# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Request class."""
from datetime import datetime
from io import BytesIO
from uuid import UUID
from falcon import errors
from falcon import request_helpers as helpers
from falcon import util
from falcon.constants import _UNSET
from falcon.constants import DEFAULT_MEDIA_TYPE
from falcon.constants import MEDIA_JSON
from falcon.forwarded import _parse_forwarded_header
# TODO: remove import in falcon 4
from falcon.forwarded import Forwarded # NOQA
from falcon.media import Handlers
from falcon.media.json import _DEFAULT_JSON_HANDLER
from falcon.stream import BoundedStream
from falcon.util import structures
from falcon.util.misc import isascii
from falcon.util.uri import parse_host
from falcon.util.uri import parse_query_string
from falcon.vendor import mimeparse
DEFAULT_ERROR_LOG_FORMAT = '{0:%Y-%m-%d %H:%M:%S} [FALCON] [ERROR] {1} {2}{3} => '
TRUE_STRINGS = frozenset(['true', 'True', 't', 'yes', 'y', '1', 'on'])
FALSE_STRINGS = frozenset(['false', 'False', 'f', 'no', 'n', '0', 'off'])
WSGI_CONTENT_HEADERS = frozenset(['CONTENT_TYPE', 'CONTENT_LENGTH'])
# PERF(kgriffs): Avoid an extra namespace lookup when using these functions
strptime = datetime.strptime
now = datetime.now
[docs]
class Request:
"""Represents a client's HTTP request.
Note:
`Request` is not meant to be instantiated directly by responders.
Args:
env (dict): A WSGI environment dict passed in from the server. See
also PEP-3333.
Keyword Arguments:
options (dict): Set of global options passed from the App handler.
Attributes:
env (dict): Reference to the WSGI environ ``dict`` passed in from the
server. (See also PEP-3333.)
context (object): Empty object to hold any data (in its attributes)
about the request which is specific to your app (e.g. session
object). Falcon itself will not interact with this attribute after
it has been initialized.
Note:
**New in 2.0:** The default `context_type` (see below) was
changed from :class:`dict` to a bare class; the preferred way to
pass request-specific data is now to set attributes directly on
the `context` object. For example::
req.context.role = 'trial'
req.context.user = 'guest'
context_type (class): Class variable that determines the factory or
type to use for initializing the `context` attribute. By default,
the framework will instantiate bare objects (instances of the bare
:class:`falcon.Context` class). However, you may override this
behavior by creating a custom child class of ``falcon.Request``,
and then passing that new class to `falcon.App()` by way of the
latter's `request_type` parameter.
Note:
When overriding `context_type` with a factory function (as
opposed to a class), the function is called like a method of
the current Request instance. Therefore the first argument is
the Request instance itself (self).
scheme (str): URL scheme used for the request. Either 'http' or
'https'.
Note:
If the request was proxied, the scheme may not
match what was originally requested by the client.
:py:attr:`forwarded_scheme` can be used, instead,
to handle such cases.
forwarded_scheme (str): Original URL scheme requested by the
user agent, if the request was proxied. Typical values are
'http' or 'https'.
The following request headers are checked, in order of
preference, to determine the forwarded scheme:
- ``Forwarded``
- ``X-Forwarded-For``
If none of these headers are available, or if the
Forwarded header is available but does not contain a
"proto" parameter in the first hop, the value of
:attr:`scheme` is returned instead.
(See also: RFC 7239, Section 1)
method (str): HTTP method requested (e.g., 'GET', 'POST', etc.)
host (str): Host request header field
forwarded_host (str): Original host request header as received
by the first proxy in front of the application server.
The following request headers are checked, in order of
preference, to determine the forwarded scheme:
- ``Forwarded``
- ``X-Forwarded-Host``
If none of the above headers are available, or if the
Forwarded header is available but the "host"
parameter is not included in the first hop, the value of
:attr:`host` is returned instead.
Note:
Reverse proxies are often configured to set the Host
header directly to the one that was originally
requested by the user agent; in that case, using
:attr:`host` is sufficient.
(See also: RFC 7239, Section 4)
port (int): Port used for the request. If the Host header is present
in the request, but does not specify a port, the default one for the
given schema is returned (80 for HTTP and 443 for HTTPS). If the
request does not include a Host header, the listening port for the
WSGI server is returned instead.
netloc (str): Returns the "host:port" portion of the request
URL. The port may be omitted if it is the default one for
the URL's schema (80 for HTTP and 443 for HTTPS).
subdomain (str): Leftmost (i.e., most specific) subdomain from the
hostname. If only a single domain name is given, `subdomain`
will be ``None``.
Note:
If the hostname in the request is an IP address, the value
for `subdomain` is undefined.
root_path (str): The initial portion of the request URI's path that
corresponds to the application object, so that the
application knows its virtual "location". This may be an
empty string, if the application corresponds to the "root"
of the server.
(Corresponds to the "SCRIPT_NAME" environ variable defined
by PEP-3333.)
app (str): Deprecated alias for :attr:`root_path`.
uri (str): The fully-qualified URI for the request.
url (str): Alias for :attr:`uri`.
forwarded_uri (str): Original URI for proxied requests. Uses
:attr:`forwarded_scheme` and :attr:`forwarded_host` in
order to reconstruct the original URI requested by the user
agent.
relative_uri (str): The path and query string portion of the
request URI, omitting the scheme and host.
prefix (str): The prefix of the request URI, including scheme,
host, and WSGI app (if any).
forwarded_prefix (str): The prefix of the original URI for
proxied requests. Uses :attr:`forwarded_scheme` and
:attr:`forwarded_host` in order to reconstruct the
original URI.
path (str): Path portion of the request URI (not including query
string).
Warning:
If this attribute is to be used by the app for any upstream
requests, any non URL-safe characters in the path must be URL
encoded back before making the request.
Note:
``req.path`` may be set to a new value by a
``process_request()`` middleware method in order to influence
routing. If the original request path was URL encoded, it will
be decoded before being returned by this attribute.
query_string (str): Query string portion of the request URI, without
the preceding '?' character.
uri_template (str): The template for the route that was matched for
this request. May be ``None`` if the request has not yet been
routed, as would be the case for ``process_request()`` middleware
methods. May also be ``None`` if your app uses a custom routing
engine and the engine does not provide the URI template when
resolving a route.
remote_addr(str): IP address of the closest client or proxy to
the WSGI server.
This property is determined by the value of ``REMOTE_ADDR``
in the WSGI environment dict. Since this address is not
derived from an HTTP header, clients and proxies can not
forge it.
Note:
If your application is behind one or more reverse
proxies, you can use :py:attr:`~.access_route`
to retrieve the real IP address of the client.
access_route(list): IP address of the original client, as well
as any known addresses of proxies fronting the WSGI server.
