cjohansen / acts_as_prototype

A Rails plugin that adds a prototype and a property list to ActiveRecord objects (prototypes can be chained)

acts_as_prototype¶ ↑

Acts as prototype allows any ActiveRecord based model object to be annotated with arbitrary properties. The object is given a prototype object, and through this it can be a part of a prototype chain, allowing a cascading property system which works much like JavaScripts objects and properties.

Installation¶ ↑

ruby script/plugin install git://github.com/cjohansen/acts_as_prototype.git

Setup database¶ ↑

ruby script/generate property_migration
rake db:migrate

Usage¶ ↑

Properties can be set and read from the global scope like a normal model:

prop = Property.set("logo_url", "/images/rails.png")
prop.save

Any object that should be configurable with properties should simply do this:

class Account < ActiveRecord::Base
  acts_as_prototype
end

Now you can get properties through an instance of MyModel:

account = Account.find 1
account.properties[:logo_url] #=> "/images/rails.png"

Override settings:

account.properties[:logo_url] = "/images/my_logo.png"
account.save # Causes properties to be saved also

Set new properties for single objects (ActiveRecord objects are stored by reference):

account.properties[:profile] = Profile.find(2)

You can generate new ActiveRecord objects which share properties with another object:

class Project < ActiveRecord::Base
  acts_as_prototype
end

project = account.beget(Project, { :name => "New project" })
project #=> New project object which shares properties with account

project.properties[:logo_url] = "/images/my_project.png"
account.properties[:logo_url] #=> "/images/my_logo.png"

Updating the original objects properties will reflect on the begotten objects as long as they haven’t overridden properties:

project.properties[:profile] #=> #<Profile id: 2...>
account.properties[:profile] = Profile.find(3)
project.properties[:profile] #=> #<Profile id: 3...>

Copyright © 2008 Christian Johansen, released under the MIT license