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Merge pull request #6454 from rafmagana/guides_rails_on_rack

[guides] Update rails on rack
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commit e8cac28917261d6001ab0dbf2da72ef028b3ab72 2 parents 4b91183 + 7cabb57
@vijaydev vijaydev authored
Showing with 41 additions and 21 deletions.
  1. +41 −21 guides/source/rails_on_rack.textile
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62 guides/source/rails_on_rack.textile
@@ -23,29 +23,49 @@ h3. Rails on Rack
h4. Rails Application's Rack Object
-<tt>ActionController::Dispatcher.new</tt> is the primary Rack application object of a Rails application. Any Rack compliant web server should be using +ActionController::Dispatcher.new+ object to serve a Rails application.
+<tt>ApplicationName::Application</tt> is the primary Rack application object of a Rails application. Any Rack compliant web server should be using +ApplicationName::Application+ object to serve a Rails application.
h4. +rails server+
-<tt>rails server</tt> does the basic job of creating a +Rack::Builder+ object and starting the webserver. This is Rails' equivalent of Rack's +rackup+ script.
+<tt>rails server</tt> does the basic job of creating a +Rack::Server+ object and starting the webserver.
-Here's how +rails server+ creates an instance of +Rack::Builder+
+Here's how +rails server+ creates an instance of +Rack::Server+
<ruby>
-app = Rack::Builder.new {
- use Rails::Rack::LogTailer unless options[:detach]
- use Rails::Rack::Debugger if options[:debugger]
- use ActionDispatch::Static
- run ActionController::Dispatcher.new
-}.to_app
+Rails::Server.new.tap { |server|
+ require APP_PATH
+ Dir.chdir(Rails.application.root)
+ server.start
+}
</ruby>
-Middlewares used in the code above are primarily useful only in the development environment. The following table explains their usage:
+The +Rails::Server+ inherits from +Rack::Server+ and calls the +Rack::Server#start+ method this way:
+
+<ruby>
+class Server < ::Rack::Server
+ def start
+ ...
+ super
+ end
+end
+</ruby>
+
+Here's how it loads the middlewares:
+
+<ruby>
+def middleware
+ middlewares = []
+ middlewares << [Rails::Rack::Debugger] if options[:debugger]
+ middlewares << [::Rack::ContentLength]
+ Hash.new(middlewares)
+end
+</ruby>
+
++Rails::Rack::Debugger+ is primarily useful only in the development environment. The following table explains the usage of the loaded middlewares:
|_.Middleware|_.Purpose|
-|+Rails::Rack::LogTailer+|Appends log file output to console|
-|+ActionDispatch::Static+|Serves static files inside +Rails.root/public+ directory|
|+Rails::Rack::Debugger+|Starts Debugger|
+|+Rack::ContentLength+|Counts the number of bytes in the response and set the HTTP Content-Length header|
h4. +rackup+
@@ -55,9 +75,9 @@ To use +rackup+ instead of Rails' +rails server+, you can put the following insi
# Rails.root/config.ru
require "config/environment"
-use Rails::Rack::LogTailer
-use ActionDispatch::Static
-run ActionController::Dispatcher.new
+use Rack::Debugger
+use Rack::ContentLength
+run ApplicationName::Application
</ruby>
And start the server:
@@ -72,11 +92,11 @@ To find out more about different +rackup+ options:
$ rackup --help
</shell>
-h3. Action Controller Middleware Stack
+h3. Action Dispatcher Middleware Stack
-Many of Action Controller's internal components are implemented as Rack middlewares. +ActionController::Dispatcher+ uses +ActionController::MiddlewareStack+ to combine various internal and external middlewares to form a complete Rails Rack application.
+Many of Action Dispatchers's internal components are implemented as Rack middlewares. +Rails::Application+ uses +ActionDispatch::MiddlewareStack+ to combine various internal and external middlewares to form a complete Rails Rack application.
-NOTE: +ActionController::MiddlewareStack+ is Rails' equivalent of +Rack::Builder+, but built for better flexibility and more features to meet Rails' requirements.
+NOTE: +ActionDispatch::MiddlewareStack+ is Rails' equivalent of +Rack::Builder+, but built for better flexibility and more features to meet Rails' requirements.
h4. Inspecting Middleware Stack
@@ -111,7 +131,7 @@ use ActionDispatch::Head
use Rack::ConditionalGet
use Rack::ETag
use ActionDispatch::BestStandardsSupport
-run Blog::Application.routes
+run ApplicationName::Application.routes
</ruby>
Purpose of each of this middlewares is explained in the "Internal Middlewares":#internal-middleware-stack section.
@@ -172,7 +192,7 @@ use ActionDispatch::Static
use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x00000001c304c8>
use Rack::Runtime
...
-run Myapp::Application.routes
+run Blog::Application.routes
</shell>
h4. Internal Middleware Stack
@@ -264,7 +284,7 @@ config.middleware.clear
<ruby>
# config.ru
use MyOwnStackFromScratch
-run ActionController::Dispatcher.new
+run ApplicationName::Application
</ruby>
h3. Resources
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