Question

When using nested_form_for and having a file_field in fields_for I get the following error from paperclip:

Paperclip::AdapterRegistry::NoHandlerError in ProjectsController#create

No handler found for "scan.pdf"

This is correct, because the params don’t show an #<ActionDispatch::Http::UploadedFile> object, but just the file name.

Before using nested_form_for it worked, it works when I uncomment the file_field and it also works when I build the first object for fields_for but this shouldn’t be necessary..

My setup is as follows:

• ruby 1.9.3
• rails (3.2.8)
• paperclip (3.3.0)
• nested_form (0.3.0)

The code:

# @project.schemes.build
= nested_form_for @project do |f|
  = f.fields_for :schemes do |ff|
    = ff.text_field :name
    = ff.file_field :scan

Answer 1

The generated form is not multipart and you have 2 options to solve this issue:

• specify multipart manually

  = nested_form_for @project, :html => { :multipart => true } do |f|
  

• try using nested_form gem from the master branch which have this issue solved but not yet released

  gem 'nested_form', :github => 'ryanb/nested_form'