package Dancer2::Core::Request;
$Dancer2::Core::Request::VERSION = '0.13';
# ABSTRACT: Interface for accessing incoming requests
use Moo;
use Carp;
use Encode;
use HTTP::Body;
use URI;
use URI::Escape;
use Dancer2::Core::Types;
use Dancer2::Core::Request::Upload;
with 'Dancer2::Core::Role::Headers';
# check presence of XS module to speedup request
eval { require URL::Encode::XS; };
our $XS_URL_DECODE = !$@;
eval { require CGI::Deurl::XS; };
our $XS_PARSE_QUERY_STRING = !$@;
# add an attribute for each HTTP_* variables
# (HOST is managed manually)
my @http_env_keys = (qw/
accept
accept_charset
accept_encoding
accept_language
accept_type
connection
keep_alive
referer
user_agent
x_requested_with
/);
foreach my $attr ( @http_env_keys ) {
has $attr => (
is => 'ro',
isa => Maybe[Str],
lazy => 1,
default => sub { $_[0]->env->{ 'HTTP_' . ( uc $attr ) } },
);
}
# then all the native attributes
has env => (
is => 'ro',
isa => HashRef,
default => sub { {} },
);
has path => (
is => 'ro',
isa => Str,
lazy => 1,
builder => '_build_path',
);
sub _build_path {
my $self = shift;
# Written from PSGI specs:
# http://search.cpan.org/dist/PSGI/PSGI.pod
my $path = "";
$path .= $self->script_name if defined $self->script_name;
$path .= $self->env->{PATH_INFO} if defined $self->env->{PATH_INFO};
# fallback to REQUEST_URI if nothing found
# we have to decode it, according to PSGI specs.
if ( defined $self->request_uri ) {
$path ||= $self->_url_decode( $self->request_uri );
}
croak "Cannot resolve path" if not $path;
return $path;
}
has path_info => (
is => 'rw',
isa => Str,
lazy => 1,
builder => '_build_path_info',
);
sub _build_path_info {
my $self = shift;
my $info = $self->env->{PATH_INFO};
# Empty path info will be interpreted as "root".
return $info || '/' if defined $info;
return $self->path;
}
has method => (
is => 'rw',
isa => Dancer2HTTPMethod,
default => sub {
my $self = shift;
$self->env->{REQUEST_METHOD} || 'GET';
},
coerce => sub { uc $_[0] },
);
has content_type => (
is => 'ro',
isa => Str,
lazy => 1,
default => sub {
$_[0]->env->{CONTENT_TYPE} || '';
},
);
has content_length => (
is => 'ro',
isa => Num,
lazy => 1,
default => sub {
$_[0]->env->{CONTENT_LENGTH} || 0;
},
);
has body => (
is => 'ro',
isa => Str,
default => sub {''},
);
has id => (
is => 'ro',
isa => Num,
);
