"""
HTTP Exception
--------------
This module processes Python exceptions that relate to HTTP exceptions
by defining a set of exceptions, all subclasses of HTTPException.
Each exception, in addition to being a Python exception that can be
raised and caught, is also a WSGI application and ``webob.Response``
object.
This module defines exceptions according to RFC 2068 [1]_ : codes with
100-300 are not really errors; 400's are client errors, and 500's are
server errors. According to the WSGI specification [2]_ , the application
can call ``start_response`` more then once only under two conditions:
(a) the response has not yet been sent, or (b) if the second and
subsequent invocations of ``start_response`` have a valid ``exc_info``
argument obtained from ``sys.exc_info()``. The WSGI specification then
requires the server or gateway to handle the case where content has been
sent and then an exception was encountered.
Exception
HTTPException
HTTPOk
* 200 - HTTPOk
* 201 - HTTPCreated
* 202 - HTTPAccepted
* 203 - HTTPNonAuthoritativeInformation
* 204 - HTTPNoContent
* 205 - HTTPResetContent
* 206 - HTTPPartialContent
HTTPRedirection
* 300 - HTTPMultipleChoices
* 301 - HTTPMovedPermanently
* 302 - HTTPFound
* 303 - HTTPSeeOther
* 304 - HTTPNotModified
* 305 - HTTPUseProxy
* 306 - Unused (not implemented, obviously)
* 307 - HTTPTemporaryRedirect
HTTPError
HTTPClientError
* 400 - HTTPBadRequest
* 401 - HTTPUnauthorized
* 402 - HTTPPaymentRequired
* 403 - HTTPForbidden
* 404 - HTTPNotFound
* 405 - HTTPMethodNotAllowed
* 406 - HTTPNotAcceptable
* 407 - HTTPProxyAuthenticationRequired
* 408 - HTTPRequestTimeout
* 409 - HTTPConflict
* 410 - HTTPGone
* 411 - HTTPLengthRequired
* 412 - HTTPPreconditionFailed
* 413 - HTTPRequestEntityTooLarge
* 414 - HTTPRequestURITooLong
* 415 - HTTPUnsupportedMediaType
* 416 - HTTPRequestRangeNotSatisfiable
* 417 - HTTPExpectationFailed
HTTPServerError
* 500 - HTTPInternalServerError
* 501 - HTTPNotImplemented
* 502 - HTTPBadGateway
* 503 - HTTPServiceUnavailable
* 504 - HTTPGatewayTimeout
* 505 - HTTPVersionNotSupported
Subclass usage notes:
---------------------
The HTTPException class is complicated by 4 factors:
1. The content given to the exception may either be plain-text or
as html-text.
2. The template may want to have string-substitutions taken from
the current ``environ`` or values from incoming headers. This
is especially troublesome due to case sensitivity.
3. The final output may either be text/plain or text/html
mime-type as requested by the client application.
4. Each exception has a default explanation, but those who
raise exceptions may want to provide additional detail.
Subclass attributes and call parameters are designed to provide an easier path
through the complications.
Attributes:
``code``
the HTTP status code for the exception
``title``
remainder of the status line (stuff after the code)
``explanation``
a plain-text explanation of the error message that is
not subject to environment or header substitutions;
it is accessible in the template via %(explanation)s
``detail``
a plain-text message customization that is not subject
to environment or header substitutions; accessible in
the template via %(detail)s
``body_template``
a content fragment (in HTML) used for environment and
header substitution; the default template includes both
the explanation and further detail provided in the
message
Parameters:
``detail``
a plain-text override of the default ``detail``
``headers``
a list of (k,v) header pairs
``comment``
a plain-text additional information which is
usually stripped/hidden for end-users
``body_template``
a string.Template object containing a content fragment in HTML
that frames the explanation and further detail
To override the template (which is HTML content) or the plain-text
explanation, one must subclass the given exception; or customize it
after it has been created. This particular breakdown of a message
into explanation, detail and template allows both the creation of
plain-text and html messages for various clients as well as
error-free substitution of environment variables and headers.
The subclasses of :class:`~_HTTPMove`
(:class:`~HTTPMultipleChoices`, :class:`~HTTPMovedPermanently`,
:class:`~HTTPFound`, :class:`~HTTPSeeOther`, :class:`~HTTPUseProxy` and
:class:`~HTTPTemporaryRedirect`) are redirections that require a ``Location``
field. Reflecting this, these subclasses have two additional keyword arguments:
``location`` and ``add_slash``.
