forked from s434650/CatOrNot
720 lines
20 KiB
Python
720 lines
20 KiB
Python
# -*- coding: utf-8 -*-
|
|
"""
|
|
werkzeug.exceptions
|
|
~~~~~~~~~~~~~~~~~~~
|
|
|
|
This module implements a number of Python exceptions you can raise from
|
|
within your views to trigger a standard non-200 response.
|
|
|
|
|
|
Usage Example
|
|
-------------
|
|
|
|
::
|
|
|
|
from werkzeug.wrappers import BaseRequest
|
|
from werkzeug.wsgi import responder
|
|
from werkzeug.exceptions import HTTPException, NotFound
|
|
|
|
def view(request):
|
|
raise NotFound()
|
|
|
|
@responder
|
|
def application(environ, start_response):
|
|
request = BaseRequest(environ)
|
|
try:
|
|
return view(request)
|
|
except HTTPException as e:
|
|
return e
|
|
|
|
|
|
As you can see from this example those exceptions are callable WSGI
|
|
applications. Because of Python 2.4 compatibility those do not extend
|
|
from the response objects but only from the python exception class.
|
|
|
|
As a matter of fact they are not Werkzeug response objects. However you
|
|
can get a response object by calling ``get_response()`` on a HTTP
|
|
exception.
|
|
|
|
Keep in mind that you have to pass an environment to ``get_response()``
|
|
because some errors fetch additional information from the WSGI
|
|
environment.
|
|
|
|
If you want to hook in a different exception page to say, a 404 status
|
|
code, you can add a second except for a specific subclass of an error::
|
|
|
|
@responder
|
|
def application(environ, start_response):
|
|
request = BaseRequest(environ)
|
|
try:
|
|
return view(request)
|
|
except NotFound, e:
|
|
return not_found(request)
|
|
except HTTPException, e:
|
|
return e
|
|
|
|
|
|
:copyright: (c) 2014 by the Werkzeug Team, see AUTHORS for more details.
|
|
:license: BSD, see LICENSE for more details.
|
|
"""
|
|
import sys
|
|
|
|
# Because of bootstrapping reasons we need to manually patch ourselves
|
|
# onto our parent module.
|
|
import werkzeug
|
|
werkzeug.exceptions = sys.modules[__name__]
|
|
|
|
from werkzeug._internal import _get_environ
|
|
from werkzeug._compat import iteritems, integer_types, text_type, \
|
|
implements_to_string
|
|
|
|
from werkzeug.wrappers import Response
|
|
|
|
|
|
@implements_to_string
|
|
class HTTPException(Exception):
|
|
|
|
"""
|
|
Baseclass for all HTTP exceptions. This exception can be called as WSGI
|
|
application to render a default error page or you can catch the subclasses
|
|
of it independently and render nicer error messages.
|
|
"""
|
|
|
|
code = None
|
|
description = None
|
|
|
|
def __init__(self, description=None, response=None):
|
|
Exception.__init__(self)
|
|
if description is not None:
|
|
self.description = description
|
|
self.response = response
|
|
|
|
@classmethod
|
|
def wrap(cls, exception, name=None):
|
|
"""This method returns a new subclass of the exception provided that
|
|
also is a subclass of `BadRequest`.
|
|
"""
|
|
class newcls(cls, exception):
|
|
|
|
def __init__(self, arg=None, *args, **kwargs):
|
|
cls.__init__(self, *args, **kwargs)
|
|
exception.__init__(self, arg)
|
|
newcls.__module__ = sys._getframe(1).f_globals.get('__name__')
|
|
newcls.__name__ = name or cls.__name__ + exception.__name__
|
|
return newcls
|
|
|
|
@property
|
|
def name(self):
|
|
"""The status name."""
|
|
return HTTP_STATUS_CODES.get(self.code, 'Unknown Error')
|
|
|
|
def get_description(self, environ=None):
|
|
"""Get the description."""