# Private 'read-only' attributes for request params. See the params()
# method for the public interface.
#
# _body_params, _query_params and _route_params have setter methods that
# decode byte string to characters before setting; If you know you have
# decoded (character) params, such as output from a deserializer, you can
# set these directly in the request object hash to avoid the decode op.
has _params => (
is => 'lazy',
isa => HashRef,
builder => '_build_params',
predicate => '_has_params',
);
has _body_params => (
is => 'ro',
isa => Maybe( HashRef ),
default => sub {undef},
);
sub _set_body_params {
my ( $self, $params ) = @_;
$self->{_body_params} = _decode( $params );
$self->_build_params();
}
has _query_params => (
is => 'ro',
isa => Maybe( HashRef ),
default => sub {undef},
);
sub _set_query_params {
my ( $self, $params ) = @_;
$self->{_query_params} = _decode( $params );
$self->_build_params();
}
has _route_params => (
is => 'ro',
isa => HashRef,
default => sub {{}},
);
sub _set_route_params {
my ( $self, $params ) = @_;
$self->{_route_params} = _decode( $params );
$self->_build_params();
}
has uploads => (
is => 'ro',
isa => HashRef,
);
has body_is_parsed => (
is => 'ro',
isa => Bool,
default => sub {0},
);
has is_behind_proxy => (
is => 'rw',
isa => Bool,
default => sub {0},
);
sub host {
my ($self) = @_;
if ( $self->is_behind_proxy ) {
my @hosts = split /\s*,\s*/, (
$self->env->{HTTP_X_FORWARDED_HOST} || $self->env->{X_FORWARDED_HOST}
);
return $hosts[0];
} else {
return $self->env->{'HTTP_HOST'};
}
}
#from Dancer2::Core::Role::Headers
# aliases, kept for backward compat
sub agent { $_[0]->user_agent }
sub remote_address { $_[0]->address }
sub forwarded_for_address { $_[0]->env->{'X_FORWARDED_FOR'} }
sub address { $_[0]->env->{REMOTE_ADDR} }
sub remote_host { $_[0]->env->{REMOTE_HOST} }
sub protocol { $_[0]->env->{SERVER_PROTOCOL} }
sub port { $_[0]->env->{SERVER_PORT} }
sub request_uri { $_[0]->env->{REQUEST_URI} }
sub user { $_[0]->env->{REMOTE_USER} }
sub script_name { $_[0]->env->{SCRIPT_NAME} }
sub scheme {
my ($self) = @_;
my $scheme;
if ( $self->is_behind_proxy ) {
$scheme =
$self->env->{'X_FORWARDED_PROTOCOL'}
|| $self->env->{'HTTP_X_FORWARDED_PROTOCOL'}
|| $self->env->{'HTTP_X_FORWARDED_PROTO'}
|| $self->env->{'HTTP_FORWARDED_PROTO'}
|| "";
}
return
$scheme
|| $self->env->{'psgi.url_scheme'}
|| $self->env->{'PSGI.URL_SCHEME'}
|| "";
}
has serializer => (
is => 'ro',
isa => Maybe( ConsumerOf ['Dancer2::Core::Role::Serializer'] ),
predicate => 1,
);
has data => (
is => 'ro',
lazy => 1,
default => \&deserialize,
);
sub deserialize {
my $self = shift;
return unless $self->has_serializer;
# Content-Type may contain additional parameters
# (http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7)
# which should be safe to ignore at this level.
# So accept either e.g. text/xml or text/xml; charset=utf-8
my ($content_type) = split /\s*;/, $self->content_type, 2;
return unless $self->serializer->support_content_type($content_type);
return
unless grep { $self->method eq $_ } qw/ PUT POST PATCH /;
# try to deserialize
my $body = $self->_read_to_end();
my $data = $self->serializer->deserialize($self->body);
return if !defined $data;
# Set _body_params directly rather than using the setter. Deserializiation
# returns characters and skipping the decode op in the setter ensures
# that numerical data "stays" numerical; decoding an SV that is an IV
# converts that to a PVIV. Some serializers are picky (JSON)..
$self->{_body_params} = $data;
$self->_build_params();
return $data;
}
sub secure { $_[0]->scheme eq 'https' }
sub uri { $_[0]->request_uri }
sub is_head { $_[0]->{method} eq 'HEAD' }
sub is_post { $_[0]->{method} eq 'POST' }
sub is_get { $_[0]->{method} eq 'GET' }
sub is_put { $_[0]->{method} eq 'PUT' }
sub is_delete { $_[0]->{method} eq 'DELETE' }
sub is_patch { $_[0]->{method} eq 'PATCH' }
# public interface compat with CGI.pm objects
sub request_method { method(@_) }
sub input_handle { $_[0]->env->{'psgi.input'} || $_[0]->env->{'PSGI.INPUT'} }
our $_count = 0;
sub BUILD {
my ($self) = @_;
$self->{id} = ++$_count;
$self->{_chunk_size} = 4096;
$self->{_read_position} = 0;
$self->_init_request_headers();
$self->{_http_body} =
HTTP::Body->new( $self->content_type, $self->content_length );
$self->{_http_body}->cleanup(1);
$self->data; # Deserialize body
$self->_params(); # Decode query and body prams
$self->_build_uploads();
}
sub to_string {
my ($self) = @_;
return "[#" . $self->id . "] " . $self->method . " " . $self->path;
}
# Create a new request which is a clone of the current one, apart
# from the path location, which points instead to the new location
# TODO this could be written in a more clean manner with a clone mechanism
sub make_forward_to {
my ( $self, $url, $params, $options ) = @_;
# we clone the env to make sure we don't alter the existing one in $self
my $env = { %{ $self->env } };
$env->{PATH_INFO} = $url;
my $new_request = ( ref $self )->new( env => $env, body_is_parsed => 1 );
my $new_params = _merge_params( scalar( $self->params ), $params || {} );
if ( exists( $options->{method} ) ) {
$new_request->method( $options->{method} );
}
# Copy params (these are already decoded)
$new_request->{_params} = $new_params;
$new_request->{_body_params} = $self->{_body_params};
$new_request->{_query_params} = $self->{_query_params};
$new_request->{_route_params} = $self->{_route_params};
$new_request->{body} = $self->body;
$new_request->{headers} = $self->headers;
return $new_request;
}
sub forward {
my ( $self, $context, $url, $params, $options ) = @_;
my $new_request = $self->make_forward_to( $url, $params, $options );
my $new_response = Dancer2->runner->server->dispatcher->dispatch(
$new_request->env,
$new_request,
$context,
);