Parameters:
``location``
to set the location immediately
``add_slash``
set to True to redirect to the same URL as the request, except with a
``/`` appended
Relative URLs in the location will be resolved to absolute.
References:
.. [1] http://www.python.org/peps/pep-0333.html#error-handling
.. [2] http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5
"""
import re
import urlparse
import sys
import types
from string import Template
from webob import Response, Request, html_escape
from webob.util import warn_deprecation
tag_re = re.compile(r'<.*?>', re.S)
br_re = re.compile(r'<br.*?>', re.I|re.S)
comment_re = re.compile(r'<!--|-->')
def no_escape(value):
if value is None:
return ''
if not isinstance(value, basestring):
if hasattr(value, '__unicode__'):
value = unicode(value)
else:
value = str(value)
return value
def strip_tags(value):
value = value.replace('\n', ' ')
value = value.replace('\r', '')
value = br_re.sub('\n', value)
value = comment_re.sub('', value)
value = tag_re.sub('', value)
return value
[docs]class HTTPException(Exception):
def __init__(self, message, wsgi_response):
Exception.__init__(self, message)
self.wsgi_response = wsgi_response
def __call__(self, environ, start_response):
return self.wsgi_response(environ, start_response)
# TODO: remove in version 1.3
@property
def exception(self):
warn_deprecation("Raise HTTP exceptions directly", '1.2', 2)
return self
class WSGIHTTPException(Response, HTTPException):
## You should set in subclasses:
# code = 200
# title = 'OK'
# explanation = 'why this happens'
# body_template_obj = Template('response template')
code = None
title = None
explanation = ''
body_template_obj = Template('''\
${explanation}<br /><br />
${detail}
${html_comment}
''')
plain_template_obj = Template('''\
${status}
${body}''')
html_template_obj = Template('''\
<html>
<head>
<title>${status}</title>
</head>
<body>
<h1>${status}</h1>
${body}
</body>
</html>''')
## Set this to True for responses that should have no request body
empty_body = False
def __init__(self, detail=None, headers=None, comment=None,
body_template=None, **kw):
Response.__init__(self,
status='%s %s' % (self.code, self.title),
**kw)
Exception.__init__(self, detail)
if headers:
self.headers.extend(headers)
self.detail = detail
self.comment = comment
if body_template is not None:
self.body_template = body_template
self.body_template_obj = Template(body_template)
if self.empty_body:
del self.content_type
del self.content_length
def __str__(self):
return self.detail or self.explanation
def _make_body(self, environ, escape):
args = {
'explanation': escape(self.explanation),
'detail': escape(self.detail or ''),
'comment': escape(self.comment or ''),
}
if self.comment:
args['html_comment'] = '<!-- %s -->' % escape(self.comment)
else:
args['html_comment'] = ''
body_tmpl = self.body_template_obj
if WSGIHTTPException.body_template_obj is not self.body_template_obj:
# Custom template; add headers to args
for k, v in environ.items():
args[k] = escape(v)
for k, v in self.headers.items():
args[k.lower()] = escape(v)
t_obj = self.body_template_obj
return t_obj.substitute(args)
def plain_body(self, environ):
body = self._make_body(environ, no_escape)
body = strip_tags(body)
return self.plain_template_obj.substitute(status=self.status,
title=self.title,
body=body)
def html_body(self, environ):
body = self._make_body(environ, html_escape)
return self.html_template_obj.substitute(status=self.status,
body=body)
def generate_response(self, environ, start_response):
if self.content_length is not None:
del self.content_length
headerlist = list(self.headerlist)
accept = environ.get('HTTP_ACCEPT', '')
if accept and 'html' in accept or '*/*' in accept:
content_type = 'text/html'
body = self.html_body(environ)
else:
content_type = 'text/plain'
body = self.plain_body(environ)
extra_kw = {}
if isinstance(body, unicode):
extra_kw.update(charset='utf-8')
resp = Response(body,
status=self.status,
headerlist=headerlist,
content_type=content_type,
**extra_kw
)
resp.content_type = content_type
return resp(environ, start_response)
def __call__(self, environ, start_response):
if self.body or self.empty_body:
app_iter = Response.__call__(self, environ, start_response)
else:
app_iter = self.generate_response(environ, start_response)
if environ['REQUEST_METHOD'] == 'HEAD':
app_iter = []
return app_iter
@property
def wsgi_response(self):
return self
class HTTPError(WSGIHTTPException):
"""
base class for status codes in the 400's and 500's
This is an exception which indicates that an error has occurred,
and that any work in progress should not be committed. These are
typically results in the 400's and 500's.
