariosController < ApplicationController
    cache_sweeper :campanha_sweeper, :only => [:show]

    # actions
end

我尝试在应用程序中创建一个名为 /sweepers 的目录但没有成功，我尝试在模型内部创建一个 /cache 文件夹（有一个博客以此为例）但没有工作。

我的扫地机是这样的：

class CampanhaSweeper < ActionController::Caching::Sweeper
  observe Campanha

  def after_update(campanha)
    expire_cache_for(campanha)
  end

  private
  def expire_cache_for(campanha)
    expire_page(:controller => 'formularios', :action => 'show')

    ap "Expired cache for formularios#show in formulariosweeper"
  end

结束

我在尝试启动服务器时得到以下信息：

/Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/actionpack-3.0.12/lib/action_controller/caching/sweeping.rb:41:in `const_get': uninitialized constant CampanhaSweeper (NameError)
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/actionpack-3.0.12/lib/action_controller/caching/sweeping.rb:41:in `block in cache_sweeper'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/actionpack-3.0.12/lib/action_controller/caching/sweeping.rb:39:in `each'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/actionpack-3.0.12/lib/action_controller/caching/sweeping.rb:39:in `cache_sweeper'
    from /Users/thiagomassa/Projects-ginga/ginga-campanhas/app/controllers/formularios_controller.rb:2:in `<class:FormulariosController>'
    from /Users/thiagomassa/Projects-ginga/ginga-campanhas/app/controllers/formularios_controller.rb:1:in `<top (required)>'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/engine.rb:138:in `block (2 levels) in eager_load!'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/engine.rb:137:in `each'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/engine.rb:137:in `block in eager_load!'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/engine.rb:135:in `each'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/engine.rb:135:in `eager_load!'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/application.rb:108:in `eager_load!'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/application/finisher.rb:41:in `block in <module:Finisher>'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/initializable.rb:25:in `instance_exec'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/initializable.rb:25:in `run'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/initializable.rb:50:in `block in run_initializers'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/initializable.rb:49:in `each'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/initializable.rb:49:in `run_initializers'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/application.rb:134:in `initialize!'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/application.rb:77:in `method_missing'
    from /Users/thiagomassa/Projects-ginga/ginga-campanhas/config/environment.rb:5:in `<top (required)>'
    from /Users/thiagomassa/Projects-ginga/ginga-campanhas/config.ru:3:in `block in <main>'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/rack-1.2.5/lib/rack/builder.rb:46:in `instance_eval'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/rack-1.2.5/lib/rack/builder.rb:46:in `initialize'
    from /Users/thiagomassa/Projects-ginga/ginga-campanhas/config.ru:1:in `new'
    from /Users/thiagomassa/Projects-ginga/ginga-campanhas/config.ru:1:in `<main>'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/rack-1.2.5/lib/rack/builder.rb:35:in `eval'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/rack-1.2.5/lib/rack/builder.rb:35:in `parse_file'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/rack-1.2.5/lib/rack/server.rb:162:in `app'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/rack-1.2.5/lib/rack/server.rb:253:in `wrapped_app'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/rack-1.2.5/lib/rack/server.rb:204:in `start'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/commands/server.rb:65:in `start'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/commands.rb:30:in `block in <top (required)>'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/commands.rb:27:in `tap'
    from /Users/thiagomassa/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.12/lib/rails/commands.rb:27:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

为什么没有成功？此外，是否有任何方法可以使仅视图（其呈现方式）的缓存过期。我正在动态生成视图，如果我可以使位于views/formularios/a.html.rb 的视图的缓存过期，这将非常有用

如果人们想知道我在做什么，这很简单。我使用表单生成视图，当我想更新该视图（或它的代码）并且我在生产中时，视图由于缓存而没有更新，所以我每次“更新”表单时都必须手动重置它的缓存.

谢谢。

【问题讨论】：

标签： ruby-on-rails ruby-on-rails-3 sweeper

【解决方案1】：

您是否将sweepers 目录（或您放置清扫器代码的位置）添加到application.rb 中的autoload_paths？

【讨论】：

如果application.rb，您应该找到添加到config.autoload_paths 的行。它最终应该看起来像 config.autoload_paths += %W( #{Rails.root}/path/to/sweepers ) 。可能已经有其他自动加载路径。
好的，我做到了，还添加了config.active_record.observers = [:order_sweeper]。我的模型中有cache_sweeper :order_sweeper，当我启动服务器时仍然收到错误uninitialized constant OrderSweeper (NameError)。知道有什么问题吗？
不确定，没有亲眼看到，不幸的是:(它是继承自ActionController::Caching::Sweeper吗？