如何在Rails 3中实现min/max验证器？

Question

在Rails 3中实现min max验证器的rails方式是什么？

我有一个模型,具有min_age和max_age属性.

年龄可以在0..100的范围内,但我也想验证交叉值,我的意思是最大值大于或等于min

{:min_age => 0, :max_age => 0} => true
{:min_age => 0, :max_age => 1} => true
{:min_age => 1, :max_age => 0} => false # max < min
{:min_age => 1, :max_age => 101} => false # out of 0..100 range

Answer 1

查看ActiveModel :: Validations :: NumericalityValidator: RailsAPI NumericalityValidator

规格:

it {
  subject.max_age = 10
  subject.min_age = 20
  subject.should be_invalid
  subject.errors[:min_age].should include("must be less than or equal to #{subject.max_age}")
}

码:

validates :min_age, numericality: { greater_than: 0, less_than_or_equal_to: :max_age }

validates :max_age, numericality: { less_than_or_equal_to: 100 }

我不知道您是否要验证是否存在,但您只需将其添加为验证的另一个关键,例如

validates :max_age, numericality: { less_than_or_equal_to: 100 }, presence: true

Answer 2

您也可以使用包含... in,如:

validates :height, inclusion: { in: 1..3000, message: 'The height must be between 1 and 3000' }

Answer 3

validates_numericality_of :min_age, greater_than: 0
validates_numericality_of :max_age, less_than_or_equal_to: 100
validates_numericality_of :max_age, greater_than: :min_age

您也可以使用年龄,如下所示:

validates_numericality_of :age, less_than_or_equal_to: 100, greater_than: 0