From d9a98dd536b4cac42fc9012c6184251a5ae2ad7a Mon Sep 17 00:00:00 2001 From: Prachi Shirish Khadke Date: Thu, 2 Jun 2016 11:26:28 -0700 Subject: [PATCH] Document flash message size limit Reason: Messages of size 68,493 - 91,326 characters cause flash to fail silently. Session cookies cannot have such large messages. Issue: pallets/flask#1789 --- docs/patterns/flashing.rst | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/docs/patterns/flashing.rst b/docs/patterns/flashing.rst index b2de07ce..dc20a08c 100644 --- a/docs/patterns/flashing.rst +++ b/docs/patterns/flashing.rst @@ -9,7 +9,9 @@ application. Flask provides a really simple way to give feedback to a user with the flashing system. The flashing system basically makes it possible to record a message at the end of a request and access it next request and only next request. This is usually combined with a layout -template that does this. +template that does this. Note that browsers and sometimes web servers enforce +a limit on cookie sizes. This means that flashing messages that are too +large for session cookies causes message flashing to fail silently. Simple Flashing ---------------