<% #TODO: Area necesita el autocompletar  %>
<%= simple_form_for  [:backend, resource] do |f| %>
  <%= f.association :area  %>
  <%= f.input :descripcion, input_html: {rows: "10"} %>
  <%= f.input :ingreso, as: :string, input_html: { class: 'datepicker' } %>
  <%= f.input :fojas  %>
  <%= f.input :expediente_id  %>

<%= f.submit %>
<% end %>

Add _form partial to customize the the pases edit and new page
Add _form partial to customize the the pases edit and new page