""" 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 - :class:`HTTPOk` * 201 - :class:`HTTPCreated` * 202 - :class:`HTTPAccepted` * 203 - :class:`HTTPNonAuthoritativeInformation` * 204 - :class:`HTTPNoContent` * 205 - :class:`HTTPResetContent` * 206 - :class:`HTTPPartialContent` HTTPRedirection * 300 - :class:`HTTPMultipleChoices` * 301 - :class:`HTTPMovedPermanently` * 302 - :class:`HTTPFound` * 303 - :class:`HTTPSeeOther` * 304 - :class:`HTTPNotModified` * 305 - :class:`HTTPUseProxy` * 307 - :class:`HTTPTemporaryRedirect` * 308 - :class:`HTTPPermanentRedirect` HTTPError HTTPClientError * 400 - :class:`HTTPBadRequest` * 401 - :class:`HTTPUnauthorized` * 402 - :class:`HTTPPaymentRequired` * 403 - :class:`HTTPForbidden` * 404 - :class:`HTTPNotFound` * 405 - :class:`HTTPMethodNotAllowed` * 406 - :class:`HTTPNotAcceptable` * 407 - :class:`HTTPProxyAuthenticationRequired` * 408 - :class:`HTTPRequestTimeout` * 409 - :class:`HTTPConflict` * 410 - :class:`HTTPGone` * 411 - :class:`HTTPLengthRequired` * 412 - :class:`HTTPPreconditionFailed` * 413 - :class:`HTTPRequestEntityTooLarge` * 414 - :class:`HTTPRequestURITooLong` * 415 - :class:`HTTPUnsupportedMediaType` * 416 - :class:`HTTPRequestRangeNotSatisfiable` * 417 - :class:`HTTPExpectationFailed` * 422 - :class:`HTTPUnprocessableEntity` * 423 - :class:`HTTPLocked` * 424 - :class:`HTTPFailedDependency` * 428 - :class:`HTTPPreconditionRequired` * 429 - :class:`HTTPTooManyRequests` * 431 - :class:`HTTPRequestHeaderFieldsTooLarge` * 451 - :class:`HTTPUnavailableForLegalReasons` HTTPServerError * 500 - :class:`HTTPInternalServerError` * 501 - :class:`HTTPNotImplemented` * 502 - :class:`HTTPBadGateway` * 503 - :class:`HTTPServiceUnavailable` * 504 - :class:`HTTPGatewayTimeout` * 505 - :class:`HTTPVersionNotSupported` * 511 - :class:`HTTPNetworkAuthenticationRequired` 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 json from string import Template import re import sys from webob.acceptparse import MIMEAccept from webob.compat import ( class_types, text_, text_type, urlparse, ) from webob.request import Request from webob.response import Response from webob.util import html_escape tag_re = re.compile(r'<.*?>', re.S) br_re = re.compile(r'', re.I | re.S) comment_re = re.compile(r'') class _lazified(object): def __init__(self, func, value): self.func = func self.value = value def __str__(self): return self.func(self.value) def lazify(func): def wrapper(value): return _lazified(func, value) return wrapper def no_escape(value): if value is None: return '' if not isinstance(value, text_type): if hasattr(value, '__unicode__'): value = value.__unicode__() if isinstance(value, bytes): value = text_(value, 'utf-8') else: value = text_type(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 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) class WSGIHTTPException(Response, HTTPException): ## You should set in subclasses: # code = 200 # title = 'OK' # explanation = 'why this happens' # body_template_obj = Template('response template') code = 500 title = 'Internal Server Error' explanation = '' body_template_obj = Template('''\ ${explanation}

${detail} ${html_comment} ''') plain_template_obj = Template('''\ ${status} ${body}''') html_template_obj = Template('''\ ${status}

