From 58256a2a713e335ca3cc010169fd92d118a55270 Mon Sep 17 00:00:00 2001
From: Sam Bull <git@sambull.org>
Date: Wed, 14 Aug 2024 13:08:43 +0100
Subject: [PATCH] Add cleanup_ctx example for sharing resources across subapps
 (#8694)

(cherry picked from commit d83804db6a77221c996dfa3710ba6cf6b58d08b9)
---
 docs/faq.rst | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/docs/faq.rst b/docs/faq.rst
index 2de70f97d7b..30803da3576 100644
--- a/docs/faq.rst
+++ b/docs/faq.rst
@@ -279,7 +279,18 @@ A subapplication is an isolated unit by design. If you need to share a
 database object, do it explicitly::
 
    subapp[db_key] = mainapp[db_key]
-   mainapp.add_subapp('/prefix', subapp)
+   mainapp.add_subapp("/prefix", subapp)
+
+This can also be done from a :ref:`cleanup context<aiohttp-web-cleanup-ctx>`::
+
+   async def db_context(app: web.Application) -> AsyncIterator[None]:
+      async with create_db() as db:
+         mainapp[db_key] = mainapp[subapp_key][db_key] = db
+         yield
+
+   mainapp[subapp_key] = subapp
+   mainapp.add_subapp("/prefix", subapp)
+   mainapp.cleanup_ctx.append(db_context)
 
 
 How do I perform operations in a request handler after sending the response?