hoangnghiem / rating_for

A context-based rating gem for Rails

rating_for

A context-based rating gem for Rails

This gem allows you to add multiple different rating criteria to your ActiveRecord based model. It provides column-caching, a polymorphic association for raters and works with both Rails 2 and 3.

It's a pure model gem and does not provide any view methods. Prototype, jQuery and company provide all excellent methods and plugins for this.

Installation

Rails 2:

Not supported anymore.

Rails 3:

Add the gem to your Gemfile:

gem 'rating_for'

Generate the migration to create the tables and run it:

rails g rating_for:migration
rake db:migrate

Example

Let's say you want to rate hotels by different criteria, like room service or quality. Then your model hotel.rb should look like this:

class Hotel < ActiveRecord::Base
  rating_for :room_service
  rating_for :quality
end

You can add ratings like this:

four_seasons = Hotel.find_by_name("Four Seasons")
four_seasons.rating_for_quality.add(10)
four_seasons.rating_for_room_service.add(9)

rating = Rating.new(:value => 7)
marriott = Hotel.find_by_name('Marriott')
marriott.rating_for_room_service << rating

You can also assign raters to your ratings, e.g. customers

class Customer < ActiveRecord::Base
end

or newspapers

class Newspaper < ActiveRecord::Base
end

by simply adding them to your rating:

a_customer = Customer.find(1)
nytimes = Newspaper.find_by_name("New York Times")

four_seasons.rating_for_quality.add(10, a_customer)
marriott.rating_for_room_service << Rating.new(:rater => nytimes, :value => 8)

Search over ratings is also possible:

hotels = Hotel.find_where_quality_has_average_rating_of(10)

hotel1 = hotels.first
hotel1.name
=> "Four Seasons"
hotel1.avg_rating
=> 10.0

TODO

• Add more (better) query methods
• Add more examples

License

Copyright (c) 2012 Frane Bandov, released under the MIT license