CODEWITHSUNDEEP
ruby-on-rails
saraf
saraf

Reputation: 84

Use of concern in rails 4

I tried to to use concerns in my project. I would like to build a method to get the date in french for every model I have. Here is my code. Currently, I get the error : wrong argument type Class (expected Module) at the line include DateTime in the model.

Here is my file models/concerns/date_time.rb

module DateTime
  extend ActiveSupport::Concern
  def self.included(base)
    base.extend ClassMethods
    base.class_eval do
      scope :disabled, -> { where(disabled: true) }
    end
  end


  # methods defined here are going to extend the class, not the instance of it
  module ClassMethods
    def date_string
      h = {1=>'Janvier',2=>'Février',3=>'Mars',4=>'Avril',5=>'Mai',6=>'Juin',7=>'Juillet',8=>'Août',9=>'Septembre',10=>'Octobre',11=>'Novembre',12=>'Décembre'}
      "#{self.created_at.day}-#{h[self.created_at.month]}-#{self.created_at.year}"
    end
  end
end

Here is my file models/demands.rb

class Demand < ActiveRecord::Base
  include DateTime
  belongs_to :skill
  belongs_to :project
  belongs_to :user
  has_many :transactions
  validates :project, presence: true
  validates :skill, presence: true
  validates :title, presence: true
end

Thanks in advance for your help !

Upvotes: 0

Views: 172

Answers (2)

Robert Nubel
Robert Nubel

Reputation: 7522

Your immediate issue here is that, because DateTime is a class in the Ruby standard library, Ruby is trying to include that class, not your module. If you rename the module to something unique, say, UsesDateTime, your error should go away.

That said, for this particular method, I agree with max.

Upvotes: 2

max
max

Reputation: 102046

Use the Rails built in I18n functionality instead. Doing localization in the model layer is just wrong. Models should only be concerned with data and business logic - not how data (like dates) are presented.

Upvotes: 2

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