Module: ActionDispatch::Routing::Mapper::Resources

Included in:
ActionDispatch::Routing::Mapper
Defined in:
lib/action_dispatch/routing/mapper.rb

Overview

Resource routing allows you to quickly declare all of the common routes for a given resourceful controller. Instead of declaring separate routes for your index, show, new, edit, create, update, and destroy actions, a resourceful route declares them in a single line of code:

resources :photos

Sometimes, you have a resource that clients always look up without referencing an ID. A common example, /profile always shows the profile of the currently logged in user. In this case, you can use a singular resource to map /profile (rather than /profile/:id) to the show action.

resource :profile

It’s common to have resources that are logically children of other resources:

resources :magazines do
  resources :ads
end

You may wish to organize groups of controllers under a namespace. Most commonly, you might group a number of administrative controllers under an admin namespace. You would place these controllers under the app/controllers/admin directory, and you can group them together in your router:

namespace "admin" do
  resources :posts, :comments
end

By default the :id parameter doesn’t accept dots. If you need to use dots as part of the :id parameter add a constraint which overrides this restriction, e.g:

resources :articles, id: /[^\/]+/

This allows any character other than a slash as part of your :id.

Defined Under Namespace

Classes: Resource, SingletonResource

Constant Summary collapse

VALID_ON_OPTIONS =

CANONICAL_ACTIONS holds all actions that does not need a prefix or a path appended since they fit properly in their scope level.

[:new, :collection, :member]
RESOURCE_OPTIONS =
[:as, :controller, :path, :only, :except, :param, :concerns]
CANONICAL_ACTIONS =
%w(index create new show update destroy)

Instance Method Summary collapse

Instance Method Details

#collection(&block) ⇒ Object

To add a route to the collection:

resources :photos do
  collection do
    get 'search'
  end
end

This will enable Rails to recognize paths such as /photos/search with GET, and route to the search action of PhotosController. It will also create the search_photos_url and search_photos_path route helpers.



1511
1512
1513
1514
1515
1516
1517
1518
1519
# File 'lib/action_dispatch/routing/mapper.rb', line 1511

def collection(&block)
  unless resource_scope?
    raise ArgumentError, "can't use collection outside resource(s) scope"
  end

  with_scope_level(:collection) do
    path_scope(parent_resource.collection_scope, &block)
  end
end

#draw(name) ⇒ Object

Loads another routes file with the given name located inside the config/routes directory. In that file, you can use the normal routing DSL, but do not surround it with a Rails.application.routes.draw block.

# config/routes.rb
Rails.application.routes.draw do
  draw :admin                 # Loads `config/routes/admin.rb`
  draw "third_party/some_gem" # Loads `config/routes/third_party/some_gem.rb`
end

# config/routes/admin.rb
namespace :admin do
  resources :accounts
end

# config/routes/third_party/some_gem.rb
mount SomeGem::Engine, at: "/some_gem"

CAUTION: Use this feature with care. Having multiple routes files can negatively impact discoverability and readability. For most applications — even those with a few hundred routes — it’s easier for developers to have a single routes file.



1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
# File 'lib/action_dispatch/routing/mapper.rb', line 1621

def draw(name)
  path = @draw_paths.find do |_path|
    File.exist? "#{_path}/#{name}.rb"
  end

  unless path
    msg  = "Your router tried to #draw the external file #{name}.rb,\n" \
           "but the file was not found in:\n\n"
    msg += @draw_paths.map { |_path| " * #{_path}" }.join("\n")
    raise ArgumentError, msg
  end

  route_path = "#{path}/#{name}.rb"
  instance_eval(File.read(route_path), route_path.to_s)
end

#match(path, *rest, &block) ⇒ Object

Matches a URL pattern to one or more routes. For more information, see match.

match 'path' => 'controller#action', via: :patch
match 'path', to: 'controller#action', via: :post
match 'path', 'otherpath', on: :member, via: :get


1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
# File 'lib/action_dispatch/routing/mapper.rb', line 1643

def match(path, *rest, &block)
  if rest.empty? && Hash === path
    options  = path
    path, to = options.find { |name, _value| name.is_a?(String) }

    raise ArgumentError, "Route path not specified" if path.nil?

    case to
    when Symbol
      options[:action] = to
    when String
      if to.include?("#")
        options[:to] = to
      else
        options[:controller] = to
      end
    else
      options[:to] = to
    end

    options.delete(path)
    paths = [path]
  else
    options = rest.pop || {}
    paths = [path] + rest
  end

  if options.key?(:defaults)
    defaults(options.delete(:defaults)) { map_match(paths, options, &block) }
  else
    map_match(paths, options, &block)
  end
end

#member(&block) ⇒ Object

To add a member route, add a member block into the resource block:

resources :photos do
  member do
    get 'preview'
  end
end

This will recognize /photos/1/preview with GET, and route to the preview action of PhotosController. It will also create the preview_photo_url and preview_photo_path helpers.



