attachment.rb

require 'paperclip'

class Attachment < ActiveRecord::Base
  belongs_to :channel
  belongs_to :user

  has_attached_file :file,
                    :storage         => :s3,
                    :s3_credentials  => {
                      :access_key_id     => ENV['S3_ACCESS_KEY_ID'],
                      :secret_access_key => ENV['S3_SECRET_ACCESS_KEY'],
                      :session_token     => ENV['STS_SESSION_TOKEN']
                    },
                    :bucket            => ENV['S3_BUCKET'],
                    :url             => "/:attachment/:id/:style/:basename.:extension",
                    :path            => "#{ENV['S3_PREFIX']}/:attachment/:id/:style/:basename.:extension"

  attr_accessible :file

  def url
    file.to_s
  end
end