Module ActionDispatch::Routing::Mapper::Base

Matches a url pattern to one or more routes. Any symbols in a pattern are interpreted as url query parameters and thus available as params in an action:

# sets :controller, :action and :id in params
match ':controller/:action/:id'

Two of these symbols are special, :controller maps to the controller and :action to the controller’s action. A pattern can also map wildcard segments (globs) to params:

match 'songs/*category/:title' => 'songs#show'

# 'songs/rock/classic/stairway-to-heaven' sets
#  params[:category] = 'rock/classic'
#  params[:title] = 'stairway-to-heaven'

When a pattern points to an internal route, the route’s :action and :controller should be set in options or hash shorthand. Examples:

match 'photos/:id' => 'photos#show'
match 'photos/:id', :to => 'photos#show'
match 'photos/:id', :controller => 'photos', :action => 'show'

A pattern can also point to a Rack endpoint i.e. anything that responds to call:

match 'photos/:id' => lambda {|hash| [200, {}, "Coming soon"] }
match 'photos/:id' => PhotoRackApp
# Yes, controller actions are just rack endpoints
match 'photos/:id' => PhotosController.action(:show)

Options

Any options not seen here are passed on as params with the url.

:controller

The route’s controller.

:action

The route’s action.

:path

The path prefix for the routes.

:module

The namespace for :controller.

match 'path' => 'c#a', :module => 'sekret', :controller => 'posts'
#=> Sekret::PostsController

See Scoping#namespace for its scope equivalent.

:as

The name used to generate routing helpers.

:via

Allowed HTTP verb(s) for route.

match 'path' => 'c#a', :via => :get
match 'path' => 'c#a', :via => [:get, :post]

:to

Points to a Rack endpoint. Can be an object that responds to call or a string representing a controller’s action.

match 'path', :to => 'controller#action'
match 'path', :to => lambda { |env| [200, {}, "Success!"] }
match 'path', :to => RackApp

:on

Shorthand for wrapping routes in a specific RESTful context. Valid values are :member, :collection, and :new. Only use within resource(s) block. For example:

resource :bar do
  match 'foo' => 'c#a', :on => :member, :via => [:get, :post]
end

Is equivalent to:

resource :bar do
  member do
    match 'foo' => 'c#a', :via => [:get, :post]
  end
end

:constraints

Constrains parameters with a hash of regular expressions or an object that responds to matches?

match 'path/:id', :constraints => { :id => %r[A-Z]\d{5}/ }

class Blacklist
  def matches?(request) request.remote_ip == '1.2.3.4' end
end
match 'path' => 'c#a', :constraints => Blacklist.new

See Scoping#constraints for more examples with its scope equivalent.

:defaults

Sets defaults for parameters

# Sets params[:format] to 'jpg' by default
match 'path' => 'c#a', :defaults => { :format => 'jpg' }

See Scoping#defaults for its scope equivalent.

:anchor

Boolean to anchor a match pattern. Default is true. When set to false, the pattern matches any request prefixed with the given path.

# Matches any request starting with 'path'
match 'path' => 'c#a', :anchor => false

Mount a Rack-based application to be used within the application.

mount SomeRackApp, :at => "some_route"

Alternatively:

mount(SomeRackApp => "some_route")

For options, see match, as mount uses it internally.

All mounted applications come with routing helpers to access them. These are named after the class specified, so for the above example the helper is either some_rack_app_path or some_rack_app_url. To customize this helper’s name, use the :as option:

mount(SomeRackApp => "some_route", :as => "exciting")

This will generate the exciting_path and exciting_url helpers which can be used to navigate to this mounted app.

You can specify what Rails should route “/” to with the root method:

root :to => 'pages#main'

For options, see match, as root uses it internally.

You should put the root route at the top of config/routes.rb, because this means it will be matched first. As this is the most popular route of most Rails applications, this is beneficial.