Ruby on rails Can'；t荷载等级|轨道4.2.5

轨道：4.2.5

我使用的是STI，需要获取所有子类

但和在开发环境中一样，rails进行延迟加载。所以

Model.subclass

和

Model.substands

总是返回

[]

谷歌让我看了这期杂志：

上述问题建议将以下解决方案作为初始值设定项：

ActionDispatch::Reloader.to_prepare do
  Rails.application.eager_load!
end

在这一点上，我得到了以下异常：

/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activemodel-4.2.5/lib/active_model/validations/validates.rb:120:in `rescue in block in validates': Unknown validator: 'PersenceValidator' (ArgumentError)
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activemodel-4.2.5/lib/active_model/validations/validates.rb:117:in `block in validates'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activemodel-4.2.5/lib/active_model/validations/validates.rb:113:in `each'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activemodel-4.2.5/lib/active_model/validations/validates.rb:113:in `validates'
    from /Users/vmac1/rails_projects/survd/app/models/sub_service.rb:7:in `<class:SubService>'
    from /Users/vmac1/rails_projects/survd/app/models/sub_service.rb:1:in `<top (required)>'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:457:in `load'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:457:in `block in load_file'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:647:in `new_constants_in'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:456:in `load_file'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:354:in `require_or_load'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:494:in `load_missing_constant'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:184:in `const_missing'
    from /Users/vmac1/rails_projects/survd/app/models/buffet_service.rb:1:in `<top (required)>'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:457:in `load'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:457:in `block in load_file'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:647:in `new_constants_in'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:456:in `load_file'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:354:in `require_or_load'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:317:in `depend_on'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:233:in `require_dependency'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/engine.rb:472:in `block (2 levels) in eager_load!'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/engine.rb:471:in `each'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/engine.rb:471:in `block in eager_load!'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/engine.rb:469:in `each'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/engine.rb:469:in `eager_load!'
    from /Users/vmac1/rails_projects/survd/config/initializers/eagerload_subclasses.rb:2:in `block in <top (required)>'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:446:in `instance_exec'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:446:in `block in make_lambda'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:192:in `call'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:192:in `block in simple'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:504:in `call'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:504:in `block in call'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:504:in `each'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:504:in `call'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:92:in `__run_callbacks__'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:778:in `_run_prepare_callbacks'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:81:in `run_callbacks'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/actionpack-4.2.5/lib/action_dispatch/middleware/reloader.rb:83:in `prepare!'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/actionpack-4.2.5/lib/action_dispatch/middleware/reloader.rb:55:in `prepare!'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/application/finisher.rb:50:in `block in <module:Finisher>'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/initializable.rb:30:in `instance_exec'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/initializable.rb:30:in `run'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/initializable.rb:55:in `block in run_initializers'
    from /Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/tsort.rb:226:in `block in tsort_each'
    from /Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/tsort.rb:348:in `block (2 levels) in each_strongly_connected_component'
    from /Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/tsort.rb:429:in `each_strongly_connected_component_from'
    from /Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/tsort.rb:347:in `block in each_strongly_connected_component'
    from /Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/tsort.rb:345:in `each'
    from /Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/tsort.rb:345:in `call'
    from /Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/tsort.rb:345:in `each_strongly_connected_component'
    from /Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/tsort.rb:224:in `tsort_each'
    from /Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/tsort.rb:203:in `tsort_each'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/initializable.rb:54:in `run_initializers'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/application.rb:352:in `initialize!'
    from /Users/vmac1/rails_projects/survd/config/environment.rb:5:in `<top (required)>'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `block in require'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/spring-1.6.3/lib/spring/application.rb:92:in `preload'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/spring-1.6.3/lib/spring/application.rb:143:in `serve'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/spring-1.6.3/lib/spring/application.rb:131:in `block in run'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/spring-1.6.3/lib/spring/application.rb:125:in `loop'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/spring-1.6.3/lib/spring/application.rb:125:in `run'
    from /Users/vmac1/.rvm/gems/ruby-2.2.3/gems/spring-1.6.3/lib/spring/application/boot.rb:18:in `<top (required)>'
    from /Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from /Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from -e:1:in `<main>'

/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activemodel-4.2.5/lib/active\u model/validations/validates.rb:120:在“验证中的块中救援”：未知验证程序：“PersenceValidator”（ArgumentError）
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activemodel-4.2.5/lib/active_model/validations/validates.rb:117:“块在验证中”
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activemodel-4.2.5/lib/active_model/validations/validates.rb:113:in'each'
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activemodel-4.2.5/lib/active_model/validations/validates.rb:113:in“validates”
from/Users/vmac1/rails_projects/survd/app/models/sub_service.rb:7:in`'
from/Users/vmac1/rails_projects/survd/app/models/sub_service.rb:1:in`'
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:457:in'load'
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/dependencies.rb:457:“加载文件中的块”
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/dependencies.rb:647:in“new\u constants\u in”
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/dependencies.rb:456:“加载文件”中
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/dependencies.rb:354:“需要或加载”中
从/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/dependencies.rb:494:“加载缺少常量”中
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/dependencies.rb:184:in'const\u missing'
from/Users/vmac1/rails_projects/survd/app/models/buffet_service.rb:1:in`'
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:457:in'load'
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/dependencies.rb:457:“加载文件中的块”
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/dependencies.rb:647:in“new\u constants\u in”
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/dependencies.rb:456:“加载文件”中
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/dependencies.rb:354:“需要或加载”中
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u-support/dependencies.rb:317:in'dependent\u'
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_-support/dependencies.rb:233:in“require_-dependencity”
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/engine.rb:472:in`block（2层）in eager_load！'
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/engine.rb:471:in'each'
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/engine.rb:471:in“加载时块中”
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/engine.rb:469:in'each'
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/engine.rb:469:in'eager_load！'
from/Users/vmac1/rails_projects/survd/config/initializers/eangerload_subclass.rb:2:in'block in'
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/callbacks.rb:446:in'instance\u exec'
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/callbacks.rb:446:in`block in make\u lambda'
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_-support/callbacks.rb:192:in'call'
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_-support/callbacks.rb:192:在“简单块”中
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:504:in'call'
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_-support/callbacks.rb:504:in'block in call'
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:504:in'each'
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active_support/callbacks.rb:504:in'call'
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u-support/callbacks.rb:92:在`\u run\u callbacks `中
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u-support/callbacks.rb:778:在“运行\u准备\u回调”中
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/activesupport-4.2.5/lib/active\u support/callbacks.rb:81:in“run\u callbacks”
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/actionpack-4.2.5/lib/action\u dispatch/middleware/reloader.rb:83:in'prepare！'
来自/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/actionpack-4.2.5/lib/action\u dispatch/middleware/reloader.rb:55:in'prepare！'
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/application/finisher.rb:50:in'block in'
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/initializable.rb:30:in'instance_exec'
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/initializable.rb:30:在“运行”中
from/Users/vmac1/.rvm/gems/ruby-2.2.3/gems/railties-4.2.5/lib/rails/initializable.rb:55:“运行中的块初始化器”
from/Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/tsort.rb:226:in'block in tsort_each'
from/Users/vmac1/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/tsort.rb:348:在每个强连接的com中的`块（2个级别）`