Rails Validations on Non-User chosen fields

Question

Is it necessary to create validations in the model for a field that the user does not affect?

By necessary I mean is a best-practice.

I have a before_create filter that sets a user token to a user account. Should I add validations even though I'm (the backend code) the only thing that has power over this field?

Thanks.

Answer 1

I do. It allows me to keep data integrity in my database.

Answer 2

You need to look at the order of Active record callbacks,

The most-up-to-date version of this list for the latest version of Rails can be found in the http://api.rubyonrails.org/classes/ActiveRecord/Callbacks.html . The lists for Rails 3 & 2 are below.

Rails 3

The most up-to-date version of this list can be found in the Rails 3 guides .

Creating an object

• before_validation
• after_validation
• before_save
• around_save
• before_create
• around_create
• after_create
• after_save

In this case as you are setting the value after the validation, the validation error will trigger everytime

Source - What is the order of ActiveRecord callbacks and validations?