Depot Sample in Rails 2.0, Step 3

Objective: To add validation for product input

1. add validation for product

class Product < ActiveRecord::Base
	  
	  validates_presence_of :title, :description, :image_url
	  
	  validates_numericality_of :price
	  
	  validate :price_must_be_at_least_a_cent


	  validates_uniqueness_of :title


	  validates_format_of :image_url,
	                      :with    => %r{\.(gif|jpg|png)$}i,
	                      :message => 'must be a URL for GIF, JPG ' + 'or PNG image.(gif|jpg|png)'

	  protected 
	  def price_must_be_at_least_a_cent
	    errors.add(:price, 'should be at least 0.01') if price.nil? ||
	                       price < 0.01
	  end
	end

2. That is it?!  That is it!!! Just try it, you even do not need to restart server!   ,my dear J2EE...