1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
# File 'lib/action_dispatch/routing/mapper.rb', line 1532

def member(&block)
  unless resource_scope?
    raise ArgumentError, "can't use member outside resource(s) scope"
  end

  with_scope_level(:member) do
    if shallow?
      shallow_scope {
        path_scope(parent_resource.member_scope, &block)
      }
    else
      path_scope(parent_resource.member_scope, &block)
    end
  end
end

#namespace(path, options = {}) ⇒ Object

See ActionDispatch::Routing::Mapper::Scoping#namespace.



1579
1580
1581
1582
1583
1584
1585
# File 'lib/action_dispatch/routing/mapper.rb', line 1579

def namespace(path, options = {})
  if resource_scope?
    nested { super }
  else
    super
  end
end

#nested(&block) ⇒ Object



1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
# File 'lib/action_dispatch/routing/mapper.rb', line 1558

def nested(&block)
  unless resource_scope?
    raise ArgumentError, "can't use nested outside resource(s) scope"
  end

  with_scope_level(:nested) do
    if shallow? && shallow_nesting_depth >= 1
      shallow_scope do
        path_scope(parent_resource.nested_scope) do
          scope(nested_options, &block)
        end
      end
    else
      path_scope(parent_resource.nested_scope) do
        scope(nested_options, &block)
      end
    end
  end
end

#new(&block) ⇒ Object



1548
1549
1550
1551
1552
1553
1554
1555
1556
# File 'lib/action_dispatch/routing/mapper.rb', line 1548

def new(&block)
  unless resource_scope?
    raise ArgumentError, "can't use new outside resource(s) scope"
  end

  with_scope_level(:new) do
    path_scope(parent_resource.new_scope(action_path(:new)), &block)
  end
end

#resource(*resources, &block) ⇒ Object

Sometimes, you have a resource that clients always look up without referencing an ID. A common example, /profile always shows the profile of the currently logged in user. In this case, you can use a singular resource to map /profile (rather than /profile/:id) to the show action:

resource :profile

This creates six different routes in your application, all mapping to the Profiles controller (note that the controller is named after the plural):

GET       /profile/new
GET       /profile
GET       /profile/edit
PATCH/PUT /profile
DELETE    /profile
POST      /profile

If you want instances of a model to work with this resource via record identification (e.g. in form_with or redirect_to), you will need to call resolve:

resource :profile
resolve('Profile') { [:profile] }

# Enables this to work with singular routes:
form_with(model: @profile) {}

Options

Takes same options as resources



1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
# File 'lib/action_dispatch/routing/mapper.rb', line 1303

def resource(*resources, &block)
  options = resources.extract_options!.dup

  if apply_common_behavior_for(:resource, resources, options, &block)
    return self
  end

  with_scope_level(:resource) do
    options = apply_action_options options
    resource_scope(SingletonResource.new(resources.pop, api_only?, @scope[:shallow], options)) do
      yield if block_given?

      concerns(options[:concerns]) if options[:concerns]

      new do
        get :new
      end if parent_resource.actions.include?(:new)

      set_member_mappings_for_resource

      collection do
        post :create
      end if parent_resource.actions.include?(:create)
    end
  end

  self
end

#resources(*resources, &block) ⇒ Object

In Rails, a resourceful route provides a mapping between HTTP verbs and URLs and controller actions. By convention, each action also maps to particular CRUD operations in a database. A single entry in the routing file, such as

resources :photos

creates seven different routes in your application, all mapping to the Photos controller:

GET       /photos
GET       /photos/new
POST      /photos
GET       /photos/:id
GET       /photos/:id/edit
PATCH/PUT /photos/:id
DELETE    /photos/:id

Resources can also be nested infinitely by using this block syntax:

resources :photos do
  resources :comments
end

This generates the following comments routes:

GET       /photos/:photo_id/comments
GET       /photos/:photo_id/comments/new
POST      /photos/:photo_id/comments
GET       /photos/:photo_id/comments/:id
GET       /photos/:photo_id/comments/:id/edit
PATCH/PUT /photos/:photo_id/comments/:id
DELETE    /photos/:photo_id/comments/:id

Options

Takes same options as match as well as:

:path_names

Allows you to change the segment component of the edit and new actions. Actions not specified are not changed.

resources :posts, path_names: { new: "brand_new" }

The above example will now change /posts/new to /posts/brand_new.

