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-rw-r--r--guides/source/rails_on_rack.md94
1 files changed, 36 insertions, 58 deletions
diff --git a/guides/source/rails_on_rack.md b/guides/source/rails_on_rack.md
index d53e0cd2bd..01941fa338 100644
--- a/guides/source/rails_on_rack.md
+++ b/guides/source/rails_on_rack.md
@@ -18,7 +18,7 @@ Introduction to Rack
Rack provides a minimal, modular and adaptable interface for developing web applications in Ruby. By wrapping HTTP requests and responses in the simplest way possible, it unifies and distills the API for web servers, web frameworks, and software in between (the so-called middleware) into a single method call.
-- [Rack API Documentation](http://rack.rubyforge.org/doc/)
+* [Rack API Documentation](http://rack.github.io/)
Explaining Rack is not really in the scope of this guide. In case you are not familiar with Rack's basics, you should check out the [Resources](#resources) section below.
@@ -27,10 +27,9 @@ Rails on Rack
### Rails Application's Rack Object
-`ApplicationName::Application` is the primary Rack application object of a Rails
+`Rails.application` 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. `Rails.application` refers to the same application object.
+`Rails.application` object to serve a Rails application.
### `rails server`
@@ -83,7 +82,7 @@ To use `rackup` instead of Rails' `rails server`, you can put the following insi
# Rails.root/config.ru
require ::File.expand_path('../config/environment', __FILE__)
-use Rack::Debugger
+use Rails::Rack::Debugger
use Rack::ContentLength
run Rails.application
```
@@ -112,7 +111,7 @@ NOTE: `ActionDispatch::MiddlewareStack` is Rails equivalent of `Rack::Builder`,
Rails has a handy rake task for inspecting the middleware stack in use:
```bash
-$ rake middleware
+$ bin/rake middleware
```
For a freshly generated Rails application, this might produce something like:
@@ -141,10 +140,10 @@ use ActionDispatch::ParamsParser
use Rack::Head
use Rack::ConditionalGet
use Rack::ETag
-run MyApp::Application.routes
+run Rails.application.routes
```
-Purpose of each of this middlewares is explained in the [Internal Middlewares](#internal-middleware-stack) section.
+The default middlewares shown here (and some others) are each summarized in the [Internal Middlewares](#internal-middleware-stack) section, below.
### Configuring Middleware Stack
@@ -182,27 +181,26 @@ You can swap an existing middleware in the middleware stack using `config.middle
config.middleware.swap ActionDispatch::ShowExceptions, Lifo::ShowExceptions
```
-#### Middleware Stack is an Enumerable
+#### Deleting a Middleware
-The middleware stack behaves just like a normal `Enumerable`. You can use any `Enumerable` methods to manipulate or interrogate the stack. The middleware stack also implements some `Array` methods including `[]`, `unshift` and `delete`. Methods described in the section above are just convenience methods.
-
-Append following lines to your application configuration:
+Add the following lines to your application configuration:
```ruby
# config/application.rb
config.middleware.delete "Rack::Lock"
```
-And now if you inspect the middleware stack, you'll find that `Rack::Lock` will not be part of it.
+And now if you inspect the middleware stack, you'll find that `Rack::Lock` is
+not a part of it.
```bash
-$ rake middleware
+$ bin/rake middleware
(in /Users/lifo/Rails/blog)
use ActionDispatch::Static
use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x00000001c304c8>
use Rack::Runtime
...
-run Blog::Application.routes
+run Rails.application.routes
```
If you want to remove session related middleware, do the following:
@@ -225,120 +223,100 @@ config.middleware.delete "Rack::MethodOverride"
Much of Action Controller's functionality is implemented as Middlewares. The following list explains the purpose of each of them:
- **`Rack::Sendfile`**
+**`Rack::Sendfile`**
* Sets server specific X-Sendfile header. Configure this via `config.action_dispatch.x_sendfile_header` option.
- **`ActionDispatch::Static`**
+**`ActionDispatch::Static`**
* Used to serve static assets. Disabled if `config.serve_static_assets` is `false`.