${status}

${body} ''') ## 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, json_formatter=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 if json_formatter is not None: self.json_formatter = json_formatter def __str__(self): return self.detail or self.explanation def _make_body(self, environ, escape): escape = lazify(escape) args = { 'explanation': escape(self.explanation), 'detail': escape(self.detail or ''), 'comment': escape(self.comment or ''), } if self.comment: args['html_comment'] = '' % escape(self.comment) else: args['html_comment'] = '' 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 json_formatter(self, body, status, title, environ): return {'message': body, 'code': status, 'title': title} def json_body(self, environ): body = self._make_body(environ, no_escape) jsonbody = self.json_formatter(body=body, status=self.status, title=self.title, environ=environ) return json.dumps(jsonbody) def generate_response(self, environ, start_response): if self.content_length is not None: del self.content_length headerlist = list(self.headerlist) accept_value = environ.get('HTTP_ACCEPT', '') accept = MIMEAccept(accept_value) match = accept.best_match(['text/html', 'application/json']) if match == 'text/html': content_type = 'text/html' body = self.html_body(environ) elif match == 'application/json': content_type = 'application/json' body = self.json_body(environ) else: content_type = 'text/plain' body = self.plain_body(environ) resp = Response(body, status=self.status, headerlist=headerlist, content_type=content_type, ) resp.content_type = content_type return resp(environ, start_response) def __call__(self, environ, start_response): is_head = environ['REQUEST_METHOD'] == 'HEAD' if self.has_body or self.empty_body or is_head: app_iter = Response.__call__(self, environ, start_response) else: app_iter = self.generate_response(environ, start_response) if is_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, 307 and 308 (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} ${location}; 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: if '\n' in location or '\r' in location: raise ValueError('Control characters are not allowed in location') 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' class HTTPPermanentRedirect(_HTTPMove): """ subclass of :class:`~_HTTPMove` This indicates that the requested resource resides permanently under a different URI. code: 308, title: Permanent Redirect """ code = 308 title = 'Permanent 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 """ 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.

${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 body_template_obj = Template('''\ The resource could not be generated that was acceptable to your browser (content of type ${HTTP_ACCEPT}.

${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 body_template_obj = Template('''\ The request media type ${CONTENT_TYPE} is not supported by this server.

${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. 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. 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. 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') class HTTPPreconditionRequired(HTTPClientError): """ subclass of :class:`~HTTPClientError` This indicates that the origin server requires the request to be conditional. From RFC 6585, "Additional HTTP Status Codes". code: 428, title: Precondition Required """ code = 428 title = 'Precondition Required' explanation = ('This request is required to be conditional') class HTTPTooManyRequests(HTTPClientError): """ subclass of :class:`~HTTPClientError` This indicates that the client has sent too many requests in a given amount of time. Useful for rate limiting. From RFC 6585, "Additional HTTP Status Codes". code: 429, title: Too Many Requests """ code = 429 title = 'Too Many Requests' explanation = ( 'The client has sent too many requests in a given amount of time') class HTTPRequestHeaderFieldsTooLarge(HTTPClientError): """ subclass of :class:`~HTTPClientError` This indicates that the server is unwilling to process the request because its header fields are too large. The request may be resubmitted after reducing the size of the request header fields. From RFC 6585, "Additional HTTP Status Codes". code: 431, title: Request Header Fields Too Large """ code = 431 title = 'Request Header Fields Too Large' explanation = ( 'The request header fields were too large') class HTTPUnavailableForLegalReasons(HTTPClientError): """ subclass of :class:`~HTTPClientError` This indicates that the server is unable to process the request because of legal reasons, e.g. censorship or government-mandated blocked access. From the draft "A New HTTP Status Code for Legally-restricted Resources" by Tim Bray: http://tools.ietf.org/html/draft-tbray-http-legally-restricted-status-00 code: 451, title: Unavailable For Legal Reasons """ code = 451 title = 'Unavailable For Legal Reasons' explanation = ('The resource is not available due to legal reasons.') ############################################################ ## 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' body_template_obj = Template(''' The request method ${REQUEST_METHOD} is not implemented for this server.

${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 HTTPNetworkAuthenticationRequired(HTTPServerError): """ subclass of :class:`~HTTPServerError` This indicates that the client needs to authenticate to gain network access. From RFC 6585, "Additional HTTP Status Codes". code: 511, title: Network Authentication Required """ code = 511 title = 'Network Authentication Required' explanation = ('Network authentication is required') 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: 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 parent_exc_info[1](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 list(globals().items()): if (isinstance(value, (type, class_types)) and issubclass(value, HTTPException) and not name.startswith('_')): __all__.append(name) if all(( getattr(value, 'code', None), value not in (HTTPRedirection, HTTPClientError, HTTPServerError), issubclass( value, (HTTPOk, HTTPRedirection, HTTPClientError, HTTPServerError) ) )): status_map[value.code]=value if hasattr(value, 'explanation'): value.explanation = ' '.join(value.explanation.strip().split()) del name, value