# halt the response, so no further processing is done on this request.
# (any after hooks will have already been run)
$new_response->halt;
$context->response($new_response);
$context->with_return->($new_response) if $context->has_with_return;
return $new_response; # Should never be called..
}
sub _merge_params {
my ( $params, $to_add ) = @_;
for my $key ( keys %$to_add ) {
$params->{$key} = $to_add->{$key};
}
return $params;
}
sub base {
my $self = shift;
my $uri = $self->_common_uri;
return $uri->canonical;
}
sub _common_uri {
my $self = shift;
my $path = $self->env->{SCRIPT_NAME};
my $port = $self->env->{SERVER_PORT};
my $server = $self->env->{SERVER_NAME};
my $host = $self->host;
my $scheme = $self->scheme;
my $uri = URI->new;
$uri->scheme($scheme);
$uri->authority( $host || "$server:$port" );
$uri->path( $path || '/' );
return $uri;
}
sub uri_base {
my $self = shift;
my $uri = $self->_common_uri;
my $canon = $uri->canonical;
if ( $uri->path eq '/' ) {
$canon =~ s{/$}{};
}
return $canon;
}
sub dispatch_path {
my $self = shift;
my $path = $self->path;
# Want $self->base->path, without needing the URI object,
# and trim any trailing '/'.
my $base = '';
$base .= $self->script_name if defined $self->script_name;
$base =~ s|/+$||;
# Remove base from front of path.
$path =~ s|^(\Q$base\E)?||;
$path =~ s|^/+|/|;
# PSGI spec notes that '' should be considered '/'
$path = '/' if $path eq '';
return $path;
}
sub uri_for {
my ( $self, $part, $params, $dont_escape ) = @_;
my $uri = $self->base;
# Make sure there's exactly one slash between the base and the new part
my $base = $uri->path;
$base =~ s|/$||;
$part =~ s|^/||;
$uri->path("$base/$part");
$uri->query_form($params) if $params;
return $dont_escape ? uri_unescape( $uri->canonical ) : $uri->canonical;
}
sub params {
my ( $self, $source ) = @_;
return %{ $self->_params } if wantarray && @_ == 1;
return $self->_params if @_ == 1;
if ( $source eq 'query' ) {
return %{ $self->_query_params || {} } if wantarray;
return $self->_query_params;
}
elsif ( $source eq 'body' ) {
return %{ $self->_body_params || {} } if wantarray;
return $self->_body_params;
}
if ( $source eq 'route' ) {
return %{ $self->_route_params } if wantarray;
return $self->_route_params;
}
else {
croak "Unknown source params \"$source\".";
}
}
sub captures { shift->params->{captures} }
sub splat { @{ shift->params->{splat} || [] } }
sub param { shift->params->{ $_[0] } }
sub _decode {
my ($h) = @_;
return if not defined $h;
if ( !ref($h) && !utf8::is_utf8($h) ) {
return decode( 'UTF-8', $h );
}
if ( ref($h) eq 'HASH' ) {
while ( my ( $k, $v ) = each(%$h) ) {
$h->{$k} = _decode($v);
}
return $h;
}
if ( ref($h) eq 'ARRAY' ) {
return [ map { _decode($_) } @$h ];
}
return $h;
}
sub is_ajax {
my $self = shift;
return 0 unless defined $self->headers;
return 0 unless defined $self->header('X-Requested-With');
return 0 if $self->header('X-Requested-With') ne 'XMLHttpRequest';
return 1;
}
# context-aware accessor for uploads
sub upload {
my ( $self, $name ) = @_;
my $res = $self->{uploads}{$name};
return $res unless wantarray;
return () unless defined $res;
return ( ref($res) eq 'ARRAY' ) ? @$res : $res;
}
sub _build_params {
my ($self) = @_;
# params may have been populated by before filters
# _before_ we get there, so we have to save it first
my $previous = $self->_has_params ? $self->_params : {};
