I have an app that engages physical files of several types. Each type
has different metadata associated, so i’ve broken them out in
different models. To keep thing simple, I’ll just deal use images in
my example.
I have an images table (with an Image model) that stores fuzzy info
like title, description, rating, etc. The Image model belongs_to a
Binary model that is backended by a binaries table with physical file
metadata (name, extension, size, MIME Type, etc.). My Binary model is
only a model. There’s no controller or set of views because I really
want all interaction to occur through the typed model.
I have an Images controller with the relevant views and I’d like to
accept an upload there, but then delegate to the Binary model for
handling everything related to the physical file itself (uploading,
extracting properties, saving to a new location, etc.). I can’t seem
to get that to work and my Ruby/Rails n00b-ness isn’t helping me at
all. 
Some of my syntax may simply be incorrect - I’m struggling
with the Ruby idioms, coming from a long history of C-style syntax. In
many cases, I’ve tried several variations, but I’m just going to paste
what I have now. In other cases, I’m including snippets of code that
I’ve seen elsewhere, but don’t completely understand yet
(attr_accessor is a good example).
I’m hoping someone here can help point me in the right direction. The
error that I’m currently getting is:
undefined method `original_path’ for “online-resume-req.txt”:String
It seems that the upload, in its entirely, is never making it to the
server. I’m only getting the file name as a string. Code follows:
ImagesController::create()
def create
@image = Image.new(params[:image])
@binary = Binary.new
if ( @binary.upload(params[:image][:uploaded_file]) )
#do stuff
end
end
views/images/_form.html.erb
<% form_for( @image, :multipart => true ) do |f| %>
<%= f.error_messages -%>
<%= label_tag( 'image_uploaded_file', 'File' ) -%> <%= file_field( :image, :uploaded_file ) -%>
<%= f.label :name %> <%= f.text_field :name %>
<%= f.label :description %> <%= f.text_area( :description ) %>
<%= f.submit( 'Upload' ) %>
<% end %>Image model:
class Image < ActiveRecord::Base
belongs_to :binary
validates_presence_of( :uploaded_file )\
attr_accessor :uploaded_file
end
Binary model
class Binary < ActiveRecord::Base
has_one :image
def upload(uploaded_file)
logger.info( 'Uploading: ’ + uploaded_file.to_json )
self.name = uploaded_file.original_path
self.mime_type = uploaded_file.content_type
save_as = Rails.root.join( 'public', 'bin', '_tmp',
uploaded_file.original_path )
File.open( save_as, 'w' ) do |file|
file.write( uploaded_file.read )
end
self.size = File.size( "#{save_as}" )
logger.info( 'Set file size to ' + self.size.to_s )
self.save
logger.info( 'Stored' );
end
end