lib/action_controller/metal/redirecting.rb
# frozen_string_literal: true module ActionController module Redirecting extend ActiveSupport::Concern include AbstractController::Logger include ActionController::UrlFor # Redirects the browser to the target specified in +options+. This parameter can be any one of: # # * <tt>Hash</tt> - The URL will be generated by calling url_for with the +options+. # * <tt>Record</tt> - The URL will be generated by calling url_for with the +options+, which will reference a named URL for that record. # * <tt>String</tt> starting with <tt>protocol://</tt> (like <tt>http://</tt>) or a protocol relative reference (like <tt>//</tt>) - Is passed straight through as the target for redirection. # * <tt>String</tt> not containing a protocol - The current protocol and host is prepended to the string. # * <tt>Proc</tt> - A block that will be executed in the controller's context. Should return any option accepted by +redirect_to+. # # === Examples: # # redirect_to action: "show", id: 5 # redirect_to @post # redirect_to "http://www.rubyonrails.org" # redirect_to "/images/screenshot.jpg" # redirect_to posts_url # redirect_to proc { edit_post_url(@post) } # # The redirection happens as a <tt>302 Found</tt> header unless otherwise specified using the <tt>:status</tt> option: # # redirect_to post_url(@post), status: :found # redirect_to action: 'atom', status: :moved_permanently # redirect_to post_url(@post), status: 301 # redirect_to action: 'atom', status: 302 # # The status code can either be a standard {HTTP Status code}[https://www.iana.org/assignments/http-status-codes] as an # integer, or a symbol representing the downcased, underscored and symbolized description. # Note that the status code must be a 3xx HTTP code, or redirection will not occur. # # If you are using XHR requests other than GET or POST and redirecting after the # request then some browsers will follow the redirect using the original request # method. This may lead to undesirable behavior such as a double DELETE. To work # around this you can return a <tt>303 See Other</tt> status code which will be # followed using a GET request. # # redirect_to posts_url, status: :see_other # redirect_to action: 'index', status: 303 # # It is also possible to assign a flash message as part of the redirection. There are two special accessors for the commonly used flash names # +alert+ and +notice+ as well as a general purpose +flash+ bucket. # # redirect_to post_url(@post), alert: "Watch it, mister!" # redirect_to post_url(@post), status: :found, notice: "Pay attention to the road" # redirect_to post_url(@post), status: 301, flash: { updated_post_id: @post.id } # redirect_to({ action: 'atom' }, alert: "Something serious happened") # # Statements after +redirect_to+ in our controller get executed, so +redirect_to+ doesn't stop the execution of the function. # To terminate the execution of the function immediately after the +redirect_to+, use return. # redirect_to post_url(@post) and return def redirect_to(options = {}, response_options = {}) raise ActionControllerError.new("Cannot redirect to nil!") unless options raise AbstractController::DoubleRenderError if response_body self.status = _extract_redirect_to_status(options, response_options) self.location = _compute_redirect_to_location(request, options) self.response_body = "<html><body>You are being <a href=\"#{ERB::Util.unwrapped_html_escape(response.location)}\">redirected</a>.</body></html>" end # Redirects the browser to the page that issued the request (the referrer) # if possible, otherwise redirects to the provided default fallback # location. # # The referrer information is pulled from the HTTP +Referer+ (sic) header on # the request. This is an optional header and its presence on the request is # subject to browser security settings and user preferences. If the request # is missing this header, the <tt>fallback_location</tt> will be used. # # redirect_back fallback_location: { action: "show", id: 5 } # redirect_back fallback_location: @post # redirect_back fallback_location: "http://www.rubyonrails.org" # redirect_back fallback_location: "/images/screenshot.jpg" # redirect_back fallback_location: posts_url # redirect_back fallback_location: proc { edit_post_url(@post) } # redirect_back fallback_location: '/', allow_other_host: false # # ==== Options # * <tt>:fallback_location</tt> - The default fallback location that will be used on missing +Referer+ header. # * <tt>:allow_other_host</tt> - Allow or disallow redirection to the host that is different to the current host, defaults to true. # # All other options that can be passed to <tt>redirect_to</tt> are accepted as # options and the behavior is identical. def redirect_back(fallback_location:, allow_other_host: true, **args) referer = request.headers["Referer"] redirect_to_referer = referer && (allow_other_host || _url_host_allowed?(referer)) redirect_to redirect_to_referer ? referer : fallback_location, **args end def _compute_redirect_to_location(request, options) #:nodoc: case options # The scheme name consist of a letter followed by any combination of # letters, digits, and the plus ("+"), period ("."), or hyphen ("-") # characters; and is terminated by a colon (":"). # See https://tools.ietf.org/html/rfc3986#section-3.1 # The protocol relative scheme starts with a double slash "//". when /\A([a-z][a-z\d\-+\.]*:|\/\/).*/i options when String request.protocol + request.host_with_port + options when Proc _compute_redirect_to_location request, instance_eval(&options) else url_for(options) end.delete("\0\r\n") end module_function :_compute_redirect_to_location public :_compute_redirect_to_location private def _extract_redirect_to_status(options, response_options) if options.is_a?(Hash) && options.key?(:status) Rack::Utils.status_code(options.delete(:status)) elsif response_options.key?(:status) Rack::Utils.status_code(response_options[:status]) else 302 end end def _url_host_allowed?(url) URI(url.to_s).host == request.host rescue ArgumentError, URI::Error false end end end