Example for https://github.com/gregbell/active_admin/issues/2013

user.rb

class User < ActiveRecord::Base
  # t.string :status, default: 'submitted'

  # Contrived example
  def self.status_options
    %w[approved rejected submitted]
  end
end

user_decorator.rb

class UserDecorator < Draper::Base
  decorates :user
  
  # I've recently refactored this pattern to the Olson gem.
  # See: https://github.com/carnesmedia/olson for more information.
  
  def self.status_options_for_select
    User.status_options.map { |s| [s.humanize, s] }
  end

  def status
    model.status.humanize
  end

end

users.rb

ActiveAdmin.register User do

  # ...
  
  form do
    f.inputs do
      # So, here's an example of the problem. `f.object.status` now returns "Submitted",
      # which doesn't match the actual status option: "submitted". So, the select doesn't
      # have the correct status selected.
      # This is sort of subtle, but one of those not-so-obvious bugs with big potential problems.
      f.input :status, collection: UserDecorator.status_options_for_select
    end
  end

end