Let’s see this modularity first hand by building up a CarrierWave uploader from scratch.

To begin with, we’ll install CarrierWave:

  gem install carrierwave

Then, we can make the world’s shortest uploader:

  require 'carrierwave'

  class MyUploader < CarrierWave::Uploader::Base
    storage :file
  end

Even at this point, we can start saving files:

  file = File.open('example.jpg')
  uploader = MyUploader.new
  uploader.store!(file)

[snip -ed]

If you’re ready for more, check out:

• the readme
• the wiki
• the Mocking fog when using it with CarrierWave post from Mike Gehard
• and the How to set up CarrierWave for local storage with AppCloud documentation for Engine Yard AppCloud users.

I’m sure you’ll enjoy using CarrierWave as much as I have!

[Nice.]
Source: Union Station