Use RABL to build JSON responses given by API

Gemfile

@@ -8,6 +8,8 @@ gem 'haml', '~> 3.1'
 
 gem 'bcrypt-ruby', '~> 3.0'
 
+gem 'rabl', '~> 0.6'
+
 group :development, :test do
   gem 'rspec-rails', '~> 2.6'
   gem 'capybara', '~> 1.1'

Gemfile.lock

@@ -70,6 +70,9 @@ GEM
     nokogiri (1.5.0)
     pg (0.11.0)
     polyglot (0.3.3)
+    rabl (0.6.0)
+      activesupport (>= 2.3.14)
+      multi_json (~> 1.0.3)
     rack (1.3.5)
     rack-cache (1.1)
       rack (>= 0.4)
@@ -146,6 +149,7 @@ DEPENDENCIES
   haml (~> 3.1)
   libnotify (~> 0.6)
   pg (~> 0.11)
+  rabl (~> 0.6)
   rails (~> 3.1)
   rb-inotify (~> 0.8)
   rspec-rails (~> 2.6)

Guardfile

@@ -22,4 +22,8 @@ guard 'rspec', :cli => '--drb', :notification => false do
   watch('app/controllers/application_controller.rb')  { 'spec/controllers' }
 
   watch(%r{^app/views/layouts/})      { 'spec/integration' }
+
+  watch(%r{^app/views/(.+)/(?:[^/]+).rabl}) do |m|
+    "spec/controllers/#{m[1]}_controller_spec.rb"
+  end
 end

app/controllers/api/v0/playlists_controller.rb

@@ -3,6 +3,5 @@ class Api::V0::PlaylistsController < Api::ApplicationController
 
   def index
     @playlists = Playlist.all
-    respond_with @playlists
   end
 end

app/views/api/v0/playlists/index.rabl

@@ -0,0 +1,4 @@
+collection @playlists
+
+attribute :id
+attribute :name

config/initializers/rabl_init.rb

@@ -0,0 +1,16 @@
+Rabl.configure do |config|
+  # Commented as these are defaults
+  # config.cache_sources = false
+  # config.json_engine = nil # Any multi\_json engines
+  # config.msgpack_engine = nil # Defaults to ::MessagePack
+  # config.bson_engine = nil # Defaults to ::BSON
+  # config.plist_engine = nil # Defaults to ::Plist::Emit
+  # config.include_json_root = true
+  config.include_json_root = false
+  # config.include_msgpack_root = true
+  # config.include_bson_root = true
+  # config.include_plist_root = true
+  # config.include_xml_root  = false
+  # config.enable_json_callbacks = false
+  # config.xml_options = { :dasherize  => true, :skip_types => false }
+end

spec/controllers/api/v0/playlists_controller_spec.rb

@@ -20,6 +20,10 @@ describe Api::V0::PlaylistsController do
       do_get.should have(2).items
     end
 
+    it 'lists playlists with their id' do
+      do_get.each { |t| t.keys.should include 'id' }
+    end
+
     it 'lists playlists with their name' do
       do_get.each { |t| t.keys.should include 'name' }
     end