Extract generic callbacks middleware from dispatcher

actionpack/lib/action_controller/dispatch/dispatcher.rb

@@ -1,46 +1,11 @@
+require 'active_support/core_ext/module/delegation'
+
 module ActionController
   # Dispatches requests to the appropriate controller and takes care of
   # reloading the app after each request when Dependencies.load? is true.
   class Dispatcher
-    class << self
-      def define_dispatcher_callbacks(cache_classes)
-        unless cache_classes
-          # Development mode callbacks
-          before_dispatch :reload_application
-          after_dispatch :cleanup_application
-
-          ActionView::Helpers::AssetTagHelper.cache_asset_timestamps = false
-        end
-
-        if defined?(ActiveRecord)
-          to_prepare(:activerecord_instantiate_observers) { ActiveRecord::Base.instantiate_observers }
-        end
-
-        after_dispatch :flush_logger if Base.logger && Base.logger.respond_to?(:flush)
-
-        to_prepare do
-          I18n.reload!
-        end
-      end
-
-      # Add a preparation callback. Preparation callbacks are run before every
-      # request in development mode, and before the first request in production
-      # mode.
-      #
-      # An optional identifier may be supplied for the callback. If provided,
-      # to_prepare may be called again with the same identifier to replace the
-      # existing callback. Passing an identifier is a suggested practice if the
-      # code adding a preparation block may be reloaded.
-      def to_prepare(identifier = nil, &block)
-        @prepare_dispatch_callbacks ||= ActiveSupport::Callbacks::CallbackChain.new
-        callback = ActiveSupport::Callbacks::Callback.new(:prepare_dispatch, block, :identifier => identifier)
-        @prepare_dispatch_callbacks.replace_or_append!(callback)
-      end
-
-      def run_prepare_callbacks
-        new.send :run_callbacks, :prepare_dispatch
-      end
-    end
+    cattr_accessor :prepare_each_request
+    self.prepare_each_request = false
 
     cattr_accessor :router
     self.router = Routing::Routes
@@ -51,37 +16,50 @@ module ActionController
       middleware.instance_eval(File.read(middlewares), middlewares, 1)
     end
 
-    include ActiveSupport::Callbacks
-    define_callbacks :prepare_dispatch, :before_dispatch, :after_dispatch
+    class << self
+      def define_dispatcher_callbacks(cache_classes)
+        unless cache_classes
+          # Run prepare callbacks before every request in development mode
+          self.prepare_each_request = true
 
-    def initialize
-      @app = @@middleware.build(@@router)
-      freeze
-    end
+          # Development mode callbacks
+          ActionDispatch::Callbacks.before_dispatch do |app|
+            ActionController::Dispatcher.router.reload
+          end
 
-    def call(env)
-      run_callbacks :before_dispatch
-      @app.call(env)
-    ensure
-      run_callbacks :after_dispatch, :enumerator => :reverse_each
-    end
+          ActionDispatch::Callbacks.after_dispatch do
+            # Cleanup the application before processing the current request.
+            ActiveRecord::Base.reset_subclasses if defined?(ActiveRecord)
+            ActiveSupport::Dependencies.clear
+            ActiveRecord::Base.clear_reloadable_connections! if defined?(ActiveRecord)
+          end
 
-    def reload_application
-      # Run prepare callbacks before every request in development mode
-      run_callbacks :prepare_dispatch
+          ActionView::Helpers::AssetTagHelper.cache_asset_timestamps = false
+        end
 
-      @@router.reload
-    end
+        if defined?(ActiveRecord)
+          to_prepare(:activerecord_instantiate_observers) do
+            ActiveRecord::Base.instantiate_observers
+          end
+        end
 
-    def cleanup_application
-      # Cleanup the application before processing the current request.
-      ActiveRecord::Base.reset_subclasses if defined?(ActiveRecord)
-      ActiveSupport::Dependencies.clear
-      ActiveRecord::Base.clear_reloadable_connections! if defined?(ActiveRecord)
-    end
+        if Base.logger && Base.logger.respond_to?(:flush)
+          after_dispatch do
+            Base.logger.flush
+          end
+        end
 
