使用 accepts_nested_attributes_for 时验证其他模型的数据

Question

我属于并且有很多关系。

问题是我需要检查嵌套属性的分数字段是否小于 0，它不应该保存记录而不是 return 以形成错误消息。

我正在尝试的代码是：

class QuizAttempt < ActiveRecord::Base

  has_many :quiz_answers
  accepts_nested_attributes_for :quiz_answers, reject_if: :invalid_score

  validate :score_greater_than_zero

  private

  def score_greater_than_zero
    errors.add(:quiz_answers, 'must greater than 0') if invalid_score(attributes)
  end

  def invalid_score(attributes)
    attributes['score'].to_i > 0
  end
end


class QuizAnswer < ActiveRecord::Base
  belongs_to :quiz_attempt
end

表单字段看起来像包含数组的表单字段：

name="quiz_attempt[quiz_answers_attributes][5][score]"

Answer 1

I need to check if score field from nested attributes is less 0

您需要的是访问嵌套对象 (quiz_answers) 并检查它们的属性，而不是 quiz_attempt 的属性：

  def score_greater_than_zero
    if quiz_answers.any? { |answer| answer.score <= 0 }
      errors.add(:quiz_answers, 'must be greater than 0')
    end
  end