The following request headers are checked, in order of
preference, to determine the addresses:
- ``Forwarded``
- ``X-Forwarded-For``
- ``X-Real-IP``
If none of these headers are available, the value of
:py:attr:`~.remote_addr` is used instead.
Note:
Per `RFC 7239`_, the access route may contain "unknown"
and obfuscated identifiers, in addition to IPv4 and
IPv6 addresses
.. _RFC 7239: https://tools.ietf.org/html/rfc7239
Warning:
Headers can be forged by any client or proxy. Use this
property with caution and validate all values before
using them. Do not rely on the access route to authorize
requests.
forwarded (list): Value of the Forwarded header, as a parsed list
of :class:`falcon.Forwarded` objects, or ``None`` if the header
is missing. If the header value is malformed, Falcon will
make a best effort to parse what it can.
(See also: RFC 7239, Section 4)
date (datetime): Value of the Date header, converted to a
``datetime`` instance. The header value is assumed to
conform to RFC 1123.
auth (str): Value of the Authorization header, or ``None`` if the
header is missing.
user_agent (str): Value of the User-Agent header, or ``None`` if the
header is missing.
referer (str): Value of the Referer header, or ``None`` if
the header is missing.
accept (str): Value of the Accept header, or ``'*/*'`` if the header is
missing.
client_accepts_json (bool): ``True`` if the Accept header indicates
that the client is willing to receive JSON, otherwise ``False``.
client_accepts_msgpack (bool): ``True`` if the Accept header indicates
that the client is willing to receive MessagePack, otherwise
``False``.
client_accepts_xml (bool): ``True`` if the Accept header indicates that
the client is willing to receive XML, otherwise ``False``.
cookies (dict):
A dict of name/value cookie pairs. The returned object should be
treated as read-only to avoid unintended side-effects.
If a cookie appears more than once in the request, only the first
value encountered will be made available here.
See also: :meth:`~falcon.Request.get_cookie_values`
content_type (str): Value of the Content-Type header, or ``None`` if
the header is missing.
content_length (int): Value of the Content-Length header converted
to an ``int``, or ``None`` if the header is missing.
stream: File-like input object for reading the body of the
request, if any. This object provides direct access to the
server's data stream and is non-seekable. In order to
avoid unintended side effects, and to provide maximum
flexibility to the application, Falcon itself does not
buffer or spool the data in any way.
Since this object is provided by the WSGI
server itself, rather than by Falcon, it may behave
differently depending on how you host your app. For example,
attempting to read more bytes than are expected (as
determined by the Content-Length header) may or may not
block indefinitely. It's a good idea to test your WSGI
server to find out how it behaves.
This can be particulary problematic when a request body is
expected, but none is given. In this case, the following
call blocks under certain WSGI servers::
# Blocks if Content-Length is 0
data = req.stream.read()
The workaround is fairly straightforward, if verbose::
# If Content-Length happens to be 0, or the header is
# missing altogether, this will not block.
data = req.stream.read(req.content_length or 0)
Alternatively, when passing the stream directly to a
consumer, it may be necessary to branch off the
value of the Content-Length header::
if req.content_length:
doc = json.load(req.stream)
For a slight performance cost, you may instead wish to use
:py:attr:`bounded_stream`, which wraps the native WSGI
input object to normalize its behavior.
Note:
If an HTML form is POSTed to the API using the
*application/x-www-form-urlencoded* media type, and
the :py:attr:`~.RequestOptions.auto_parse_form_urlencoded`
option is set, the framework
will consume `stream` in order to parse the parameters
and merge them into the query string parameters. In this
case, the stream will be left at EOF.
bounded_stream: File-like wrapper around `stream` to normalize
certain differences between the native input objects
employed by different WSGI servers. In particular,
`bounded_stream` is aware of the expected Content-Length of
the body, and will never block on out-of-bounds reads,
assuming the client does not stall while transmitting the
data to the server.
For example, the following will not block when
Content-Length is 0 or the header is missing altogether::
data = req.bounded_stream.read()
This is also safe::
doc = json.load(req.bounded_stream)
media (object): Property that acts as an alias for
:meth:`~.get_media`. This alias provides backwards-compatibility
for apps that were built for versions of the framework prior to
3.0::
# Equivalent to: deserialized_media = req.get_media()
deserialized_media = req.media
expect (str): Value of the Expect header, or ``None`` if the
header is missing.
range (tuple of int): A 2-member ``tuple`` parsed from the value of the
Range header, or ``None`` if the header is missing.
The two members correspond to the first and last byte
positions of the requested resource, inclusive. Negative
indices indicate offset from the end of the resource,
where -1 is the last byte, -2 is the second-to-last byte,
and so forth.
Only continuous ranges are supported (e.g., "bytes=0-0,-1" would
result in an HTTPBadRequest exception when the attribute is
accessed.)
range_unit (str): Unit of the range parsed from the value of the
Range header, or ``None`` if the header is missing
if_match (list): Value of the If-Match header, as a parsed list of
:class:`falcon.ETag` objects or ``None`` if the header is missing
or its value is blank.
This property provides a list of all ``entity-tags`` in the
header, both strong and weak, in the same order as listed in
the header.
(See also: RFC 7232, Section 3.1)
if_none_match (list): Value of the If-None-Match header, as a parsed
list of :class:`falcon.ETag` objects or ``None`` if the header is
missing or its value is blank.
This property provides a list of all ``entity-tags`` in the
header, both strong and weak, in the same order as listed in
the header.
(See also: RFC 7232, Section 3.2)
if_modified_since (datetime): Value of the If-Modified-Since header,
or ``None`` if the header is missing.
if_unmodified_since (datetime): Value of the If-Unmodified-Since
header, or ``None`` if the header is missing.
if_range (str): Value of the If-Range header, or ``None`` if the
header is missing.
headers (dict): Raw HTTP headers from the request with
canonical dash-separated names. Parsing all the headers
to create this dict is done the first time this attribute
is accessed, and the returned object should be treated as
read-only. Note that this parsing can be costly, so unless you
need all the headers in this format, you should instead use the
``get_header()`` method or one of the convenience attributes
to get a value for a specific header.
params (dict): The mapping of request query parameter names to their
values. Where the parameter appears multiple times in the query
string, the value mapped to that parameter key will be a list of
all the values in the order seen.
options (dict): Set of global options passed from the App handler.
