/ 
Dancer2-1.1.0
River stage three • 162 direct dependents • 183 total dependents
/ Dancer2::Core::Request

NAME

Dancer2::Core::Request - Interface for accessing incoming requests

VERSION

version 1.1.0

SYNOPSIS

In a route handler, the current request object can be accessed by the request keyword:

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
    # ...
};

DESCRIPTION

An object representing a Dancer2 request. It aims to provide a proper interface to anything you might need from a web request.

METHODS

address

Return the IP address of the client.

base

Returns an absolute URI for the base of the application. Returns a URI object (which stringifies to the URL, as you'd expect).

body_parameters

Returns a Hash::MultiValue object representing the POST parameters.

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 psgi.input by hand. Dancer2::Core::Request already did it for you and kept the raw body untouched in there.

body_data

Returns the body of the request in data form, making it possible to distinguish between body_parameters, a representation of the request parameters (Hash::MultiValue) and other forms of content.

If a serializer is set, this is the deserialized request body. Otherwise this is the decoded body parameters (if any), or the body content itself.

content

Returns the undecoded byte string POST body.

cookies

Returns a reference to a hash containing cookies, where the keys are the names of the cookies and values are Dancer2::Core::Cookie objects.

data

If the application has a serializer and if the request has serialized content, returns the deserialized structure as a hashref.

dispatch_path

Alias for path. Deprecated.

env

Return the current PSGI environment hash reference.

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.

headers

Returns either an HTTP::Headers or an HTTP::Headers::Fast object representing the headers.

id

The ID of the request. This allows you to trace a specific request in loggers, per the string created using to_string.

The ID of the request is essentially the number of requests run in the current class.

input

Alias to input_handle method below.

input_handle

Alias to the PSGI input handle (request->env->{'psgi.input'})

is_ajax

Return true if the value of the header X-Requested-With is XMLHttpRequest.

is_delete

Return true if the method requested by the client is 'DELETE'

is_get

Return true if the method requested by the client is 'GET'

is_head

Return true if the method requested by the client is 'HEAD'

is_post

Return true if the method requested by the client is 'POST'

is_put

Return true if the method requested by the client is 'PUT'

is_options

Return true if the method requested by the client is 'OPTIONS'

logger

Returns the psgix.logger code reference, if exists.

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.

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 );

There are two additional parameters for instantiation:

  • serializer

    A serializer object to work with when reading the request body.

  • body_params

    Provide body parameters.

    Used internally when we need to avoid parsing the body again.

param($key)

Calls the params method below and fetches the key provided.

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 and value pairs, so you could use:

my %allparams = params;

Parameters are merged in the following order: query, body, route - i.e. route parameters have the highest priority:

POST /hello/Ruth?name=Quentin

name=Bobbie

post '/hello/:name' => sub {
    return "Hello, " . route_parameters->get('name') . "!"; # returns Ruth
    return "Hello, " . query_parameters->get('name') . "!"; # returns Quentin
    return "Hello, " . body_parameters->get('name') . "!";  # returns Bobbie
    return "Hello, " . param('name') . "!";                 # returns Ruth
};

The "query_parameters", "route_parameters", and "body_parameters" keywords provide a Hash::MultiValue result from the three different parameters. We recommend using these rather than params, because of the potential for unintentional behaviour - consider the following request and route handler:

POST /artist/104/new-song

name=Careless Dancing

post '/artist/:id/new-song' => sub {
  find_artist(param('id'))->create_song(params);
  # oops! we just passed id into create_song,
  # but we probably only intended to pass name
  find_artist(param('id'))->create_song(body_parameters);
};

POST /artist/104/join-band

id=4
name=Dancing Misfits

post '/artist/:id/new-song' => sub {
  find_artist(param('id'))->join_band(params);
  # oops! we just passed an id of 104 into join_band,
  # but we probably should have passed an id of 4
};

parameters

Returns a Hash::MultiValue object with merged GET and POST parameters.

Parameters are merged in the following order: query, body, route - i.e. route parameters have the highest priority - see "params" for how this works, and associated risks and alternatives.

path

The path requested by the client, normalized. This is effectively path_info or a single forward /.

path_info

The raw requested path. This could be empty. Use path instead.

port

Return the port of the server.

protocol

Return the protocol (HTTP/1.0 or HTTP/1.1) used for the request.

query_parameters

Returns a Hash::MultiValue parameters object.

query_string

Returns the portion of the request defining the query itself - this is what comes after the ? in a URI.

raw_body

Alias to content method.

remote_address

Alias for address method.

