Question

I am following the Rails guide for doing multi-model nested form. I have 2 models, Page and Picture. Page has_many Pictures. I’m putting the Picture file field within the Edit Page form using fields_for.

Each time I upload an image, the form will add an additional file field to allow for a new Picture to be uploaded.

The behavior I want is for the Page form to only always have one file field which will create a new Picture. I don’t need previous pictures to be editable.

The questions thus are 1) how can I do the above? 2) should I even be using nested form? Because I’m not editing other parts of the Page when creating a picture.

Answer 1

You can just use:

#routes.rb
resources pages do
  resources pictures
end

#PicturesController.new
@picture = Picture.new

#views/pictures/new.haml
= form_for @picture 
#form code here

Or you can place form wherever you want and send it to pictures controller:

#views/pages/show.haml
= form_for [@page, Picture.new] do |f|
  = f.hidden_field :page_id, :value => @page.id
  = f.file_field :file #change to your own
  = f.button :submit

#PicturesController
def create
  @picture = Picture.new(params[:picture])
  if @picture.save
    redirect_to :back, :notice => "success"
  else
    #some code
  end
end