|
|
return u'<p>%s</p>' % escape(self.description)
|
|
|
|
def get_body(self, environ=None):
|
|
"""Get the HTML body."""
|
|
return text_type((
|
|
u'<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">\n'
|
|
u'<title>%(code)s %(name)s</title>\n'
|
|
u'<h1>%(name)s</h1>\n'
|
|
u'%(description)s\n'
|
|
) % {
|
|
'code': self.code,
|
|
'name': escape(self.name),
|
|
'description': self.get_description(environ)
|
|
})
|
|
|
|
def get_headers(self, environ=None):
|
|
"""Get a list of headers."""
|
|
return [('Content-Type', 'text/html')]
|
|
|
|
def get_response(self, environ=None):
|
|
"""Get a response object. If one was passed to the exception
|
|
it's returned directly.
|
|
|
|
:param environ: the optional environ for the request. This
|
|
can be used to modify the response depending
|
|
on how the request looked like.
|
|
:return: a :class:`Response` object or a subclass thereof.
|
|
"""
|
|
if self.response is not None:
|
|
return self.response
|
|
if environ is not None:
|
|
environ = _get_environ(environ)
|
|
headers = self.get_headers(environ)
|
|
return Response(self.get_body(environ), self.code, headers)
|
|
|
|
def __call__(self, environ, start_response):
|
|
"""Call the exception as WSGI application.
|
|
|
|
:param environ: the WSGI environment.
|
|
:param start_response: the response callable provided by the WSGI
|
|
server.
|
|
"""
|
|
response = self.get_response(environ)
|
|
return response(environ, start_response)
|
|
|
|
def __str__(self):
|
|
code = self.code if self.code is not None else '???'
|
|
return '%s %s: %s' % (code, self.name, self.description)
|
|
|
|
def __repr__(self):
|
|
code = self.code if self.code is not None else '???'
|
|
return "<%s '%s: %s'>" % (self.__class__.__name__, code, self.name)
|
|
|
|
|
|
class BadRequest(HTTPException):
|
|
|
|
"""*400* `Bad Request`
|
|
|
|
Raise if the browser sends something to the application the application
|
|
or server cannot handle.
|
|
"""
|
|
code = 400
|
|
description = (
|
|
'The browser (or proxy) sent a request that this server could '
|
|
'not understand.'
|
|
)
|
|
|
|
|
|
class ClientDisconnected(BadRequest):
|
|
|
|
"""Internal exception that is raised if Werkzeug detects a disconnected
|
|
client. Since the client is already gone at that point attempting to
|
|
send the error message to the client might not work and might ultimately
|
|
result in another exception in the server. Mainly this is here so that
|
|
it is silenced by default as far as Werkzeug is concerned.
|
|
|
|
Since disconnections cannot be reliably detected and are unspecified
|
|
by WSGI to a large extent this might or might not be raised if a client
|
|
is gone.
|
|
|
|
.. versionadded:: 0.8
|
|
"""
|
|
|
|
|
|
class SecurityError(BadRequest):
|
|
|
|
"""Raised if something triggers a security error. This is otherwise
|
|
exactly like a bad request error.
|
|
|
|
.. versionadded:: 0.9
|
|
"""
|
|
|
|
|
|
class BadHost(BadRequest):
|
|
|
|
"""Raised if the submitted host is badly formatted.
|
|
|
|
.. versionadded:: 0.11.2
|
|
"""
|
|
|
|
|
|
class Unauthorized(HTTPException):
|
|
|
|
"""*401* `Unauthorized`
|
|
|
|
Raise if the user is not authorized. Also used if you want to use HTTP
|
|
basic auth.
|
|
"""
|
|
code = 401
|
|
description = (
|
|
'The server could not verify that you are authorized to access '
|
|
'the URL requested. You either supplied the wrong credentials (e.g. '
|
|
'a bad password), or your browser doesn\'t understand how to supply '
|
|
'the credentials required.'
