Rails 3.1中是否已取消“def验证”？

Question

Rails 3.1中是否已取消“def validate”？我在Rails 3.1之前，它似乎没有工作

class Category < ActiveRecord::Base
  validates_presence_of :title

  private 

  def validate
    errors.add(:description, "is too short") if (description.size < 200)
  end 
end

“标题”验证有效，但“描述”验证不起作用。

Answer 1

这样的事情对你有用吗？

class Category < ActiveRecord::Base
  validates_presence_of :title
  validate :description_length

  def description_length
    errors.add(:description, "is too short") if (description.size < 200)
  end 
end

Answer 2

class Category < ActiveRecord::Base
  validates_presence_of :title

  private 

  validate do
    errors.add(:description, "is too short") if (description.size < 200)
  end 
end

Answer 3

对于其他类型的验证，您还可以添加“Validators”，如下所示：

http://edgeguides.rubyonrails.org/3_0_release_notes.html#validations

class TitleValidator < ActiveModel::EachValidator
  Titles = ['Mr.', 'Mrs.', 'Dr.']
  def validate_each(record, attribute, value)
    unless Titles.include?(value)
      record.errors[attribute] << 'must be a valid title'
    end
  end
end

class Person
  include ActiveModel::Validations
  attr_accessor :title
  validates :title, :presence => true, :title => true
end

# Or for Active Record

class Person < ActiveRecord::Base
  validates :title, :presence => true, :title => true
end