"""
__slots__ = (
'__dict__',
'_bounded_stream',
'_cached_access_route',
'_cached_forwarded',
'_cached_forwarded_prefix',
'_cached_forwarded_uri',
'_cached_headers',
'_cached_prefix',
'_cached_relative_uri',
'_cached_uri',
'_params',
'_wsgierrors',
'content_type',
'context',
'env',
'method',
'options',
'path',
'query_string',
'stream',
'uri_template',
'_media',
'_media_error',
'is_websocket',
)
_cookies = None
_cookies_collapsed = None
_cached_if_match = None
_cached_if_none_match = None
# Child classes may override this
context_type = structures.Context
_wsgi_input_type_known = False
def __init__(self, env, options=None):
self.is_websocket = False
self.env = env
self.options = options if options else RequestOptions()
self._wsgierrors = env['wsgi.errors']
self.method = env['REQUEST_METHOD']
self.uri_template = None
self._media = _UNSET
self._media_error = None
# NOTE(kgriffs): PEP 3333 specifies that PATH_INFO may be the
# empty string, so normalize it in that case.
path = env['PATH_INFO'] or '/'
# PEP 3333 specifies that the PATH_INFO variable is always
# "bytes tunneled as latin-1" and must be encoded back.
#
# NOTE(kgriffs): The decoded path may contain UTF-8 characters.
# But according to the WSGI spec, no strings can contain chars
# outside ISO-8859-1. Therefore, to reconcile the URI
# encoding standard that allows UTF-8 with the WSGI spec
# that does not, WSGI servers tunnel the string via
# ISO-8859-1, e.g.:
#
# tunnelled_path = path.encode('utf-8').decode('iso-8859-1')
# perf(vytas): Only decode the tunnelled path in case it is not ASCII.
# For ASCII-strings, the below decoding chain is a no-op.
if not isascii(path):
path = path.encode('iso-8859-1').decode('utf-8', 'replace')
if (
self.options.strip_url_path_trailing_slash
and len(path) != 1
and path.endswith('/')
):
self.path = path[:-1]
else:
self.path = path
# PERF(ueg1990): try/catch cheaper and faster (and more Pythonic)
try:
self.query_string = env['QUERY_STRING']
except KeyError:
self.query_string = ''
self._params = {}
else:
if self.query_string:
self._params = parse_query_string(
self.query_string,
keep_blank=self.options.keep_blank_qs_values,
csv=self.options.auto_parse_qs_csv,
)
else:
self._params = {}
self._cached_access_route = None
self._cached_forwarded = None
self._cached_forwarded_prefix = None
self._cached_forwarded_uri = None
self._cached_headers = None
self._cached_prefix = None
self._cached_relative_uri = None
self._cached_uri = None
try:
self.content_type = self.env['CONTENT_TYPE']
except KeyError:
self.content_type = None
self.stream = env['wsgi.input']
self._bounded_stream = None # Lazy wrapping
# PERF(kgriffs): Technically, we should spend a few more
# cycles and parse the content type for real, but
# this heuristic will work virtually all the time.
if (
self.options.auto_parse_form_urlencoded
and self.content_type is not None
and 'application/x-www-form-urlencoded' in self.content_type
and
# NOTE(kgriffs): Within HTTP, a payload for a GET or HEAD
# request has no defined semantics, so we don't expect a
# body in those cases. We would normally not expect a body
# for OPTIONS either, but RFC 7231 does allow for it.
self.method not in ('GET', 'HEAD')
):
self._parse_form_urlencoded()
self.context = self.context_type()
def __repr__(self):
return '<%s: %s %r>' % (self.__class__.__name__, self.method, self.url)
# ------------------------------------------------------------------------
# Properties
# ------------------------------------------------------------------------
user_agent = helpers.header_property('HTTP_USER_AGENT')
auth = helpers.header_property('HTTP_AUTHORIZATION')
expect = helpers.header_property('HTTP_EXPECT')
if_range = helpers.header_property('HTTP_IF_RANGE')
referer = helpers.header_property('HTTP_REFERER')
@property
def forwarded(self):
# PERF(kgriffs): We could DRY up this memoization pattern using
# a decorator, but that would incur additional overhead without
# resorting to some trickery to rewrite the body of the method
# itself (vs. simply wrapping it with some memoization logic).
# At some point we might look into this but I don't think
# it's worth it right now.
if self._cached_forwarded is None:
forwarded = self.get_header('Forwarded')
if forwarded is None:
return None
self._cached_forwarded = _parse_forwarded_header(forwarded)
return self._cached_forwarded
@property
def client_accepts_json(self):
return self.client_accepts('application/json')
@property
def client_accepts_msgpack(self):
return self.client_accepts('application/x-msgpack') or self.client_accepts(
'application/msgpack'
)
@property
def client_accepts_xml(self):
return self.client_accepts('application/xml')
@property
def accept(self):
# NOTE(kgriffs): Per RFC, a missing accept header is
# equivalent to '*/*'
try:
return self.env['HTTP_ACCEPT'] or '*/*'
except KeyError:
return '*/*'
@property
def content_length(self):
try:
value = self.env['CONTENT_LENGTH']
except KeyError:
return None
# NOTE(kgriffs): Normalize an empty value to behave as if
# the header were not included; wsgiref, at least, inserts
# an empty CONTENT_LENGTH value if the request does not
# set the header. Gunicorn and uWSGI do not do this, but
# others might if they are trying to match wsgiref's
# behavior too closely.
if not value:
return None
try:
value_as_int = int(value)
except ValueError:
msg = 'The value of the header must be a number.'
raise errors.HTTPInvalidHeader(msg, 'Content-Length')
if value_as_int < 0:
msg = 'The value of the header must be a positive number.'
raise errors.HTTPInvalidHeader(msg, 'Content-Length')
return value_as_int
@property
def bounded_stream(self):
if self._bounded_stream is None:
self._bounded_stream = self._get_wrapped_wsgi_input()
return self._bounded_stream
@property
def date(self):
return self.get_header_as_datetime('Date')
@property
def if_match(self):
# TODO(kgriffs): It may make sense at some point to create a
# header property generator that DRY's up the memoization
# pattern for us.
# PERF(kgriffs): It probably isn't worth it to set
# self._cached_if_match to a special type/object to distinguish
# between the variable being unset and the header not being
# present in the request. The reason is that if the app
# gets a None back on the first reference to property, it
# probably isn't going to access the property again (TBD).
if self._cached_if_match is None:
header_value = self.env.get('HTTP_IF_MATCH')
if header_value:
self._cached_if_match = helpers._parse_etags(header_value)
return self._cached_if_match
@property
def if_none_match(self):
if self._cached_if_none_match is None:
header_value = self.env.get('HTTP_IF_NONE_MATCH')
if header_value:
self._cached_if_none_match = helpers._parse_etags(header_value)
return self._cached_if_none_match
@property
def if_modified_since(self):
return self.get_header_as_datetime('If-Modified-Since')
@property
def if_unmodified_since(self):
return self.get_header_as_datetime('If-Unmodified-Since')
@property
def range(self):
value = self.get_header('Range')
if value is None:
return None
if '=' in value:
unit, sep, req_range = value.partition('=')
else:
msg = "The value must be prefixed with a range unit, e.g. 'bytes='"
raise errors.HTTPInvalidHeader(msg, 'Range')
if ',' in req_range:
msg = 'The value must be a continuous range.'
