172 lines
6.0 KiB
Python
172 lines
6.0 KiB
Python
import os
|
|
import typing as t
|
|
from warnings import warn
|
|
|
|
from .app import Flask
|
|
from .blueprints import Blueprint
|
|
from .globals import _request_ctx_stack
|
|
|
|
|
|
class UnexpectedUnicodeError(AssertionError, UnicodeError):
|
|
"""Raised in places where we want some better error reporting for
|
|
unexpected unicode or binary data.
|
|
"""
|
|
|
|
|
|
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 = [
|
|
f"You tried to access the file {key!r} in the request.files"
|
|
" dictionary but it does not exist. The mimetype for the"
|
|
f" request is {request.mimetype!r} 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.'
|
|
]
|
|
if form_matches:
|
|
names = ", ".join(repr(x) for x in form_matches)
|
|
buf.append(
|
|
"\n\nThe browser instead transmitted some file names. "
|
|
f"This was submitted: {names}"
|
|
)
|
|
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 = [
|
|
f"A request was sent to this URL ({request.url}) but a"
|
|
" redirect was issued automatically by the routing system"
|
|
f" to {exc.new_url!r}."
|
|
]
|
|
|
|
# In case just a slash was appended we can be extra helpful
|
|
if f"{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"
|
|
f" {request.method}-request to this URL since we can't make"
|
|
" browsers or HTTP clients redirect with form data reliably"
|
|
" or without user interaction."
|
|
)
|
|
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:
|
|
if key not in request.form:
|
|
raise
|
|
raise DebugFilesKeyError(request, key)
|
|
|
|
newcls.__name__ = oldcls.__name__
|
|
newcls.__module__ = oldcls.__module__
|
|
request.files.__class__ = newcls
|
|
|
|
|
|
def _dump_loader_info(loader) -> t.Generator:
|
|
yield f"class: {type(loader).__module__}.{type(loader).__name__}"
|
|
for key, value in sorted(loader.__dict__.items()):
|
|
if key.startswith("_"):
|
|
continue
|
|
if isinstance(value, (tuple, list)):
|
|
if not all(isinstance(x, str) for x in value):
|
|
continue
|
|
yield f"{key}:"
|
|
for item in value:
|
|
yield f" - {item}"
|
|
continue
|
|
elif not isinstance(value, (str, int, float, bool)):
|
|
continue
|
|
yield f"{key}: {value!r}"
|
|
|
|
|
|
def explain_template_loading_attempts(app: Flask, template, attempts) -> None:
|
|
"""This should help developers understand what failed"""
|
|
info = [f"Locating template {template!r}:"]
|
|
total_found = 0
|
|
blueprint = None
|
|
reqctx = _request_ctx_stack.top
|
|
if reqctx is not None and reqctx.request.blueprint is not None:
|
|
blueprint = reqctx.request.blueprint
|
|
|
|
for idx, (loader, srcobj, triple) in enumerate(attempts):
|
|
if isinstance(srcobj, Flask):
|
|
src_info = f"application {srcobj.import_name!r}"
|
|
elif isinstance(srcobj, Blueprint):
|
|
src_info = f"blueprint {srcobj.name!r} ({srcobj.import_name})"
|
|
else:
|
|
src_info = repr(srcobj)
|
|
|
|
info.append(f"{idx + 1:5}: trying loader of {src_info}")
|
|
|
|
for line in _dump_loader_info(loader):
|
|
info.append(f" {line}")
|
|
|
|
if triple is None:
|
|
detail = "no match"
|
|
else:
|
|
detail = f"found ({triple[1] or '<string>'!r})"
|
|
total_found += 1
|
|
info.append(f" -> {detail}")
|
|
|
|
seems_fishy = False
|
|
if total_found == 0:
|
|
info.append("Error: the template could not be found.")
|
|
seems_fishy = True
|
|
elif total_found > 1:
|
|
info.append("Warning: multiple loaders returned a match for the template.")
|
|
seems_fishy = True
|
|
|
|
if blueprint is not None and seems_fishy:
|
|
info.append(
|
|
" The template was looked up from an endpoint that belongs"
|
|
f" to the blueprint {blueprint!r}."
|
|
)
|
|
info.append(" Maybe you did not place a template in the right folder?")
|
|
info.append(" See https://flask.palletsprojects.com/blueprints/#templates")
|
|
|
|
app.logger.info("\n".join(info))
|
|
|
|
|
|
def explain_ignored_app_run() -> None:
|
|
if os.environ.get("WERKZEUG_RUN_MAIN") != "true":
|
|
warn(
|
|
Warning(
|
|
"Silently ignoring app.run() because the application is"
|
|
" run from the flask command line executable. Consider"
|
|
' putting app.run() behind an if __name__ == "__main__"'
|
|
" guard to silence this warning."
|
|
),
|
|
stacklevel=3,
|
|
)
|