Ruby-on-rails Rails - 仅在创建时验证

Rails - Validate on Create Only

提问by oprogfrogo

I'm trying to get my custom validation to work on create. But when I do a findthen save, rails treats it as createand runs the custom validation. How do I get the validations to only work when creating a new record on not on the update of a found record?

我正在尝试让我的自定义验证在create. 但是当我执行findthen 时save，rails 将其视为create并运行自定义验证。如何使验证仅在创建新记录时才起作用，而不是在更新已找到的记录时起作用？

回答by Tonys

Try this on your line of validation code:

在您的验证代码行上试试这个：

validate :custom_validation, :on => :create

this specifies to only run the validation on the createaction. Here's the link to the apidocs

这指定仅对操作运行验证create。这是apidocs的链接

回答by Matt

TL;DR; Full example:

TL; 博士; 完整示例：

class MyPerson < ActiveRecord::Base
  validate :age_requirement


  private

  def age_requirement
    unless self.age > 21 
      errors.add(:age, "must be at least 10 characters in length")
    end
  end

end

To have the validator run only if a new object is being created, you can change the 2nd line of the example to: validate :age_requirement, on: :create

要仅在创建新对象时运行验证器，您可以将示例的第二行更改为： validate :age_requirement, on: :create

Only on updates: validate :age_requirement, on: :update

仅在更新： validate :age_requirement, on: :update

Hope that helps the next person!

希望对下一个人有所帮助！