-    def flush_logger
-      Base.logger.flush
+        to_prepare do
+          I18n.reload!
+        end
+      end
+
+      delegate :to_prepare, :prepare_dispatch, :before_dispatch, :after_dispatch,
+        :to => ActionDispatch::Callbacks
+
+      def new
+        @@middleware.build(@@router)
+      end
     end
   end
 end

actionpack/lib/action_controller/dispatch/middlewares.rb

@@ -3,6 +3,7 @@ use "Rack::Lock", :if => lambda {
 }
 
 use "ActionDispatch::ShowExceptions", lambda { ActionController::Base.consider_all_requests_local }
+use "ActionDispatch::Callbacks", lambda { ActionController::Dispatcher.prepare_each_request }
 use "ActionDispatch::Rescue", lambda {
   controller = (::ApplicationController rescue ActionController::Base)
   # TODO: Replace with controller.action(:_rescue_action)

actionpack/lib/action_dispatch.rb

@@ -38,6 +38,7 @@ module ActionDispatch
   autoload :Response, 'action_dispatch/http/response'
   autoload :StatusCodes, 'action_dispatch/http/status_codes'
 
+  autoload :Callbacks, 'action_dispatch/middleware/callbacks'
   autoload :ParamsParser, 'action_dispatch/middleware/params_parser'
   autoload :Rescue, 'action_dispatch/middleware/rescue'
   autoload :ShowExceptions, 'action_dispatch/middleware/show_exceptions'

actionpack/lib/action_dispatch/middleware/callbacks.rb

@@ -0,0 +1,40 @@
+module ActionDispatch
+  class Callbacks
+    include ActiveSupport::Callbacks
+    define_callbacks :prepare, :before, :after
+
+    class << self
+      # DEPRECATED
+      alias_method :prepare_dispatch, :prepare
+      alias_method :before_dispatch, :before
+      alias_method :after_dispatch, :after
+    end
+
+    # Add a preparation callback. Preparation callbacks are run before every
+    # request in development mode, and before the first request in production
+    # mode.
+    #
+    # An optional identifier may be supplied for the callback. If provided,
+    # to_prepare may be called again with the same identifier to replace the
+    # existing callback. Passing an identifier is a suggested practice if the
+    # code adding a preparation block may be reloaded.
+    def self.to_prepare(identifier = nil, &block)
+      @prepare_callbacks ||= ActiveSupport::Callbacks::CallbackChain.new
+      callback = ActiveSupport::Callbacks::Callback.new(:prepare, block, :identifier => identifier)
+      @prepare_callbacks.replace_or_append!(callback)
+    end
+
+    def initialize(app, prepare_each_request = false)
+      @app, @prepare_each_request = app, prepare_each_request
+      run_callbacks :prepare
+    end
+
+    def call(env)
+      run_callbacks :before
+      run_callbacks :prepare if @prepare_each_request
+      @app.call(env)
+    ensure
+      run_callbacks :after, :enumerator => :reverse_each
+    end
+  end
+end

actionpack/test/controller/dispatcher_test.rb

@@ -6,20 +6,20 @@ class DispatcherTest < Test::Unit::TestCase
   def setup
     ENV['REQUEST_METHOD'] = 'GET'
 
-    Dispatcher.middleware = ActionDispatch::MiddlewareStack.new do |middleware|
-      middlewares = File.expand_path(File.join(File.dirname(__FILE__), "../../lib/action_controller/dispatch/middlewares.rb"))
-      middleware.instance_eval(File.read(middlewares))
-    end
-
     # Clear callbacks as they are redefined by Dispatcher#define_dispatcher_callbacks
-    Dispatcher.instance_variable_set("@prepare_dispatch_callbacks", ActiveSupport::Callbacks::CallbackChain.new)
-    Dispatcher.instance_variable_set("@before_dispatch_callbacks", ActiveSupport::Callbacks::CallbackChain.new)
-    Dispatcher.instance_variable_set("@after_dispatch_callbacks", ActiveSupport::Callbacks::CallbackChain.new)
+    ActionDispatch::Callbacks.instance_variable_set("@prepare_callbacks", ActiveSupport::Callbacks::CallbackChain.new)
+    ActionDispatch::Callbacks.instance_variable_set("@before_callbacks", ActiveSupport::Callbacks::CallbackChain.new)
+    ActionDispatch::Callbacks.instance_variable_set("@after_callbacks", ActiveSupport::Callbacks::CallbackChain.new)
 
