Module: Recommendable::Ratable::ClassMethods

Defined in:
lib/recommendable/ratable.rb

Instance Method Summary collapse

Instance Method Details

#make_recommendable! ⇒ Object 



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# File 'lib/recommendable/ratable.rb', line 11

def make_recommendable!
  Recommendable.configure { |config| config.ratable_classes << self }

  class_eval do
    include Likable
    include Dislikable

    if ancestors.include?(ActiveRecord::Base) || include?(Mongoid::Document) || include?(MongoMapper::Document) || include?(MongoMapper::EmbeddedDocument)
      before_destroy :remove_from_recommendable!
    elsif include?(DataMapper::Resource)
      before :destroy, :remove_from_recommendable!
    end

    # Whether or not items belonging to this class can be recommended.
    #
    # @return true if a user class `recommends :this`
    def self.recommendable?() true end

    # Check to see if anybody has rated (liked or disliked) this object
    #
    # @return true if anybody has liked/disliked this
    def rated?
      liked_by_count > 0 || disliked_by_count > 0
    end

    # Query for the top-N items sorted by score
    #
    # @param [Fixnum] count the number of items to fetch (defaults to 1)
    # @return [Array] the top items belonging to this class, sorted by score
    def self.top(count = 1)
      score_set = Recommendable::Helpers::RedisKeyMapper.score_set_for(self)
      ids = Recommendable.redis.zrevrange(score_set, 0, count - 1)

      Recommendable.query(self, ids).sort_by { |item| ids.index(item.id.to_s) }
    end

    private

    # Completely removes this item from redis. Called from a before_destroy hook.
    # @private
    def remove_from_recommendable!
      # Remove this item from the score zset
      Recommendable.redis.zrem(Recommendable::Helpers::RedisKeyMapper.score_set_for(self.class), id)

      # Remove this item's liked_by/disliked_by sets
      %w[liked_by disliked_by].each do |action|
        set = Recommendable::Helpers::RedisKeyMapper.send("#{action}_set_for", self.class, id)
        Recommendable.redis.del(set)
      end

      # Remove this item from any user's like/dislike/hidden/bookmark sets
      %w[liked disliked hidden bookmarked].each do |action|
        set = Recommendable::Helpers::RedisKeyMapper.send("#{action}_set_for", self.class, id)
        Recommendable.redis.keys(set).each do |set|
          Recommendable.redis.srem(set, id)
        end
      end

      # Remove this item from any user's recommendation zset
      Recommendable.redis.keys(Recommendable::Helpers::RedisKeyMapper.recommended_set_for(self.class, '*')).each do |zset|
        Recommendable.redis.zrem(zset, id)
      end
    end
  end
end

#recommendable? ⇒ Boolean

Whether or not items belonging to this class can be recommended.

Returns:

  • (Boolean) —

    true if a user class ‘recommends :this`



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# File 'lib/recommendable/ratable.rb', line 80

def recommendable?() false end