You can get the video version of this podcast here.

I've also updated the audio files for episodes 2 & 3 so you can hear them now. Sorry for the trouble.

Ruby on Rails provides some excellent ways to validate the data you save in your models. Validations are methods called within the class definition specifying an attribute to check and what to look for.

class User < ActiveRecord::Base

validates_presence_of :username

end

Validations are called when you call 'save', 'create', or 'valid?'. If there are validation errors, create will return a new but not saved (to the database) version of the object you were creating. 'save' and 'valid?' will return false.

You can get validation errors from the object by calling 'errors'.

I also go over some of the common validations in the podcast.