ruby-on-rails – 在模型中使用accepts_nested_attributes_for时出现Rails 4.1错误

这个类赋值的代码在rails v4.0.5之前是可以的
但它从rails 4.1.x发出错误

有一个api documentation,所以我猜它没有被弃用.

我不知道这是什么问题.

Loading development environment (Rails 4.1.1)
2.1.1 :001 > class Assignment < ActiveRecord::Base
2.1.1 :002?>     belongs_to :group
2.1.1 :003?>     has_one :event
2.1.1 :004?>     accepts_nested_attributes_for :event
2.1.1 :005?>   end
NameError: undefined local variable or method `generated_feature_methods' for #<Class:0x0000010a262e28>
    from /Users/me/.rvm/gems/ruby-2.1.1@xxx/gems/activerecord-4.1.1/lib/active_record/dynamic_matchers.rb:26:in `method_missing'
    from /Users/me/.rvm/gems/ruby-2.1.1@xxx/gems/protected_attributes-1.0.5/lib/active_record/mass_assignment_security/nested_attributes.rb:30:in `block in accepts_nested_attributes_for'
    from /Users/me/.rvm/gems/ruby-2.1.1@xxx/gems/protected_attributes-1.0.5/lib/active_record/mass_assignment_security/nested_attributes.rb:16:in `each'
    from /Users/me/.rvm/gems/ruby-2.1.1@xxx/gems/protected_attributes-1.0.5/lib/active_record/mass_assignment_security/nested_attributes.rb:16:in `accepts_nested_attributes_for'
    from (irb):4:in `<class:Assignment>'
    from (irb):1
    from /Users/me/.rvm/gems/ruby-2.1.1@xxx/gems/railties-4.1.1/lib/rails/commands/console.rb:90:in `start'
    from /Users/me/.rvm/gems/ruby-2.1.1@xxx/gems/railties-4.1.1/lib/rails/commands/console.rb:9:in `start'
    from /Users/me/.rvm/gems/ruby-2.1.1@xxx/gems/railties-4.1.1/lib/rails/commands/commands_tasks.rb:69:in `console'
    from /Users/me/.rvm/gems/ruby-2.1.1@xxx/gems/railties-4.1.1/lib/rails/commands/commands_tasks.rb:40:in `run_command!'
    from /Users/me/.rvm/gems/ruby-2.1.1@xxx/gems/railties-4.1.1/lib/rails/commands.rb:17:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'

在Rails 4.0.5上没问题

Loading development environment (Rails 4.0.5)
2.1.1 :001 > class Assignment < ActiveRecord::Base
2.1.1 :002?>     belongs_to :group
2.1.1 :003?>     has_one :event
2.1.1 :004?>     accepts_nested_attributes_for :event
2.1.1 :005?>   end
 => [:event]

可能重复 Rails 4.1.0.beta1 upgrade gives me undefined local variable or method generated_feature_methods.就像在那里说的那样,尝试更新protected_attributes gem：

bundle update protected_attributes