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-rw-r--r--guides/source/configuring.textile2
-rw-r--r--guides/source/debugging_rails_applications.textile2
-rw-r--r--guides/source/getting_started.textile2
-rw-r--r--guides/source/initialization.textile108
4 files changed, 77 insertions, 37 deletions
diff --git a/guides/source/configuring.textile b/guides/source/configuring.textile
index f114075cae..af46538bf5 100644
--- a/guides/source/configuring.textile
+++ b/guides/source/configuring.textile
@@ -585,7 +585,7 @@ After loading the framework and any gems in your application, Rails turns to loa
NOTE: You can use subfolders to organize your initializers if you like, because Rails will look into the whole file hierarchy from the initializers folder on down.
-TIP: If you have any ordering dependency in your initializers, you can control the load order by naming. For example, +01_critical.rb+ will be loaded before +02_normal.rb+.
+TIP: If you have any ordering dependency in your initializers, you can control the load order through naming. Initializer files are loaded in alphabetical order by their path. For example, +01_critical.rb+ will be loaded before +02_normal.rb+.
h3. Initialization events
diff --git a/guides/source/debugging_rails_applications.textile b/guides/source/debugging_rails_applications.textile
index 45fa4ada78..0802a2db26 100644
--- a/guides/source/debugging_rails_applications.textile
+++ b/guides/source/debugging_rails_applications.textile
@@ -698,7 +698,7 @@ There are some Rails plugins to help you to find errors and debug your applicati
h3. References
-* "ruby-debug Homepage":http://www.datanoise.com/ruby-debug
+* "ruby-debug Homepage":http://bashdb.sourceforge.net/ruby-debug/home-page.html
* "debugger Homepage":http://github.com/cldwalker/debugger
* "Article: Debugging a Rails application with ruby-debug":http://www.sitepoint.com/article/debug-rails-app-ruby-debug/
* "ruby-debug Basics screencast":http://brian.maybeyoureinsane.net/blog/2007/05/07/ruby-debug-basics-screencast/
diff --git a/guides/source/getting_started.textile b/guides/source/getting_started.textile
index e25dac22da..c129aeb2e1 100644
--- a/guides/source/getting_started.textile
+++ b/guides/source/getting_started.textile
@@ -13,8 +13,6 @@ endprologue.
WARNING. This Guide is based on Rails 3.2. Some of the code shown here will not
work in earlier versions of Rails.
-WARNING: The Edge version of this guide is currently being re-worked. Please excuse us while we re-arrange the place.
-
h3. Guide Assumptions
This guide is designed for beginners who want to get started with a Rails
diff --git a/guides/source/initialization.textile b/guides/source/initialization.textile
index 155a439e64..12b2eb7458 100644
--- a/guides/source/initialization.textile
+++ b/guides/source/initialization.textile
@@ -1,13 +1,15 @@
h2. The Rails Initialization Process
-This guide explains the internals of the initialization process in Rails as of Rails 3.1. It is an extremely in-depth guide and recommended for advanced Rails developers.
+This guide explains the internals of the initialization process in Rails
+as of Rails 4. It is an extremely in-depth guide and recommended for advanced Rails developers.
* Using +rails server+
* Using Passenger
endprologue.
-This guide goes through every single file, class and method call that is required to boot up the Ruby on Rails stack for a default Rails 3.1 application, explaining each part in detail along the way. For this guide, we will be focusing on how the two most common methods (+rails server+ and Passenger) boot a Rails application.
+This guide goes through every single file, class and method call that is
+required to boot up the Ruby on Rails stack for a default Rails 4 application, explaining each part in detail along the way. For this guide, we will be focusing on how the two most common methods (+rails server+ and Passenger) boot a Rails application.
NOTE: Paths in this guide are relative to Rails or a Rails application unless otherwise specified.