# now parse environment params...
$self->_parse_get_params();
if ( $self->body_is_parsed ) {
$self->{_body_params} ||= {};
}
else {
$self->_parse_post_params();
}
# and merge everything
$self->{_params} = {
%$previous, %{ $self->_query_params || {} },
%{ $self->_route_params }, %{ $self->_body_params || {} },
};
}
sub _url_decode {
my ( $self, $encoded ) = @_;
return URL::Encode::XS::url_decode($encoded) if $XS_URL_DECODE;
my $clean = $encoded;
$clean =~ tr/\+/ /;
$clean =~ s/%([a-fA-F0-9]{2})/pack "H2", $1/eg;
return $clean;
}
sub _parse_post_params {
my ($self) = @_;
return $self->_body_params if defined $self->_body_params;
my $body = $self->_read_to_end();
$self->_set_body_params( $self->{_http_body}->param );
}
sub _parse_get_params {
my ($self) = @_;
return $self->_query_params if defined $self->{_query_params};
my $query_params = {};
my $source = $self->env->{QUERY_STRING};
return if !defined $source || $source eq '';
if ($XS_PARSE_QUERY_STRING) {
$self->_set_query_params(
CGI::Deurl::XS::parse_query_string($source) || {}
);
return $self->_query_params;
}
foreach my $token ( split /[&;]/, $source ) {
my ( $key, $val ) = split( /=/, $token );
next unless defined $key;
$val = ( defined $val ) ? $val : '';
$key = $self->_url_decode($key);
$val = $self->_url_decode($val);
# looking for multi-value params
if ( exists $query_params->{$key} ) {
my $prev_val = $query_params->{$key};
if ( ref($prev_val) && ref($prev_val) eq 'ARRAY' ) {
push @{ $query_params->{$key} }, $val;
}
else {
$query_params->{$key} = [ $prev_val, $val ];
}
}
# simple value param (first time we see it)
else {
$query_params->{$key} = $val;
}
}
$self->_set_query_params( $query_params );
return $self->_query_params;
}
sub _read_to_end {
my ($self) = @_;
my $content_length = $self->content_length;
return unless $self->_has_something_to_read();
if ( $content_length > 0 ) {
while ( my $buffer = $self->_read() ) {
$self->{body} .= $buffer;
$self->{_http_body}->add($buffer);
}
}
return $self->{body};
}
sub _has_something_to_read {
my ($self) = @_;
return 0 unless defined $self->input_handle;
}
# taken from Miyagawa's Plack::Request::BodyParser
sub _read {
my ( $self, ) = @_;
my $remaining = $self->content_length - $self->{_read_position};
my $maxlength = $self->{_chunk_size};
return if ( $remaining <= 0 );
my $readlen = ( $remaining > $maxlength ) ? $maxlength : $remaining;
my $buffer;
my $rc;
$rc = $self->input_handle->read( $buffer, $readlen );
if ( defined $rc ) {
$self->{_read_position} += $rc;
return $buffer;
}
else {
croak "Unknown error reading input: $!";
}
}
sub _init_request_headers {
my ($self) = @_;
my $env = $self->env;
$self->headers(
HTTP::Headers->new(
map {
( my $field = $_ ) =~ s/^HTTPS?_//;
( $field => $env->{$_} );
}
grep {/^(?:HTTP|CONTENT|COOKIE)/i} keys %$env
)
);
