app/views/admin/pages/_page.html.erb
<%= content_tag :tr, id: "page_#{page.id}_row" do %>
<td style="padding-left: <%= 16 + page.depth * 16 %>px"><span class="glyphicon glyphicon-file"></td>
<td class="title"></span> <%= editable page, :title %></td>
<td class="updated not_editable">
<%= updated page %>
</td>
<td class="actions not_editable">
<%= link_to "Add Child", new_admin_page_path(page: { parent_id: page.id }) %>
<%= link_to "Edit", edit_admin_page_path(page) %>
</td>
<% end -%>
<%= render page.children %>