:path

Allows you to change the path prefix for the resource.

resources :posts, path: 'postings'

The resource and all segments will now route to /postings instead of /posts.

:only

Only generate routes for the given actions.

resources :cows, only: :show
resources :cows, only: [:show, :index]
:except

Generate all routes except for the given actions.

resources :cows, except: :show
resources :cows, except: [:show, :index]
:shallow

Generates shallow routes for nested resource(s). When placed on a parent resource, generates shallow routes for all nested resources.

resources :posts, shallow: true do
  resources :comments
end

Is the same as:

resources :posts do
  resources :comments, except: [:show, :edit, :update, :destroy]
end
resources :comments, only: [:show, :edit, :update, :destroy]

This allows URLs for resources that otherwise would be deeply nested such as a comment on a blog post like /posts/a-long-permalink/comments/1234 to be shortened to just /comments/1234.

Set shallow: false on a child resource to ignore a parent’s shallow parameter.

:shallow_path

Prefixes nested shallow routes with the specified path.

scope shallow_path: "sekret" do
  resources :posts do
    resources :comments, shallow: true
  end
end

The comments resource here will have the following routes generated for it:

post_comments    GET       /posts/:post_id/comments(.:format)
post_comments    POST      /posts/:post_id/comments(.:format)
new_post_comment GET       /posts/:post_id/comments/new(.:format)
edit_comment     GET       /sekret/comments/:id/edit(.:format)
comment          GET       /sekret/comments/:id(.:format)
comment          PATCH/PUT /sekret/comments/:id(.:format)
comment          DELETE    /sekret/comments/:id(.:format)
:shallow_prefix

Prefixes nested shallow route names with specified prefix.

scope shallow_prefix: "sekret" do
  resources :posts do
    resources :comments, shallow: true
  end
end

The comments resource here will have the following routes generated for it:

post_comments           GET       /posts/:post_id/comments(.:format)
post_comments           POST      /posts/:post_id/comments(.:format)
new_post_comment        GET       /posts/:post_id/comments/new(.:format)
edit_sekret_comment     GET       /comments/:id/edit(.:format)
sekret_comment          GET       /comments/:id(.:format)
sekret_comment          PATCH/PUT /comments/:id(.:format)
sekret_comment          DELETE    /comments/:id(.:format)
:format

Allows you to specify the default value for optional format segment or disable it by supplying false.

:param

Allows you to override the default param name of :id in the URL.

Examples

# routes call +Admin::PostsController+
resources :posts, module: "admin"

# resource actions are at /admin/posts.
resources :posts, path: "admin/posts"


1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
# File 'lib/action_dispatch/routing/mapper.rb', line 1469

def resources(*resources, &block)
  options = resources.extract_options!.dup

  if apply_common_behavior_for(:resources, resources, options, &block)
    return self
  end

  with_scope_level(:resources) do
    options = apply_action_options options
    resource_scope(Resource.new(resources.pop, api_only?, @scope[:shallow], options)) do
      yield if block_given?

      concerns(options[:concerns]) if options[:concerns]

      collection do
        get  :index if parent_resource.actions.include?(:index)
        post :create if parent_resource.actions.include?(:create)
      end

      new do
        get :new
      end if parent_resource.actions.include?(:new)

      set_member_mappings_for_resource
    end
  end

  self
end

#resources_path_names(options) ⇒ Object



1268
1269
1270
# File 'lib/action_dispatch/routing/mapper.rb', line 1268

def resources_path_names(options)
  @scope[:path_names].merge!(options)
end

#root(path, options = {}) ⇒ Object

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 can also pass a string which will expand

root 'pages#main'

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.



1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
# File 'lib/action_dispatch/routing/mapper.rb', line 1690

def root(path, options = {})
  if path.is_a?(String)
    options[:to] = path
  elsif path.is_a?(Hash) && options.empty?
    options = path
  else
    raise ArgumentError, "must be called with a path and/or options"
  end

  if @scope.resources?
    with_scope_level(:root) do
      path_scope(parent_resource.path) do
        match_root_route(options)
      end
    end
  else
    match_root_route(options)
  end
end

#shallowObject



1587
1588
1589
1590
1591
1592
# File 'lib/action_dispatch/routing/mapper.rb', line 1587

def shallow
  @scope = @scope.new(shallow: true)
  yield
ensure
  @scope = @scope.parent
end

#shallow?Boolean

Returns:

  • (Boolean)


1594
1595
1596
# File 'lib/action_dispatch/routing/mapper.rb', line 1594

def shallow?
  !parent_resource.singleton? && @scope[:shallow]
end