O'Reilly logo

The Rails™ 3 Way, Second Edition by Obie Fernandez

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Chapter 8. Validations

I have bought this wonderful machine a computer. Now I am rather an authority on gods, so I identified the machine it seems to me to be an Old Testament god with a lot of rules and no mercy.

Joseph Campbell

The Validations API in Active Model, along with its supplementary functionality in Active Record allows you to declaratively define valid states for your model objects. The validation methods hook into the life cycle of an Active Record model object and are able to inspect the object to determine whether certain attributes are set, have values in a given range, or pass any other logical hurdles that you specify.

In this chapter, we’ll describe the validation methods available and how to use them effectively. We’ll ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required