from django.utils import httpwrappers class BaseHandler: def __init__(self): self._request_middleware = self._view_middleware = self._response_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 = [] for middleware_path in settings.MIDDLEWARE_CLASSES: dot = middleware_path.rindex('.') 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) def get_response(self, path, request): "Returns an HttpResponse object for the given HttpRequest" from django.core import db, exceptions, urlresolvers from django.core.mail import mail_admins from django.conf.settings import DEBUG, INTERNAL_IPS, ROOT_URLCONF # Apply request middleware for middleware_method in self._request_middleware: response = middleware_method(request) if response: return response resolver = urlresolvers.RegexURLResolver(r'^/', ROOT_URLCONF) try: callback, param_dict = resolver.resolve(path) # Apply view middleware for middleware_method in self._view_middleware: response = middleware_method(request, callback, param_dict) if response: return response response = callback(request, **param_dict) # Complain if the view returned None (a common error). if response is None: raise ValueError, "The view %s.%s didn't return an HttpResponse object." % (callback.__module__, callback.func_name) return response except exceptions.Http404, e: if DEBUG: return self.get_technical_error_response(is404=True, exception=e) else: callback, param_dict = resolver.resolve404() return callback(request, **param_dict) except db.DatabaseError: db.db.rollback() if DEBUG: return self.get_technical_error_response() else: subject = 'Database error (%s IP): %s' % ((request.META.get('REMOTE_ADDR') in INTERNAL_IPS and 'internal' or 'EXTERNAL'), getattr(request, 'path', '')) message = "%s\n\n%s" % (self._get_traceback(), request) mail_admins(subject, message, fail_silently=True) return self.get_friendly_error_response(request, resolver) except exceptions.PermissionDenied: return httpwrappers.HttpResponseForbidden('

Permission denied

') except: # Handle everything else, including SuspiciousOperation, etc. if DEBUG: return self.get_technical_error_response() else: subject = 'Coding error (%s IP): %s' % ((request.META.get('REMOTE_ADDR') in INTERNAL_IPS and 'internal' or 'EXTERNAL'), getattr(request, 'path', '')) try: request_repr = repr(request) except: request_repr = "Request repr() unavailable" message = "%s\n\n%s" % (self._get_traceback(), request_repr) mail_admins(subject, message, fail_silently=True) return self.get_friendly_error_response(request, resolver) def get_friendly_error_response(self, request, resolver): """ Returns an HttpResponse that displays a PUBLIC error message for a fundamental database or coding error. """ from django.core import urlresolvers callback, param_dict = resolver.resolve500() return callback(request, **param_dict) def get_technical_error_response(self, is404=False, exception=None): """ Returns an HttpResponse that displays a TECHNICAL error message for a fundamental database or coding error. """ if is404: from django.conf.settings import ROOT_URLCONF from django.utils.html import escape html = [''] html.append('Error 404') # Explicitly tell robots not to archive this, in case this slips # onto a production site. html.append('') html.append('

Error 404

') try: tried = exception.args[0]['tried'] except (IndexError, TypeError): if exception.args: html.append('

%s

' % escape(exception.args[0])) else: html.append('

Using the URLconf defined in %s, Django tried these URL patterns, in this order:

' % ROOT_URLCONF) html.append('' % ''.join(['
  • %s
  • ' % escape(t).replace(' ', ' ') for t in tried])) html.append("

    The current URL, %r, didn't match any of these.

    " % exception.args[0]['path']) html.append("

    You're seeing this error because you have DEBUG = True in your Django settings file. Change that to False, and Django will display a standard 404 page.

    ") html.append('') return httpwrappers.HttpResponseNotFound('\n'.join(html)) else: output = "There's been an error:\n\n%s" % self._get_traceback() return httpwrappers.HttpResponseServerError(output, mimetype='text/plain') def _get_traceback(self): "Helper function to return the traceback as a string" import sys, traceback return '\n'.join(traceback.format_exception(*sys.exc_info()))