title: Activeadmin: Customize form
body: <p>In my active admin form I'm retrieving multiple users with email, name, mobile attribute. I want to display this in table format like email, name, mobile as indexes.</p>
  
  <pre><code>     f.input :user_ids, :label =&gt; "Users", 
    :multiple =&gt; true,  collection: @user.collect{|u| [[u.email, u.name, u.mobile].to_s.gsub('"',""), u.id]}, 
    :required =&gt; true, :input_html =&gt; { :class =&gt; "users_checkboxes", :size =&gt; 20 
  </code></pre>
  
  <p><strong>Ex:</strong>
  Above code display the following:</p>
  
  <p>[rr@example.com,Robert,78789799]</p>
  
  <p>[avrtyjoserc@example.com,Kamal,99098889]</p>
  
  <p>I want to display in proper order like space between email, name and mobile, so that make appearance better.</p>