Redirect user back to the current site after logout

Without this, the user will remain at the login screen of Blender ID
after logging out. This is still the default behaviour when
`LOGOUT_REDIRECT_URL` is not set (or a falsy value).

README.rst

@@ -28,7 +28,10 @@ Quick start
 
     LOGIN_URL = '/oauth/login'
     LOGOUT_URL = '/oauth/logout'
-    LOGIN_REDIRECT_URL = '/'
+    LOGIN_REDIRECT_URL = '/redir-target-after-login'
+
+    # Set to empty string to remain on Blender ID after logging out:
+    LOGOUT_REDIRECT_URL = '/redir-target-after-logout'
 
 - Include the URLconf in your project urls.py like this::
 

blender_id_oauth_client/views.py

@@ -9,6 +9,7 @@ from django.conf import settings
 from django.contrib.auth.models import User
 from django.core.exceptions import ObjectDoesNotExist
 from django.db import transaction
+from django.http import HttpRequest
 from django.shortcuts import redirect
 from django.urls import reverse
 from django.utils.timezone import utc
@@ -107,11 +108,20 @@ def callback_view(request):
     return redirect(settings.LOGIN_REDIRECT_URL)
 
 
-def logout_view(request):
-    """Logout from My Data, and then from Blender ID.
+def logout_view(request: HttpRequest):
+    """Logout from this site, and then from Blender ID.
 
-    This helps perceiving My Data as part of Blender ID.
+    This helps perceiving the current site as part of Blender ID.
     """
+    from urllib.parse import quote
+
     blender_id_oauth = blender_id_oauth_settings()
     django.contrib.auth.logout(request)
-    return redirect(blender_id_oauth.url_logout)
+
+    redirect_url = blender_id_oauth.url_logout
+    if settings.LOGOUT_REDIRECT_URL:
+        next_url = request.build_absolute_uri(settings.LOGOUT_REDIRECT_URL)
+        quoted_next_url = quote(next_url)
+        redirect_url = f'{redirect_url}?next={quoted_next_url}'
+
+    return redirect(redirect_url)