def start_response(self, status, response_headers, exc_info=None):
'''WSGI compliant ``start_response`` callable, see pep3333_.
The application may call start_response more than once, if and only
if the ``exc_info`` argument is provided.
More precisely, it is a fatal error to call ``start_response`` without
the ``exc_info`` argument if start_response has already been called
within the current invocation of the application.
:parameter status: an HTTP ``status`` string like ``200 OK`` or
``404 Not Found``.
:parameter response_headers: a list of ``(header_name, header_value)``
tuples. It must be a Python list. Each header_name must be a valid
HTTP header field-name (as defined by RFC 2616_, Section 4.2),
without a trailing colon or other punctuation.
:parameter exc_info: optional python ``sys.exc_info()`` tuple.
This argument should be supplied by the application only if
``start_response`` is being called by an error handler.
:return: The :meth:`write` method.
``HOP_HEADERS`` are not considered but no error is raised.
.. _pep3333: http://www.python.org/dev/peps/pep-3333/
.. _2616: http://www.faqs.org/rfcs/rfc2616.html
'''
if exc_info:
try:
if self._headers_sent:
# if exc_info is provided, and the HTTP headers have
# already been sent, start_response must raise an error,
# and should re-raise using the exc_info tuple
reraise(*exc_info)
finally:
# Avoid circular reference
exc_info = None
elif self._status:
# Headers already set. Raise error
raise HttpException("Response headers already set!")
self._status = status
if type(response_headers) is not list:
raise TypeError("Headers must be a list of name/value tuples")
for header, value in response_headers:
if header.lower() in HOP_HEADERS:
# These features are the exclusive province of this class,
# this should be considered a fatal error for an application
# to attempt sending them, but we don't raise an error,
# just log a warning
self.logger.warning('Application passing hop header "%s"',
header)
continue
self.headers.add_header(header, value)
return self.write
def start_response(self, status, response_headers, exc_info=None):
'''WSGI compliant ``start_response`` callable, see pep3333_.
The application may call start_response more than once, if and only
if the ``exc_info`` argument is provided.
More precisely, it is a fatal error to call ``start_response`` without
the ``exc_info`` argument if start_response has already been called
within the current invocation of the application.
:parameter status: an HTTP ``status`` string like ``200 OK`` or
``404 Not Found``.
:parameter response_headers: a list of ``(header_name, header_value)``
tuples. It must be a Python list. Each header_name must be a valid
HTTP header field-name (as defined by RFC 2616_, Section 4.2),
without a trailing colon or other punctuation.
:parameter exc_info: optional python ``sys.exc_info()`` tuple.
This argument should be supplied by the application only if
``start_response`` is being called by an error handler.
:return: The :meth:`write` method.
``HOP_HEADERS`` are not considered but no error is raised.
.. _pep3333: http://www.python.org/dev/peps/pep-3333/
.. _2616: http://www.faqs.org/rfcs/rfc2616.html
'''
if exc_info:
try:
if self._headers_sent:
# if exc_info is provided, and the HTTP headers have
# already been sent, start_response must raise an error,
# and should re-raise using the exc_info tuple
reraise(*exc_info)
finally:
# Avoid circular reference
exc_info = None
elif self._status:
# Headers already set. Raise error
raise HttpException("Response headers already set!")
self._status = status
if type(response_headers) is not list:
raise TypeError("Headers must be a list of name/value tuples")
for header, value in response_headers:
if header.lower() in HOP_HEADERS:
# These features are the exclusive province of this class,
# this should be considered a fatal error for an application
# to attempt sending them, but we don't raise an error,
# just log a warning
self.logger.warning('Application passing hop header "%s"',
header)
continue
self.headers.add_header(header, value)
return self.write
