Module | ActionController::Routing
In: | lib/action_controller/routing/builder.rb lib/action_controller/routing/optimisations.rb lib/action_controller/routing/recognition_optimisation.rb lib/action_controller/routing/route.rb lib/action_controller/routing/route_set.rb lib/action_controller/routing/segments.rb lib/action_controller/routing.rb

## Routing

The routing module provides URL rewriting in native Ruby. It‘s a way to redirect incoming requests to controllers and actions. This replaces mod_rewrite rules. Best of all, Rails’ Routing works with any web server. Routes are defined in `config/routes.rb`.

Consider the following route, installed by Rails when you generate your application:

      map.connect ':controller/:action/:id'

This route states that it expects requests to consist of a `:controller` followed by an `:action` that in turn is fed some `:id`.

Suppose you get an incoming request for `/blog/edit/22`, you‘ll end up with:

      params = { :controller => 'blog',
                 :action     => 'edit',
                 :id         => '22'
              }

Think of creating routes as drawing a map for your requests. The map tells them where to go based on some predefined pattern:

      ActionController::Routing::Routes.draw do |map|
        Pattern 1 tells some request to go to one place
        Pattern 2 tell them to go to another
        ...
      end

The following symbols are special:

      :controller maps to your controller name
      :action     maps to an action with your controllers

Other names simply map to a parameter as in the case of `:id`.

## Route priority

Not all routes are created equally. Routes have priority defined by the order of appearance of the routes in the `config/routes.rb` file. The priority goes from top to bottom. The last route in that file is at the lowest priority and will be applied last. If no route matches, 404 is returned.

Within blocks, the empty pattern is at the highest priority. In practice this works out nicely:

      ActionController::Routing::Routes.draw do |map|
        map.with_options :controller => 'blog' do |blog|
          blog.show '',  :action => 'list'
        end
        map.connect ':controller/:action/:view'
      end

In this case, invoking blog controller (with an URL like ’/blog/’) without parameters will activate the ‘list’ action by default.

## Defaults routes and default parameters

Setting a default route is straightforward in Rails - you simply append a Hash at the end of your mapping to set any default parameters.

Example:

      ActionController::Routing:Routes.draw do |map|
        map.connect ':controller/:action/:id', :controller => 'blog'
      end

This sets up `blog` as the default controller if no other is specified. This means visiting ’/’ would invoke the blog controller.

More formally, you can include arbitrary parameters in the route, thus:

      map.connect ':controller/:action/:id', :action => 'show', :page => 'Dashboard'

This will pass the :page parameter to all incoming requests that match this route.

Note: The default routes, as provided by the Rails generator, make all actions in every controller accessible via GET requests. You should consider removing them or commenting them out if you‘re using named routes and resources.

## Named routes

Routes can be named with the syntax `map.name_of_route options`, allowing for easy reference within your source as `name_of_route_url` for the full URL and `name_of_route_path` for the URI path.

Example:

      # In routes.rb
      map.login 'login', :controller => 'accounts', :action => 'login'

      # With render, redirect_to, tests, etc.
      redirect_to login_url

Arguments can be passed as well.

      redirect_to show_item_path(:id => 25)

Use `map.root` as a shorthand to name a route for the root path "".

      # In routes.rb
      map.root :controller => 'blogs'

      # would recognize http://www.example.com/ as
      params = { :controller => 'blogs', :action => 'index' }

      # and provide these named routes
      root_url   # => 'http://www.example.com/'
      root_path  # => ''

You can also specify an already-defined named route in your `map.root` call:

      # In routes.rb
      map.new_session :controller => 'sessions', :action => 'new'
      map.root :new_session

Note: when using `with_options`, the route is simply named after the method you call on the block parameter rather than map.

      # In routes.rb
      map.with_options :controller => 'blog' do |blog|
        blog.show    '',            :action  => 'list'
        blog.delete  'delete/:id',  :action  => 'delete',
        blog.edit    'edit/:id',    :action  => 'edit'
      end

      # provides named routes for show, delete, and edit
      link_to @article.title, show_path(:id => @article.id)

## Pretty URLs

Routes can generate pretty URLs. For example:

      map.connect 'articles/:year/:month/:day',
                  :controller => 'articles',
                  :action     => 'find_by_date',
                  :year       => /\d{4}/,
                  :month      => /\d{1,2}/,
                  :day        => /\d{1,2}/

Using the route above, the URL "localhost:3000/articles/2005/11/06" maps to

      params = {:year => '2005', :month => '11', :day => '06'}

## Regular Expressions and parameters

You can specify a regular expression to define a format for a parameter.

      map.geocode 'geocode/:postalcode', :controller => 'geocode',
                  :action => 'show', :postalcode => /\d{5}(-\d{4})?/

or, more formally:

      map.geocode 'geocode/:postalcode', :controller => 'geocode',
                  :action => 'show', :requirements => { :postalcode => /\d{5}(-\d{4})?/ }

