Rails Paperclip & Multiple File Uploads

amazon-s3, file-upload, paperclip, ruby-on-rails

Solution

So there are a few issues here.

First, Paperclip's `has_attached_file` method isn't an association to many files. It looks like you're trying to build an "asset" as if it's a Rails association. All Paperclip does is put a couple of fields into your table to store some meta-data about the file and you get one attached file per declaration of `has_attached_file`. If you want to attach 5 files, you would need to do something like:

has_attached_file :asset1
has_attached_file :asset2
has_attached_file :asset3
has_attached_file :asset4
has_attached_file :asset5

OR, alternatively, you could create another model just to store the files. For example:

class Listing < ActiveRecord::Base
  has_many :assets
end

class Asset < ActiveRecord::Base
  belongs_to :listing
  has_attached_file :picture
end

That way, you could have multiple assets attached to one listing (you didn't say what the original object was so I just called it "listing").

Second, there is no such thing as a multiple file upload in HTML (and, as such, the `file_field` method doesn't take a `:multiple => true` argument. You'll have to use something beyond Rails built-in form handling if you want multiple-file upload. Uploadify is a decent choice (that I've used before). There is a gem that will transform file fields to use uploadify (and will support the `:multiple => true` syntax that you want): https://github.com/mateomurphy/uploadify_rails3/wiki. However, I cannot vouch for how good it is.

My advice would be to start step-by-step. Uploading via Flash to Rails can be a complicated process that involves dealing with the CSRF meta-tag and other fields in your form. Start by making a form that allows a user to upload one file and stores it through Paperclip. Then maybe break the `has_attached_file` declaration into another model so that you can have 1 or many files associated with a model (as shown in the multi-model code block above). Then try adding Uploadify or another alternative. Ernie Miller has a decent tutorial on integrating Uploadify: http://erniemiller.org/2010/07/09/uploadify-and-rails-3/.

To start, remember that `has_attached_file` can only attach one file. When you try calling `@listing.assets` there is no "assets". There is an asset. You need to create a separate model yourself and use Rails' associations if you want multiple files.

Problem

I am looking for a solution to give the user the ability to upload multiple images through one file_field. I have looked in to options such a Jquery File Upload and Uploadify but have yet to come across good examples with a working solution. I already have multiple images setup, ``` has_attached_file :asset, :styles => { :large => "640x480", :medium => "300x300", :thumb => "100x100" }, :storage => :s3, :s3_credentials => "#{Rails.root}/config/s3.yml", :path => "/:contributor_id/:listing_name/:filename" ``` Right now I am displaying 5 individual file_fields ``` def new @listing = Listing.new 5.times {@listing.assets.build } respond_to do |format| format.html # new.html.erb format.json { render json: @listing } end end ``` I would like to have ``` <%= f.file_field :asset, :multiple => true %> ``` That allows the user to select multiple files in their file browser. But how can I process these with a nested model? And get them to upload.

Original source