"""
class HTTPRedirection(WSGIHTTPException):
"""
base class for 300's status code (redirections)
This is an abstract base class for 3xx redirection. It indicates
that further action needs to be taken by the user agent in order
to fulfill the request. It does not necessarly signal an error
condition.
"""
class HTTPOk(WSGIHTTPException):
"""
Base class for the 200's status code (successful responses)
code: 200, title: OK
"""
code = 200
title = 'OK'
############################################################
## 2xx success
############################################################
class HTTPCreated(HTTPOk):
"""
subclass of :class:`~HTTPOk`
This indicates that request has been fulfilled and resulted in a new
resource being created.
code: 201, title: Created
"""
code = 201
title = 'Created'
class HTTPAccepted(HTTPOk):
"""
subclass of :class:`~HTTPOk`
This indicates that the request has been accepted for processing, but the
processing has not been completed.
code: 202, title: Accepted
"""
code = 202
title = 'Accepted'
explanation = 'The request is accepted for processing.'
class HTTPNonAuthoritativeInformation(HTTPOk):
"""
subclass of :class:`~HTTPOk`
This indicates that the returned metainformation in the entity-header is
not the definitive set as available from the origin server, but is
gathered from a local or a third-party copy.
code: 203, title: Non-Authoritative Information
"""
code = 203
title = 'Non-Authoritative Information'
class HTTPNoContent(HTTPOk):
"""
subclass of :class:`~HTTPOk`
This indicates that the server has fulfilled the request but does
not need to return an entity-body, and might want to return updated
metainformation.
code: 204, title: No Content
"""
code = 204
title = 'No Content'
empty_body = True
class HTTPResetContent(HTTPOk):
"""
subclass of :class:`~HTTPOk`
This indicates that the the server has fulfilled the request and
the user agent SHOULD reset the document view which caused the
request to be sent.
code: 205, title: Reset Content
"""
code = 205
title = 'Reset Content'
empty_body = True
class HTTPPartialContent(HTTPOk):
"""
subclass of :class:`~HTTPOk`
This indicates that the server has fulfilled the partial GET
request for the resource.
code: 206, title: Partial Content
"""
code = 206
title = 'Partial Content'
############################################################
## 3xx redirection
############################################################
class _HTTPMove(HTTPRedirection):
"""
redirections which require a Location field
Since a 'Location' header is a required attribute of 301, 302, 303,
305 and 307 (but not 304), this base class provides the mechanics to
make this easy.
You can provide a location keyword argument to set the location
immediately. You may also give ``add_slash=True`` if you want to
redirect to the same URL as the request, except with a ``/`` added
to the end.
Relative URLs in the location will be resolved to absolute.
"""
explanation = 'The resource has been moved to'
body_template_obj = Template('''\
${explanation} <a href="${location}">${location}</a>;
you should be redirected automatically.
${detail}
${html_comment}''')
def __init__(self, detail=None, headers=None, comment=None,
body_template=None, location=None, add_slash=False):
super(_HTTPMove, self).__init__(
detail=detail, headers=headers, comment=comment,
body_template=body_template)
if location is not None:
self.location = location
if add_slash:
raise TypeError(
"You can only provide one of the arguments location and add_slash")
self.add_slash = add_slash
def __call__(self, environ, start_response):
req = Request(environ)
if self.add_slash:
url = req.path_url
url += '/'
if req.environ.get('QUERY_STRING'):
url += '?' + req.environ['QUERY_STRING']
self.location = url
self.location = urlparse.urljoin(req.path_url, self.location)
return super(_HTTPMove, self).__call__(
environ, start_response)
class HTTPMultipleChoices(_HTTPMove):
"""
subclass of :class:`~_HTTPMove`
This indicates that the requested resource corresponds to any one
of a set of representations, each with its own specific location,
and agent-driven negotiation information is being provided so that
the user can select a preferred representation and redirect its
request to that location.
