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
# 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 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
end
end
end