Avoid calls to Rails::Application since this is not the official API.

Your application should *always* reference your application const (as Blog::Application) and Rails.application should be used just internally.

actionpack/lib/action_dispatch/routing.rb

@@ -167,7 +167,7 @@ module ActionDispatch
   #
   # You can reload routes if you feel you must:
   #
-  #   Rails::Application.reload_routes!
+  #   Rails.application.reload_routes!
   #
   # This will clear all named routes and reload routes.rb if the file has been modified from
   # last load. To absolutely force reloading, use <tt>reload!</tt>.

activerecord/lib/active_record/railties/databases.rake

@@ -1,7 +1,7 @@
 namespace :db do
   task :load_config => :rails_env do
     require 'active_record'
-    ActiveRecord::Base.configurations = Rails::Application.config.database_configuration
+    ActiveRecord::Base.configurations = Rails.application.config.database_configuration
   end
 
   namespace :create do

activesupport/lib/active_support/file_update_checker.rb

@@ -1,16 +1,15 @@
 module ActiveSupport
   # This class is responsible to track files and invoke the given block
   # whenever one of these files are changed. For example, this class
-  # is used by Rails to reload routes whenever they are changed upon
-  # a new request.
+  # is used by Rails to reload the I18n framework whenever they are
+  # changed upon a new request.
   #
-  #   routes_reloader = ActiveSupport::FileUpdateChecker.new(paths) do
-  #     paths.each { |p| load(p) }
-  #     Rails::Application.routes.reload!
+  #   i18n_reloader = ActiveSupport::FileUpdateChecker.new(paths) do
+  #     I18n.reload!
   #   end
   #
   #   ActionDispatch::Callbacks.to_prepare do
-  #     routes_reloader.execute_if_updated
+  #     i18n_reloader.execute_if_updated
   #   end
   #
   class FileUpdateChecker

railties/guides/source/initialization.textile

@@ -11,7 +11,7 @@ This guide first describes the process of +rails server+ then explains the Passe
 
 h3. Launch!
 
-As of Rails 3, +script/server+ has become +rails server+. This was done to centralise all rails related commands to one common file.
+As of Rails 3, +script/server+ has become +rails server+. This was done to centralize all rails related commands to one common file.
 
 The actual +rails+ command is kept in _railties/bin/rails_ and goes like this:
 
@@ -58,11 +58,8 @@ In +script/rails+ we see the following:
   #!/usr/bin/env ruby
   # This command will automatically be run when you run "rails" with Rails 3 gems installed from the root of your application.
 
-  ENV_PATH  = File.expand_path('../../config/environment',  __FILE__)
-  BOOT_PATH = File.expand_path('../../config/boot',  __FILE__)
-  APP_PATH  = File.expand_path('../../config/application',  __FILE__)
-
-  require BOOT_PATH
+  APP_PATH = File.expand_path('../../config/application',  __FILE__)
+  require File.expand_path('../../config/boot',  __FILE__)
   require 'rails/commands'
 </ruby>
 
@@ -79,15 +76,19 @@ h3. _config/boot.rb_
 _config/boot.rb_ is the first stop for everything for initializing your application. This boot process does quite a bit of work for you and so this section attempts to go in-depth enough to explain what each of the pieces does.
 
 <ruby>
-  # Use Bundler (preferred)
+  require 'rubygems'
+
+  # Set up gems listed in the Gemfile.
+  gemfile = File.expand_path('../../Gemfile', __FILE__)
   begin
-    require File.expand_path('../../.bundle/environment', __FILE__)
-  rescue LoadError
-    require 'rubygems'
+    ENV['BUNDLE_GEMFILE'] = gemfile
     require 'bundler'
     Bundler.setup
-  end
-
+  rescue Bundler::GemNotFound => e
+    STDERR.puts e.message
+    STDERR.puts "Try running `bundle install`."
+    exit!
+  end if File.exist?(gemfile)
 </ruby>
 
 h3. Bundled Rails (3.x)
@@ -164,33 +165,7 @@ TODO: Prettify when it becomes more stable.
 
 I won't go into what each of these gems are, as that is really something that needs covering on a case-by-case basis. We will however just dig a little under the surface of Bundler.
 
-Back in _config/boot.rb_, the first line will try to include _.bundle/environment.rb_, which doesn't exist in a bare-bones Rails application and because this file does not exist Ruby will raise a +LoadError+ which will be rescued and run the following code:
-
-<ruby>
-  require 'rubygems'
-  require 'bundler'
-  Bundler.setup
-</ruby>
-
-+Bundler.setup+ here will load and parse the +Gemfile+ and add the _lib_ directory of the gems mentioned **and** their dependencies (**and** their dependencies' dependencies, and so on) to the +$LOAD_PATH+.
-
-Now we will go down the alternate timeline where we generate a _.bundle/environment.rb_ file using the +bundle lock+ command. This command also creates a _Gemfile.lock_ file which is actually a YAML file loaded by this method in Bundler before it moves on to check for _Gemfile_:
-
-<ruby>
-  def definition(gemfile = default_gemfile)
-    configure
-    root = Pathname.new(gemfile).dirname
-    lockfile = root.join("Gemfile.lock")
-    if lockfile.exist?
-      Definition.from_lock(lockfile)
-    else
-      Definition.from_gemfile(gemfile)
-    end
-  end
-</ruby>
-
-
-The _.bundle/environment.rb_ file adds the _lib_ directory of all the gems specified in +Gemfile.lock+ to +$LOAD_PATH+.
+Back in _config/boot.rb_, we call +Bundler.setup+ which will load and parse the +Gemfile+ and add the _lib_ directory of the gems mentioned **and** their dependencies (**and** their dependencies' dependencies, and so on) to the +$LOAD_PATH+.
 
