shyamkkhadka / dragonfly

An on-the-fly processing/encoding framework written as a Rack application.

Dragonfly

Dragonfly is a Rack framework for on-the-fly image handling.

Ideal for using with Ruby on Rails (2.3 and 3), Sinatra and all that gubbins.

For the lazy Rails user...

Gemfile:

gem 'rmagick',    :require => 'RMagick'
gem 'rack-cache', :require => 'rack/cache'
gem 'dragonfly', '~>0.7.5'

Initializer (e.g. config/initializers/dragonfly.rb):

require 'dragonfly/rails/images'

Migration:

add_column :albums, :cover_image_uid, :string

Model:

class Album < ActiveRecord::Base
  image_accessor :cover_image            # 'image_accessor' is provided by Dragonfly
                                         # this defines a reader/writer for cover_image
  # ...
end

View (for uploading via a file field):

<% form_for @album, :html => {:multipart => true} do |f| %>
  ...
  <%= f.file_field :cover_image %>
  ...
<% end %>

NB: REMEMBER THE MULTIPART BIT!!!

View (to display):

<%= image_tag @album.cover_image.url %>
<%= image_tag @album.cover_image.thumb('400x200#').url %>
<%= image_tag @album.cover_image.jpg.url %>
<%= image_tag @album.cover_image.process(:greyscale).encode(:tiff).url %>
...etc.

If using Capistrano with the above, you probably will want to keep the cache between deploys, so in deploy.rb:

namespace :dragonfly do
  desc "Symlink the Rack::Cache files"
  task :symlink, :roles => [:app] do
    run "mkdir -p #{shared_path}/tmp/dragonfly && ln -nfs #{shared_path}/tmp/dragonfly #{release_path}/tmp/dragonfly"
  end
end
after 'deploy:update_code', 'dragonfly:symlink'

Using outside of rails, custom storage/processing/encoding/analysis, and more...

Dragonfly is primarily a Rack app, so you can use it as a standalone app, or with Sinatra, Merb, etc.

It's highly customizable, and works with any data type (not just images).

For more info, consult the DOCUMENTATION

Issues

Please use the github issue tracker if you have any issues.

Suggestions/Questions

Google group dragonfly-users

Credits

• Mark Evans (author)

Copyright

Copyright (c) 2009-2010 Mark Evans. See LICENSE for details.