ruby-on-rails - rails 4 : How to cancel save on a "before_save" callback?

Question

我有复杂的模型/表格。我不想重复记录，所以我想合并具有相似属性的记录。如何使用 before_save 回调取消“保存”？这就是我的想法:

class ProductsColor < ActiveRecord::Base


  before_save :check_for_similar_record

  def check_for_similar_record
    if ProductsColor.exist?(color_id: self.color_id, product_id: self.product_id)
      # merge values with existing ProductsColor and stop self from saving
    end
  end

end

Answer 1

为了防止记录被保存，你应该简单地返回 false :

def check_for_similar_record
  if ProductsColor.exists?(color_id: self.color_id, product_id: self.product_id)
    # merge values
    false
  else
    true
  end
end