For more info about using Rack applications, see the docs at http://rack.rubyforge.org/

Basic usage involves storing data (e.g. images), then serving it in some form.

A basic rackup file config.ru:

require 'rubygems'
require 'dragonfly'

Dragonfly[:my_app_name].configure do |c|
  # ... configuration here

run Dragonfly:App[:my_app_name]

See Configuration for more details.

The basic flow is instantiate an app -> configure it -> run it.

Example: Using to serve resized images


require 'rubygems'
require 'dragonfly'

app = Dragonfly[:images].configure_with(:imagemagick)

run app

This enables the app to use all the ImageMagick goodies provided by Dragonfly (see Configuration). By default the file data store is used.

In the console:

app = Dragonfly[:images]

# Store
uid = app.store(File.new('path/to/image.png'))      # ===> unique uid

# Get the url for a thumbnail
url = app.fetch(uid).thumb('400x300').url           # ===> "/media/BAhbBlsHOgZmIg9hc..."

Now when we visit the url /media/BAhbBlsHOgZmIg9hc... in the browser, we get a resized image!

Mounting in Rack

See URLs