I am developing a form for registration in a selective process and after the user send the registration data I would like to generate the registration number in the following format: 00012018. I found only one answer to that but it did not work.
Rails 5.
This 00012018 you want does not have to be persisted, and can be used for viewing only. To do this, you can implement a method in the template.
class Inscricao < ApplicationRecord
def numero_inscricao
return nil unless self.persisted?
id_com_zeros = "%04d" % self.id
"#{id_com_zeros}#{self.created_at.year}"
end
end
This will give you:
foo.numero_inscricao
=> "00012018"
As it uses #created_at , it will work for the next years and for the records that are already in the database, because it is a function executed in memory.
Just be sure that the ID is an integer, not a UUID, as is possible.