# frozen_string_literal: true
# :markup: markdown
module ActionDispatch
module Routing
# # Action Dispatch Routing UrlFor
#
# In `config/routes.rb` you define URL-to-controller mappings, but the reverse
# is also possible: a URL can be generated from one of your routing definitions.
# URL generation functionality is centralized in this module.
#
# See ActionDispatch::Routing for general information about routing and
# `config/routes.rb`.
#
# **Tip:** If you need to generate URLs from your models or some other place,
# then ActionDispatch::Routing::UrlFor is what you're looking for. Read on for
# an introduction. In general, this module should not be included on its own, as
# it is usually included by `url_helpers` (as in
# `Rails.application.routes.url_helpers`).
#
# ## URL generation from parameters
#
# As you may know, some functions, such as `ActionController::Base#url_for` and
# ActionView::Helpers::UrlHelper#link_to, can generate URLs given a set of
# parameters. For example, you've probably had the chance to write code like
# this in one of your views:
#
# <%= link_to('Click here', controller: 'users',
# action: 'new', message: 'Welcome!') %>
# # => <a href="/users/new?message=Welcome%21">Click here</a>
#
# `link_to`, and all other functions that require URL generation functionality,
# actually use ActionDispatch::Routing::UrlFor under the hood. And in
# particular, they use the ActionDispatch::Routing::UrlFor#url_for method. One
# can generate the same path as the above example by using the following code:
#
# include ActionDispatch::Routing::UrlFor
# url_for(controller: 'users',
# action: 'new',
# message: 'Welcome!',
# only_path: true)
# # => "/users/new?message=Welcome%21"
#
# Notice the `only_path: true` part. This is because UrlFor has no information
# about the website hostname that your Rails app is serving. So if you want to
# include the hostname as well, then you must also pass the `:host` argument:
#
# include UrlFor
# url_for(controller: 'users',
# action: 'new',
# message: 'Welcome!',
# host: 'www.example.com')
# # => "http://www.example.com/users/new?message=Welcome%21"
#
# By default, all controllers and views have access to a special version of
# `url_for`, that already knows what the current hostname is. So if you use
# `url_for` in your controllers or your views, then you don't need to explicitly
# pass the `:host` argument.
#
# For convenience, mailers also include ActionDispatch::Routing::UrlFor. So
# within mailers, you can use url_for. However, mailers cannot access incoming
# web requests in order to derive hostname information, so you have to provide
# the `:host` option or set the default host using `default_url_options`. For
# more information on url_for in mailers see the ActionMailer::Base
# documentation.
#
# ## URL generation for named routes
#
# UrlFor also allows one to access methods that have been auto-generated from
# named routes. For example, suppose that you have a 'users' resource in your
# `config/routes.rb`:
#
# resources :users
#
# This generates, among other things, the method `users_path`. By default, this
# method is accessible from your controllers, views, and mailers. If you need to
# access this auto-generated method from other places (such as a model), then
# you can do that by including `Rails.application.routes.url_helpers` in your
# class:
#
# class User < ActiveRecord::Base
# include Rails.application.routes.url_helpers
#
# def base_uri
# user_path(self)
# end
# end
#
# User.find(1).base_uri # => "/users/1"
#
module UrlFor
extend ActiveSupport::Concern
include PolymorphicRoutes
included do
unless method_defined?(:default_url_options)
# Including in a class uses an inheritable hash. Modules get a plain hash.
if respond_to?(:class_attribute)
class_attribute :default_url_options
else
mattr_writer :default_url_options
end
self.default_url_options = {}
end
include(*_url_for_modules) if respond_to?(:_url_for_modules)
end
def initialize(...)