raise errors.HTTPInvalidHeader(msg, 'Range')
try:
first, sep, last = req_range.partition('-')
if not sep:
raise ValueError()
if first and last:
first, last = (int(first), int(last))
if last < first:
raise ValueError()
elif first:
first, last = (int(first), -1)
elif last:
first, last = (-int(last), -1)
if first >= 0:
raise ValueError()
else:
msg = 'The range offsets are missing.'
raise errors.HTTPInvalidHeader(msg, 'Range')
return first, last
except ValueError:
href = 'https://tools.ietf.org/html/rfc7233'
href_text = 'HTTP/1.1 Range Requests'
msg = 'It must be a range formatted according to RFC 7233.'
raise errors.HTTPInvalidHeader(msg, 'Range', href=href, href_text=href_text)
@property
def range_unit(self):
value = self.get_header('Range')
if value is None:
return None
if value and '=' in value:
unit, sep, req_range = value.partition('=')
return unit
else:
msg = "The value must be prefixed with a range unit, e.g. 'bytes='"
raise errors.HTTPInvalidHeader(msg, 'Range')
@property
def root_path(self):
# PERF(kgriffs): try..except is faster than get() assuming that
# we normally expect the key to exist. Even though PEP-3333
# allows WSGI servers to omit the key when the value is an
# empty string, uwsgi, gunicorn, waitress, and wsgiref all
# include it even in that case.
try:
return self.env['SCRIPT_NAME']
except KeyError:
return ''
app = root_path
@property
def scheme(self):
return self.env['wsgi.url_scheme']
@property
def forwarded_scheme(self):
# PERF(kgriffs): Since the Forwarded header is still relatively
# new, we expect X-Forwarded-Proto to be more common, so
# try to avoid calling self.forwarded if we can, since it uses a
# try...catch that will usually result in a relatively expensive
# raised exception.
if 'HTTP_FORWARDED' in self.env:
forwarded = self.forwarded
if forwarded:
# Use first hop, fall back on own scheme
scheme = forwarded[0].scheme or self.scheme
else:
scheme = self.scheme
else:
# PERF(kgriffs): This call should normally succeed, so
# just go for it without wasting time checking it
# first. Note also that the indexing operator is
# slightly faster than using get().
try:
scheme = self.env['HTTP_X_FORWARDED_PROTO'].lower()
except KeyError:
scheme = self.env['wsgi.url_scheme']
return scheme
@property
def uri(self):
if self._cached_uri is None:
# PERF: For small numbers of items, '+' is faster
# than ''.join(...). Concatenation is also generally
# faster than formatting.
value = self.scheme + '://' + self.netloc + self.relative_uri
self._cached_uri = value
return self._cached_uri
url = uri
@property
def forwarded_uri(self):
if self._cached_forwarded_uri is None:
# PERF: For small numbers of items, '+' is faster
# than ''.join(...). Concatenation is also generally
# faster than formatting.
value = (
self.forwarded_scheme + '://' + self.forwarded_host + self.relative_uri
)
self._cached_forwarded_uri = value
return self._cached_forwarded_uri
@property
def relative_uri(self):
if self._cached_relative_uri is None:
if self.query_string:
self._cached_relative_uri = (
self.app + self.path + '?' + self.query_string
)
else:
self._cached_relative_uri = self.app + self.path
return self._cached_relative_uri
@property
def prefix(self):
if self._cached_prefix is None:
self._cached_prefix = self.scheme + '://' + self.netloc + self.app
return self._cached_prefix
@property
def forwarded_prefix(self):
if self._cached_forwarded_prefix is None:
self._cached_forwarded_prefix = (
self.forwarded_scheme + '://' + self.forwarded_host + self.app
)
return self._cached_forwarded_prefix
@property
def host(self):
try:
# NOTE(kgriffs): Prefer the host header; the web server
# isn't supposed to mess with it, so it should be what
# the client actually sent.
host_header = self.env['HTTP_HOST']
host, port = parse_host(host_header)
except KeyError:
# PERF(kgriffs): According to PEP-3333, this header
# will always be present.
host = self.env['SERVER_NAME']
return host
@property
def forwarded_host(self):
# PERF(kgriffs): Since the Forwarded header is still relatively
# new, we expect X-Forwarded-Host to be more common, so
# try to avoid calling self.forwarded if we can, since it uses a
# try...catch that will usually result in a relatively expensive
# raised exception.
if 'HTTP_FORWARDED' in self.env:
forwarded = self.forwarded
if forwarded:
# Use first hop, fall back on self
host = forwarded[0].host or self.netloc
else:
host = self.netloc
else:
# PERF(kgriffs): This call should normally succeed, assuming
# that the caller is expecting a forwarded header, so
# just go for it without wasting time checking it
# first.
try:
host = self.env['HTTP_X_FORWARDED_HOST']
except KeyError:
host = self.netloc
return host
@property
def subdomain(self):
# PERF(kgriffs): .partition is slightly faster than .split
subdomain, sep, remainder = self.host.partition('.')
return subdomain if sep else None
@property
def headers(self):
# NOTE(kgriffs: First time here will cache the dict so all we
# have to do is clone it in the future.
if self._cached_headers is None:
headers = self._cached_headers = {}
env = self.env
for name, value in env.items():
if name.startswith('HTTP_'):
# NOTE(kgriffs): Don't take the time to fix the case
# since headers are supposed to be case-insensitive
# anyway.
headers[name[5:].replace('_', '-')] = value
elif name in WSGI_CONTENT_HEADERS:
headers[name.replace('_', '-')] = value
return self._cached_headers
@property
def params(self):
return self._params
@property
def cookies(self):
if self._cookies_collapsed is None:
if self._cookies is None:
header_value = self.get_header('Cookie')
if header_value:
self._cookies = helpers.parse_cookie_header(header_value)
else:
self._cookies = {}
self._cookies_collapsed = {n: v[0] for n, v in self._cookies.items()}
return self._cookies_collapsed
@property
def access_route(self):
if self._cached_access_route is None:
