Create middleware.py

src/swing_cookie/middleware/middleware.py

@@ -0,0 +1,61 @@
+# -*- coding: utf-8 -*-
+from typing import Optional
+
+from .cache import all_cookie_groups
+from .conf import settings
+from .util import get_cookie_dict_from_request, is_cookie_consent_enabled
+
+
+def _should_delete_cookie(group_version: Optional[str]) -> bool:
+    # declined after it was accepted (and set) before
+    if group_version == settings.COOKIE_CONSENT_DECLINE:
+        return True
+
+    # if you need to opt-out instead of opt-in, then we only delete the cookie in the
+    # above scenario -> when the group is explicitly declined
+    if settings.COOKIE_CONSENT_OPT_OUT:
+        return False
+
+    # when we are opt-in and have no information whether the cookie group was accepted
+    # or declined, delete the cookie(s).
+    if group_version is None:
+        return True
+
+    return False
+
+
+class CleanCookiesMiddleware:
+    """
+    Clean declined or non-accepted cookies.
+
+    Note that this only applies if COOKIE_CONSENT_OPT_OUT is not set.
+    """
+
+    def __init__(self, get_response):
+        self.get_response = get_response
+
+    def __call__(self, request):
+        response = self.get_response(request)
+        if is_cookie_consent_enabled(request):
+            self.process_response(request, response)
+        return response
+
+    def process_response(self, request, response):
+        cookie_dic = get_cookie_dict_from_request(request)
+
+        cookies_to_delete = []
+        for cookie_group in all_cookie_groups().values():
+            if not cookie_group.is_deletable:
+                continue
+
+            group_version = cookie_dic.get(cookie_group.varname, None)
+            for cookie in cookie_group.cookie_set.all():
+                if cookie.name not in request.COOKIES:
+                    continue
+                if _should_delete_cookie(group_version):
+                    cookies_to_delete.append(cookie)
+
+        for cookie in cookies_to_delete:
+            response.delete_cookie(cookie.name, cookie.path, cookie.domain)
+
+        return response