93 lines
3.2 KiB
Ruby
93 lines
3.2 KiB
Ruby
module JamRuby
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class Review < ActiveRecord::Base
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include HtmlSanitize
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html_sanitize strict: [:description]
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attr_accessible :target, :rating, :description, :user, :user_id, :target_id, :target_type
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belongs_to :target, polymorphic: true
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belongs_to :user, foreign_key: 'user_id', class_name: "JamRuby::User"
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belongs_to :deleted_by_user, foreign_key: 'deleted_by_user_id', class_name: "JamRuby::User"
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scope :available, -> { where("deleted_at iS NULL") }
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scope :all, -> { select("*") }
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validates :description, length: {maximum: 16000}, no_profanity: true, :allow_blank => true
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validates :rating, presence: true, numericality: {only_integer: true, minimum: 1, maximum: 5}
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validates :target, presence: true
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validates :user_id, presence: true
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validates :target_id, uniqueness: {scope: :user_id, message: "There is already a review for this User and Target."}
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after_save :reduce
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def self.index(options={})
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if options.key?(:include_deleted)
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arel = Review.all
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else
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arel = Review.available
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end
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if options.key?(:target_id)
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arel = arel.where("target_id=?", options[:target_id])
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end
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if options.key?(:user_id)
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arel = arel.where("user_id=?", options[:user_id])
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end
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arel
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end
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# Create review_summary records by grouping reviews
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def self.reduce_all
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ReviewSummary.transaction do
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ReviewSummary.destroy_all
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Review.select("target_id, target_type AS target_type, AVG(rating) as avg_rating, count(*) as review_count, SUM(CASE WHEN rating>=3.0 THEN 1 ELSE 0 END) AS pos_count")
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.where("deleted_at IS NULL")
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.group("target_type, target_id")
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.each do |r|
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wilson_score = ci_lower_bound(r.pos_count, r.review_count)
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ReviewSummary.create!(
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target_id: r.target_id,
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target_type: r.target_type,
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avg_rating: r.avg_rating,
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wilson_score: wilson_score,
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review_count: r.review_count
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)
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end
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end
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end
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# http://www.evanmiller.org/how-not-to-sort-by-average-rating.html
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def self.ci_lower_bound(pos, n, confidence=0.95)
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pos=pos.to_f
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n=n.to_f
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return 0 if n == 0
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z = 1.96 # Statistics2.pnormaldist(1-(1-confidence)/2)
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phat = 1.0*pos/n
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(phat + z*z/(2*n) - z * Math.sqrt((phat*(1-phat)+z*z/(4*n))/n))/(1+z*z/n)
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end
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def reduce
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ReviewSummary.transaction do
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ReviewSummary.where(target_type: target_type, target_id: target_id).destroy_all
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Review.select("target_id, target_type AS target_type, AVG(rating) as avg_rating, count(*) as review_count, SUM(CASE WHEN rating>=3.0 THEN 1 ELSE 0 END) AS pos_count")
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.where("deleted_at IS NULL")
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.where(target_type: target_type, target_id: target_id)
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.group("target_type, target_id")
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.each do |r|
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wilson_score = Review.ci_lower_bound(r.pos_count, r.review_count)
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ReviewSummary.create!(
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target_id: r.target_id,
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target_type: r.target_type,
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avg_rating: r.avg_rating,
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wilson_score: wilson_score,
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review_count: r.review_count
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)
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end
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end
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end
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end
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end |