Question

我正在回答我自己的问题 - 只是把它放在谷歌这里，以防它帮助其他人。此代码允许您验证列表中是否存在一个字段。请参阅代码中的注释以了解用法只需将其粘贴到lib / custom_validations.rb中，然后将“custom_validations”添加到您的environment.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，虽然我只是在验证是否存在一个或另一个字段：

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last_name的存在。您只需要一个，因为在错误条件下两者都是空白的，因此在company_name上有一个验证器也是多余的。唯一令人烦恼的是它在消息之前吐出了列名，我使用了this关于人化属性的问题的答案来绕过它（只是将last_name humanized属性设置为“”

如何验证来自许多领域的一个领域的存在

1 个答案: