From 747e2945851384b2b9f4c9fa9a51484b552a3ae8 Mon Sep 17 00:00:00 2001 From: "T. Bayer" Date: Fri, 5 Oct 2018 14:29:03 -0700 Subject: [PATCH] mediawiki.user: Clarify sessionId documentation The existing documentation creates the impression that this ID remains the same until the browser session ends (like a session cookie), which has led to misunderstandings about the results of past data analyses. See T118063#4547178 ff. Change-Id: Ia2e156088b9e903836ceb8e2f9e77f9fb46a49fe --- resources/src/mediawiki.user.js | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/resources/src/mediawiki.user.js b/resources/src/mediawiki.user.js index aada50c52a..5f629e7dcb 100644 --- a/resources/src/mediawiki.user.js +++ b/resources/src/mediawiki.user.js @@ -136,10 +136,21 @@ }, /** - * Get an automatically generated random ID (persisted in sessionStorage) + * Retrieve a random ID persisted in sessionStorage, generating it if needed * - * This ID is ephemeral for everyone, staying in their browser only until they - * close their browsing session. + * This ID is stored in sessionStorage and persists within a single tab, + * including between page views through links and form submissions, + * and when going forwards/backwards in browser history, and when restoring + * a closed tab, or restoring a closed browser session. + * + * This is different from session cookies, because it is not shared between + * tabs of the same browser. Two simultaneous pageviews in the same browser + * can have different session IDs. The ID is also not re-used when opening + * a new tab to a website after fully closing others. + * + * See https://phabricator.wikimedia.org/T118063#4547178 and + * https://developer.mozilla.org/en-US/docs/Web/API/Window/sessionStorage + * for more information. * * @return {string} Random session ID */ -- 2.20.1