timestamped_booleans

= Timestamped Booleans

== Introduction

Sometimes you have an attribute on a model that stores a time stamp in the database, because sometimes you want to know when an event happens. But mostly what you want to know is whether it has actually happened at all or not. This plugin gives us an easy way to specify that, rather than having to explicitly write methods to implement the boolean methods on top of the datetime attribute methods.

Tested to work with Rails 2.3

== Example

Let's say I have a Book model which records when a book has been published in the published_at field. But for the most part, I'm just interested in whether the book has been published already or not. We can set up the time stamped boolean in the model as follows:

class Book < ActiveRecord::Base
  timestamped_boolean :published_at
end

Now, in addition to the published_at and published_at= methods to manipulate the attribute, we have published? and published= which treats the field as a boolean. Let's see how that works:

irb(main):001:0> b = Book.new
=> #<Book id: nil, published_at: nil, created_at: nil, updated_at: nil>
irb(main):002:0> b.published?
=> false
irb(main):003:0> b.published = true
=> true
irb(main):004:0> b.published?
=> true
irb(main):005:0> b.published_at
=> Thu, 10 Apr 2008 08:06:43 IST +01:00
irb(main):006:0> b.published = false
=> false
irb(main):007:0> b.published_at
=> nil
irb(main):008:0> b.published?
=> false

== TODO

• Parameterize the value we set so that it isn't necessarily +Time.now+. I suspect some people will want to specify a different value, probably as a lambda. However, I don't need that functionality yet. :-)

Copyright (c) 2008-2009 Rubaidh Ltd, released under the MIT license