CODEWITHSUNDEEP
ruby-on-rails-4
ARTLoe
ARTLoe

Reputation: 1799

Writing a Scope containing a method - Rails 4

i am new to rails and any help or advise would be much appreciated

user.rb

scope :ratings_equal_and_greater_than_4, where('average_rating_final_score >= 4')

def average_rating_final_score
    if self.average_rating_score == 1.0
      1
    elsif self.average_rating_score == 2.0
      2
    elsif self.average_rating_score == 3.0
      3
    elsif self.average_rating_score == 4.0
      4
    elsif self.average_rating_score == 5.0
      5
    else
      self.average_rating_score
    end    
  end

  def average_rating_score
    ratings_total.to_f / ratings_count
  end

the scope works well when written like this:

<% if user.average_rating_final_score >= 4 %>
   # display users with ratings equal to or greater than 4 star
<% end %>

but i would like to write something like this in my views

@users.ratings_equal_and_greater_than_4

could one kindly advise me how to write this correctly as a scope

Upvotes: 1

Views: 31

Answers (1)

rootatdarkstar
rootatdarkstar

Reputation: 1526

Rails scopes is the AREL - a kind of ruby wrapped sql. It's mean you can't call ruby code from SQL WHERE statement like this:

where('average_rating_final_score >= 4')

But you can define class method that will work as you want:

def self.ratings_equal_and_greater_than_4
  all.reject{ |record| record.average_rating_final_score < 4 }
end

Also you can write propper SQL query:

where('(`table_name.ratings_total` / `table_name.ratings_count`) >= 4')

Upvotes: 2

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