ruby-on-rails - 如何验证多个字段中的一个字段是否存在

Question

我正在回答我自己的问题 - 只是将其放在这里供 google-fu 以防对其他人有所帮助。此代码允许您验证列表中某个字段是否存在。使用方法请参见代码中的注释。只需将其粘贴到 lib/custom_validations.rb 并将 require 'custom_validations' 添加到您的环境中。rb

#good post on how to do stuff like this  http://www.marklunds.com/articles/one/312

module ActiveRecord
  module Validations
    module ClassMethods

      # Use to check for this, that or those was entered... example:
      #  :validates_presence_of_at_least_one_field :last_name, :company_name  - would require either last_name or company_name to be filled in
      #  also works with arrays
      #  :validates_presence_of_at_least_one_field :email, [:name, :address, :city, :state] - would require email or a mailing type address
      def validates_presence_of_at_least_one_field(*attr_names)
        msg = attr_names.collect {|a| a.is_a?(Array) ? " ( #{a.join(", ")} ) " : a.to_s}.join(", ") +
                    "can't all be blank.  At least one field (set) must be filled in."
        configuration = {
          :on => :save,
          :message => msg }
        configuration.update(attr_names.extract_options!)

        send(validation_method(configuration[:on]), configuration) do |record|
          found = false
          attr_names.each do |a|
            a = [a] unless a.is_a?(Array)
            found = true
            a.each do |attr|
              value = record.respond_to?(attr.to_s) ? record.send(attr.to_s) : record[attr.to_s]
              found = !value.blank?
            end
            break if found
          end
          record.errors.add_to_base(configuration[:message]) unless found
        end
      end

    end
  end
end

Answer 1

这在 Rails 3 中对我有用，尽管我只是验证一个或另一个字段是否存在:

validates :last_name, :presence => {unless => Proc.new { |a| a.company_name.present? }, :message => "You must enter a last name, company name, or both"}

如果公司名称为空，则仅验证姓氏是否存在。您只需要其中一个，因为在错误情况下两者都将为空白，因此在 company_name 上也有一个验证器是多余的。唯一烦人的是它在消息之前吐出列名，我使用了 this 中的答案关于人性化属性的问题来解决它(只需将last_name人性化属性设置为“”