Source code for django.contrib.sessions.middleware

import time
from importlib import import_module

from django.conf import settings
from django.contrib.sessions.backends.base import UpdateError
from django.contrib.sessions.exceptions import SessionInterrupted
from django.utils.cache import patch_vary_headers
from django.utils.deprecation import MiddlewareMixin
from django.utils.http import http_date


[docs] class SessionMiddleware(MiddlewareMixin): def __init__(self, get_response): super().__init__(get_response) engine = import_module(settings.SESSION_ENGINE) self.SessionStore = engine.SessionStore def process_request(self, request): session_key = request.COOKIES.get(settings.SESSION_COOKIE_NAME) request.session = self.SessionStore(session_key) def process_response(self, request, response): """ If request.session was modified, or if the configuration is to save the session every time, save the changes and set a session cookie or delete the session cookie if the session has been emptied. """ try: accessed = request.session.accessed modified = request.session.modified empty = request.session.is_empty() except AttributeError: return response # First check if we need to delete this cookie. # The session should be deleted only if the session is entirely empty. if settings.SESSION_COOKIE_NAME in request.COOKIES and empty: response.delete_cookie( settings.SESSION_COOKIE_NAME, path=settings.SESSION_COOKIE_PATH, domain=settings.SESSION_COOKIE_DOMAIN, samesite=settings.SESSION_COOKIE_SAMESITE, ) patch_vary_headers(response, ("Cookie",)) else: if accessed: patch_vary_headers(response, ("Cookie",)) if (modified or settings.SESSION_SAVE_EVERY_REQUEST) and not empty: if request.session.get_expire_at_browser_close(): max_age = None expires = None else: max_age = request.session.get_expiry_age() expires_time = time.time() + max_age expires = http_date(expires_time) # Save the session data and refresh the client cookie. # Skip session save for 5xx responses. if response.status_code < 500: try: request.session.save() except UpdateError: raise SessionInterrupted( "The request's session was deleted before the " "request completed. The user may have logged " "out in a concurrent request, for example." ) response.set_cookie( settings.SESSION_COOKIE_NAME, request.session.session_key, max_age=max_age, expires=expires, domain=settings.SESSION_COOKIE_DOMAIN, path=settings.SESSION_COOKIE_PATH, secure=settings.SESSION_COOKIE_SECURE or None, httponly=settings.SESSION_COOKIE_HTTPONLY or None, samesite=settings.SESSION_COOKIE_SAMESITE, ) return response