---
title: 'Ruby Science: Improving Callbacks and Validations'
teaser:
tags: web,ruby,rails
author: Joe Ferris
published_on: 2013-01-18
---

We have three new chapters to announce this week in Ruby Science. If you're
already reading Ruby Science, make sure to log into GitHub and download the
latest version.

Here's what's new:

### Code smells

* Callback

### Solutions

* Extract Validator
* Replace Callback with Method

The book is a work in progress, and currently contains around 76 pages of
content. Purchasing the book also gets you access to the companion example
application, as well as the ability to send thoughtbot your toughest Ruby,
Rails, and refactoring questions.

If you haven't already purchased it, you can still get access for the early
purchase price of $39. In less than two weeks, the price will increase to $49.

[Download a free sample of Ruby Science today.](http://rubyscience.com?utm_source=giantrobots&utm_medium=blog&utm_campaign=newchapters)