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Diffstat (limited to 'websdk/flask/debughelpers.py')
-rw-r--r-- | websdk/flask/debughelpers.py | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/websdk/flask/debughelpers.py b/websdk/flask/debughelpers.py new file mode 100644 index 0000000..edf8c11 --- /dev/null +++ b/websdk/flask/debughelpers.py @@ -0,0 +1,79 @@ +# -*- 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. +""" + + +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).encode('utf-8') + + 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, e: + if key not in request.form: + raise + raise DebugFilesKeyError(request, key) + newcls.__name__ = oldcls.__name__ + newcls.__module__ = oldcls.__module__ + request.files.__class__ = newcls |