# NOTE(kgriffs): Try different headers in order of
# preference; if none are found, fall back to REMOTE_ADDR.
#
# If one of these headers is present, but its value is
# malformed such that we end up with an empty list, or
# a non-empty list containing malformed values, go ahead
# and return the results as-is. The alternative would be
# to fall back to another header or to REMOTE_ADDR, but
# that only masks the problem; the operator needs to be
# aware that an upstream proxy is malfunctioning.
if 'HTTP_FORWARDED' in self.env:
self._cached_access_route = []
for hop in self.forwarded:
if hop.src is not None:
host, __ = parse_host(hop.src)
self._cached_access_route.append(host)
elif 'HTTP_X_FORWARDED_FOR' in self.env:
addresses = self.env['HTTP_X_FORWARDED_FOR'].split(',')
self._cached_access_route = [ip.strip() for ip in addresses]
elif 'HTTP_X_REAL_IP' in self.env:
self._cached_access_route = [self.env['HTTP_X_REAL_IP']]
if self._cached_access_route:
if self._cached_access_route[-1] != self.remote_addr:
self._cached_access_route.append(self.remote_addr)
else:
self._cached_access_route = [self.remote_addr]
return self._cached_access_route
@property
def remote_addr(self):
try:
value = self.env['REMOTE_ADDR']
except KeyError:
value = '127.0.0.1'
return value
@property
def port(self):
try:
host_header = self.env['HTTP_HOST']
default_port = 80 if self.env['wsgi.url_scheme'] == 'http' else 443
host, port = parse_host(host_header, default_port=default_port)
except KeyError:
# NOTE(kgriffs): Normalize to an int, since that is the type
# returned by parse_host().
#
# NOTE(kgriffs): In the case that SERVER_PORT was used,
# PEP-3333 requires that the port never be an empty string.
port = int(self.env['SERVER_PORT'])
return port
@property
def netloc(self):
env = self.env
# NOTE(kgriffs): According to PEP-3333 we should first
# try to use the Host header if present.
#
# PERF(kgriffs): try..except is faster than get() when we
# expect the key to be present most of the time.
try:
netloc_value = env['HTTP_HOST']
except KeyError:
netloc_value = env['SERVER_NAME']
port = env['SERVER_PORT']
if self.scheme == 'https':
if port != '443':
netloc_value += ':' + port
else:
if port != '80':
netloc_value += ':' + port
return netloc_value
media = property(get_media)
# ------------------------------------------------------------------------
# Methods
# ------------------------------------------------------------------------
[docs]
def client_accepts(self, media_type):
"""Determine whether or not the client accepts a given media type.
Args:
media_type (str): An Internet media type to check.
Returns:
bool: ``True`` if the client has indicated in the Accept header
that it accepts the specified media type. Otherwise, returns
``False``.
"""
accept = self.accept
# PERF(kgriffs): Usually the following will be true, so
# try it first.
if (accept == media_type) or (accept == '*/*'):
return True
# Fall back to full-blown parsing
try:
return mimeparse.quality(media_type, accept) != 0.0
except ValueError:
return False
[docs]
def client_prefers(self, media_types):
"""Return the client's preferred media type, given several choices.
Args:
media_types (iterable of str): One or more Internet media types
from which to choose the client's preferred type. This value
**must** be an iterable collection of strings.
Returns:
str: The client's preferred media type, based on the Accept
header. Returns ``None`` if the client does not accept any
of the given types.
"""
try:
# NOTE(kgriffs): best_match will return '' if no match is found
preferred_type = mimeparse.best_match(media_types, self.accept)
except ValueError:
# Value for the accept header was not formatted correctly
preferred_type = ''
return preferred_type if preferred_type else None
[docs]
def get_cookie_values(self, name):
"""Return all values provided in the Cookie header for the named cookie.
(See also: :ref:`Getting Cookies <getting-cookies>`)
Args:
name (str): Cookie name, case-sensitive.
Returns:
list: Ordered list of all values specified in the Cookie header for
the named cookie, or ``None`` if the cookie was not included in
the request. If the cookie is specified more than once in the
header, the returned list of values will preserve the ordering of
the individual ``cookie-pair``'s in the header.
"""
if self._cookies is None:
# PERF(kgriffs): While this code isn't exactly DRY (the same code
# is duplicated by the cookies property) it does make things a bit
# more performant by removing the extra function call that would
# be required to factor this out. If we ever have to do this in a
# *third* place, we would probably want to factor it out at that
# point.
header_value = self.get_header('Cookie')
if header_value:
self._cookies = helpers.parse_cookie_header(header_value)
else:
self._cookies = {}
return self._cookies.get(name)
[docs]
def get_param(self, name, required=False, store=None, default=None):
"""Return the raw value of a query string parameter as a string.
Note:
If an HTML form is POSTed to the API using the
*application/x-www-form-urlencoded* media type, Falcon can
automatically parse the parameters from the request body
and merge them into the query string parameters. To enable
this functionality, set
:py:attr:`~.RequestOptions.auto_parse_form_urlencoded` to
``True`` via :any:`App.req_options`.
Note, however, that the
:attr:`~.RequestOptions.auto_parse_form_urlencoded` option is
considered deprecated as of Falcon 3.0 in favor of accessing the
URL-encoded form via :attr:`~Request.media`, and it may be removed
in a future release.
See also: :ref:`access_urlencoded_form`
Note:
Similar to the way multiple keys in form data are handled, if a
query parameter is included in the query string multiple times,
only one of those values will be returned, and it is undefined which
one. This caveat also applies when
:attr:`~falcon.RequestOptions.auto_parse_qs_csv` is enabled and the
given parameter is assigned to a comma-separated list of values
(e.g., ``foo=a,b,c``).
When multiple values are expected for a parameter,
:meth:`~.get_param_as_list` can be used to retrieve all of
them at once.
Args:
name (str): Parameter name, case-sensitive (e.g., 'sort').
Keyword Args:
required (bool): Set to ``True`` to raise
``HTTPBadRequest`` instead of returning ``None`` when the
parameter is not found (default ``False``).
store (dict): A ``dict``-like object in which to place
the value of the param, but only if the param is present.
default (any): If the param is not found returns the
given value instead of ``None``
Returns:
str: The value of the param as a string, or ``None`` if param is
not found and is not required.
Raises:
HTTPBadRequest: A required param is missing from the request.
"""
params = self._params
# PERF: Use if..in since it is a good all-around performer; we don't
# know how likely params are to be specified by clients.
if name in params:
# NOTE(warsaw): If the key appeared multiple times, it will be
# stored internally as a list. We do not define which one
# actually gets returned, but let's pick the last one for grins.
param = params[name]
if isinstance(param, list):
param = param[-1]
if store is not None:
store[name] = param
return param
if not required:
return default
raise errors.HTTPMissingParam(name)
[docs]
def get_param_as_int(
self,
name,
required=False,
min_value=None,
max_value=None,
store=None,
default=None,
):
"""Return the value of a query string parameter as an int.
Args:
name (str): Parameter name, case-sensitive (e.g., 'limit').
