ruby-on-rails - 如何加载不直接从 Rails 5 中的 Rails 验证器类继承的自定义验证器？

Question

我正在为我一直从事的 Rails 5 项目编写一些自定义验证程序。例如:

class EmailValidator < ActiveModel::EachValidator
  def validate_each(record, attribute, value)
    if value.present? && !/\A[^\p{Z}]+@[^\p{Z}]+\.[^\p{Z}]+\z/.match?(value)
      record.errors.add(attribute, "must be an email")
    end
  end
end

这种方法效果很好，但我的许多自定义验证器都在类似地检查正则表达式匹配，所以我决定创建一个抽象的 RegexValidator 类:

class RegexValidator < ActiveModel::EachValidator
  self.abstract_class = true

  def regex
    raise "Children of this class must implement the 'regex' method."
  end

  def message(record, attribute, value)
    raise "Children of this class must implement the 'message(record, attribute, value)' method."
  end

  def validate_each(record, attribute, value)
    if value.present? && !regex.match?(value)
      record.errors.add(attribute, message(record, attribute, value))
    end
  end
end

所以现在 EmailValidator 是这样实现的:

class EmailValidator < RegexValidator
  def regex
    /\A[^\p{Z}]+@[^\p{Z}]+\.[^\p{Z}]+\z/
  end

  def message(record, attribute, value)
    "must be an email"
  end
end

但是，由于此更改 Rails 5 不再自动加载我的 EmailValidator，即使 RegexValidator 和 EmailValidator 都放在适当命名的文件中，regex_validator.rb 和 email_validator.rb，在之前自动加载的 app/validators 文件夹中(这使得这个问题不同于 similar question ).我怀疑这是因为 EmailValidator 不再直接继承自 ActiveModel::EachValidator，但这应该无关紧要。

供引用，我尝试生成迁移文件时出现了以下错误:

/var/lib/gems/2.5.0/gems/activemodel-5.2.2/lib/active_model/validations/validates.rb:121:in `rescue in block in validates': Unknown validator: 'EmailValidator' (ArgumentError)
        from /var/lib/gems/2.5.0/gems/activemodel-5.2.2/lib/active_model/validations/validates.rb:118:in `block in validates'
        from /var/lib/gems/2.5.0/gems/activemodel-5.2.2/lib/active_model/validations/validates.rb:114:in `each'
        from /var/lib/gems/2.5.0/gems/activemodel-5.2.2/lib/active_model/validations/validates.rb:114:in `validates'
        from /home/tomeraberbach/Desktop/msf/src/app/models/user.rb:7:in `<class:User>'
        from /home/tomeraberbach/Desktop/msf/src/app/models/user.rb:4:in `<main>'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:50:in `load'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:50:in `load'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:476:in `block in load_file'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:661:in `new_constants_in'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:475:in `load_file'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:373:in `block in require_or_load'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:37:in `block in load_interlock'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies/interlock.rb:14:in `block in loading'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/concurrency/share_lock.rb:151:in `exclusive'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies/interlock.rb:13:in `loading'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:37:in `load_interlock'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:356:in `require_or_load'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/active_support.rb:46:in `block in require_or_load'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/active_support.rb:16:in `allow_bootsnap_retry'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/active_support.rb:45:in `require_or_load'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:510:in `load_missing_constant'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/active_support.rb:58:in `block in load_missing_constant'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/active_support.rb:16:in `allow_bootsnap_retry'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/active_support.rb:57:in `load_missing_constant'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:195:in `const_missing'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/inflector/methods.rb:283:in `const_get'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/inflector/methods.rb:283:in `block in constantize'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/inflector/methods.rb:281:in `each'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/inflector/methods.rb:281:in `inject'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/inflector/methods.rb:281:in `constantize'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:582:in `get'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:613:in `constantize'
        from /var/lib/gems/2.5.0/gems/devise-4.5.0/lib/devise.rb:316:in `get'
        from /var/lib/gems/2.5.0/gems/devise-4.5.0/lib/devise/mapping.rb:83:in `to'
        from /var/lib/gems/2.5.0/gems/devise-4.5.0/lib/devise/mapping.rb:78:in `modules'
        from /var/lib/gems/2.5.0/gems/devise-4.5.0/lib/devise/mapping.rb:95:in `routes'
        from /var/lib/gems/2.5.0/gems/devise-4.5.0/lib/devise/mapping.rb:162:in `default_used_route'
        from /var/lib/gems/2.5.0/gems/devise-4.5.0/lib/devise/mapping.rb:72:in `initialize'
        from /var/lib/gems/2.5.0/gems/devise-4.5.0/lib/devise.rb:346:in `new'
        from /var/lib/gems/2.5.0/gems/devise-4.5.0/lib/devise.rb:346:in `add_mapping'
        from /var/lib/gems/2.5.0/gems/devise-4.5.0/lib/devise/rails/routes.rb:243:in `block in devise_for'
        from /var/lib/gems/2.5.0/gems/devise-4.5.0/lib/devise/rails/routes.rb:242:in `each'
        from /var/lib/gems/2.5.0/gems/devise-4.5.0/lib/devise/rails/routes.rb:242:in `devise_for'
        from /home/tomeraberbach/Desktop/msf/src/config/routes.rb:3:in `block (2 levels) in <main>'
        from /var/lib/gems/2.5.0/gems/actionpack-5.2.2/lib/action_dispatch/routing/mapper.rb:879:in `scope'
        from /home/tomeraberbach/Desktop/msf/src/config/routes.rb:2:in `block in <main>'
        from /var/lib/gems/2.5.0/gems/actionpack-5.2.2/lib/action_dispatch/routing/route_set.rb:432:in `instance_exec'
        from /var/lib/gems/2.5.0/gems/actionpack-5.2.2/lib/action_dispatch/routing/route_set.rb:432:in `eval_block'
        from /var/lib/gems/2.5.0/gems/actionpack-5.2.2/lib/action_dispatch/routing/route_set.rb:414:in `draw'
        from /home/tomeraberbach/Desktop/msf/src/config/routes.rb:1:in `<main>'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:50:in `load'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:50:in `load'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:285:in `block in load'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:257:in `load_dependency'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:285:in `load'
        from /var/lib/gems/2.5.0/gems/railties-5.2.2/lib/rails/application/routes_reloader.rb:41:in `block in load_paths'
        from /var/lib/gems/2.5.0/gems/railties-5.2.2/lib/rails/application/routes_reloader.rb:41:in `each'
        from /var/lib/gems/2.5.0/gems/railties-5.2.2/lib/rails/application/routes_reloader.rb:41:in `load_paths'
        from /var/lib/gems/2.5.0/gems/railties-5.2.2/lib/rails/application/routes_reloader.rb:20:in `reload!'
        from /var/lib/gems/2.5.0/gems/railties-5.2.2/lib/rails/application/routes_reloader.rb:30:in `block in updater'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/file_update_checker.rb:83:in `execute'
        from /var/lib/gems/2.5.0/gems/railties-5.2.2/lib/rails/application/routes_reloader.rb:10:in `execute'                                                      
        from /var/lib/gems/2.5.0/gems/railties-5.2.2/lib/rails/application/finisher.rb:130:in `block in <module:Finisher>'
        from /var/lib/gems/2.5.0/gems/railties-5.2.2/lib/rails/initializable.rb:32:in `instance_exec'
        from /var/lib/gems/2.5.0/gems/railties-5.2.2/lib/rails/initializable.rb:32:in `run'
        from /var/lib/gems/2.5.0/gems/railties-5.2.2/lib/rails/initializable.rb:61:in `block in run_initializers'
        from /usr/lib/ruby/2.5.0/tsort.rb:228:in `block in tsort_each'
        from /usr/lib/ruby/2.5.0/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
        from /usr/lib/ruby/2.5.0/tsort.rb:431:in `each_strongly_connected_component_from'
        from /usr/lib/ruby/2.5.0/tsort.rb:349:in `block in each_strongly_connected_component'
        from /usr/lib/ruby/2.5.0/tsort.rb:347:in `each'
        from /usr/lib/ruby/2.5.0/tsort.rb:347:in `call'
        from /usr/lib/ruby/2.5.0/tsort.rb:347:in `each_strongly_connected_component'
        from /usr/lib/ruby/2.5.0/tsort.rb:226:in `tsort_each'
        from /usr/lib/ruby/2.5.0/tsort.rb:205:in `tsort_each'
        from /var/lib/gems/2.5.0/gems/railties-5.2.2/lib/rails/initializable.rb:60:in `run_initializers'
        from /var/lib/gems/2.5.0/gems/railties-5.2.2/lib/rails/application.rb:361:in `initialize!'
        from /home/tomeraberbach/Desktop/msf/src/config/environment.rb:5:in `<main>'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:21:in `require'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:21:in `block in require_with_bootsnap_lfi'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/loaded_features_index.rb:65:in `register'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:20:in `require_with_bootsnap_lfi'
        from /var/lib/gems/2.5.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:29:in `require'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:291:in `block in require'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:257:in `load_dependency'
        from /var/lib/gems/2.5.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:291:in `require'
        from /var/lib/gems/2.5.0/gems/spring-2.0.2/lib/spring/application.rb:102:in `preload'
        from /var/lib/gems/2.5.0/gems/spring-2.0.2/lib/spring/application.rb:153:in `serve'
        from /var/lib/gems/2.5.0/gems/spring-2.0.2/lib/spring/application.rb:141:in `block in run'
        from /var/lib/gems/2.5.0/gems/spring-2.0.2/lib/spring/application.rb:135:in `loop'
        from /var/lib/gems/2.5.0/gems/spring-2.0.2/lib/spring/application.rb:135:in `run'
        from /var/lib/gems/2.5.0/gems/spring-2.0.2/lib/spring/application/boot.rb:19:in `<top (required)>'
        from /usr/local/lib/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require'
        from /usr/local/lib/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require'
        from -e:1:in `<main>'

我的用户类:

##
# A class representing a user account for this web application
# Instances of this class represent rows in the +users+ table on the database.
class User < ApplicationRecord
  # Validation
  validates_presence_of :email, :encrypted_password
  validates :email, email: true

  # Associations
  devise :database_authenticatable, :registerable, :recoverable,
         :rememberable, :trackable, :validatable
  has_and_belongs_to_many :roles

  # Events
  before_validation do
    # Removes unnecessary whitespace
    self.email = email.strip
  end
end

有什么想法吗？

Answer 1

我发现了问题。 RegexValidator 中的 self.abstract_class = true 行默默地引发错误，因为类中没有 self.abstract_class 方法。我以为是因为我在 ApplicationRecord 类中看到它，但我现在意识到这是在 ActiveRecord::Base 类中定义的。

我通过将 require_relative "../validators/email_validator" 添加到 user.rb 文件的顶部来确定这一点。这样做之后，我能够看到之前没有提示的错误:

/home/tomeraberbach/Desktop/msf/src/app/validators/regex_validator.rb:4:in `<class:RegexValidator>': undefined method `abstract_class=' for RegexValidator:Class (NoMethodError)

删除 self.abstract_class = true 行和 require_relative "../validators/email_validator" 行后，问题就解决了。