module ActionController # In routes.rb one defines 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 ActionController::Routing and ActionController::Resources for general # information about routing and routes.rb. # # Tip: If you need to generate URLs from your models or some other place, # then ActionController::UrlWriter is what you're looking for. Read on for # an introduction. # # == 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!') %> # # #=> Generates a link to: /users/new?message=Welcome%21 # # link_to, and all other functions that require URL generation functionality, # actually use ActionController::UrlWriter under the hood. And in particular, # they use the ActionController::UrlWriter#url_for method. One can generate # the same path as the above example by using the following code: # # include UrlWriter # 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 UrlWriter 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 UrlWriter # url_for(:controller => 'users', # :action => 'new', # :message => 'Welcome!', # :host => 'www.example.com') # Changed this. # # => "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::UrlWriter#url_for. # So within mailers, you only have to type 'url_for' instead of 'ActionController::UrlWriter#url_for' # in full. However, mailers don't have hostname information, and what's why you'll still # have to specify the :host argument when generating URLs in mailers. # # # == URL generation for named routes # # UrlWriter 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 # routes.rb: # # map.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 in two ways. # # The first way is to include ActionController::UrlWriter in your class: # # class User < ActiveRecord::Base # include ActionController::UrlWriter # !!! # # def name=(value) # write_attribute('name', value) # write_attribute('base_uri', users_path) # !!! # end # end # # The second way is to access them through ActionController::UrlWriter. # The autogenerated named routes methods are available as class methods: # # class User < ActiveRecord::Base # def name=(value) # write_attribute('name', value) # path = ActionController::UrlWriter.users_path # !!! # write_attribute('base_uri', path) # !!! # end # end module UrlWriter # The default options for urls written by this writer. Typically a :host # pair is provided. mattr_accessor :default_url_options self.default_url_options = {} def self.included(base) #:nodoc: ActionController::Routing::Routes.install_helpers(base) base.mattr_accessor :default_url_options base.default_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 targetted at. # If :only_path is false, this option must be # provided either explicitly, or via +default_url_options+. # * :port - Optionally specify the port to connect to. # * :anchor - An anchor name to be appended to the path. # * :skip_relative_url_root - If true, the url is not constructed using the # +relative_url_root+ set in ActionController::Base.relative_url_root. # * :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. # # Examples: # # 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) options = self.class.default_url_options.merge(options) url = '' unless options.delete(:only_path) url << (options.delete(:protocol) || 'http') url << '://' unless url.match("://") raise "Missing host to link to! Please provide :host parameter or set default_url_options[:host]" unless options[:host] url << options.delete(:host) url << ":#{options.delete(:port)}" if options.key?(:port) else # Delete the unused options to prevent their appearance in the query string. [:protocol, :host, :port, :skip_relative_url_root].each { |k| options.delete(k) } end trailing_slash = options.delete(:trailing_slash) if options.key?(:trailing_slash) url << ActionController::Base.relative_url_root.to_s unless options[:skip_relative_url_root] anchor = "##{CGI.escape options.delete(:anchor).to_param.to_s}" if options[:anchor] generated = Routing::Routes.generate(options, {}) url << (trailing_slash ? generated.sub(/\?|\z/) { "/" + $& } : generated) url << anchor if anchor url end end # Rewrites URLs for Base.redirect_to and Base.url_for in the controller. class UrlRewriter #:nodoc: RESERVED_OPTIONS = [:anchor, :params, :only_path, :host, :protocol, :port, :trailing_slash, :skip_relative_url_root] def initialize(request, parameters) @request, @parameters = request, parameters end def rewrite(options = {}) rewrite_url(options) end def to_str "#{@request.protocol}, #{@request.host_with_port}, #{@request.path}, #{@parameters[:controller]}, #{@parameters[:action]}, #{@request.parameters.inspect}" end alias_method :to_s, :to_str private # Given a path and options, returns a rewritten URL string def rewrite_url(options) rewritten_url = "" unless options[:only_path] rewritten_url << (options[:protocol] || @request.protocol) rewritten_url << "://" unless rewritten_url.match("://") rewritten_url << rewrite_authentication(options) rewritten_url << (options[:host] || @request.host_with_port) rewritten_url << ":#{options.delete(:port)}" if options.key?(:port) end path = rewrite_path(options) rewritten_url << ActionController::Base.relative_url_root.to_s unless options[:skip_relative_url_root] rewritten_url << (options[:trailing_slash] ? path.sub(/\?|\z/) { "/" + $& } : path) rewritten_url << "##{options[:anchor]}" if options[:anchor] rewritten_url end # Given a Hash of options, generates a route def rewrite_path(options) options = options.symbolize_keys options.update(options[:params].symbolize_keys) if options[:params] if (overwrite = options.delete(:overwrite_params)) options.update(@parameters.symbolize_keys) options.update(overwrite.symbolize_keys) end RESERVED_OPTIONS.each { |k| options.delete(k) } # Generates the query string, too Routing::Routes.generate(options, @request.symbolized_path_parameters) end def rewrite_authentication(options) if options[:user] && options[:password] "#{CGI.escape(options.delete(:user))}:#{CGI.escape(options.delete(:password))}@" else "" end end end end