ruby-on-rails - 保存验证部分失败的模型

Question

假设我有以下模型:

class Car < ActiveRecord::Base

attr_accessible :wheels,
                :engine_cylinders

validates :wheels, :engine_cylinders, presence: true, numericality: true

end

假设我有以下 Controller 操作:

@car = Car.find(params[:id])
@car.wheels = "foo"
@car.engine_cylinders = 4
@car.save

此保存将失败，因为轮子将无法满足数值条件。

有什么方法可以保留成功的属性(在本例中为 engine_cylinders)，同时将无效的属性添加到错误数组中？例如。 Rails 中有“软”验证吗？

Answer 1

你想写一个 Custom Validator .

class Car < ActiveRecord::Base
  validate :wheel_range,
           :engine_cylinder_range

  def engine_cylinder_range
    flash[:notice] = "engine_cylinder was not saved because it wasn't a number" unless engine_cylinder.is_a? Fixnum
    # set engine_cylinder back to old value
  end

  def wheel_range
    flash[:notice] = "wheels was not saved because it wasn't a number" unless wheels.is_a? Fixnum
    # set wheels back to old value
  end
end

您不必在这里使用flash，您可以使用任何变量进行内部处理或重新显示。

您可能还想对 :before_save hook 进行自定义验证检查.使用 _was magic method获取旧值。