@_routes = nil
super
end
# Hook overridden in controller to add request information with
# `default_url_options`. Application logic should not go into url_options.
def url_options
default_url_options
end
# Generate a URL based on the options provided, `default_url_options`, and the
# routes defined in `config/routes.rb`. The following options are supported:
#
# * `:only_path` - If true, the relative URL is returned. Defaults to `false`.
# * `:protocol` - The protocol to connect to. Defaults to `"http"`.
# * `:host` - Specifies the host the link should be targeted at. If
# `:only_path` is false, this option must be provided either explicitly, or
# via `default_url_options`.
# * `:subdomain` - Specifies the subdomain of the link, using the `tld_length`
# to split the subdomain from the host. If false, removes all subdomains
# from the host part of the link.
# * `:domain` - Specifies the domain of the link, using the `tld_length` to
# split the domain from the host.
# * `:tld_length` - Number of labels the TLD id composed of, only used if
# `:subdomain` or `:domain` are supplied. Defaults to
# `ActionDispatch::Http::URL.tld_length`, which in turn defaults to 1.
# * `:port` - Optionally specify the port to connect to.
# * `:anchor` - An anchor name to be appended to the path.
# * `:params` - The query parameters to be appended to the path.
# * `:path_params` - The query parameters that will only be used for the named
# dynamic segments of path. If unused, they will be discarded.
# * `:trailing_slash` - If true, adds a trailing slash, as in
# `"/archive/2009/"`.
# * `:script_name` - Specifies application path relative to domain root. If
# provided, prepends application path.
#
#
# Any other key (`:controller`, `:action`, etc.) given to `url_for` is forwarded
# to the Routes module.
#
# url_for controller: 'tasks', action: 'testing', host: 'somehost.org', port: '8080'
# # => 'http://somehost.org:8080/tasks/testing'
# url_for controller: 'tasks', action: 'testing', host: 'somehost.org', anchor: 'ok', only_path: true
# # => '/tasks/testing#ok'
# url_for controller: 'tasks', action: 'testing', trailing_slash: true
# # => 'http://somehost.org/tasks/testing/'
# url_for controller: 'tasks', action: 'testing', host: 'somehost.org', number: '33'
# # => 'http://somehost.org/tasks/testing?number=33'
# url_for controller: 'tasks', action: 'testing', host: 'somehost.org', script_name: "/myapp"
# # => 'http://somehost.org/myapp/tasks/testing'
# url_for controller: 'tasks', action: 'testing', host: 'somehost.org', script_name: "/myapp", only_path: true
# # => '/myapp/tasks/testing'
#
# Missing routes keys may be filled in from the current request's parameters
# (e.g. `:controller`, `:action`, `:id`, and any other parameters that are
# placed in the path). Given that the current action has been reached through
# `GET /users/1`:
#
# url_for(only_path: true) # => '/users/1'
# url_for(only_path: true, action: 'edit') # => '/users/1/edit'
# url_for(only_path: true, action: 'edit', id: 2) # => '/users/2/edit'
#
# Notice that no `:id` parameter was provided to the first `url_for` call and
# the helper used the one from the route's path. Any path parameter implicitly
# used by `url_for` can always be overwritten like shown on the last `url_for`
# calls.
def url_for(options = nil)
full_url_for(options)
end
def full_url_for(options = nil) # :nodoc:
case options
when nil
_routes.url_for(url_options.symbolize_keys)
when Hash, ActionController::Parameters
route_name = options.delete :use_route
merged_url_options = options.to_h.symbolize_keys.reverse_merge!(url_options)
_routes.url_for(merged_url_options, route_name)
when String
options
when Symbol
HelperMethodBuilder.url.handle_string_call self, options
when Array
components = options.dup
polymorphic_url(components, components.extract_options!)
when Class
HelperMethodBuilder.url.handle_class_call self, options
else
HelperMethodBuilder.url.handle_model_call self, options
end
end
# Allows calling direct or regular named route.
#
# resources :buckets
#
# direct :recordable do |recording|
# route_for(:bucket, recording.bucket)
# end
#
# direct :threadable do |threadable|
# route_for(:recordable, threadable.parent)
# end
#
# This maintains the context of the original caller on whether to return a path
# or full URL, e.g:
#
# threadable_path(threadable) # => "/buckets/1"
# threadable_url(threadable) # => "http://example.com/buckets/1"
#
def route_for(name, *args)
public_send(:"#{name}_url", *args)
end
protected
def optimize_routes_generation?
_routes.optimize_routes_generation? && default_url_options.empty?
end
private
def _with_routes(routes) # :doc:
old_routes, @_routes = @_routes, routes
yield
ensure
@_routes = old_routes
end
def _routes_context # :doc:
self
end
end
end
end