Create a variable in after_find of model in Ruby on Rails

Question

I need generate a variable for send a the view, for example i have this:

def after_find
    unless self.photo.nil?
        if File.exist?(Rails.root + 'public/uploads/tournaments/' +  self.photo)
            self.photo = '/uploads/tournaments/' + self.photo
        else
            self.photo = "http://placehold.it/250x400"
        end
    else    
        self.photo = "http://placehold.it/250x400"
    end
end

It runs well that variable is an attribute of db migration,the problem is when I declare something that is not an attribute of db migration

self.variable1 = "hello world"

Possible duplicate of [Non persistent ActiveRecord model attributes](http://stackoverflow.com/questions/11986792/non-persistent-activerecord-model-attributes) — zwippie, Jan 18 '16 at 13:05

Mike Szyndel · Accepted Answer · 2016-01-18T13:07:57.390

3

If you want to have an attribute on a model but this attribute is not part of your database you can define it as accessor. In your model just add

#app/models/tournament.rb
class Tournament < ActiveRecord::Base
   attr_accessor :variable1
end

EDIT:

However in this particular case you should consider the performance penalty from checking the filesystem every time you load a Tournament object.

Using gem like Carrierwave or Paperclip is a much better solution!

edited Jan 18 '16 at 13:07

answered Jan 18 '16 at 13:04

Mike Szyndel

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Thanks for your answer , i will add this gem :D – Jorge Mora Pérez Jan 18 '16 at 13:23
From those two I would recommend Paperclip move – Mike Szyndel Jan 18 '16 at 13:24

Create a variable in after_find of model in Ruby on Rails

1 Answers1