code: 300, title: Multiple Choices
"""
code = 300
title = 'Multiple Choices'
class HTTPMovedPermanently(_HTTPMove):
"""
subclass of :class:`~_HTTPMove`
This indicates that the requested resource has been assigned a new
permanent URI and any future references to this resource SHOULD use
one of the returned URIs.
code: 301, title: Moved Permanently
"""
code = 301
title = 'Moved Permanently'
class HTTPFound(_HTTPMove):
"""
subclass of :class:`~_HTTPMove`
This indicates that the requested resource resides temporarily under
a different URI.
code: 302, title: Found
"""
code = 302
title = 'Found'
explanation = 'The resource was found at'
# This one is safe after a POST (the redirected location will be
# retrieved with GET):
class HTTPSeeOther(_HTTPMove):
"""
subclass of :class:`~_HTTPMove`
This indicates that the response to the request can be found under
a different URI and SHOULD be retrieved using a GET method on that
resource.
code: 303, title: See Other
"""
code = 303
title = 'See Other'
class HTTPNotModified(HTTPRedirection):
"""
subclass of :class:`~HTTPRedirection`
This indicates that if the client has performed a conditional GET
request and access is allowed, but the document has not been
modified, the server SHOULD respond with this status code.
code: 304, title: Not Modified
"""
# TODO: this should include a date or etag header
code = 304
title = 'Not Modified'
empty_body = True
class HTTPUseProxy(_HTTPMove):
"""
subclass of :class:`~_HTTPMove`
This indicates that the requested resource MUST be accessed through
the proxy given by the Location field.
code: 305, title: Use Proxy
"""
# Not a move, but looks a little like one
code = 305
title = 'Use Proxy'
explanation = (
'The resource must be accessed through a proxy located at')
class HTTPTemporaryRedirect(_HTTPMove):
"""
subclass of :class:`~_HTTPMove`
This indicates that the requested resource resides temporarily
under a different URI.
code: 307, title: Temporary Redirect
"""
code = 307
title = 'Temporary Redirect'
############################################################
## 4xx client error
############################################################
class HTTPClientError(HTTPError):
"""
base class for the 400's, where the client is in error
This is an error condition in which the client is presumed to be
in-error. This is an expected problem, and thus is not considered
a bug. A server-side traceback is not warranted. Unless specialized,
this is a '400 Bad Request'
"""
code = 400
title = 'Bad Request'
explanation = ('The server could not comply with the request since\r\n'
'it is either malformed or otherwise incorrect.\r\n')
class HTTPBadRequest(HTTPClientError):
pass
class HTTPUnauthorized(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the request requires user authentication.
code: 401, title: Unauthorized
"""
code = 401
title = 'Unauthorized'
explanation = (
'This server could not verify that you are authorized to\r\n'
'access the document you requested. Either you supplied the\r\n'
'wrong credentials (e.g., bad password), or your browser\r\n'
'does not understand how to supply the credentials required.\r\n')
class HTTPPaymentRequired(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
code: 402, title: Payment Required
"""
code = 402
title = 'Payment Required'
explanation = ('Access was denied for financial reasons.')
class HTTPForbidden(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the server understood the request, but is
refusing to fulfill it.
code: 403, title: Forbidden
"""
code = 403
title = 'Forbidden'
explanation = ('Access was denied to this resource.')
class HTTPNotFound(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the server did not find anything matching the
Request-URI.
code: 404, title: Not Found
"""
code = 404
title = 'Not Found'
explanation = ('The resource could not be found.')
class HTTPMethodNotAllowed(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the method specified in the Request-Line is
not allowed for the resource identified by the Request-URI.
code: 405, title: Method Not Allowed
"""
code = 405
title = 'Method Not Allowed'
# override template since we need an environment variable
body_template_obj = Template('''\
The method ${REQUEST_METHOD} is not allowed for this resource. <br /><br />
${detail}''')
class HTTPNotAcceptable(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates 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.
code: 406, title: Not Acceptable
"""
code = 406
title = 'Not Acceptable'
# override template since we need an environment variable
template = Template('''\
The resource could not be generated that was acceptable to your browser
(content of type ${HTTP_ACCEPT}. <br /><br />
${detail}''')
class HTTPProxyAuthenticationRequired(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This is similar to 401, but indicates that the client must first
authenticate itself with the proxy.
