gistfile1.rb

class Upload < ActiveRecord::Base
 
  belongs_to :uploadable, :polymorphic => true
  
  attr_accessible :uploadable_id, :uploadable_type, :attachment, :shape, :description
  
  # Make :parent_type available for Paperclip :path & :url options.
  # Path on S3 should contain the parent class (e.g. "member") for
  # better readability.
  Paperclip.interpolates :parent_type do |attachment, style|
    attachment.instance.uploadable_type.downcase
  end
  # Paperclip settings, basic settings are in Rails.root/config/initializers/paperclip.rb
  has_attached_file :attachment,
    :path => ":class/:parent_type/:id/:style.:extension",
    :styles => lambda { |a|
      # Don't apply set_shape (= do not set style) when content_type == picture
      if ['image/jpeg','image/png','image/gif'].include?(a.instance_read(:content_type))
        a.instance.assign_shape 
      else
        {}
      end
    }

  # Defining image sizes (shapes) depending on @shape parameter
  # Adding a new @shape: add a new 'when "name"' section, then pass
  # params with upload helper.
  # Also, don't forget to add a new img.class_shape section in shared.sass 
  # for correct image rendering.
  def assign_shape
    case shape
    when "gallery"
      { :preview => "700x467>", :mid => "350x234>", :small => "230x153>" , :tiny => "100x67>" }
    when "photo"
      { :preview => "270x346>", :small => "100x128>" , :tiny => "78x100>" }
    when "logo"
      { :preview => "250x250>", :small => "150x150>" , :tiny => "70x70>" }
    when "sponsor"
      { :preview => "250x250>", :super => "728x90>" , :halfsize => "234x60!" }
    when "generic_file"
      {}
    else
      { :standard => "500x500>", :small => "250x250>", :tiny => "125x125>" }  
    end
  end

  scope :graphics, where("attachment_content_type IN ('image/jpeg','image/png','image/gif')")
  scope :documents, all - graphics
  


end