Keyword Args:
required (bool): Set to ``True`` to raise
``HTTPBadRequest`` instead of returning ``None`` when the
parameter is not found or is not an integer (default
``False``).
min_value (int): Set to the minimum value allowed for this
param. If the param is found and it is less than min_value, an
``HTTPError`` is raised.
max_value (int): Set to the maximum value allowed for this
param. If the param is found and its value is greater than
max_value, an ``HTTPError`` is raised.
store (dict): A ``dict``-like object in which to place
the value of the param, but only if the param is found
(default ``None``).
default (any): If the param is not found returns the
given value instead of ``None``
Returns:
int: The value of the param if it is found and can be converted to
an ``int``. If the param is not found, returns ``None``, unless
`required` is ``True``.
Raises
HTTPBadRequest: The param was not found in the request, even though
it was required to be there, or it was found but could not
be converted to an ``int``. Also raised if the param's value
falls outside the given interval, i.e., the value must be in
the interval: min_value <= value <= max_value to avoid
triggering an error.
"""
params = self._params
# PERF: Use if..in since it is a good all-around performer; we don't
# know how likely params are to be specified by clients.
if name in params:
val = params[name]
if isinstance(val, list):
val = val[-1]
try:
val = int(val)
except ValueError:
msg = 'The value must be an integer.'
raise errors.HTTPInvalidParam(msg, name)
if min_value is not None and val < min_value:
msg = 'The value must be at least ' + str(min_value)
raise errors.HTTPInvalidParam(msg, name)
if max_value is not None and max_value < val:
msg = 'The value may not exceed ' + str(max_value)
raise errors.HTTPInvalidParam(msg, name)
if store is not None:
store[name] = val
return val
if not required:
return default
raise errors.HTTPMissingParam(name)
[docs]
def get_param_as_float(
self,
name,
required=False,
min_value=None,
max_value=None,
store=None,
default=None,
):
"""Return the value of a query string parameter as an float.
Args:
name (str): Parameter name, case-sensitive (e.g., 'limit').
Keyword Args:
required (bool): Set to ``True`` to raise
``HTTPBadRequest`` instead of returning ``None`` when the
parameter is not found or is not an float (default
``False``).
min_value (float): Set to the minimum value allowed for this
param. If the param is found and it is less than min_value, an
``HTTPError`` is raised.
max_value (float): Set to the maximum value allowed for this
param. If the param is found and its value is greater than
max_value, an ``HTTPError`` is raised.
store (dict): A ``dict``-like object in which to place
the value of the param, but only if the param is found
(default ``None``).
default (any): If the param is not found returns the
given value instead of ``None``
Returns:
float: The value of the param if it is found and can be converted to
an ``float``. If the param is not found, returns ``None``, unless
`required` is ``True``.
Raises
HTTPBadRequest: The param was not found in the request, even though
it was required to be there, or it was found but could not
be converted to an ``float``. Also raised if the param's value
falls outside the given interval, i.e., the value must be in
the interval: min_value <= value <= max_value to avoid
triggering an error.
"""
params = self._params
# PERF: Use if..in since it is a good all-around performer; we don't
# know how likely params are to be specified by clients.
if name in params:
val = params[name]
if isinstance(val, list):
val = val[-1]
try:
val = float(val)
except ValueError:
msg = 'The value must be a float.'
raise errors.HTTPInvalidParam(msg, name)
if min_value is not None and val < min_value:
msg = 'The value must be at least ' + str(min_value)
raise errors.HTTPInvalidParam(msg, name)
if max_value is not None and max_value < val:
msg = 'The value may not exceed ' + str(max_value)
raise errors.HTTPInvalidParam(msg, name)
if store is not None:
store[name] = val
return val
if not required:
return default
raise errors.HTTPMissingParam(name)
[docs]
def get_param_as_uuid(self, name, required=False, store=None, default=None):
"""Return the value of a query string parameter as an UUID.
The value to convert must conform to the standard UUID string
representation per RFC 4122. For example, the following
strings are all valid::
# Lowercase
'64be949b-3433-4d36-a4a8-9f19d352fee8'
# Uppercase
'BE71ECAA-F719-4D42-87FD-32613C2EEB60'
# Mixed
'81c8155C-D6de-443B-9495-39Fa8FB239b5'
Args:
name (str): Parameter name, case-sensitive (e.g., 'id').
Keyword Args:
required (bool): Set to ``True`` to raise
``HTTPBadRequest`` instead of returning ``None`` when the
parameter is not found or is not a UUID (default
``False``).
store (dict): A ``dict``-like object in which to place
the value of the param, but only if the param is found
(default ``None``).
default (any): If the param is not found returns the
given value instead of ``None``
Returns:
UUID: The value of the param if it is found and can be converted to
a ``UUID``. If the param is not found, returns
``default`` (default ``None``), unless `required` is ``True``.
Raises
HTTPBadRequest: The param was not found in the request, even though
it was required to be there, or it was found but could not
be converted to a ``UUID``.
"""
params = self._params
# PERF: Use if..in since it is a good all-around performer; we don't
# know how likely params are to be specified by clients.
if name in params:
val = params[name]
if isinstance(val, list):
val = val[-1]
try:
val = UUID(val)
except ValueError:
msg = 'The value must be a UUID string.'
raise errors.HTTPInvalidParam(msg, name)
if store is not None:
store[name] = val
return val
if not required:
return default
raise errors.HTTPMissingParam(name)
[docs]
def get_param_as_bool(
self, name, required=False, store=None, blank_as_true=True, default=None
):
"""Return the value of a query string parameter as a boolean.
This method treats valueless parameters as flags. By default, if no
value is provided for the parameter in the query string, ``True`` is
assumed and returned. If the parameter is missing altogether, ``None``
is returned as with other ``get_param_*()`` methods, which can be
easily treated as falsy by the caller as needed.
The following boolean strings are supported::
TRUE_STRINGS = ('true', 'True', 't', 'yes', 'y', '1', 'on')
FALSE_STRINGS = ('false', 'False', 'f', 'no', 'n', '0', 'off')
Args:
name (str): Parameter name, case-sensitive (e.g., 'detailed').
Keyword Args:
required (bool): Set to ``True`` to raise
``HTTPBadRequest`` instead of returning ``None`` when the
parameter is not found or is not a recognized boolean
string (default ``False``).
store (dict): A ``dict``-like object in which to place
the value of the param, but only if the param is found (default
``None``).
blank_as_true (bool): Valueless query string parameters
are treated as flags, resulting in ``True`` being
returned when such a parameter is present, and ``False``
otherwise. To require the client to explicitly opt-in to a
truthy value, pass ``blank_as_true=False`` to return ``False``
when a value is not specified in the query string.
default (any): If the param is not found, return this
value instead of ``None``.
