Ajaxful Rating

Provides a simple way to add rating functionality to your application.

Repository

Find it at github.com/edgarjs/ajaxful-rating

Demo

You can find a demo working app for this plugin at http://github.com/edgarjs/ajaxful-rating_demo_app
Just migrate and run…

Or view it live: http://axr.heroku.com

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Instructions

Install

To install the gem run the next command:

gem install ajaxful_rating

You can configure it in your environment.rb file also:

config.gem "ajaxful_rating"

Generate

script/generate ajaxful_rating UserModelName

The generator takes one argument: UserModelName, which is the name of your current
user model. This is necessary to link both the rate and user models.

Also this generator copies the necesary images, styles, etc.

Example:
I suppose you have generated already an authenticated model…

script/generate authenticated user sessions
script/generate ajaxful_rating user

So this call will create a Rate model and will link it to your User model.

Prepare

To let a model be rateable just add ajaxful_rateable. You can pass a hash of options to
customise this call:

• :stars Max number of stars that can be submitted.
• :allow_update Set to true if you want users to be able to update their votes.
• :cache_column Name of the column for storing the cached rating average.
• :dimensions Array of dimensions. Allows to rate the model on various specs,
  like for example: a car could be rated for its speed, beauty or price.

class Car < ActiveRecord::Base
  ajaxful_rateable :stars => 10, :dimensions => [:speed, :beauty, :price]
end

Then you need to add a call ajaxful_rater in the user model. This includes a simple line so
you can add it by your own as well (has_many :rates).

class User < ActiveRecord::Base
  ajaxful_rater
end

Finally, as a mere recomendation to make it even easier, modify your routes to
map a rate action:

map.resources :cars, :member => {:rate => :post}

Use it

To add the star links you need to call the helper method ratings_for.
It tries to call current_user method as the rater instance. You can pass :static
as the second param to display only the static stars (not clickables).
And also you can pass the dimension you want to show the ratings for.

#show.html.erb
<%= ratings_for @article %>

#To display static stars:
<%= ratings_for @article, :static %>

#To display the ratings for a dimension:
<%= ratings_for @article, :dimension => :speed %>

Or you can specify a custom user instance by passing it as parameter.

<%= ratings_for @article, @user %>

By default ratings_for will display the average user rating. If you would like it to
display the rating for the current_user, then set the :show_user_rating parameter to true.
For example:

# To display the rating for the current user (current_user):
<%= ratings_for @article, :show_user_rating => true %>

# To display the rating for the user specified by @user:
<%= ratings_for @article, @user, :show_user_rating => true %>

There’s a condition here, if you didn’t add the route rate to your resource
(as shown above) or you named it different, you’ll need to pass the url to the
correct action in your controller:

<%= ratings_for @article, :remote_options => {:url => your_rate_path(@article)} %>

To display the stars properly you need to add a call in the head of your layout, which will generate the
required CSS style for the list. Also don’t forget to include the javascripts.

  #within the head tags of your layout...
  <%= javascript_include_tag :defaults %>
  <%= ajaxful_rating_style %>

When a user submits a rating it will call the action in your controller, for
example (if you added the rate route):

  def rate
    @car = Car.find(params[:id])
    @car.rate(params[:stars], current_user, params[:dimension])
    render :update do |page|
      page.replace_html @car.wrapper_dom_id(params), ratings_for(@car, params.merge(:wrap => false))
      page.visual_effect :highlight, @car.wrapper_dom_id(params)
    end
  end

There are some more options for this helper, please see the rdoc for details.

Dimensions

From now on you can pass an optional parameter to the rates method for your rateable object to retrieve the
corresponding rates for the dimension you want.

For example, you defined these dimensions:

class Car < ActiveRecord::Base
  ajaxful_rateable :dimensions => [:speed, :beauty, :price]
end

And hence you can call car.rates(:price) for the price rates or car.rates(:speed) for the speed ratings and so on.

Namespaces

If you use the plugin inside a namespace you’ll need to specify the rating url which should points to
a controller inside a namespace. Your files should be like these:

routes.rb:
map.namespace :admin do |admin|
  admin.resources :articles, :member => {:rate => :post}
end

views/admin/articles/show.html.erb
<%= ratings_for @article, :remote_options => {:url => rate_admin_article_path(@article)} %>

Cache

To cache the model’s rating average add a column named rating_average to your model table:

class AddRatingAverageToArticles < ActiveRecord::Migration
  def self.up
    add_column :articles, :rating_average, :decimal, :default => 0, :precision => 6, :scale => 2
  end

  def self.down
    remove_column :articles, :rating_average
  end
end

If you want to customise the name of the cache column just pass it in the options hash:

class Article < ActiveRecord::Base
  ajaxful_rateable :cache_column => :my_cached_rating
end

To use caching with dimensions, make sure you have a cache column defined for each dimension you want cached.
So if you want to cache the spelling dimension, you’ll need to have a column called rating_average_spelling on the articles table.
If you use a custom cache column name, follow the pattern cache_column_name_dimension_name to add cache columns for dimensions.

About backwards compatibility

Version 2.0 of the plugin works only from Rails 2.2 and on. It uses the module I18n which is new in rails 2.2. Please note that you can use it in past versions as long as you customise the source code.

I decided to jump directly to version 2.0 because there are many important changes. You can always
checkout the version 1.0 from the repository though.

Feedback

If you find bugs please open a ticket at http://github.com/edgarjs/ajaxful-rating/issues

I’ll really appreciate your feedback, please contact me at e[at]dgar[dot]org

Credits

The helper’s style is from komodomedia with author’s permission.

If you need the psd files of the stars you can grab them here

Thanks to bborn for the dimensions base implementation.

License

This code is released under Creative Commons Attribution-Share Alike 3.0 license.