1 files changed, 100 insertions, 0 deletions
diff --git a/actionpack/lib/sprockets/railtie.rb b/actionpack/lib/sprockets/railtie.rb
new file mode 100644
index 0000000000..9c10decd60
--- /dev/null
+++ b/actionpack/lib/sprockets/railtie.rb
@@ -0,0 +1,100 @@
+module Sprockets
+  class Railtie < Rails::Railtie
+    def self.using_coffee?
+      require 'coffee-script'
+      defined?(CoffeeScript)
+    rescue LoadError
+      false
+    end
+
+    def self.using_scss?
+      require 'sass'
+      defined?(Sass)
+    rescue LoadError
+      false
+    end
+
+    config.app_generators.javascript_engine :coffee if using_coffee?
+    config.app_generators.stylesheet_engine :scss   if using_scss?
+
+    # Configure ActionController to use sprockets.
+    initializer "sprockets.set_configs", :after => "action_controller.set_configs" do |app|
+      ActiveSupport.on_load(:action_controller) do
+        self.use_sprockets = app.config.assets.enabled
+      end
+    end
+
+    # We need to configure this after initialization to ensure we collect
+    # paths from all engines. This hook is invoked exactly before routes
+    # are compiled.
+    config.after_initialize do |app|
+      assets = app.config.assets
+      next unless assets.enabled
+
+      app.assets = asset_environment(app)
+
+      ActiveSupport.on_load(:action_view) do
+        app.assets.context.instance_eval do
+          include ::ActionView::Helpers::SprocketsHelper
+        end
+      end
+
+      app.routes.append do
+        mount app.assets => assets.prefix
+      end
+
+      if config.action_controller.perform_caching
+        app.assets = app.assets.index
+      end
+    end
+
+    protected
+
+    def asset_environment(app)
+      require "sprockets"
+      assets = app.config.assets
+      env = Sprockets::Environment.new(app.root.to_s)
+      env.static_root = File.join(app.root.join("public"), assets.prefix)
+      env.paths.concat assets.paths
+      env.logger = Rails.logger
+      env.js_compressor = expand_js_compressor(assets.js_compressor)
+      env.css_compressor = expand_css_compressor(assets.css_compressor)
+      env
+    end
+
+    def expand_js_compressor(sym)
+      case sym
+      when :closure
+        require 'closure-compiler'
+        Closure::Compiler.new
+      when :uglifier
+        require 'uglifier'
+        Uglifier.new
+      when :yui
+        require 'yui/compressor'
+        YUI::JavaScriptCompressor.new
+      else
+        sym
+      end
+    end
+
+    def expand_css_compressor(sym)
+      case sym
+      when :scss
+        require 'sass'
+        compressor = Object.new
+        def compressor.compress(source)
+          Sass::Engine.new(source,
+            :syntax => :scss, :style => :compressed
+          ).render
+        end
+        compressor
+      when :yui
+        require 'yui/compressor'
+        YUI::JavaScriptCompressor.new(:munge => true)
+      else
+        sym
+      end
+    end
+  end
+end