|
|
)
|
|
|
|
|
|
class Forbidden(HTTPException):
|
|
|
|
"""*403* `Forbidden`
|
|
|
|
Raise if the user doesn't have the permission for the requested resource
|
|
but was authenticated.
|
|
"""
|
|
code = 403
|
|
description = (
|
|
'You don\'t have the permission to access the requested resource. '
|
|
'It is either read-protected or not readable by the server.'
|
|
)
|
|
|
|
|
|
class NotFound(HTTPException):
|
|
|
|
"""*404* `Not Found`
|
|
|
|
Raise if a resource does not exist and never existed.
|
|
"""
|
|
code = 404
|
|
description = (
|
|
'The requested URL was not found on the server. '
|
|
'If you entered the URL manually please check your spelling and '
|
|
'try again.'
|
|
)
|
|
|
|
|
|
class MethodNotAllowed(HTTPException):
|
|
|
|
"""*405* `Method Not Allowed`
|
|
|
|
Raise if the server used a method the resource does not handle. For
|
|
example `POST` if the resource is view only. Especially useful for REST.
|
|
|
|
The first argument for this exception should be a list of allowed methods.
|
|
Strictly speaking the response would be invalid if you don't provide valid
|
|
methods in the header which you can do with that list.
|
|
"""
|
|
code = 405
|
|
description = 'The method is not allowed for the requested URL.'
|
|
|
|
def __init__(self, valid_methods=None, description=None):
|
|
"""Takes an optional list of valid http methods
|
|
starting with werkzeug 0.3 the list will be mandatory."""
|
|
HTTPException.__init__(self, description)
|
|
self.valid_methods = valid_methods
|
|
|
|
def get_headers(self, environ):
|
|
headers = HTTPException.get_headers(self, environ)
|
|
if self.valid_methods:
|
|
headers.append(('Allow', ', '.join(self.valid_methods)))
|
|
return headers
|
|
|
|
|
|
class NotAcceptable(HTTPException):
|
|
|
|
"""*406* `Not Acceptable`
|
|
|
|
Raise if the server can't return any content conforming to the
|
|
`Accept` headers of the client.
|
|
"""
|
|
code = 406
|
|
|
|
description = (
|
|
'The resource identified by the request is only capable of '
|
|
'generating response entities which have content characteristics '
|
|
'not acceptable according to the accept headers sent in the '
|
|
'request.'
|
|
)
|
|
|
|
|
|
class RequestTimeout(HTTPException):
|
|
|
|
"""*408* `Request Timeout`
|
|
|
|
Raise to signalize a timeout.
|
|
"""
|
|
code = 408
|
|
description = (
|
|
'The server closed the network connection because the browser '
|
|
'didn\'t finish the request within the specified time.'
|
|
)
|
|
|
|
|
|
class Conflict(HTTPException):
|
|
|
|
"""*409* `Conflict`
|
|
|
|
Raise to signal that a request cannot be completed because it conflicts
|
|
with the current state on the server.
|
|
|
|
.. versionadded:: 0.7
|
|
"""
|
|
code = 409
|
|
description = (
|
|
'A conflict happened while processing the request. The resource '
|
|
'might have been modified while the request was being processed.'
|
|
)
|
|
|
|
|
|
class Gone(HTTPException):
|
|
|
|
"""*410* `Gone`
|
|
|
|
Raise if a resource existed previously and went away without new location.
|
|
"""
|
|
code = 410
|
|
description = (
|
|
'The requested URL is no longer available on this server and there '
|
|
'is no forwarding address. If you followed a link from a foreign '
|
|
'page, please contact the author of this page.'
|
|
)
|
|
|
|
|
|
class LengthRequired(HTTPException):
|
|
|
|
"""*411* `Length Required`
|
|
|
|
Raise if the browser submitted data but no ``Content-Length`` header which
|
|
is required for the kind of processing the server does.