 h3. Requiring Rails
 
@@ -326,6 +301,11 @@ As you can see for the duration of the +eager_autoload+ block the class variable
   module ActiveSupport
     extend ActiveSupport::Autoload
 
+    autoload :DescendantsTracker
+    autoload :FileUpdateChecker
+    autoload :LogSubscriber
+    autoload :Notifications
+
     # TODO: Narrow this list down
     eager_autoload do
       autoload :BacktraceCleaner
@@ -348,7 +328,6 @@ As you can see for the duration of the +eager_autoload+ block the class variable
       autoload :OptionMerger
       autoload :OrderedHash
       autoload :OrderedOptions
-      autoload :Notifications
       autoload :Rescuable
       autoload :SecureRandom
       autoload :StringInquirer
@@ -589,19 +568,20 @@ This file (_railties/lib/rails.rb_) requires the very, very basics that Rails ne
   require 'action_dispatch/railtie'
 </ruby>
 
-+require 'pathname'+ requires the Pathname class which is used for returning a Pathname object for +Rails.root+ so that instead of doing:
-
-<ruby>
-  File.join(Rails.root, "app/controllers")
-</ruby>
-
-You may do:
++require 'pathname'+ requires the Pathname class which is used for returning a Pathname object for +Rails.root+. Although is coming to use this path name to generate paths as below:
 
 <ruby>
   Rails.root.join("app/controllers")
 </ruby>
 
-Although this is not new to Rails 3 (it was available in 2.3.5), it is something worthwhile pointing out.
+Pathname can also be converted to string, so the following syntax is preferred:
+
+<ruby>
+  "#{Rails.root}/app/controllers"
+</ruby>
+
+
+This works because Ruby automatically handles file path conversions. Although this is not new to Rails 3 (it was available in 2.3.5), it is something worthwhile pointing out.
 
 Inside this file there are other helpful helper methods defined, such as +Rails.root+, +Rails.env+, +Rails.logger+ and +Rails.application+.
 
@@ -1833,7 +1813,7 @@ We do not already have a +Rails.application+, so instead this resorts to calling
   end
 </ruby>
 
-This +called_from+ setting looks a little overwhelming to begin with, but the short end of it is that it returns the route to your application's config directory, something like: _/home/you/yourapp/config_. After +called_from+ has been set, +super+ is again called and this means the +Rails::Railtie#inherited+ method (in _railties/lib/rails/railtie.rb_):
+This +called_from+ setting looks a little overwhelming to begin with, but the short end of it is that it returns your application's root, something like: _/home/you/yourapp_. After +called_from+ has been set, +super+ is again called and this means the +Rails::Railtie#inherited+ method (in _railties/lib/rails/railtie.rb_):
 
 <ruby>
   def inherited(base)

railties/lib/rails/application.rb

@@ -8,14 +8,6 @@ module Rails
   # In Rails 3.0, a Rails::Application object was introduced which is nothing more than
   # an Engine but with the responsibility of coordinating the whole boot process.
   #
-  # Opposite to Rails::Engine, you can only have one Rails::Application instance
-  # in your process and both Rails::Application and YourApplication::Application
-  # points to it.
-  #
-  # In other words, Rails::Application is Singleton and whenever you are accessing
-  # Rails::Application.config or YourApplication::Application.config, you are actually
-  # accessing YourApplication::Application.instance.config.
-  #
   # == Initialization
   #
   # Rails::Application is responsible for executing all railties, engines and plugin
@@ -57,6 +49,10 @@ module Rails
 
       def instance
         if self == Rails::Application
+          if Rails.application
+            ActiveSupport::Deprecation.warn "Calling a method in Rails::Application is deprecated, " <<
+              "please call it directly in your application constant #{Rails.application.class.name}.", caller
+          end
           Rails.application
         else
           @@instance ||= new

railties/lib/rails/commands.rb

@@ -13,27 +13,27 @@ command = aliases[command] || command
 case command
 when 'generate', 'destroy', 'plugin', 'benchmarker', 'profiler'
   require APP_PATH
-  Rails::Application.require_environment!
+  Rails.application.require_environment!
   require "rails/commands/#{command}"
 
 when 'console'
   require 'rails/commands/console'
   require APP_PATH
-  Rails::Application.require_environment!
-  Rails::Console.start(Rails::Application)
+  Rails.application.require_environment!
+  Rails::Console.start(Rails.application)
 
