<% if book.available_copies > 0 %> <% unless current_user.books.include?book %> <%= link_to 'Borrow', borrow_path(book), class: "btn btn-success", remote: true %> <% else %> <%= link_to 'Borrowed', 'javascript:;', class: "btn btn-primary", remote: true %> <% end %> <% else %> Not available <% end %>