|
|
"""
|
|
code = 411
|
|
description = (
|
|
'A request with this method requires a valid <code>Content-'
|
|
'Length</code> header.'
|
|
)
|
|
|
|
|
|
class PreconditionFailed(HTTPException):
|
|
|
|
"""*412* `Precondition Failed`
|
|
|
|
Status code used in combination with ``If-Match``, ``If-None-Match``, or
|
|
``If-Unmodified-Since``.
|
|
"""
|
|
code = 412
|
|
description = (
|
|
'The precondition on the request for the URL failed positive '
|
|
'evaluation.'
|
|
)
|
|
|
|
|
|
class RequestEntityTooLarge(HTTPException):
|
|
|
|
"""*413* `Request Entity Too Large`
|
|
|
|
The status code one should return if the data submitted exceeded a given
|
|
limit.
|
|
"""
|
|
code = 413
|
|
description = (
|
|
'The data value transmitted exceeds the capacity limit.'
|
|
)
|
|
|
|
|
|
class RequestURITooLarge(HTTPException):
|
|
|
|
"""*414* `Request URI Too Large`
|
|
|
|
Like *413* but for too long URLs.
|
|
"""
|
|
code = 414
|
|
description = (
|
|
'The length of the requested URL exceeds the capacity limit '
|
|
'for this server. The request cannot be processed.'
|
|
)
|
|
|
|
|
|
class UnsupportedMediaType(HTTPException):
|
|
|
|
"""*415* `Unsupported Media Type`
|
|
|
|
The status code returned if the server is unable to handle the media type
|
|
the client transmitted.
|
|
"""
|
|
code = 415
|
|
description = (
|
|
'The server does not support the media type transmitted in '
|
|
'the request.'
|
|
)
|
|
|
|
|
|
class RequestedRangeNotSatisfiable(HTTPException):
|
|
|
|
"""*416* `Requested Range Not Satisfiable`
|
|
|
|
The client asked for an invalid part of the file.
|
|
|
|
.. versionadded:: 0.7
|
|
"""
|
|
code = 416
|
|
description = (
|
|
'The server cannot provide the requested range.'
|
|
)
|
|
|
|
def __init__(self, length=None, units="bytes", description=None):
|
|
"""Takes an optional `Content-Range` header value based on ``length``
|
|
parameter.
|
|
"""
|
|
HTTPException.__init__(self, description)
|
|
self.length = length
|
|
self.units = units
|
|
|
|
def get_headers(self, environ):
|
|
headers = HTTPException.get_headers(self, environ)
|
|
if self.length is not None:
|
|
headers.append(
|
|
('Content-Range', '%s */%d' % (self.units, self.length)))
|
|
return headers
|
|
|
|
|
|
class ExpectationFailed(HTTPException):
|
|
|
|
"""*417* `Expectation Failed`
|
|
|
|
The server cannot meet the requirements of the Expect request-header.
|
|
|
|
.. versionadded:: 0.7
|
|
"""
|
|
code = 417
|
|
description = (
|
|
'The server could not meet the requirements of the Expect header'
|
|
)
|
|
|
|
|
|
class ImATeapot(HTTPException):
|
|
|
|
"""*418* `I'm a teapot`
|
|
|
|
The server should return this if it is a teapot and someone attempted
|
|
to brew coffee with it.
|
|
|
|
.. versionadded:: 0.7
|
|
"""
|
|
code = 418
|
|
description = (
|
|
'This server is a teapot, not a coffee machine'
|
|
)
|
|
|
|
|
|
class UnprocessableEntity(HTTPException):
|
|
|
|
"""*422* `Unprocessable Entity`
|
|
|
|
Used if the request is well formed, but the instructions are otherwise
|
|
incorrect.
|
|
"""
|
|
code = 422
|
|
description = (
|
|
'The request was well-formed but was unable to be followed '
|
|
'due to semantic errors.'