@@ -22,16 +24,15 @@ The actual +rails+ command is kept in _bin/rails_:
<ruby>
#!/usr/bin/env ruby
-begin
- require "rails/cli"
-rescue LoadError
- railties_path = File.expand_path('../../railties/lib', __FILE__)
+if File.exists?(File.join(File.expand_path('../../..', __FILE__), '.git'))
+ railties_path = File.expand_path('../../lib', __FILE__)
$:.unshift(railties_path)
- require "rails/cli"
end
+require "rails/cli"
</ruby>
-This file will attempt to load +rails/cli+. If it cannot find it then +railties/lib+ is added to the load path (+$:+) before retrying.
+This file will first attempt to push the +railties/lib+ directory if
+present, and then require +rails/cli+.
h4. +railties/lib/rails/cli.rb+
@@ -46,7 +47,7 @@ require 'rails/script_rails_loader'
Rails::ScriptRailsLoader.exec_script_rails!
require 'rails/ruby_version_check'
-Signal.trap("INT") { puts; exit }
+Signal.trap("INT") { puts; exit(1) }
if ARGV.first == 'plugin'
ARGV.shift
@@ -56,7 +57,7 @@ else
end
</ruby>
-The +rbconfig+ file from the Ruby standard library provides us with the +RbConfig+ class which contains detailed information about the Ruby environment, including how Ruby was compiled. We can see this in use in +railties/lib/rails/script_rails_loader+.
+The +rbconfig+ file from the Ruby standard library provides us with the +RbConfig+ class which contains detailed information about the Ruby environment, including how Ruby was compiled. We can see thisin use in +railties/lib/rails/script_rails_loader+.
<ruby>
require 'pathname'
@@ -120,6 +121,9 @@ exec RUBY, SCRIPT_RAILS, *ARGV if in_rails_application?
This is effectively the same as running +ruby script/rails [arguments]+, where +[arguments]+ at this point in time is simply "server".
+TIP: If you execute +script/rails+ directly from your Rails app you will
+avoid executing the code that we just described.
+
h4. +script/rails+
This file is as follows:
@@ -134,23 +138,23 @@ The +APP_PATH+ constant will be used later in +rails/commands+. The +config/boot
h4. +config/boot.rb+
-+config/boot.rb+ contains this:
++config/boot.rb+ contains:
<ruby>
# Set up gems listed in the Gemfile.
-gemfile = File.expand_path('../../Gemfile', __FILE__)
-begin
- ENV['BUNDLE_GEMFILE'] = gemfile
- require 'bundler'
- Bundler.setup
-rescue Bundler::GemNotFound => e
- STDERR.puts e.message
- STDERR.puts "Try running `bundle install`."
- exit!
-end if File.exist?(gemfile)
+ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
+
+require 'bundler/setup' if File.exists?(ENV['BUNDLE_GEMFILE'])
</ruby>
-In a standard Rails application, there's a +Gemfile+ which declares all dependencies of the application. +config/boot.rb+ sets +ENV["BUNDLE_GEMFILE"]+ to the location of this file, then requires Bundler and calls +Bundler.setup+ which adds the dependencies of the application (including all the Rails parts) to the load path, making them available for the application to load. The gems that a Rails 3.1 application depends on are as follows:
+In a standard Rails application, there's a +Gemfile+ which declares all
+dependencies of the application. +config/boot.rb+ sets
++ENV['BUNDLE_GEMFILE']+ to the location of this file. If the Gemfile
+exists, +bundler/setup+ is then required.
+
+The gems that a Rails 4 application depends on are as follows:
+
+TODO: change these when the Rails 4 release is near.
* abstract (1.0.0)
* actionmailer (3.1.0.beta)
@@ -183,6 +187,8 @@ h4. +rails/commands.rb+
Once +config/boot.rb+ has finished, the next file that is required is +rails/commands+ which will execute a command based on the arguments passed in. In this case, the +ARGV+ array simply contains +server+ which is extracted into the +command+ variable using these lines:
<ruby>
+ARGV << '--help' if ARGV.empty?
