module ActionDispatch module Routing # In config/routes.rb you define URL-to-controller mappings, but the reverse # is also possible: an 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 routes.rb. # # Tip: If you need to generate URLs from your models or some other place, # then ActionController::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!') %> # # => "/users/new?message=Welcome%21" # # link_to, and all other functions that require URL generation functionality, # actually use ActionController::UrlFor under the hood. And in particular, # they use the ActionController::UrlFor#url_for method. One can generate # the same path as the above example by using the following code: # # include 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 reasons, mailers provide a shortcut for ActionController::UrlFor#url_for. # So within mailers, you only have to type 'url_for' instead of 'ActionController::UrlFor#url_for' # in full. However, mailers don't have hostname information, and that's why you'll still # have to specify the :host argument when generating URLs in mailers. # # # == 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 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. # * :trailing_slash - If true, adds a trailing slash, as in "/archive/2009/" # # 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' def url_for(options = nil) case options when nil _routes.url_for(url_options.symbolize_keys) when Hash _routes.url_for(options.symbolize_keys.reverse_merge!(url_options)) when String options else polymorphic_url(options) end end protected def optimize_routes_generation? return @_optimized_routes if defined?(@_optimized_routes) @_optimized_routes = _routes.optimize_routes_generation? && default_url_options.empty? end def _with_routes(routes) old_routes, @_routes = @_routes, routes yield ensure @_routes = old_routes end def _routes_context self end end end end