Virtus
This is a partial extraction of the DataMapper Property API with various modifications. My goal is to provide a common API to define attributes on a model along with (auto-)validations so all ORMs/ODMs could use it instead of reinventing the wheel all over again. It would be also suitable for any other usecase where you need to extend your ruby objects with various attributes that require typecasting and/or validations.
Installation
gem i virtus
Basic Usage
require 'virtus'
class User
include Virtus
attribute :name, String
attribute :age, Integer
attribute :birthday, DateTime
end
# setting attributes in the constructor
user = User.new(:age => 28)
# attribute readers
user.name # => "Piotr"
# hash of attributes
user.attributes # => { :name => "Piotr" }
# automatic typecasting
user.age = '28'
user.age # => 28
user.birthday = 'November 18th, 1983'
user.birthday # => #<DateTime: 1983-11-18T00:00:00+00:00 (4891313/2,0/1,2299161)>
Custom Attributes
require 'virtus'
require 'json'
module MyApp
module Attributes
class JSON < Virtus::Attributes::Object
primitive Hash
def typecast(value, model = nil)
::JSON.parse(value)
end
end
end
class User
include Virtus
attribute :info, Attributes::JSON
end
end
user = MyApp::User.new
user.info = '{"email" : "[email protected]" }'
user.info # => {"email"=>"[email protected]"}
Note on Patches/Pull Requests
- Fork the project.
- Make your feature addition or bug fix.
- Add tests for it. This is important so I don't break it in a future version unintentionally.
- Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
- Send me a pull request. Bonus points for topic branches.
Copyright
Copyright (c) 2011 Piotr Solnica. See LICENSE for details.