se-hub/lib/flask/debughelpers.py

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2015-05-09 19:00:14 +00:00
# -*- coding: utf-8 -*-
"""
flask.debughelpers
~~~~~~~~~~~~~~~~~~
Various helpers to make the development experience better.
:copyright: (c) 2011 by Armin Ronacher.
:license: BSD, see LICENSE for more details.
"""
from ._compat import implements_to_string
class UnexpectedUnicodeError(AssertionError, UnicodeError):
"""Raised in places where we want some better error reporting for
unexpected unicode or binary data.
"""
@implements_to_string
class DebugFilesKeyError(KeyError, AssertionError):
"""Raised from request.files during debugging. The idea is that it can
provide a better error message than just a generic KeyError/BadRequest.
"""
def __init__(self, request, key):
form_matches = request.form.getlist(key)
buf = ['You tried to access the file "%s" in the request.files '
'dictionary but it does not exist. The mimetype for the request '
'is "%s" instead of "multipart/form-data" which means that no '
'file contents were transmitted. To fix this error you should '
'provide enctype="multipart/form-data" in your form.' %
(key, request.mimetype)]
if form_matches:
buf.append('\n\nThe browser instead transmitted some file names. '
'This was submitted: %s' % ', '.join('"%s"' % x
for x in form_matches))
self.msg = ''.join(buf)
def __str__(self):
return self.msg
class FormDataRoutingRedirect(AssertionError):
"""This exception is raised by Flask in debug mode if it detects a
redirect caused by the routing system when the request method is not
GET, HEAD or OPTIONS. Reasoning: form data will be dropped.
"""
def __init__(self, request):
exc = request.routing_exception
buf = ['A request was sent to this URL (%s) but a redirect was '
'issued automatically by the routing system to "%s".'
% (request.url, exc.new_url)]
# In case just a slash was appended we can be extra helpful
if request.base_url + '/' == exc.new_url.split('?')[0]:
buf.append(' The URL was defined with a trailing slash so '
'Flask will automatically redirect to the URL '
'with the trailing slash if it was accessed '
'without one.')
buf.append(' Make sure to directly send your %s-request to this URL '
'since we can\'t make browsers or HTTP clients redirect '
'with form data reliably or without user interaction.' %
request.method)
buf.append('\n\nNote: this exception is only raised in debug mode')
AssertionError.__init__(self, ''.join(buf).encode('utf-8'))
def attach_enctype_error_multidict(request):
"""Since Flask 0.8 we're monkeypatching the files object in case a
request is detected that does not use multipart form data but the files
object is accessed.
"""
oldcls = request.files.__class__
class newcls(oldcls):
def __getitem__(self, key):
try:
return oldcls.__getitem__(self, key)
except KeyError as e:
if key not in request.form:
raise
raise DebugFilesKeyError(request, key)
newcls.__name__ = oldcls.__name__
newcls.__module__ = oldcls.__module__
request.files.__class__ = newcls