- **`Rack::Lock`**
+**`Rack::Lock`**
* Sets `env["rack.multithread"]` flag to `false` and wraps the application within a Mutex.
- **`ActiveSupport::Cache::Strategy::LocalCache::Middleware`**
+**`ActiveSupport::Cache::Strategy::LocalCache::Middleware`**
* Used for memory caching. This cache is not thread safe.
- **`Rack::Runtime`**
+**`Rack::Runtime`**
* Sets an X-Runtime header, containing the time (in seconds) taken to execute the request.
- **`Rack::MethodOverride`**
+**`Rack::MethodOverride`**
* Allows the method to be overridden if `params[:_method]` is set. This is the middleware which supports the PUT and DELETE HTTP method types.
- **`ActionDispatch::RequestId`**
+**`ActionDispatch::RequestId`**
* Makes a unique `X-Request-Id` header available to the response and enables the `ActionDispatch::Request#uuid` method.
- **`Rails::Rack::Logger`**
+**`Rails::Rack::Logger`**
* Notifies the logs that the request has began. After request is complete, flushes all the logs.
- **`ActionDispatch::ShowExceptions`**
+**`ActionDispatch::ShowExceptions`**
* Rescues any exception returned by the application and calls an exceptions app that will wrap it in a format for the end user.
- **`ActionDispatch::DebugExceptions`**
+**`ActionDispatch::DebugExceptions`**
* Responsible for logging exceptions and showing a debugging page in case the request is local.
- **`ActionDispatch::RemoteIp`**
+**`ActionDispatch::RemoteIp`**
* Checks for IP spoofing attacks.
- **`ActionDispatch::Reloader`**
+**`ActionDispatch::Reloader`**
* Provides prepare and cleanup callbacks, intended to assist with code reloading during development.
- **`ActionDispatch::Callbacks`**
+**`ActionDispatch::Callbacks`**
* Runs the prepare callbacks before serving the request.
- **`ActiveRecord::Migration::CheckPending`**
+**`ActiveRecord::Migration::CheckPending`**
* Checks pending migrations and raises `ActiveRecord::PendingMigrationError` if any migrations are pending.
- **`ActiveRecord::ConnectionAdapters::ConnectionManagement`**
+**`ActiveRecord::ConnectionAdapters::ConnectionManagement`**
* Cleans active connections after each request, unless the `rack.test` key in the request environment is set to `true`.
- **`ActiveRecord::QueryCache`**
+**`ActiveRecord::QueryCache`**
* Enables the Active Record query cache.
- **`ActionDispatch::Cookies`**
+**`ActionDispatch::Cookies`**
* Sets cookies for the request.
- **`ActionDispatch::Session::CookieStore`**
+**`ActionDispatch::Session::CookieStore`**
* Responsible for storing the session in cookies.
- **`ActionDispatch::Flash`**
+**`ActionDispatch::Flash`**
* Sets up the flash keys. Only available if `config.action_controller.session_store` is set to a value.
- **`ActionDispatch::ParamsParser`**
+**`ActionDispatch::ParamsParser`**
* Parses out parameters from the request into `params`.
- **`ActionDispatch::Head`**
+**`ActionDispatch::Head`**
* Converts HEAD requests to `GET` requests and serves them as so.
- **`Rack::ConditionalGet`**
+**`Rack::ConditionalGet`**
* Adds support for "Conditional `GET`" so that server responds with nothing if page wasn't changed.
- **`Rack::ETag`**
+**`Rack::ETag`**
* Adds ETag header on all String bodies. ETags are used to validate cache.
TIP: It's possible to use any of the above middlewares in your custom Rack stack.
-### Using Rack Builder
-
-The following shows how to replace use `Rack::Builder` instead of the Rails supplied `MiddlewareStack`.
-
-<strong>Clear the existing Rails middleware stack</strong>
-
-```ruby
-# config/application.rb
-config.middleware.clear
-```
-
-<br>
-<strong>Add a `config.ru` file to `Rails.root`</strong>
-
-```ruby
-# config.ru
-use MyOwnStackFromScratch
-run Rails.application
-```
-
Resources
---------