Change object permalink length to be of the size of a predefined length

Question

Let´s say I have a model, called Car, and I can access my car show action at /cars/:id. The first record will live in /cars/1 but I don´t want it. I want the permalink to have a length of 8 numbers, no matter what´s the id of the car. So for example, the first permalink would be 00000001 not 1.

I don´t know how to implement that, what to do in the model (to_param method probably) or what to do in the routes.

Please help me if you can, I appreciate any hint.

Answer 1

Have you tried using friendly_id gem. If you can use it and I strongly recommend you use it. From the comments in the code:

FriendlyId always uses a method as the basis of the slug text - not a column. At first glance, this may sound confusing, but remember that Active Record provides methods for each column in a model's associated table, and that's what FriendlyId uses.

Here's an example of a class that uses a custom method to generate the slug:

class Person < ActiveRecord::Base
  friendly_id :name_and_location
  def name_and_location
    "#{name} from #{location}"
  end
end

bob = Person.create! :name => "Bob Smith", :location => "New York City"
bob.friendly_id #=> "bob-smith-from-new-york-city"

So, I guess you can do:

class Car < AR::Base
  friendly_id :id_of_length_eight
  def id_of_length_eight
    # logic here to add leading zeroes
  end
end