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from zope.deprecation import deprecated
from zope.interface import implements
from zope.interface.interface import InterfaceClass
from webob import Request as WebobRequest
from repoze.bfg.interfaces import IRequest
class Request(WebobRequest):
"""
A subclass of the :term:`WebOb` Request class. An instance of
this class is created by the :term:`router` and is provided to a
view callable (and to other subsystems) as the ``request``
argument.
The documentation below (save for the ``add_response_callback``
and ''add_finished_callback`` methods, which are defined in this
subclass itself, and the attributes ``context``, ``registry``,
``root``, ``subpath``, ``traversed``, ``view_name``,
``virtual_root`` , and ``virtual_root_path``, each of which is
added to the request at by the :term:`router` at request ingress
time) are autogenerated from the WebOb source code used when this
documentation was generated.
Due to technical constraints, we can't yet display the WebOb
version number from which this documentation is autogenerated, but
it will be the 'prevailing WebOb version' at the time of the
release of this :mod:`repoze.bfg` version. See
http://http://pythonpaste.org/webob/ for further information.
"""
implements(IRequest)
response_callbacks = ()
finished_callbacks = ()
exception = None
def add_response_callback(self, callback):
"""
Add a callback to the set of callbacks to be called by the
:term:`router` at a point after a :term:`response` object is
successfully created. :mod:`repoze.bfg` does not have a
global response object: this functionality allows an
application to register an action to be performed against the
response once one is created.
A 'callback' is a callable which accepts two positional
parameters: ``request`` and ``response``. For example:
.. code-block:: python
:linenos:
def cache_callback(request, response):
'Set the cache_control max_age for the response'
response.cache_control.max_age = 360
request.add_response_callback(cache_callback)
Response callbacks are called in the order they're added
(first-to-most-recently-added). No response callback is
called if an exception happens in application code, or if the
response object returned by :term:`view` code is invalid.
All response callbacks are called *after* the
:class:`repoze.bfg.interfaces.INewResponse` event is sent.
Errors raised by callbacks are not handled specially. They
will be propagated to the caller of the :mod:`repoze.bfg`
router application.
.. note: ``add_response_callback`` is new in :mod:`repoze.bfg`
1.3.
See also: :ref:`using_response_callbacks`.
"""
callbacks = self.response_callbacks
if not callbacks:
callbacks = []
callbacks.append(callback)
self.response_callbacks = callbacks
def _process_response_callbacks(self, response):
callbacks = self.response_callbacks
while callbacks:
callback = callbacks.pop(0)
callback(self, response)
def add_finished_callback(self, callback):
"""
Add a callback to the set of callbacks to be called
unconditionally by the :term:`router` at the very end of
request processing.
``callback`` is a callable which accepts a single positional
parameter: ``request``. For example:
.. code-block:: python
:linenos:
import transaction
def commit_callback(request):
'''commit or abort the transaction associated with request'''
if request.exception is not None:
transaction.abort()
else:
transaction.commit()
request.add_finished_callback(commit_callback)
Finished callbacks are called in the order they're added (
first- to most-recently- added). Finished callbacks (unlike
response callbacks) are *always* called, even if an exception
happens in application code that prevents a response from
being generated.
The set of finished callbacks associated with a request are
called *very late* in the processing of that request; they are
essentially the last thing called by the :term:`router`. They
are called after response processing has already occurred in a
top-level ``finally:`` block within the router request
processing code. As a result, mutations performed to the
``request`` provided to a finished callback will have no
meaningful effect, because response processing will have
already occurred, and the request's scope will expire almost
immediately after all finished callbacks have been processed.
Errors raised by finished callbacks are not handled specially.
They will be propagated to the caller of the :mod:`repoze.bfg`
router application.
.. note: ``add_finished_callback`` is new in :mod:`repoze.bfg`
1.3.
See also: :ref:`using_finished_callbacks`.
"""
callbacks = self.finished_callbacks
if not callbacks:
callbacks = []
callbacks.append(callback)
self.finished_callbacks = callbacks
def _process_finished_callbacks(self):
callbacks = self.finished_callbacks
while callbacks:
callback = callbacks.pop(0)
callback(self)
# override default WebOb "environ['adhoc_attr']" mutation behavior
__getattr__ = object.__getattribute__
__setattr__ = object.__setattr__
__delattr__ = object.__delattr__
# b/c dict interface for "root factory" code that expects a bare
# environ. Explicitly omitted dict methods: clear (unnecessary),
# copy (implemented by WebOb), fromkeys (unnecessary)
def __contains__(self, k):
return self.environ.__contains__(k)
def __delitem__(self, k):
return self.environ.__delitem__(k)
def __getitem__(self, k):
return self.environ.__getitem__(k)
def __iter__(self):
return iter(self.environ)
def __setitem__(self, k, v):
self.environ[k] = v
def get(self, k, default=None):
return self.environ.get(k, default)
def has_key(self, k):
return self.environ.has_key(k)
def items(self):
return self.environ.items()
def iteritems(self):
return self.environ.iteritems()
def iterkeys(self):
return self.environ.iterkeys()
def itervalues(self):
return self.environ.itervalues()
def keys(self):
return self.environ.keys()
def pop(self, k):
return self.environ.pop(k)
def popitem(self):
return self.environ.popitem()
def setdefault(self, v, default):
return self.environ.setdefault(v, default)
def update(self, v, **kw):
return self.environ.update(v, **kw)
def values(self):
return self.environ.values()
def route_request_iface(name, bases=()):
iface = InterfaceClass('%s_IRequest' % name, bases=bases)
# for exception view lookups
iface.combined = InterfaceClass('%s_combined_IRequest' % name,
bases=(iface, IRequest))
return iface
def add_global_response_headers(request, headerlist):
def add_headers(request, response):
for k, v in headerlist:
response.headerlist.append((k, v))
request.add_response_callback(add_headers)
from repoze.bfg.threadlocal import get_current_request as get_request # b/c
get_request # prevent PyFlakes complaints
deprecated('get_request',
'As of repoze.bfg 1.0, any import of get_request from'
'``repoze.bfg.request`` is '
'deprecated. Use ``from repoze.bfg.threadlocal import '
'get_current_request instead.')
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