product_reviews_ratings_extension.rb

class ProductReviewsRatingsExtension < Spree::Extension
  version "1.0"
  description "Product Reviews and Ratings"
  url "http://spreehq.org/"

  def activate
    Admin::ConfigurationsController.class_eval do
      before_filter :add_product_reviews_link, :only => :index
      def add_product_reviews_link
        @extension_links << { :link => admin_reviews_url, :link_text => 'Product Reviews', :description => 'Product Reviews' }
      end
    end

    ProductsController.class_eval do
      before_filter :set_user_review_and_rating, :only => :show
      
      def set_user_review_and_rating
        @review_rating_header = ''
        if Spree::ProductReviewsRatings::Config[:can_review_product] == 1
          @review_rating_header = t(:review)
          @reviews = Review.find(:all, :conditions => { :review_status_id => 2, :product_id => object.id }, :limit => Spree::ProductReviewsRatings::Config[:review_count], :include => :rating)
          @review_count = Review.find(:all, :conditions => { :review_status_id => 2, :product_id => object.id }).size
          @user_review = current_user ? Review.find_or_create_by_product_id_and_user_id(:product_id => object.id, :user_id => current_user.id) : Review.new
        end
        if Spree::ProductReviewsRatings::Config[:can_rate_product] == 1
          @review_rating_header = Spree::ProductReviewsRatings::Config[:can_review_product] == 1 ? t(:review_and_rate) : t(:rate)
					@user_rating = current_user ? Rating.find_or_create_by_product_id_and_user_id(:product_id => object.id, :user_id => current_user.id) : Rating.new
        end
        @review_rating_header += t(:this_product)
      end
    end

    Product.class_eval do
      has_many :reviews
      has_many :ratings

      named_scope :descend_by_rating,
      :joins => "LEFT JOIN ratings ON ratings.product_id = products.id",
      :group => "id",
      :select => "products.*,  SUM(ratings.rating) / COUNT(ratings.rating) AS rating_average",
      :order => "rating_average DESC"
    end
  end
end