Returns:
bool: The value of the param if it is found and can be converted
to a ``bool``. If the param is not found, returns ``None``
unless `required` is ``True``.
Raises:
HTTPBadRequest: A required param is missing from the request, or
can not be converted to a ``bool``.
"""
params = self._params
# PERF: Use if..in since it is a good all-around performer; we don't
# know how likely params are to be specified by clients.
if name in params:
val = params[name]
if isinstance(val, list):
val = val[-1]
if val in TRUE_STRINGS:
val = True
elif val in FALSE_STRINGS:
val = False
elif not val:
val = blank_as_true
else:
msg = 'The value of the parameter must be "true" or "false".'
raise errors.HTTPInvalidParam(msg, name)
if store is not None:
store[name] = val
return val
if not required:
return default
raise errors.HTTPMissingParam(name)
[docs]
def get_param_as_list(
self, name, transform=None, required=False, store=None, default=None
):
"""Return the value of a query string parameter as a list.
List items must be comma-separated or must be provided
as multiple instances of the same param in the query string
ala *application/x-www-form-urlencoded*.
Note:
To enable the interpretation of comma-separated parameter values,
the :attr:`~falcon.RequestOptions.auto_parse_qs_csv` option must
be set to ``True`` (default ``False``).
Args:
name (str): Parameter name, case-sensitive (e.g., 'ids').
Keyword Args:
transform (callable): An optional transform function
that takes as input each element in the list as a ``str`` and
outputs a transformed element for inclusion in the list that
will be returned. For example, passing ``int`` will
transform list items into numbers.
required (bool): Set to ``True`` to raise ``HTTPBadRequest``
instead of returning ``None`` when the parameter is not
found (default ``False``).
store (dict): A ``dict``-like object in which to place
the value of the param, but only if the param is found (default
``None``).
default (any): If the param is not found returns the
given value instead of ``None``
Returns:
list: The value of the param if it is found. Otherwise, returns
``None`` unless *required* is ``True``.
Empty list elements will be included by default, but this behavior
can be configured by setting the
:attr:`~falcon.RequestOptions.keep_blank_qs_values` option. For
example, by default the following query strings would both result in
``['1', '', '3']``::
things=1&things=&things=3
things=1,,3
Note, however, that for the second example string above to be
interpreted as a list, the
:attr:`~falcon.RequestOptions.auto_parse_qs_csv` option must be
set to ``True``.
Raises:
HTTPBadRequest: A required param is missing from the request, or
a transform function raised an instance of ``ValueError``.
"""
params = self._params
# PERF: Use if..in since it is a good all-around performer; we don't
# know how likely params are to be specified by clients.
if name in params:
items = params[name]
# NOTE(warsaw): When a key appears multiple times in the request
# query, it will already be represented internally as a list.
# NOTE(kgriffs): Likewise for comma-delimited values.
if not isinstance(items, list):
items = [items]
# PERF(kgriffs): Use if-else rather than a DRY approach
# that sets transform to a passthrough function; avoids
# function calling overhead.
if transform is not None:
try:
items = [transform(i) for i in items]
except ValueError:
msg = 'The value is not formatted correctly.'
raise errors.HTTPInvalidParam(msg, name)
if store is not None:
store[name] = items
return items
if not required:
return default
raise errors.HTTPMissingParam(name)
[docs]
def get_param_as_datetime(
self,
name,
format_string='%Y-%m-%dT%H:%M:%SZ',
required=False,
store=None,
default=None,
):
"""Return the value of a query string parameter as a datetime.
Args:
name (str): Parameter name, case-sensitive (e.g., 'ids').
Keyword Args:
format_string (str): String used to parse the param value
into a ``datetime``. Any format recognized by strptime() is
supported (default ``'%Y-%m-%dT%H:%M:%SZ'``).
required (bool): Set to ``True`` to raise
``HTTPBadRequest`` instead of returning ``None`` when the
parameter is not found (default ``False``).
store (dict): A ``dict``-like object in which to place
the value of the param, but only if the param is found (default
``None``).
default (any): If the param is not found returns the
given value instead of ``None``
Returns:
datetime.datetime: The value of the param if it is found and can be
converted to a ``datetime`` according to the supplied format
string. If the param is not found, returns ``None`` unless
required is ``True``.
Raises:
HTTPBadRequest: A required param is missing from the request, or
the value could not be converted to a ``datetime``.
"""
param_value = self.get_param(name, required=required)
if param_value is None:
return default
try:
date_time = strptime(param_value, format_string)
except ValueError:
msg = 'The date value does not match the required format.'
raise errors.HTTPInvalidParam(msg, name)
if store is not None:
store[name] = date_time
return date_time
[docs]
def get_param_as_date(
self, name, format_string='%Y-%m-%d', required=False, store=None, default=None
):
"""Return the value of a query string parameter as a date.
Args:
name (str): Parameter name, case-sensitive (e.g., 'ids').
Keyword Args:
format_string (str): String used to parse the param value
into a date. Any format recognized by strptime() is
supported (default ``"%Y-%m-%d"``).
required (bool): Set to ``True`` to raise
``HTTPBadRequest`` instead of returning ``None`` when the
parameter is not found (default ``False``).
store (dict): A ``dict``-like object in which to place
the value of the param, but only if the param is found (default
``None``).
default (any): If the param is not found returns the
given value instead of ``None``
Returns:
datetime.date: The value of the param if it is found and can be
converted to a ``date`` according to the supplied format
string. If the param is not found, returns ``None`` unless
required is ``True``.
Raises:
HTTPBadRequest: A required param is missing from the request, or
the value could not be converted to a ``date``.
"""
date_time = self.get_param_as_datetime(name, format_string, required)
if date_time:
date = date_time.date()
else:
return default
if store is not None:
store[name] = date
return date
[docs]
def get_param_as_json(self, name, required=False, store=None, default=None):
"""Return the decoded JSON value of a query string parameter.
Given a JSON value, decode it to an appropriate Python type,
(e.g., ``dict``, ``list``, ``str``, ``int``, ``bool``, etc.)
Warning:
If the :attr:`~falcon.RequestOptions.auto_parse_qs_csv` option is
set to ``True`` (default ``False``), the framework will
misinterpret any JSON values that include literal
(non-percent-encoded) commas. If the query string may include
JSON, you can use JSON array syntax in lieu of CSV as a workaround.
Args:
name (str): Parameter name, case-sensitive (e.g., 'payload').
Keyword Args:
required (bool): Set to ``True`` to raise ``HTTPBadRequest``
instead of returning ``None`` when the parameter is not
found (default ``False``).
store (dict): A ``dict``-like object in which to place the
value of the param, but only if the param is found
(default ``None``).
default (any): If the param is not found returns the
given value instead of ``None``
Returns:
dict: The value of the param if it is found. Otherwise, returns
``None`` unless required is ``True``.
