CODEWITHSUNDEEP
ruby-on-railsruby
Victor
Victor

Reputation: 13378

Search same class in Rails Model

Using Rails 3.2.17. I have the following in my model:

class Shop < ActiveRecord::Base
  before_create :set_next_position

  private

  def set_next_position
    self.position = self.class.where(country_id: country_id).
                    maximum(:position).to_i + 1
  end
end

self is a Shop object. Note the line self.class.where... which is equivalent to Shop.where.... In this case, I don't know what is the best practice - to use Shop.where... or self.class.where...? It is code smell to me.

Upvotes: 0

Views: 60

Answers (2)

Babar Al-Amin
Babar Al-Amin

Reputation: 3984

I would say self.class.where is better than Shop.where inside the class body. This way, you won't have to change inside, if for some reason you want to rename the class and so on.

Upvotes: 1

Kamen Kanev
Kamen Kanev

Reputation: 311

The only difference that I now about is in case of inheritance. When you have:

class Base
  def self.example
    42
  end

  def run_example
    Base.example
  end
end

class A < Base
  def self.example
    'not 42'
  end
end

A.new.run_example
=> 42

So when don't have inheritance I prefer Base.example. In the other case self.class.example.

Upvotes: 0

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