acts_as_state_machine is a great plugin really useful when you want to add constraints and behavior to your model objects.
Note : Those who don’t know what this plugin is all about should stop reading right there or risk being completely lost.
One thing that seems impossible to do with the plugin is to have variable “initial states” [...]

I used to be a fan of the has_finder gem written by Nick Kallen.
Now with Rails 2.1, this functionnality is built-in so you don’t need to install the gem.
The named_scope method allows you to add finders to any model. A code snippet is worth 10000 words :
class Story < ActiveRecord::Base
named_scope :hilarious, :conditions => [...]

It’s been a while since the last edition of Rubyize this. I have waited all this time because I like when people become impatient. I have received 254 939 emails from desperate people asking me : “When will you post your 5th edition?”, “Is it hard to be that excellent?”, “You rock Frank. Warm kisses… [...]