UUID concern for rails models - To allow rails paths to be of the form `foo/63950bdb-6c3b-4744-ad6f-f5df5aed1a76` rather than `foo/1`

use_uuid.rb

require 'active_support/concern'
module UseUuid
  extend ActiveSupport::Concern

  included do
    before_save :generate_uuid
  end

  def to_param
    uuid
  end

  private

  def generate_uuid
    return true if uuid?
    self.uuid = SecureRandom.uuid
  end

end

For this to work, the model needs an attribute uuid (string), which should be indexed. Once that is in place you can:

class Foo < ActiveRecord::Base
  include UseUuid
end

Also in controllers and route path methods, find or specify uuid rather than id. So

# Without uuid
foo = Foo.find(params[:id])
redirect_to foo_path(foo)

# With uuid
foo = Foo.find_by(uuid: params[:id])
redirect_to foo_path(id: foo.uuid)