web.rb

A sinatra block

post '/play_list/?' do
  puts params.inspect
  id = very_clean( params[:_id] )

  # validations
  raise "Id cannot be blank" if id.nil?
  raise "Id cannot be blank" if id.empty?
  raise "Id must be a String" unless id.is_a? String
  raise "That play list already exists" if find_play_list( id )

  # make sure to use a clean id
  play_list = params
  play_list["_id"] = id

  # return
  content_type :json
  settings.play_lists.insert play_list
  return find_play_list( id ).to_json
end