Active Admin Image Upload Form

milestone.rb

ActiveAdmin.register Milestone do
  scope :all, :default => true
  scope :global
  scope :user_specific
  
  index do
    column :title
    column :description
    column :required_litres
    column :is_active
    column :is_global
    column :image
    default_actions
  end
  
  form :html => { :enctype => "multipart/form-data" } do |f|
    f.inputs 'Details' do
      f.input :title
      f.input :description, :as => :text
      f.input :required_litres
      f.input :is_active
      f.input :is_global
    end
    
    f.inputs 'Images' do
      f.input :image, :label => 'Milestone image'
    end
    
    f.buttons
  end
  
end