 when 'server'
   require 'rails/commands/server'
   Rails::Server.new.tap { |server|
     require APP_PATH
-    Dir.chdir(Rails::Application.root)
+    Dir.chdir(Rails.application.root)
     server.start
   }
 
 when 'dbconsole'
   require 'rails/commands/dbconsole'
   require APP_PATH
-  Rails::DBConsole.start(Rails::Application)
+  Rails::DBConsole.start(Rails.application)
 
 when 'application', 'runner'
   require "rails/commands/#{command}"

railties/lib/rails/commands/runner.rb

@@ -37,7 +37,7 @@ ARGV.delete(code_or_file)
 ENV["RAILS_ENV"] = options[:environment]
 
 require APP_PATH
-Rails::Application.require_environment!
+Rails.application.require_environment!
 
 begin
   if code_or_file.nil?

railties/lib/rails/generators/rails/app/templates/Rakefile

@@ -4,4 +4,4 @@
 require File.expand_path('../config/application', __FILE__)
 require 'rake'
 
-Rails::Application.load_tasks
+<%= app_const %>.load_tasks

railties/lib/rails/generators/rails/app/templates/config/initializers/secret_token.rb.tt

@@ -4,4 +4,4 @@
 # If you change this key, all old signed cookies will become invalid!
 # Make sure the secret is at least 30 characters and all random,
 # no regular words or you'll be exposed to dictionary attacks.
-Rails.application.config.secret_token = '<%= app_secret %>'
+<%= app_const %>.config.secret_token = '<%= app_secret %>'

railties/lib/rails/generators/rails/app/templates/config/initializers/session_store.rb.tt

@@ -1,8 +1,8 @@
 # Be sure to restart your server when you modify this file.
 
-Rails.application.config.session_store :cookie_store, :key => '_<%= app_name %>_session'
+<%= app_const %>.config.session_store :cookie_store, :key => '_<%= app_name %>_session'
 
 # Use the database for sessions instead of the cookie-based default,
 # which shouldn't be used to store highly confidential information
 # (create the session table with "rake db:sessions:create")
-# Rails.application.config.session_store :active_record_store
+# <%= app_const %>.config.session_store :active_record_store

railties/lib/rails/info_routes.rb

@@ -1,3 +1,3 @@
-Rails.application.routes.draw do |map|
+Rails.application.routes.draw do
   match '/rails/info/properties' => "rails/info#properties"
 end

railties/lib/rails/tasks/middleware.rake

@@ -3,5 +3,5 @@ task :middleware => :environment do
   Rails.configuration.middleware.each do |middleware|
     puts "use #{middleware.inspect}"
   end
-  puts "run #{Rails::Application.instance.class.name}.routes"
+  puts "run #{Rails.application.class.name}.routes"
 end

railties/lib/rails/tasks/routes.rake

@@ -1,6 +1,6 @@
 desc 'Print out all defined routes in match order, with names. Target specific controller with CONTROLLER=x.'
 task :routes => :environment do
-  Rails::Application.reload_routes!
+  Rails.application.reload_routes!
   all_routes = ENV['CONTROLLER'] ? Rails.application.routes.routes.select { |route| route.defaults[:controller] == ENV['CONTROLLER'] } : Rails.application.routes.routes
   routes = all_routes.collect do |route|
     # TODO: The :index method is deprecated in 1.9 in favor of :key

railties/test/application/initializers/frameworks_test.rb

@@ -36,7 +36,7 @@ module ApplicationTests
 
     test "allows me to configure default url options for ActionMailer" do
       app_file "config/environments/development.rb", <<-RUBY
-        Rails::Application.configure do
+        AppTemplate::Application.configure do
           config.action_mailer.default_url_options = { :host => "test.rails" }
         end
       RUBY

railties/test/application/initializers/i18n_test.rb

@@ -16,7 +16,7 @@ module ApplicationTests
     end
 
     def app
-      @app ||= Rails::Application
+      @app ||= Rails.application
     end
 
     def assert_fallbacks(fallbacks)

railties/test/application/rake_test.rb

@@ -24,11 +24,11 @@ module ApplicationTests
       app_file "config/environment.rb", <<-RUBY
         SuperMiddleware = Struct.new(:app)
 
-        Rails::Application.configure do
+        AppTemplate::Application.configure do
           config.middleware.use SuperMiddleware
         end
 
-        Rails::Application.initialize!
+        AppTemplate::Application.initialize!
       RUBY
 
       assert_match "SuperMiddleware", Dir.chdir(app_path){ `rake middleware` }

railties/test/rails_info_controller_test.rb

@@ -11,7 +11,7 @@ class InfoControllerTest < ActionController::TestCase
   tests Rails::InfoController
 
   def setup
-    Rails.application.routes.draw do |map|
+    Rails.application.routes.draw do
       match '/rails/info/properties' => "rails/info#properties"
     end
     @controller.stubs(:consider_all_requests_local? => false, :local_request? => true)