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.

request_method

Alias to the method accessor, for backward-compatibility with CGI interface.

request_uri

Return the raw, undecoded request URI path.

route

Return the route which this request matched.

scheme

Return the scheme of the request

script_name

Return script_name from the environment.

secure

Return true or false, indicating whether the connection is secure - this is effectively checking if the scheme is HTTPS or not.

serializer

Returns the optional serializer object used to deserialize request parameters.

session

Returns the psgix.session hash, if exists.

session_options

Returns the psgix.session.options hash, if exists.

to_string

Return a string representing the request object (e.g., GET /some/path).

upload($name)

Context-aware accessor for uploads. It's a wrapper around an access to the hash table provided by uploads(). It looks at the calling context and returns a corresponding value.

If you have many file uploads under the same name, and call 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 arrayref:

my @uploads = request->uploads->{'many_uploads'};
# $uploads[0]: ARRAY(0xXXXXX)

That is why this accessor should be used instead of a manual access to uploads.

uploads

Returns a reference to a hash containing uploads. Values can be either a Dancer2::Core::Request::Upload object, or an arrayref of Dancer2::Core::Request::Upload objects.

You should probably use the upload($name) accessor instead of manually accessing the uploads hash table.

uri

An alias to request_uri.

uri_base

Same thing as 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 http://myserver/, uri_base will return 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" />

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.

Thus, with the following base:

http://localhost:5000/foo

You get the following behavior:

my $uri = request->uri_for('/bar', { baz => 'baz' });
print $uri; # http://localhost:5000/foo/bar?baz=baz

uri_for returns a URI object (which can stringify to the value).

uri_for_route(route_name, route_params, query_params, escape)

Constructs a URI from the base and the path of the specified route name.

Read more about it in the Dancer2::Manual::Keywords document under uri_for_route.

user

Return remote user if defined.

var

By-name interface to variables stored in this request object.

my $stored = $request->var('some_variable');

returns the value of 'some_variable', while

$request->var('some_variable' => 'value');

will set it.

vars

Access to the internal hash of variables:

my $value = $request->vars->{'my_key'};

You want to use var above.

Common HTTP request headers

Commonly used client-supplied HTTP request headers are available through specific accessors:

accept

HTTP header: HTTP_ACCEPT.

accept_charset

HTTP header: HTTP_ACCEPT_CHARSET.

accept_encoding

HTTP header: HTTP_ACCEPT_ENCODING.

accept_language

HTTP header: HTTP_ACCEPT_LANGUAGE.

agent

Alias for user_agent) below.

connection

HTTP header: HTTP_CONNECTION.

content_encoding

HTTP header: HTTP_CONTENT_ENCODING.

content_length

HTTP header: HTTP_CONTENT_LENGTH.

content_type

HTTP header: HTTP_CONTENT_TYPE.

forwarded_for_address

HTTP header: HTTP_X_FORWARDED_FOR.

forwarded_host

HTTP header: HTTP_X_FORWARDED_HOST.

forwarded_protocol

One of either HTTP_X_FORWARDED_PROTOCOL, HTTP_X_FORWARDED_PROTO, or HTTP_FORWARDED_PROTO.

host

Checks whether we are behind a proxy using the behind_proxy configuration option, and if so returns the first HTTP_X_FORWARDED_HOST, since this is a comma separated list.

If you have not configured that you are behind a proxy, it returns HTTP header HTTP_HOST.

keep_alive

HTTP header: HTTP_KEEP_ALIVE.

referer

HTTP header: HTTP_REFERER.

user_agent

HTTP header: HTTP_USER_AGENT.

x_requested_with

HTTP header: HTTP_X_REQUESTED_WITH.

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 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 $source param to params():

my %querystring_params = params('query');
my %route_params       = params('route');
my %post_params        = params('body');

If source equals route, then only params parsed from the route pattern are returned.

If source equals query, then only params parsed from the query string are returned.

If source equals body, then only params sent in the request body will be returned.

If another value is given for $source, then an exception is triggered.

EXTRA SPEED

If Dancer2::Core::Request detects the following modules as installed, it will use them to speed things up:

AUTHOR

Dancer Core Developers

COPYRIGHT AND LICENSE

This software is copyright (c) 2023 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.