|
|
)
|
|
|
|
|
|
class Locked(HTTPException):
|
|
|
|
"""*423* `Locked`
|
|
|
|
Used if the resource that is being accessed is locked.
|
|
"""
|
|
code = 423
|
|
description = (
|
|
'The resource that is being accessed is locked.'
|
|
)
|
|
|
|
|
|
class PreconditionRequired(HTTPException):
|
|
|
|
"""*428* `Precondition Required`
|
|
|
|
The server requires this request to be conditional, typically to prevent
|
|
the lost update problem, which is a race condition between two or more
|
|
clients attempting to update a resource through PUT or DELETE. By requiring
|
|
each client to include a conditional header ("If-Match" or "If-Unmodified-
|
|
Since") with the proper value retained from a recent GET request, the
|
|
server ensures that each client has at least seen the previous revision of
|
|
the resource.
|
|
"""
|
|
code = 428
|
|
description = (
|
|
'This request is required to be conditional; try using "If-Match" '
|
|
'or "If-Unmodified-Since".'
|
|
)
|
|
|
|
|
|
class TooManyRequests(HTTPException):
|
|
|
|
"""*429* `Too Many Requests`
|
|
|
|
The server is limiting the rate at which this user receives responses, and
|
|
this request exceeds that rate. (The server may use any convenient method
|
|
to identify users and their request rates). The server may include a
|
|
"Retry-After" header to indicate how long the user should wait before
|
|
retrying.
|
|
"""
|
|
code = 429
|
|
description = (
|
|
'This user has exceeded an allotted request count. Try again later.'
|
|
)
|
|
|
|
|
|
class RequestHeaderFieldsTooLarge(HTTPException):
|
|
|
|
"""*431* `Request Header Fields Too Large`
|
|
|
|
The server refuses to process the request because the header fields are too
|
|
large. One or more individual fields may be too large, or the set of all
|
|
headers is too large.
|
|
"""
|
|
code = 431
|
|
description = (
|
|
'One or more header fields exceeds the maximum size.'
|
|
)
|
|
|
|
|
|
class UnavailableForLegalReasons(HTTPException):
|
|
|
|
"""*451* `Unavailable For Legal Reasons`
|
|
|
|
This status code indicates that the server is denying access to the
|
|
resource as a consequence of a legal demand.
|
|
"""
|
|
code = 451
|
|
description = (
|
|
'Unavailable for legal reasons.'
|
|
)
|
|
|
|
|
|
class InternalServerError(HTTPException):
|
|
|
|
"""*500* `Internal Server Error`
|
|
|
|
Raise if an internal server error occurred. This is a good fallback if an
|
|
unknown error occurred in the dispatcher.
|
|
"""
|
|
code = 500
|
|
description = (
|
|
'The server encountered an internal error and was unable to '
|
|
'complete your request. Either the server is overloaded or there '
|
|
'is an error in the application.'
|
|
)
|
|
|
|
|
|
class NotImplemented(HTTPException):
|
|
|
|
"""*501* `Not Implemented`
|
|
|
|
Raise if the application does not support the action requested by the
|
|
browser.
|
|
"""
|
|
code = 501
|
|
description = (
|
|
'The server does not support the action requested by the '
|
|
'browser.'
|
|
)
|
|
|
|
|
|
class BadGateway(HTTPException):
|
|
|
|
"""*502* `Bad Gateway`
|
|
|
|
If you do proxying in your application you should return this status code
|
|
if you received an invalid response from the upstream server it accessed
|
|
in attempting to fulfill the request.
|
|
"""
|
|
code = 502
|
|
description = (
|
|
'The proxy server received an invalid response from an upstream '
|
|
'server.'
|
|
)
|
|
|
|
|
|
class ServiceUnavailable(HTTPException):
|
|
|
|
"""*503* `Service Unavailable`
|
|
|
|
Status code you should return if a service is temporarily unavailable.
