如何在 Ruby/Rails 中抽象出与父类类似的验证/关系？

Question

我有这些非常相似的课程：

class DeliveryDocument < CommercialDocument
  # Relations
  belongs_to :biller, :class_name => 'Company'
  belongs_to :customer, :class_name => 'Company'
  belongs_to :customer_center, :class_name => 'Center'
  has_many :delivery_document_lines, :dependent => :destroy
  alias_attribute :lines, :delivery_document_lines
  # Some configuration
  accepts_nested_attributes_for :delivery_document_lines
  acts_as_freezable :only_dependencies => true,
    :has_many => [:delivery_document_lines],
    :belongs_to => [:biller, :customer, :customer_center]
  acts_as_clonable :has_many => [:delivery_document_lines]
  validates_each :lines do |record, attr, value|
    # ...
  end
end

还有：

class InvoiceDocument < CommercialDocument
  self.
  # Relations
  belongs_to :biller, :class_name => 'Company'
  belongs_to :customer, :class_name => 'Company'
  belongs_to :customer_center, :class_name => 'Center'
  has_many :invoice_document_lines, :dependent => :destroy
  alias_attribute :lines, :invoice_document_lines
  # Some configuration
  accepts_nested_attributes_for :invoice_document_lines
  acts_as_freezable :only_dependencies => true,
    :has_many => [:invoice_document_lines],
    :belongs_to => [:biller, :customer, :customer_center]
  acts_as_clonable :has_many => [:invoice_document_lines]
  # Validations
  validates_each :lines do |record, attr, value|
    # ...
  end
end

我还有一些我没有粘贴的方法可以提取到父级。我只需要知道父类中的类名。当我这样做时：

class CommercialDocument < Document  # document inherits from AR::Base
  # ...
  has_many :"#{self.to_s.underscore}_lines", :dependent => :destroy
  # ...
  accepts_nested_attributes_for :"#{self.to_s.underscore}_lines"
  # ...
end

它不起作用，因为self.to_s 是CommercialDocument。

你会如何在父类中重构这种行为？ 我可以将东西放在一个模块中并导入它，但随后整个文档层次结构变得几乎毫无用处。 我已经有了文档的层次结构，所以如果可以的话，如果有办法，我想使用它。

Answer 1

你可以试试Class.inherited