code: 407, title: Proxy Authentication Required
"""
code = 407
title = 'Proxy Authentication Required'
explanation = ('Authentication with a local proxy is needed.')
class HTTPRequestTimeout(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the client did not produce a request within
the time that the server was prepared to wait.
code: 408, title: Request Timeout
"""
code = 408
title = 'Request Timeout'
explanation = ('The server has waited too long for the request to '
'be sent by the client.')
class HTTPConflict(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the request could not be completed due to a
conflict with the current state of the resource.
code: 409, title: Conflict
"""
code = 409
title = 'Conflict'
explanation = ('There was a conflict when trying to complete '
'your request.')
class HTTPGone(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the requested resource is no longer available
at the server and no forwarding address is known.
code: 410, title: Gone
"""
code = 410
title = 'Gone'
explanation = ('This resource is no longer available. No forwarding '
'address is given.')
class HTTPLengthRequired(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the the server refuses to accept the request
without a defined Content-Length.
code: 411, title: Length Required
"""
code = 411
title = 'Length Required'
explanation = ('Content-Length header required.')
class HTTPPreconditionFailed(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the precondition given in one or more of the
request-header fields evaluated to false when it was tested on the
server.
code: 412, title: Precondition Failed
"""
code = 412
title = 'Precondition Failed'
explanation = ('Request precondition failed.')
class HTTPRequestEntityTooLarge(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the server is refusing to process a request
because the request entity is larger than the server is willing or
able to process.
code: 413, title: Request Entity Too Large
"""
code = 413
title = 'Request Entity Too Large'
explanation = ('The body of your request was too large for this server.')
class HTTPRequestURITooLong(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the server is refusing to service the request
because the Request-URI is longer than the server is willing to
interpret.
code: 414, title: Request-URI Too Long
"""
code = 414
title = 'Request-URI Too Long'
explanation = ('The request URI was too long for this server.')
class HTTPUnsupportedMediaType(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the server is refusing to service the request
because the entity of the request is in a format not supported by
the requested resource for the requested method.
code: 415, title: Unsupported Media Type
"""
code = 415
title = 'Unsupported Media Type'
# override template since we need an environment variable
template_obj = Template('''\
The request media type ${CONTENT_TYPE} is not supported by this server.
<br /><br />
${detail}''')
class HTTPRequestRangeNotSatisfiable(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
The server SHOULD return a response with this status code if a
request included a Range request-header field, and none of the
range-specifier values in this field overlap the current extent
of the selected resource, and the request did not include an
If-Range request-header field.
code: 416, title: Request Range Not Satisfiable
"""
code = 416
title = 'Request Range Not Satisfiable'
explanation = ('The Range requested is not available.')
class HTTPExpectationFailed(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indidcates that the expectation given in an Expect
request-header field could not be met by this server.
code: 417, title: Expectation Failed
"""
code = 417
title = 'Expectation Failed'
explanation = ('Expectation failed.')
class HTTPUnprocessableEntity(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the server is unable to process the contained
instructions. Only for WebDAV.
code: 422, title: Unprocessable Entity
"""
## Note: from WebDAV
code = 422
title = 'Unprocessable Entity'
explanation = 'Unable to process the contained instructions'
class HTTPLocked(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the resource is locked. Only for WebDAV
code: 423, title: Locked
"""
## Note: from WebDAV
code = 423
title = 'Locked'
explanation = ('The resource is locked')
class HTTPFailedDependency(HTTPClientError):
"""
subclass of :class:`~HTTPClientError`
This indicates that the method could not be performed because the
requested action depended on another action and that action failed.
Only for WebDAV.
code: 424, title: Failed Dependency
"""
## Note: from WebDAV
code = 424
title = 'Failed Dependency'
explanation = ('The method could not be performed because the requested '
'action dependended on another action and that action failed')
############################################################
## 5xx Server Error
############################################################
# Response status codes beginning with the digit "5" indicate cases in
# which the server is aware that it has erred or is incapable of
# performing the request. Except when responding to a HEAD request, the
# server SHOULD include an entity containing an explanation of the error
# situation, and whether it is a temporary or permanent condition. User
# agents SHOULD display any included entity to the user. These response
# codes are applicable to any request method.
class HTTPServerError(HTTPError):
"""
base class for the 500's, where the server is in-error
This is an error condition in which the server is presumed to be
in-error. This is usually unexpected, and thus requires a traceback;
ideally, opening a support ticket for the customer. Unless specialized,
this is a '500 Internal Server Error'
"""
code = 500
title = 'Internal Server Error'
explanation = (
'The server has either erred or is incapable of performing\r\n'
'the requested operation.\r\n')
class HTTPInternalServerError(HTTPServerError):
pass
class HTTPNotImplemented(HTTPServerError):
"""
subclass of :class:`~HTTPServerError`
This indicates that the server does not support the functionality
required to fulfill the request.