|
|
"""
|
|
code = 503
|
|
description = (
|
|
'The server is temporarily unable to service your request due to '
|
|
'maintenance downtime or capacity problems. Please try again '
|
|
'later.'
|
|
)
|
|
|
|
|
|
class GatewayTimeout(HTTPException):
|
|
|
|
"""*504* `Gateway Timeout`
|
|
|
|
Status code you should return if a connection to an upstream server
|
|
times out.
|
|
"""
|
|
code = 504
|
|
description = (
|
|
'The connection to an upstream server timed out.'
|
|
)
|
|
|
|
|
|
class HTTPVersionNotSupported(HTTPException):
|
|
|
|
"""*505* `HTTP Version Not Supported`
|
|
|
|
The server does not support the HTTP protocol version used in the request.
|
|
"""
|
|
code = 505
|
|
description = (
|
|
'The server does not support the HTTP protocol version used in the '
|
|
'request.'
|
|
)
|
|
|
|
|
|
default_exceptions = {}
|
|
__all__ = ['HTTPException']
|
|
|
|
|
|
def _find_exceptions():
|
|
for name, obj in iteritems(globals()):
|
|
try:
|
|
is_http_exception = issubclass(obj, HTTPException)
|
|
except TypeError:
|
|
is_http_exception = False
|
|
if not is_http_exception or obj.code is None:
|
|
continue
|
|
__all__.append(obj.__name__)
|
|
old_obj = default_exceptions.get(obj.code, None)
|
|
if old_obj is not None and issubclass(obj, old_obj):
|
|
continue
|
|
default_exceptions[obj.code] = obj
|
|
_find_exceptions()
|
|
del _find_exceptions
|
|
|
|
|
|
class Aborter(object):
|
|
|
|
"""
|
|
When passed a dict of code -> exception items it can be used as
|
|
callable that raises exceptions. If the first argument to the
|
|
callable is an integer it will be looked up in the mapping, if it's
|
|
a WSGI application it will be raised in a proxy exception.
|
|
|
|
The rest of the arguments are forwarded to the exception constructor.
|
|
"""
|
|
|
|
def __init__(self, mapping=None, extra=None):
|
|
if mapping is None:
|
|
mapping = default_exceptions
|
|
self.mapping = dict(mapping)
|
|
if extra is not None:
|
|
self.mapping.update(extra)
|
|
|
|
def __call__(self, code, *args, **kwargs):
|
|
if not args and not kwargs and not isinstance(code, integer_types):
|
|
raise HTTPException(response=code)
|
|
if code not in self.mapping:
|
|
raise LookupError('no exception for %r' % code)
|
|
raise self.mapping[code](*args, **kwargs)
|
|
|
|
|
|
def abort(status, *args, **kwargs):
|
|
'''
|
|
Raises an :py:exc:`HTTPException` for the given status code or WSGI
|
|
application::
|
|
|
|
abort(404) # 404 Not Found
|
|
abort(Response('Hello World'))
|
|
|
|
Can be passed a WSGI application or a status code. If a status code is
|
|
given it's looked up in the list of exceptions and will raise that
|
|
exception, if passed a WSGI application it will wrap it in a proxy WSGI
|
|
exception and raise that::
|
|
|
|
abort(404)
|
|
abort(Response('Hello World'))
|
|
|
|
'''
|
|
return _aborter(status, *args, **kwargs)
|
|
|
|
_aborter = Aborter()
|
|
|
|
|
|
#: an exception that is used internally to signal both a key error and a
|
|
#: bad request. Used by a lot of the datastructures.
|
|
BadRequestKeyError = BadRequest.wrap(KeyError)
|
|
|
|
|
|
# imported here because of circular dependencies of werkzeug.utils
|
|
from werkzeug.utils import escape
|
|
from werkzeug.http import HTTP_STATUS_CODES
|