Rails The simple form of a multi-page file does not work

Question

I use simple_form, and multi-user upload does not work (single file upload works). Rails file_field_tag ​​works ...
Rails 3.2.13

<%= simple_form_for @building, input_html: {multipart: true} do |f| %> ... <%= f.simple_fields_for :paintings do |p| %> <%= p.input :image, as: :file %> <% end %> <% end %> 

Answer 1

You should use html instead of input_html :

<%= simple_form_for @building, html: {multipart: true} do |f| %>