Raises:
HTTPBadRequest: A required param is missing from the request, or
the value could not be parsed as JSON.
"""
param_value = self.get_param(name, required=required)
if param_value is None:
return default
handler, _, _ = self.options.media_handlers._resolve(
MEDIA_JSON, MEDIA_JSON, raise_not_found=False
)
if handler is None:
handler = _DEFAULT_JSON_HANDLER
try:
# TODO(CaselIT): find a way to avoid encode + BytesIO if handlers
# interface is refactored. Possibly using the WS interface?
val = handler.deserialize(
BytesIO(param_value.encode()), MEDIA_JSON, len(param_value)
)
except errors.HTTPBadRequest:
msg = 'It could not be parsed as JSON.'
raise errors.HTTPInvalidParam(msg, name)
if store is not None:
store[name] = val
return val
[docs]
def has_param(self, name):
"""Determine whether or not the query string parameter already exists.
Args:
name (str): Parameter name, case-sensitive (e.g., 'sort').
Returns:
bool: ``True`` if param is found, or ``False`` if param is
not found.
"""
if name in self._params:
return True
else:
return False
[docs]
def log_error(self, message):
"""Write an error message to the server's log.
Prepends timestamp and request info to message, and writes the
result out to the WSGI server's error stream (`wsgi.error`).
Args:
message (str): Description of the problem.
"""
if self.query_string:
query_string_formatted = '?' + self.query_string
else:
query_string_formatted = ''
log_line = DEFAULT_ERROR_LOG_FORMAT.format(
now(), self.method, self.path, query_string_formatted
)
self._wsgierrors.write(log_line + message + '\n')
# ------------------------------------------------------------------------
# Helpers
# ------------------------------------------------------------------------
def _get_wrapped_wsgi_input(self):
try:
content_length = self.content_length or 0
# NOTE(kgriffs): This branch is indeed covered in test_wsgi.py
# even though coverage isn't able to detect it.
except errors.HTTPInvalidHeader: # pragma: no cover
# NOTE(kgriffs): The content-length header was specified,
# but it had an invalid value. Assume no content.
content_length = 0
return BoundedStream(self.env['wsgi.input'], content_length)
def _parse_form_urlencoded(self):
content_length = self.content_length
if not content_length:
return
body = self.stream.read(content_length)
# NOTE(kgriffs): According to http://goo.gl/6rlcux the
# body should be US-ASCII. Enforcing this also helps
# catch malicious input.
try:
body = body.decode('ascii')
except UnicodeDecodeError:
body = None
self.log_error(
'Non-ASCII characters found in form body '
'with Content-Type of '
'application/x-www-form-urlencoded. Body '
'will be ignored.'
)
if body:
extra_params = parse_query_string(
body,
keep_blank=self.options.keep_blank_qs_values,
csv=self.options.auto_parse_qs_csv,
)
self._params.update(extra_params)
# PERF: To avoid typos and improve storage space and speed over a dict.
[docs]
class RequestOptions:
"""Defines a set of configurable request options.
An instance of this class is exposed via :attr:`falcon.App.req_options` and
:attr:`falcon.asgi.App.req_options` for configuring certain
:class:`~.Request` and :class:`falcon.asgi.Request` behaviors,
respectively.
Attributes:
keep_blank_qs_values (bool): Set to ``False`` to ignore query string
params that have missing or blank values (default ``True``).
For comma-separated values, this option also determines
whether or not empty elements in the parsed list are
retained.
auto_parse_form_urlencoded: Set to ``True`` in order to
automatically consume the request stream and merge the
results into the request's query string params when the
request's content type is
*application/x-www-form-urlencoded* (default ``False``).
Enabling this option for WSGI apps makes the form parameters
accessible via :attr:`~falcon.Request.params`,
:meth:`~falcon.Request.get_param`, etc.
Warning:
The `auto_parse_form_urlencoded` option is not supported for
ASGI apps, and is considered deprecated for WSGI apps as of
Falcon 3.0, in favor of accessing URL-encoded forms
through :attr:`~Request.media`.
See also: :ref:`access_urlencoded_form`
Warning:
When this option is enabled, the request's body
stream will be left at EOF. The original data is
not retained by the framework.
Note:
The character encoding for fields, before
percent-encoding non-ASCII bytes, is assumed to be
UTF-8. The special `_charset_` field is ignored if
present.
Falcon expects form-encoded request bodies to be
encoded according to the standard W3C algorithm (see
also http://goo.gl/6rlcux).
auto_parse_qs_csv: Set to ``True`` to split query string values on
any non-percent-encoded commas (default ``False``).
When ``False``,
values containing commas are left as-is. In this mode, list items
are taken only from multiples of the same parameter name within the
query string (i.e. ``t=1,2,3&t=4`` becomes ``['1,2,3', '4']``).
When `auto_parse_qs_csv` is set to ``True``, the query string value
is also split on non-percent-encoded commas and these items
are added to the final list (i.e. ``t=1,2,3&t=4,5``
becomes ``['1', '2', '3', '4', '5']``).
Warning:
Enabling this option will cause the framework to misinterpret
any JSON values that include literal (non-percent-encoded)
commas. If the query string may include JSON, you can
use JSON array syntax in lieu of CSV as a workaround.
strip_url_path_trailing_slash: Set to ``True`` in order to
strip the trailing slash, if present, at the end of the URL
path (default ``False``). When this option is enabled,
the URL path is normalized by stripping the trailing slash
character. This lets the application define a single route
to a resource for a path that may or may not end in a
forward slash. However, this behavior can be problematic in
certain cases, such as when working with authentication
schemes that employ URL-based signatures.
default_media_type (str): The default media-type used to
deserialize a request body, when the Content-Type header is
missing or ambiguous. This value is normally
set to the media type provided to the :class:`falcon.App` or
:class:`falcon.asgi.App` initializer; however, if created
independently, this will default to
:attr:`falcon.DEFAULT_MEDIA_TYPE`.
media_handlers (Handlers): A dict-like object for configuring the
media-types to handle. By default, handlers are provided for the
``application/json``, ``application/x-www-form-urlencoded`` and
``multipart/form-data`` media types.
"""
__slots__ = (
'keep_blank_qs_values',
'auto_parse_form_urlencoded',
'auto_parse_qs_csv',
'strip_url_path_trailing_slash',
'default_media_type',
'media_handlers',
)
def __init__(self):
self.keep_blank_qs_values = True
self.auto_parse_form_urlencoded = False
self.auto_parse_qs_csv = False
self.strip_url_path_trailing_slash = False
self.default_media_type = DEFAULT_MEDIA_TYPE
self.media_handlers = Handlers()