+
aliases = {
"g" => "generate",
"c" => "console",
@@ -195,6 +201,9 @@ command = ARGV.shift
command = aliases[command] || command
</ruby>
+TIP: As you can see, an empty ARGV list will make Rails show the help
+snippet.
+
If we used <tt>s</tt> rather than +server+, Rails will use the +aliases+ defined in the file and match them to their respective commands. With the +server+ command, Rails will run this code:
<ruby>
@@ -361,8 +370,9 @@ This method is defined like this:
<ruby>
def start
+ url = "#{options[:SSLEnable] ? 'https' : 'http'}://#{options[:Host]}:#{options[:Port]}"
puts "=> Booting #{ActiveSupport::Inflector.demodulize(server)}"
- puts "=> Rails #{Rails.version} application starting in #{Rails.env} on http://#{options[:Host]}:#{options[:Port]}"
+ puts "=> Rails #{Rails.version} application starting in #{Rails.env} on #{url}"
puts "=> Call with -d to detach" unless options[:daemonize]
trap(:INT) { exit }
puts "=> Ctrl-C to shutdown server" unless options[:daemonize]
@@ -372,6 +382,15 @@ def start
FileUtils.mkdir_p(Rails.root.join('tmp', dir_to_make))
end
+ unless options[:daemonize]
+ wrapped_app # touch the app so the logger is set up
+
+ console = ActiveSupport::Logger.new($stdout)
+ console.formatter = Rails.logger.formatter
+
+ Rails.logger.extend(ActiveSupport::Logger.broadcast(console))
+ end
+
super
ensure
# The '-h' option calls exit before @options is set.
@@ -380,10 +399,18 @@ ensure
end
</ruby>
-This is where the first output of the Rails initialization happens. This method creates a trap for +INT+ signals, so if you +CTRL+C+ the server, it will exit the process. As we can see from the code here, it will create the +tmp/cache+, +tmp/pids+, +tmp/sessions+ and +tmp/sockets+ directories if they don't already exist prior to calling +super+. The +super+ method will call +Rack::Server.start+ which begins its definition like this:
+This is where the first output of the Rails initialization happens. This
+method creates a trap for +INT+ signals, so if you +CTRL-C+ the server,
+it will exit the process. As we can see from the code here, it will
+create the +tmp/cache+, +tmp/pids+, +tmp/sessions+ and +tmp/sockets+
+directories. It then calls +wrapped_app+ which is responsible for
+creating the Rack app, before creating and assignig an
+instance of +ActiveSupport::Logger+.
+
+The +super+ method will call +Rack::Server.start+ which begins its definition like this:
<ruby>
-def start
+def start &blk
if options[:warn]
$-w = true
end
@@ -403,22 +430,37 @@ def start
pp wrapped_app
pp app
end
-end
-</ruby>
-In a Rails application, these options are not set at all and therefore aren't used at all. The first line of code that's executed in this method is a call to this method:
+ check_pid! if options[:pid]
-<ruby>
-wrapped_app
+ # Touch the wrapped app, so that the config.ru is loaded before
+ # daemonization (i.e. before chdir, etc).
+ wrapped_app
+
+ daemonize_app if options[:daemonize]
+
+ write_pid if options[:pid]
+
+ trap(:INT) do
+ if server.respond_to?(:shutdown)
+ server.shutdown
+ else
+ exit
+ end
+ end
+
+ server.run wrapped_app, options, &blk
+end
</ruby>
-This method calls another method:
+The interesting part for a Rails app is the last line, +server.run+. Here we encounter the +wrapped_app+ method again, which this time
+we're going to explore more.
<ruby>
@wrapped_app ||= build_app app
</ruby>
-Then the +app+ method here is defined like so:
+The +app+ method here is defined like so:
<ruby>
def app
@@ -440,7 +482,7 @@ The +options[:config]+ value defaults to +config.ru+ which contains this:
# This file is used by Rack-based servers to start the application.
require ::File.expand_path('../config/environment', __FILE__)
-run YourApp::Application
+run <%= app_const %>
</ruby>