Question

我正在学习Michael Hartl的Ruby on Rails教程，并且我一直在考验。这是我在控制台中的测试：

root@sample_app# rails console
Loading development environment (Rails 4.2.0)
user = User.new(name: "", email: "mhartl@example.com")
#=> #<User id: nil, name: "", email: "mhartl@example.com", created_at: nil, updated_at: nil>
user.valid?
#=> true

user = User.new(name: "Example User", email: "mhartl@example.com")
#=> #<User id: nil, name: "Example User", email: "mhartl@example.com", created_at: nil, updated_at: nil>
user.valid?
#=> true

无论名称是什么，user.valid?始终返回true。有谁知道为什么？

Answer 1

除非你告诉它需要应用一些验证，否则它会假设有一个空名称是正确的。

此示例的验证示例如下：

validates :name, presence: true, allow_blank: false

您可以阅读有关验证here

的信息

Answer 2

原因是：在rails控制台中，我需要输入验证。

root@sample_app# rails console --sandbox
Loading development environment in sandbox (Rails 4.2.0)
Any modifications you make will be rolled back on exit

>> class User < ActiveRecord::Base
>>   validates(:name, presence: true)
>> end
=> {:presence=>true}
>> user = User.new(name: "", email: "mhartl@example.com")
=> #<User id: nil, name: "", email: "mhartl@example.com", created_at: nil, updated_at: nil>
>> user.valid?
=> false

>> user = User.new(name: "Example User", email: "mhartl@example.com")
=> #<User id: nil, name: "Example User", email: "mhartl@example.com", created_at: nil, updated_at: nil>
>> user.valid?
=> true
>>

期望`有效？`返回`false`，但总是得到'true`

2 个答案: