Paperclip: "missing" image - ruby-on-rails

Question

I'm working on a website that allows people who run bed and breakfast businesses to post their accommodations.
I would like to require that they include a "profile image" of the accommodation when they post it, but I also want to give them the option to add more images later (this will be developed after).
I thought the best thing to do would be to use the Paperclip gem and have a Accommodation and a Photo in my application, the later belonging to the first as an association.
A new Photo record is created when they create an Accommodation. It has both id and accommodation_id attributes. However, the image is never uploaded and none of the Paperclip attributes get set (image_file_name: nil, image_content_type: nil, image_file_size: nil), so I get Paperclip's "missing" photo.
Any ideas on this one? It's been keeping me stuck for a few days now.
Accommodation
models/accommodation.rb
class Accommodation < ActiveRecord::Base
validates_presence_of :title, :description, :photo, :thing, :location
attr_accessible :title, :description, :thing, :borough, :location, :spaces, :price
has_one :photo
end
controllers/accommodation_controller.erb
class AccommodationsController < ApplicationController
before_filter :login_required, :only => {:new, :edit}
uses_tiny_mce ( :options => {
:theme => 'advanced',
:theme_advanced_toolbar_location => 'top',
:theme_advanced_toolbar_align => 'left',
:theme_advanced_buttons1 => 'bold,italic,underline,bullist,numlist,separator,undo,redo',
:theme_advanced_buttons2 => '',
:theme_advanced_buttons3 => ''
})
def index
#accommodations = Accommodation.all
end
def show
#accommodation = Accommodation.find(params[:id])
end
def new
#accommodation = Accommodation.new
end
def create
#accommodation = Accommodation.new(params[:accommodation])
#accommodation.photo = Photo.new(params[:photo])
#accommodation.user_id = current_user.id
if #accommodation.save
flash[:notice] = "Successfully created your accommodation."
render :action => 'show'
else
render :action => 'new'
end
end
def edit
#accommodation = Accommodation.find(params[:id])
end
def update
#accommodation = Accommodation.find(params[:id])
if #accommodation.update_attributes(params[:accommodation])
flash[:notice] = "Successfully updated accommodation."
render :action => 'show'
else
render :action => 'edit'
end
end
def destroy
#accommodation = Accommodation.find(params[:id])
#accommodation.destroy
flash[:notice] = "Successfully destroyed accommodation."
redirect_to :inkeep
end
end
views/accommodations/_form.html.erb
<%= form_for #accommodation, :html => {:multipart => true} do |f| %>
<%= f.error_messages %>
<p>
Title<br />
<%= f.text_field :title, :size => 60 %>
</p>
<p>
Description<br />
<%= f.text_area :description, :rows => 17, :cols => 75, :class => "mceEditor" %>
</p>
<p>
Photo<br />
<%= f.file_field :photo %>
</p>
[... snip ...]
<p><%= f.submit %></p>
<% end %>
Photo
The controller and views are still the same as when Rails generated them.
models/photo.erb
class Photo < ActiveRecord::Base
attr_accessible :image_file_name, :image_content_type, :image_file_size
belongs_to :accommodation
has_attached_file :image,
:styles => {
:thumb=> "100x100#",
:small => "150x150>" }
end

Answer 1

To create an upload with paperclip, you need to use the name you provided for the has_attached_file line, on the model you defined it on. In your case, this will result in this view code:
<%= form_for #accommodation, :html => { :multipart => true } do |f| %>
<%= f.fields_for :photo do |photo_fields| %>
<p>
Photo<br />
<%= photo_fields.file_field :image %>
</p>
<% end %>
<% end %>
In the controller:
class AccommodationsController < ApplicationController
# also protect create and update actions!
before_filter :login_required, :only => [ :new, :create, :edit, :update ]
def new
# always make objects through their owner
#accommodation = current_user.accommodations.build
#accommodation.build_photo
end
def create
#accommodation = current_user.accommodations.build(params[:accommodation])
if #accommodation.save
# always redirect after successful save/update
redirect_to #accommodation
else
render :new
end
end
end
Tell Rails to handle the nested form:
class Accommodation
has_one :photo
accepts_nested_attributes :photo
attr_accessible :photo_attributes, :title, :description, :etc
end
And make sure to set the accessible attributes right in your photo model:
class Photo
attr_accessible :image # individual attributes such as image_file_name shouldn't be accessible
has_attached_file :image, :styles => "etc"
end
Be sure to watch your log files to spot things that are protected by attr_accessible, but still are in your form.