django1/django/core/handlers/base.py

156 lines
6.8 KiB
Python

import sys
from django import http
from django.core import signals
from django.dispatch import dispatcher
class BaseHandler(object):
# Changes that are always applied to a response (in this order).
response_fixes = [
http.fix_location_header,
http.conditional_content_removal,
http.fix_IE_for_attach,
http.fix_IE_for_vary,
]
def __init__(self):
self._request_middleware = self._view_middleware = self._response_middleware = self._exception_middleware = None
def load_middleware(self):
"""
Populate middleware lists from settings.MIDDLEWARE_CLASSES.
Must be called after the environment is fixed (see __call__).
"""
from django.conf import settings
from django.core import exceptions
self._request_middleware = []
self._view_middleware = []
self._response_middleware = []
self._exception_middleware = []
for middleware_path in settings.MIDDLEWARE_CLASSES:
try:
dot = middleware_path.rindex('.')
except ValueError:
raise exceptions.ImproperlyConfigured, '%s isn\'t a middleware module' % middleware_path
mw_module, mw_classname = middleware_path[:dot], middleware_path[dot+1:]
try:
mod = __import__(mw_module, {}, {}, [''])
except ImportError, e:
raise exceptions.ImproperlyConfigured, 'Error importing middleware %s: "%s"' % (mw_module, e)
try:
mw_class = getattr(mod, mw_classname)
except AttributeError:
raise exceptions.ImproperlyConfigured, 'Middleware module "%s" does not define a "%s" class' % (mw_module, mw_classname)
try:
mw_instance = mw_class()
except exceptions.MiddlewareNotUsed:
continue
if hasattr(mw_instance, 'process_request'):
self._request_middleware.append(mw_instance.process_request)
if hasattr(mw_instance, 'process_view'):
self._view_middleware.append(mw_instance.process_view)
if hasattr(mw_instance, 'process_response'):
self._response_middleware.insert(0, mw_instance.process_response)
if hasattr(mw_instance, 'process_exception'):
self._exception_middleware.insert(0, mw_instance.process_exception)
def get_response(self, request):
"Returns an HttpResponse object for the given HttpRequest"
from django.core import exceptions, urlresolvers
from django.core.mail import mail_admins
from django.conf import settings
# Apply request middleware
for middleware_method in self._request_middleware:
response = middleware_method(request)
if response:
return response
# Get urlconf from request object, if available. Otherwise use default.
urlconf = getattr(request, "urlconf", settings.ROOT_URLCONF)
resolver = urlresolvers.RegexURLResolver(r'^/', urlconf)
try:
callback, callback_args, callback_kwargs = resolver.resolve(request.path)
# Apply view middleware
for middleware_method in self._view_middleware:
response = middleware_method(request, callback, callback_args, callback_kwargs)
if response:
return response
try:
response = callback(request, *callback_args, **callback_kwargs)
except Exception, e:
# If the view raised an exception, run it through exception
# middleware, and if the exception middleware returns a
# response, use that. Otherwise, reraise the exception.
for middleware_method in self._exception_middleware:
response = middleware_method(request, e)
if response:
return response
raise
# Complain if the view returned None (a common error).
if response is None:
try:
view_name = callback.func_name # If it's a function
except AttributeError:
view_name = callback.__class__.__name__ + '.__call__' # If it's a class
raise ValueError, "The view %s.%s didn't return an HttpResponse object." % (callback.__module__, view_name)
return response
except http.Http404, e:
if settings.DEBUG:
from django.views import debug
return debug.technical_404_response(request, e)
else:
callback, param_dict = resolver.resolve404()
return callback(request, **param_dict)
except exceptions.PermissionDenied:
return http.HttpResponseForbidden('<h1>Permission denied</h1>')
except SystemExit:
# Allow sys.exit() to actually exit. See tickets #1023 and #4701
raise
except: # Handle everything else, including SuspiciousOperation, etc.
# Get the exception info now, in case another exception is thrown later.
exc_info = sys.exc_info()
receivers = dispatcher.send(signal=signals.got_request_exception, request=request)
if settings.DEBUG_PROPAGATE_EXCEPTIONS:
raise
elif settings.DEBUG:
from django.views import debug
return debug.technical_500_response(request, *exc_info)
else:
# When DEBUG is False, send an error message to the admins.
subject = 'Error (%s IP): %s' % ((request.META.get('REMOTE_ADDR') in settings.INTERNAL_IPS and 'internal' or 'EXTERNAL'), request.path)
try:
request_repr = repr(request)
except:
request_repr = "Request repr() unavailable"
message = "%s\n\n%s" % (self._get_traceback(exc_info), request_repr)
mail_admins(subject, message, fail_silently=True)
# Return an HttpResponse that displays a friendly error message.
callback, param_dict = resolver.resolve500()
return callback(request, **param_dict)
def _get_traceback(self, exc_info=None):
"Helper function to return the traceback as a string"
import traceback
return '\n'.join(traceback.format_exception(*(exc_info or sys.exc_info())))
def apply_response_fixes(self, request, response):
"""
Applies each of the functions in self.response_fixes to the request and
response, modifying the response in the process. Returns the new
response.
"""
for func in self.response_fixes:
response = func(request, response)
return response