=Paperclip

Paperclip is a lightweight attachment manager for ActiveRecord. It saves and manages your attachments, be they images or Word Docs, with one line of code. You can automatically thumbnail images as they're uploaded, and you don't have to worry about installing any ruby-specific libraries. You don't have to worry about compiling headaches with RMagick, concurrency issues and race conditions with MiniMagick, or unsupported image types with ImageScience. All you need is a working Image- or GraphicsMagick installation -- the +convert+ command is all you need.

Paperclip uses the filesystem to save your files. You specify a root that the files will be saved to, and, if you're attaching images, any other sizes they need to be converted to, and they'll all be saved to the right place when your object saves.

See the documentation for the +has_attached_file+ method for extensive details.

==Usage

In your model:

  class Photo < ActiveRecord::Base
    has_attached_file :image, :thumbnails => { :medium => "300x300>", :thumb => "100x100>" }
  end

In your edit and new views:

  <% form_for :photo, @photo, :url => photo_path, :html => { :multipart => true } do |form| %>
    <%= form.file_field :image %>
  <% end %>

In your controller:

  def create
    @photo = Photo.create( params[:photo] )
  end

In your show view:

  <%= image_tag @photo.image_url %>
  <%= image_tag @photo.image_url(:original) %>
  <%= image_tag @photo.image_url(:medium) %>
  <%= image_tag @photo.image_url(:thumb) %>