require 'active_support/core_ext/module/attribute_accessors' module ActionDispatch module Http module MimeNegotiation extend ActiveSupport::Concern included do mattr_accessor :ignore_accept_header self.ignore_accept_header = false end # The MIME type of the HTTP request, such as Mime[:xml]. # # For backward compatibility, the post \format is extracted from the # X-Post-Data-Format HTTP header if present. def content_mime_type fetch_header("action_dispatch.request.content_type") do |k| v = if get_header('CONTENT_TYPE') =~ /^([^,\;]*)/ Mime::Type.lookup($1.strip.downcase) else nil end set_header k, v end end def content_type content_mime_type && content_mime_type.to_s end def has_content_type? has_header? 'CONTENT_TYPE' end # Returns the accepted MIME type for the request. def accepts fetch_header("action_dispatch.request.accepts") do |k| header = get_header('HTTP_ACCEPT').to_s.strip v = if header.empty? [content_mime_type] else Mime::Type.parse(header) end set_header k, v end end # Returns the MIME type for the \format used in the request. # # GET /posts/5.xml | request.format => Mime[:xml] # GET /posts/5.xhtml | request.format => Mime[:html] # GET /posts/5 | request.format => Mime[:html] or Mime[:js], or request.accepts.first # def format(view_path = []) formats.first || Mime::NullType.instance end def formats fetch_header("action_dispatch.request.formats") do |k| params_readable = begin parameters[:format] rescue ActionController::BadRequest false end v = if params_readable Array(Mime[parameters[:format]]) elsif use_accept_header && valid_accept_header accepts elsif extension_format = format_from_path_extension [extension_format] elsif xhr? [Mime[:js]] else [Mime[:html]] end set_header k, v end end # Sets the \variant for template. def variant=(variant) variant = Array(variant) if variant.all? { |v| v.is_a?(Symbol) } @variant = ActiveSupport::ArrayInquirer.new(variant) else raise ArgumentError, "request.variant must be set to a Symbol or an Array of Symbols. " \ "For security reasons, never directly set the variant to a user-provided value, " \ "like params[:variant].to_sym. Check user-provided value against a whitelist first, " \ "then set the variant: request.variant = :tablet if params[:variant] == 'tablet'" end end def variant @variant ||= ActiveSupport::ArrayInquirer.new end # Sets the \format by string extension, which can be used to force custom formats # that are not controlled by the extension. # # class ApplicationController < ActionController::Base # before_action :adjust_format_for_iphone # # private # def adjust_format_for_iphone # request.format = :iphone if request.env["HTTP_USER_AGENT"][/iPhone/] # end # end def format=(extension) parameters[:format] = extension.to_s set_header "action_dispatch.request.formats", [Mime::Type.lookup_by_extension(parameters[:format])] end # Sets the \formats by string extensions. This differs from #format= by allowing you # to set multiple, ordered formats, which is useful when you want to have a fallback. # # In this example, the :iphone format will be used if it's available, otherwise it'll fallback # to the :html format. # # class ApplicationController < ActionController::Base # before_action :adjust_format_for_iphone_with_html_fallback # # private # def adjust_format_for_iphone_with_html_fallback # request.formats = [ :iphone, :html ] if request.env["HTTP_USER_AGENT"][/iPhone/] # end # end def formats=(extensions) parameters[:format] = extensions.first.to_s set_header "action_dispatch.request.formats", extensions.collect { |extension| Mime::Type.lookup_by_extension(extension) } end # Receives an array of mimes and return the first user sent mime that # matches the order array. # def negotiate_mime(order) formats.each do |priority| if priority == Mime::ALL return order.first elsif order.include?(priority) return priority end end order.include?(Mime::ALL) ? format : nil end protected BROWSER_LIKE_ACCEPTS = /,\s*\*\/\*|\*\/\*\s*,/ def valid_accept_header (xhr? && (accept.present? || content_mime_type)) || (accept.present? && accept !~ BROWSER_LIKE_ACCEPTS) end def use_accept_header !self.class.ignore_accept_header end def format_from_path_extension path = @env['action_dispatch.original_path'] || @env['PATH_INFO'] if match = path && path.match(/\.(\w+)\z/) Mime[match.captures.first] end end end end end