如何在Ruby on rails上获取验证错误消息？

Question

I'm currently learning Ruby on rails with OpenClassrooms, and they are using that piece of code :

validates :name, presence: {
    message: "Give a name"
}

When I try to create an object without the name, I'm not getting any error. For example :

me = Person.new name:""
me.errors.to_hash
=> {}

With the same example (just not the same classes), OpenClassrooms get an error and I don't know why I don't get any error

Answer 1

Errors are added to an object after validation. When you call new , you're not validating anything, so the object has no errors.

If you try and save it and then check the errors, you will get what you're looking for:

me = Person.new name:""
me.errors.to_hash
=> {}

me = Person.new name:""
me.save
=> false
me.errors.to_hash
=> ActiveModel::Errors...

Answer 2

Call me.validate before checking the error object. You can also call #valid? .

me = Person.new name: ""
me.validate
me.errors.to_hash
=> { ... }

All saving methods call this #validate method internally, such as #save and #save! .