audit view

index.html.erb

<% for audit in @audits %>
  <tr>
      <%if audit.user.present? #<--- Guard against nil users.%>  
          <td><%= link_to(audit.user.to_label, url_for(audit.user)) %></td>
      <%else #<--- Present "Missing" on nil user.%>  
          <td>Missing</td>
      <%end%>

      <td><%= audit.kind %></td>

      <% if audit.auditable.present? %>
      <td><%= link_to(audit.auditable.to_label, url_for(audit.auditable) ) %></td>
    <% else %>
      <td>Missing</td>
    <% end %>
    <td><%= audit.created_at %></td>
  </tr>
<% end %>