background_image.rb

 require 'RMagick'

class BackgroundImage < ActiveRecord::Base
  attr_accessible :parent_id, :uploaded_data, :filename

  has_one :child, :class_name => "BackgroundImage", :foreign_key => :parent_id

  # You may want to pass other options to has_attachment.
  # See the attachment_fu README.
  has_attachment :content_type => :image,
                 :min_size => 1.kilobyte,
                 :max_size => 4.megabyte,
                 :storage => :db_file,
                 :resize_to => '1600x',
                 # Process thumbnail to:
                 :thumbnails => {:thumbnail => '400x'}
  validates_as_attachment
  
  # Load seeds - in here so I can call it from db:seeds and capistrano
  def self.load_seed_data
    fileglob = "#{RAILS_ROOT}/public/backgrounds/*.jpg"
    Dir.glob(fileglob).each {|file|
      if self.find_by_filename(file.split("/")[-1])
        # Do nothing
      else
        @bg_image = self.new(:uploaded_data => ActionController::TestUploadedFile.new(file, "image/jpeg"))
        @bg_image.save
      end
    }
  end
end

load_background_images.rake

namespace :empcms do
  desc "Load background images from the file system into the admin interface - and then set one as the current backgrou\
nd"
  task :seed_background_images => :environment do
    # load new files
    BackgroundImage.load_seed_data

    # Pick a random image for this site's background
    if SitePreference.instance.background_image_path.blank?
      background_images = BackgroundImage.originals
      bg_image_path = background_images[Kernel.rand(background_images.length)].public_filename
      SitePreference.instance.update_attributes(:background_image_path => bg_image_path)
    end
  end
end