apps/web/templates/books/index.html.erb
<h2>All books</h2>
<div id="books">
<% if books.any? %>
<ul>
<% books.each do |book| %>
<li class="book">
<%= link_to title_and_author(book), routes.edit_book_path(book.id) %>
<%=
form_for delete_form(book), {} do
submit 'Delete'
end
%>
</li>
<% end %>
</ul>
<% else %>
<p class="placeholder">There are no books yet.</p>
<% end %>
</div>
<%= link_to 'Add a book', routes.new_book_path %>