Talk JSON(P) with Rdio via Sinatra

app.rb

require 'sinatra'
require './rdio'

configure do
  ENV['RDIO_API_KEY'] = 'your key'
  ENV['RDIO_API_SHARED_SECRET'] = 'your secret'
  ENV['DOMAIN'] = 'yourapp.domain.com'
end

before do
  @rdio = Rdio.new ENV["RDIO_API_KEY"], ENV["RDIO_API_SHARED_SECRET"]
end

get '/' do
  'try /[username]/[API method]'
end

get '/:name/:method' do |name, method|
  content_type 'application/json', :charset => 'utf-8'
  cache_control :public, :max_age => 60*60

  callback = params.delete('callback')
  user = @rdio.findUser vanityName: name

  json = @rdio.send(method.to_sym, user: user['key']).to_json

  if callback
    content_type :js
    response = "#{callback}(#{json})" 
  else
    content_type :json
    response = json
  end

  response
end

Gemfile

source :rubygems

gem 'sinatra'
gem 'oauth'
gem 'json'

rdio.rb

require 'oauth/consumer'
OAuth::VERSION = 1

require 'json'

SITE = 'http://api.rdio.com'

PATH = '/1/'

class Rdio
  def initialize(key, secret)
    puts "Initializing Rdio consumer"
    @consumer = OAuth::Consumer.new key, secret, {:site => SITE}
    @consumer.http.read_timeout = 600 # ten-minute timeout, thanks
    puts "Initializing Rdio access token"
    @access_token = OAuth::AccessToken.new @consumer
    puts "Rdio API ready"
  end

  def method_missing(method, args = {})
    args[:method] = method.to_s
    puts "Rdio request for %s" % method.to_s
    response = @access_token.post PATH, args
    puts "Rdio request complete for %s" % method.to_s
    JSON::parse(response.body)["result"] if response.code.match("2..")
  end
end