title: Rails Activeadmin - custom association select box
body: <p>In my Rails application, I have the following model:</p>
  
  <pre><code>class Idea &lt; ActiveRecord::Base
    belongs_to :user
  end
  
  class User &lt; ActiveRecord::Base
    has_many :ideas
  end
  </code></pre>
  
  <p>I am creating <a href="http://www.activeadmin.info/">ActiveAdmin</a> CRUD for my <code>Idea</code> model with the custom form that looks something like that looks something like that:</p>
  
  <pre><code>form do |f|
    f.inputs do
      f.input :member
      f.input :description
    end
  end
  </code></pre>
  
  <p>The requirement is to have the custom text for a content of the member association, i.e <code>"#{last_name}, #{first_name}"</code>.  Is it possible to customize my member select box to achieve it?</p>
  
  <p>Any help will be appreciated.</p>