}
# Taken gently from Plack::Request, thanks to Plack authors.
sub _build_uploads {
my ($self) = @_;
my $uploads = _decode( $self->{_http_body}->upload );
my %uploads;
for my $name ( keys %{$uploads} ) {
my $files = $uploads->{$name};
$files = ref $files eq 'ARRAY' ? $files : [$files];
my @uploads;
for my $upload ( @{$files} ) {
push(
@uploads,
Dancer2::Core::Request::Upload->new(
headers => $upload->{headers},
tempname => $upload->{tempname},
size => $upload->{size},
filename => $upload->{filename},
)
);
}
$uploads{$name} = @uploads > 1 ? \@uploads : $uploads[0];
# support access to the filename as a normal param
my @filenames = map { $_->{filename} } @uploads;
$self->{_body_params}{$name} =
@filenames > 1 ? \@filenames : $filenames[0];
}
$self->{uploads} = \%uploads;
$self->_build_params();
}
has cookies => (
is => 'rw',
isa => HashRef,
lazy => 1,
builder => '_build_cookies',
);
sub _build_cookies {
my ($self) = @_;
my $env_str = $self->env->{COOKIE} || $self->env->{HTTP_COOKIE};
return {} unless defined $env_str;
my $cookies = {};
foreach my $cookie ( split( /[,;]\s/, $env_str ) ) {
# here, we don't want more than the 2 first elements
# a cookie string can contains something like:
# cookie_name="foo=bar"
# we want `cookie_name' as the value and `foo=bar' as the value
my ( $name, $value ) = split( /\s*=\s*/, $cookie, 2 );
my @values;
if ( $value ne '' ) {
@values = map { uri_unescape($_) } split( /[&;]/, $value );
}
$cookies->{$name} =
Dancer2::Core::Cookie->new( name => $name, value => \@values );
}
return $cookies;
}
1;
__END__
=pod
=head1 NAME
Dancer2::Core::Request - Interface for accessing incoming requests
=head1 VERSION
version 0.13
=head1 SYNOPSIS
In a route handler, the current request object can be accessed by the C<request>
method, like in the following example:
get '/foo' => sub {
request->params; # request, params parsed as a hash ref
request->body; # returns the request body, unparsed
request->path; # the path requested by the client
# ...
};
A route handler should not read the environment by itself, but should instead
use the current request object.
=head1 DESCRIPTION
This class implements a common interface for accessing incoming requests in
a Dancer2 application.
=head1 METHODS
=head2 env()
Return the current environment (C<%ENV>), as a hashref.
=head2 path()
Return the path requested by the client.
=head2 method()
Return the HTTP method used by the client to access the application.
While this method returns the method string as provided by the environment, it's
better to use one of the following boolean accessors if you want to inspect the
requested method.
=head2 content_type()
Return the content type of the request.
=head2 content_length()
Return the content length of the request.
=head2 body()
Return the raw body of the request, unparsed.
If you need to access the body of the request, you have to use this accessor and
should not try to read C<psgi.input> by hand. C<Dancer2::Core::Request>
already did it for you and kept the raw body untouched in there.
=head2 uploads()
Returns a reference to a hash containing uploads. Values can be either a
L<Dancer2::Core::Request::Upload> object, or an arrayref of
L<Dancer2::Core::Request::Upload>
objects.
You should probably use the C<upload($name)> accessor instead of manually accessing the
C<uploads> hash table.
=head2 header($name)
Return the value of the given header, if present. If the header has multiple
values, returns an the list of values if called in list context, the first one
in scalar.
=head2 new()
The constructor of the class, used internally by Dancer2's core to create request
objects.
It uses the environment hash table given to build the request object:
Dancer2::Core::Request->new(env => \%ENV);
It also accepts the C<body_is_parsed> boolean flag, if the new request object should
not parse request body.
=head2 address()
Return the IP address of the client.
=head2 remote_host()
Return the remote host of the client. This only works with web servers configured
to do a reverse DNS lookup on the client's IP address.
=head2 protocol()
Return the protocol (HTTP/1.0 or HTTP/1.1) used for the request.
=head2 port()
Return the port of the server.
=head2 request_uri()
Return the raw, undecoded request URI path.
=head2 user()
Return remote user if defined.
=head2 script_name()
Return script_name from the environment.
=head2 scheme()
Return the scheme of the request
=head2 serializer()
Returns the optional serializer object used to deserialize request parameters.
=head2 data()
If the application has a serializer and if the request has serialized
content, returns the deserialized structure as a hashref.
=head2 secure()
Return true of false, indicating whether the connection is secure
=head2 uri()
An alias to request_uri()
=head2 is_get()
Return true if the method requested by the client is 'GET'
=head2 is_head()
Return true if the method requested by the client is 'HEAD'
=head2 is_post()
Return true if the method requested by the client is 'POST'
=head2 is_put()
Return true if the method requested by the client is 'PUT'
=head2 is_delete()
Return true if the method requested by the client is 'DELETE'
=head2 request_method
Alias to the C<method> accessor, for backward-compatibility with C<CGI> interface.
=head2 input_handle
Alias to the PSGI input handle (C<< <request->env->{psgi.input}> >>)
=head2 to_string()
Return a string representing the request object (eg: C<"GET /some/path">)
=head2 forward($request, $new_location)
Create a new request which is a clone of the current one, apart
from the path location, which points instead to the new location.
