app/views/user_lacquers/_user_lacquer_on_loan.html.erb
<td class="on-loan" id="0<%= user_lacquer.id %>">
<% if user_lacquer.loanable %>
<% if user_lacquer.on_loan %>
<%= link_to "✔", user_lacquer_path(user_lacquer, params: {"user_lacquer[on_loan]" => false}), {:method => "PATCH", :remote => true, :class =>"btn btn-success btn-xs"} %>
<% else %>
<%= link_to "✕", user_lacquer_path(user_lacquer, params: {"user_lacquer[on_loan]" => true}), {:method => "PATCH", :remote => true, :class =>"btn btn-danger btn-xs"} %>
<% end %>
<% end %>
</td>