+    @old_router, Dispatcher.router = Dispatcher.router, mock()
+    Dispatcher.router.stubs(:call).returns([200, {}, 'response'])
+    Dispatcher.router.stubs(:reload)
     Dispatcher.stubs(:require_dependency)
   end
 
   def teardown
+    Dispatcher.router = @old_router
+    @dispatcher = nil
     ENV.delete 'REQUEST_METHOD'
   end
 
@@ -29,12 +29,12 @@ class DispatcherTest < Test::Unit::TestCase
   end
 
   def test_reloads_routes_before_dispatch_if_in_loading_mode
-    ActionController::Routing::Routes.expects(:reload).once
+    Dispatcher.router.expects(:reload).once
     dispatch(false)
   end
 
   def test_leaves_dependencies_after_dispatch_if_not_in_loading_mode
-    ActionController::Routing::Routes.expects(:reload).never
+    Dispatcher.router.expects(:reload).never
     ActiveSupport::Dependencies.expects(:clear).never
 
     dispatch
@@ -55,7 +55,7 @@ class DispatcherTest < Test::Unit::TestCase
     assert_nil a || b || c
 
     # Run callbacks
-    Dispatcher.run_prepare_callbacks
+    dispatch
 
     assert_equal 1, a
     assert_equal 2, b
@@ -72,16 +72,22 @@ class DispatcherTest < Test::Unit::TestCase
     Dispatcher.to_prepare(:unique_id) { |*args| a = b = 1 }
     Dispatcher.to_prepare(:unique_id) { |*args| a = 2 }
 
-    Dispatcher.run_prepare_callbacks
+    dispatch
     assert_equal 2, a
     assert_equal nil, b
   end
 
   private
     def dispatch(cache_classes = true)
-      ActionController::Routing::RouteSet.any_instance.stubs(:call).returns([200, {}, 'response'])
+      ActionController::Dispatcher.prepare_each_request = false
       Dispatcher.define_dispatcher_callbacks(cache_classes)
-      Dispatcher.new.call({'rack.input' => StringIO.new('')})
+      Dispatcher.middleware = ActionDispatch::MiddlewareStack.new do |middleware|
+        middlewares = File.expand_path(File.join(File.dirname(__FILE__), "../../lib/action_controller/dispatch/middlewares.rb"))
+        middleware.instance_eval(File.read(middlewares))
+      end
+
+      @dispatcher ||= Dispatcher.new
+      @dispatcher.call({'rack.input' => StringIO.new(''), 'action_dispatch.show_exceptions' => false})
     end
 
     def assert_subclasses(howmany, klass, message = klass.subclasses.inspect)

railties/lib/console_app.rb

@@ -26,8 +26,7 @@ end
 #reloads the environment
 def reload!
   puts "Reloading..."
-  dispatcher = ActionController::Dispatcher.new
-  dispatcher.cleanup_application
-  dispatcher.reload_application
+  ActionController::Dispatcher.new
+  ActionController::Dispatcher.router.reload
   true
 end

railties/lib/initializer.rb

@@ -632,7 +632,6 @@ Run `rake gems:install` to install the missing gems.
       return unless configuration.frameworks.include?(:action_controller)
       require 'dispatcher' unless defined?(::Dispatcher)
       Dispatcher.define_dispatcher_callbacks(configuration.cache_classes)
-      Dispatcher.run_prepare_callbacks
     end
 
     def disable_dependency_loading