This is used internally to chain requests using the forward keyword.
Note that the new location should be a hash reference. Only one key is
required, the C<to_url>, that should point to the URL that forward
will use. Optional values are the key C<params> to a hash of
parameters to be added to the current request parameters, and the key
C<options> that points to a hash of options about the redirect (for
instance, C<method> pointing to a new request method).
=head2 base()
Returns an absolute URI for the base of the application. Returns a L<URI>
object (which stringifies to the URL, as you'd expect).
=head2 uri_base()
Same thing as C<base> above, except it removes the last trailing slash in the
path if it is the only path.
This means that if your base is I<http://myserver/>, C<uri_base> will return
I<http://myserver> (notice no trailing slash). This is considered very useful
when using templates to do the following thing:
<link rel="stylesheet" href="[% request.uri_base %]/css/style.css" />
=head2 dispatch_path()
The part of the C<path> after C<base>. This is the path used
for dispatching the request to routes.
=head2 uri_for(path, params)
Constructs a URI from the base and the passed path. If params (hashref) is
supplied, these are added to the query string of the uri. If the base is
C<http://localhost:5000/foo>, C<< request->uri_for('/bar', { baz => 'baz' }) >>
would return C<http://localhost:5000/foo/bar?baz=baz>. Returns a L<URI> object
(which stringifies to the URL, as you'd expect).
=head2 params($source)
Called in scalar context, returns a hashref of params, either from the specified
source (see below for more info on that) or merging all sources.
So, you can use, for instance:
my $foo = params->{foo}
If called in list context, returns a list of key => value pairs, so you could use:
my %allparams = params;
=head3 Fetching only params from a given source
If a required source isn't specified, a mixed hashref (or list of key value
pairs, in list context) will be returned; this will contain params from all
sources (route, query, body).
In practical terms, this means that if the param C<foo> is passed both on the
querystring and in a POST body, you can only access one of them.
If you want to see only params from a given source, you can say so by passing
the C<$source> param to C<params()>:
my %querystring_params = params('query');
my %route_params = params('route');
my %post_params = params('body');
If source equals C<route>, then only params parsed from the route pattern
are returned.
If source equals C<query>, then only params parsed from the query string are
returned.
If source equals C<body>, then only params sent in the request body will be
returned.
If another value is given for C<$source>, then an exception is triggered.
=head2 is_ajax()
Return true if the value of the header C<X-Requested-With> is XMLHttpRequest.
=head2 upload($name)
Context-aware accessor for uploads. It's a wrapper around an access to the hash
table provided by C<uploads()>. It looks at the calling context and returns a
corresponding value.
If you have many file uploads under the same name, and call C<upload('name')> in
an array context, the accessor will unroll the ARRAY ref for you:
my @uploads = request->upload('many_uploads'); # OK
Whereas with a manual access to the hash table, you'll end up with one element
in @uploads, being the ARRAY ref:
my @uploads = request->uploads->{'many_uploads'}; # $uploads[0]: ARRAY(0xXXXXX)
That is why this accessor should be used instead of a manual access to
C<uploads>.
=head2 cookies()
Returns a reference to a hash containing cookies, where the keys are the names of the
cookies and values are L<Dancer2::Core::Cookie> objects.
=head1 HTTP environment variables
All HTTP environment variables that are in %ENV will be provided in the
L<Dancer2::Core::Request> object through specific accessors, here are those
supported:
=over 4
=item C<accept>
=item C<accept_charset>
=item C<accept_encoding>
=item C<accept_language>
=item C<accept_type>
=item C<agent> (alias for C<user_agent>)
=item C<connection>
=item C<forwarded_for_address>
=item C<forwarded_protocol>
=item C<forwarded_host>
=item C<host>
=item C<keep_alive>
=item C<path_info>
=item C<referer>
=item C<remote_address>
=item C<user_agent>
=item C<x_requested_with>
=back
=head1 EXTRA SPEED
Install URL::Encode::XS and CGI::Deurl::XS for extra speed.
Dancer2::Core::Request will use it if they detect their presence.
=head1 SEE ALSO
L<Dancer2>
=head1 AUTHOR
Dancer Core Developers
=head1 COPYRIGHT AND LICENSE
This software is copyright (c) 2014 by Alexis Sukrieh.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=cut