module Paperclip
  class DataUriAdapter < StringioAdapter

    REGEXP = /\Adata:([-\w]+\/[-\w\+\.]+)?;base64,(.*)/m

    def initialize(target_uri)
      super(extract_target(target_uri))
    end

    private

    def extract_target(uri)
      data_uri_parts = uri.match(REGEXP) || []
      StringIO.new(Base64.decode64(data_uri_parts[2] || ''))
    end

  end
end

Paperclip.io_adapters.register Paperclip::DataUriAdapter do |target|
  String === target && target =~ Paperclip::DataUriAdapter::REGEXP
end