Formats can include the ‘ignorecase’ and ‘extended syntax’ regular expression modifiers:

      map.geocode 'geocode/:postalcode', :controller => 'geocode',
                  :action => 'show', :postalcode => /hx\d\d\s\d[a-z]{2}/i

      map.geocode 'geocode/:postalcode', :controller => 'geocode',
                  :action => 'show',:requirements => {
                    :postalcode => /# Postcode format
                                    \d{5} #Prefix
                                    (-\d{4})? #Suffix
                                    /x
                  }

Using the multiline match modifier will raise an ArgumentError. Encoding regular expression modifiers are silently ignored. The match will always use the default encoding or ASCII.

## Route globbing

Specifying `*[string]` as part of a rule like:

      map.connect '*path' , :controller => 'blog' , :action => 'unrecognized?'

will glob all remaining parts of the route that were not recognized earlier. The globbed values are in `params[:path]` as an array of path segments.

## Route conditions

With conditions you can define restrictions on routes. Currently the only valid condition is `:method`.

- `:method` - Allows you to specify which method can access the route. Possible values are `:post`, `:get`, `:put`, `:delete` and `:any`. The default value is `:any`, `:any` means that any method can access the route.

Example:

      map.connect 'post/:id', :controller => 'posts', :action => 'show',
                  :conditions => { :method => :get }
      map.connect 'post/:id', :controller => 'posts', :action => 'create_comment',
                  :conditions => { :method => :post }

Now, if you POST to `/posts/:id`, it will route to the `create_comment` action. A GET on the same URL will route to the `show` action.

## Reloading routes

You can reload routes if you feel you must:

      ActionController::Routing::Routes.reload

This will clear all named routes and reload routes.rb if the file has been modified from last load. To absolutely force reloading, use `reload!`.

## Testing Routes

The two main methods for testing your routes:

### `assert_routing`

      def test_movie_route_properly_splits
       opts = {:controller => "plugin", :action => "checkout", :id => "2"}
       assert_routing "plugin/checkout/2", opts
      end

`assert_routing` lets you test whether or not the route properly resolves into options.

### `assert_recognizes`

      def test_route_has_options
       opts = {:controller => "plugin", :action => "show", :id => "12"}
       assert_recognizes opts, "/plugins/show/12"
      end

Note the subtle difference between the two: `assert_routing` tests that a URL fits options while `assert_recognizes` tests that a URL breaks into parameters properly.

In tests you can simply pass the URL or named route to `get` or `post`.

      def send_to_jail
        get '/jail'
        assert_response :success
        assert_template "jail/front"
      end

      def goes_to_login
        get login_url
        #...
      end

## View a list of all your routes

Run `rake routes`.

### Methods

controller_relative_to inflections_with_route_reloading normalize_paths possible_controllers use_controllers! with_controllers

### Classes and Modules

Module ActionController::Routing::Helpers
Module ActionController::Routing::Optimisation
Class ActionController::Routing::OptionalFormatSegment

### Constants

SEPARATORS | = | %w( / . ? )
HTTP_METHODS | = | [:get, :head, :post, :put, :delete, :options]
ALLOWED_REQUIREMENTS_FOR_OPTIMISATION | = | [:controller, :action].to_set
Routes | = | RouteSet.new

### Public Class methods

controller_relative_to(controller, previous)

Returns a controller path for a new `controller` based on a `previous` controller path. Handles 4 scenarios:

- stay in the previous controller:

        controller_relative_to( nil, "groups/discussion" ) # => "groups/discussion"

- stay in the previous namespace:

        controller_relative_to( "posts", "groups/discussion" ) # => "groups/posts"

- forced move to the root namespace:

        controller_relative_to( "/posts", "groups/discussion" ) # => "posts"

- previous namespace is root:

        controller_relative_to( "posts", "anything_with_no_slashes" ) # =>"posts"

normalize_paths(paths)

Returns an array of paths, cleaned of double-slashes and relative path references.

- "\\" and "//" become "\" or "/".
- "/foo/bar/../config" becomes "/foo/config".

The returned array is sorted by length, descending.

possible_controllers()

Returns the array of controller names currently available to ActionController::Routing.

use_controllers!(controller_names)

Replaces the internal list of controllers available to ActionController::Routing with the passed argument.

      ActionController::Routing.use_controllers!([ "posts", "comments", "admin/comments" ])

with_controllers(names) {|| ...}

Expects an array of controller names as the first argument. Executes the passed block with only the named controllers named available. This method is used in internal Rails testing.

### Public Instance methods

inflections_with_route_reloading(&block)

Ensures that routes are reloaded when Rails inflections are updated.

[Validate]