Validating the User Model

Create validation rules

In this lesson, we will update our model to define validation rules. These rules are described in the template in app/models/user.rb.

Ruby on Rails provides a complete validation mechanism in their official documentation.

For the User model, we only want to validate three things:

1. The email must be unique.
2. The email must have a valid format.
3. The password must be filled in.