fields_for nested form

Question

I have a photos model and a gallery model. The gallery model(I used nifty scaffold) just has one field, a gallery name. In my photo edit form I want to link each photo to a gallery, eg. I create 2 separate galleries 2009 and 2010, I want to have a dropdown list on each photo edit page with the list of galleries, so each photo can be placed in a gallery. I've been using this and this as starting points but I'm stuck, and can't get the galleries to appear in my photo form.

 class Gallery < ActiveRecord::Base
  has_many :photos
  attr_accessible :name
 end

class Photo < ActiveRecord::Base
  belongs_to :gallery
  accepts_nested_attributes_for :gallery, :allow_destroy => true

views/photos/_form.html.erb

<% form_for @photo, :html => { :multipart => true } do |photo_form| %>

  <p>
    <%= photo_form.label :title %><br />
    <%= photo_form.text_field :title %>
  </p>

<p>
    <% photo_form.fields_for :gallery do |gal_form| %>

        <%= gal_form.label :name %> 
        <%= gal_form.collection_select :gallery_id, Gallery.all, :id, :name %>
  </p>

      <% end %>

  <p>
    <%= submit_tag %>
  </p>

<% end %>

Currently there is no dropdown list on the photo form page, though I'm not receiving any errors and there is no mention of it either in the page source. I'd appreciate any help or to be pointed in the right direction...

Answer 1

If your photo belongs to the gallery then isn't the gallery_id on the photo? So the gallery_id would be a member of the photo_form not the the gal_form.

<%= photo_form.collection_select :gallery_id, Gallery.all, :id, :name %> 

UPDATE:

Here is how I would see your view:

<% form_for @photo, :html => { :multipart => true } do |photo_form| %>

  <p>
    <%= photo_form.label :title %><br />
    <%= photo_form.text_field :title %><br />
    <%= photo_form.collection_select :gallery_id, Gallery.all, :id, :name %>
  </p>
  <p>
    <%= submit_tag %>
  </p>

<% end %>

Your model:

class Gallery < ActiveRecord::Base
  has_many :photos
end

class Photo < ActiveRecord::Base
  belongs_to :gallery
end

Answer 2

It sounds like you don't need a nested form. I would drop accepts_nested_attributes_for entirely.

The work flow should be: 1) select a gallery 2) Upload and describe photo

You can have a separate controller/view for managing galleries.

Once you've done that and verified your schema, the example above should work (collection select on galleries tied directly to Photo)

Answer 3

@Raphael:

The column name should be gallery_id(model name + id), after adding it

Try this below line in your ruby console

photos = Photo.find_all_by_gallery_id(Gallery.first)

This should give you list of all photos in the first gallery.