code: 501, title: Not Implemented
"""
code = 501
title = 'Not Implemented'
template = Template('''
The request method ${REQUEST_METHOD} is not implemented for this server. <br /><br />
${detail}''')
class HTTPBadGateway(HTTPServerError):
"""
subclass of :class:`~HTTPServerError`
This indicates that the server, while acting as a gateway or proxy,
received an invalid response from the upstream server it accessed
in attempting to fulfill the request.
code: 502, title: Bad Gateway
"""
code = 502
title = 'Bad Gateway'
explanation = ('Bad gateway.')
class HTTPServiceUnavailable(HTTPServerError):
"""
subclass of :class:`~HTTPServerError`
This indicates that the server is currently unable to handle the
request due to a temporary overloading or maintenance of the server.
code: 503, title: Service Unavailable
"""
code = 503
title = 'Service Unavailable'
explanation = ('The server is currently unavailable. '
'Please try again at a later time.')
class HTTPGatewayTimeout(HTTPServerError):
"""
subclass of :class:`~HTTPServerError`
This indicates that the server, while acting as a gateway or proxy,
did not receive a timely response from the upstream server specified
by the URI (e.g. HTTP, FTP, LDAP) or some other auxiliary server
(e.g. DNS) it needed to access in attempting to complete the request.
code: 504, title: Gateway Timeout
"""
code = 504
title = 'Gateway Timeout'
explanation = ('The gateway has timed out.')
class HTTPVersionNotSupported(HTTPServerError):
"""
subclass of :class:`~HTTPServerError`
This indicates that the server does not support, or refuses to
support, the HTTP protocol version that was used in the request
message.
code: 505, title: HTTP Version Not Supported
"""
code = 505
title = 'HTTP Version Not Supported'
explanation = ('The HTTP version is not supported.')
class HTTPInsufficientStorage(HTTPServerError):
"""
subclass of :class:`~HTTPServerError`
This indicates that the server does not have enough space to save
the resource.
code: 507, title: Insufficient Storage
"""
code = 507
title = 'Insufficient Storage'
explanation = ('There was not enough space to save the resource')
class HTTPExceptionMiddleware(object):
"""
Middleware that catches exceptions in the sub-application. This
does not catch exceptions in the app_iter; only during the initial
calling of the application.
This should be put *very close* to applications that might raise
these exceptions. This should not be applied globally; letting
*expected* exceptions raise through the WSGI stack is dangerous.
"""
def __init__(self, application):
self.application = application
def __call__(self, environ, start_response):
try:
return self.application(environ, start_response)
except HTTPException, exc:
parent_exc_info = sys.exc_info()
def repl_start_response(status, headers, exc_info=None):
if exc_info is None:
exc_info = parent_exc_info
return start_response(status, headers, exc_info)
return exc(environ, repl_start_response)
try:
from paste import httpexceptions
except ImportError: # pragma: no cover
# Without Paste we don't need to do this fixup
pass
else: # pragma: no cover
for name in dir(httpexceptions):
obj = globals().get(name)
if (obj and isinstance(obj, type) and issubclass(obj, HTTPException)
and obj is not HTTPException
and obj is not WSGIHTTPException):
obj.__bases__ = obj.__bases__ + (getattr(httpexceptions, name),)
del name, obj, httpexceptions
__all__ = ['HTTPExceptionMiddleware', 'status_map']
status_map={}
for name, value in globals().items():
if (isinstance(value, (type, types.ClassType)) and issubclass(value, HTTPException)
and not name.startswith('_')):
__all__.append(name)
if getattr(value, 'code', None):
status_map[value.code]=value
if hasattr(value, 'explanation'):
value.explanation = ' '.join(value.explanation.strip().split())
del name, value