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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
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resolver = urlresolvers . RegexURLResolver ( r ' ^/ ' , ROOT_URLCONF )
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try :
callback , param_dict = resolver . resolve ( path )
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# Apply view middleware
for middleware_method in self . _view_middleware :
response = middleware_method ( request , callback , param_dict )
if response :
return response
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response = callback ( request , * * param_dict )
# Complain if the view returned None (a common error).
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if response is None :
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raise ValueError , " The view %s . %s didn ' t return an HttpResponse object. " % ( callback . __module__ , callback . func_name )
return response
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except exceptions . Http404 , e :
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if DEBUG :
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return self . get_technical_error_response ( is404 = True , exception = e )
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else :
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callback , param_dict = resolver . resolve404 ( )
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return callback ( request , * * param_dict )
except db . DatabaseError :
db . db . rollback ( )
if DEBUG :
return self . get_technical_error_response ( )
else :
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subject = ' Database error ( %s IP): %s ' % ( ( request . META . get ( ' REMOTE_ADDR ' ) in INTERNAL_IPS and ' internal ' or ' EXTERNAL ' ) , getattr ( request , ' path ' , ' ' ) )
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message = " %s \n \n %s " % ( self . _get_traceback ( ) , request )
mail_admins ( subject , message , fail_silently = True )
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return self . get_friendly_error_response ( request , resolver )
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except exceptions . PermissionDenied :
return httpwrappers . HttpResponseForbidden ( ' <h1>Permission denied</h1> ' )
except : # Handle everything else, including SuspiciousOperation, etc.
if DEBUG :
return self . get_technical_error_response ( )
else :
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subject = ' Coding error ( %s IP): %s ' % ( ( request . META . get ( ' REMOTE_ADDR ' ) in INTERNAL_IPS and ' internal ' or ' EXTERNAL ' ) , getattr ( request , ' path ' , ' ' ) )
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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 )
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return self . get_friendly_error_response ( request , resolver )
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def get_friendly_error_response ( self , request , resolver ) :
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"""
Returns an HttpResponse that displays a PUBLIC error message for a
fundamental database or coding error .
"""
from django . core import urlresolvers
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callback , param_dict = resolver . resolve500 ( )
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return callback ( request , * * param_dict )
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def get_technical_error_response ( self , is404 = False , exception = None ) :
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"""
Returns an HttpResponse that displays a TECHNICAL error message for a
fundamental database or coding error .
"""
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if is404 :
from django . conf . settings import ROOT_URLCONF
from django . utils . html import escape
html = [ ' <!DOCTYPE html PUBLIC " -//W3C//DTD XHTML 1.0 Transitional//EN " " http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd " > ' ]
html . append ( ' <html><head><title>Error 404</title> ' )
# Explicitly tell robots not to archive this, in case this slips
# onto a production site.
html . append ( ' <meta name= " robots " content= " NONE,NOARCHIVE " /> ' )
html . append ( ' </head><body><h1>Error 404</h1> ' )
try :
tried = exception . args [ 0 ] [ ' tried ' ]
except ( IndexError , TypeError ) :
if exception . args :
html . append ( ' <p> %s </p> ' % escape ( exception . args [ 0 ] ) )
else :
html . append ( ' <p>Using the URLconf defined in <code> %s </code>, Django tried these URL patterns, in this order:</p> ' % ROOT_URLCONF )
html . append ( ' <ul> %s </ul> ' % ' ' . join ( [ ' <li><code> %s </code></li> ' % escape ( t ) . replace ( ' ' , ' ' ) for t in tried ] ) )
html . append ( " <p>The current URL, <code><strong> %r </strong></code>, didn ' t match any of these.</p> " % exception . args [ 0 ] [ ' path ' ] )
html . append ( " <hr /><p>You ' re seeing this error because you have <code>DEBUG = True</code> in your Django settings file. Change that to <code>False</code>, and Django will display a standard 404 page.</p> " )
html . append ( ' </body></html> ' )
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 ' )
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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 ( ) ) )