From 5a51142cfeeb2a3aa428a49ef8b50141bf16489c Mon Sep 17 00:00:00 2001
From: Maciej Pienczyn <maciej.pienczyn@inpi.pl>
Date: Fri, 10 Apr 2026 06:56:24 +0200
Subject: [PATCH] fix: sendBeacon 415 error - wrap payload in Blob with
 application/json

navigator.sendBeacon() with a string sends text/plain Content-Type,
causing Flask to reject with 415 Unsupported Media Type.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 static/js/analytics-tracker.min.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/static/js/analytics-tracker.min.js b/static/js/analytics-tracker.min.js
index 922ee6d..e61047e 100644
--- a/static/js/analytics-tracker.min.js
+++ b/static/js/analytics-tracker.min.js
@@ -69,12 +69,12 @@ type: 'page_time',
 page_view_id: currentPageViewId,
 time_seconds: timeOnPage
 });
-navigator.sendBeacon(TRACK_ENDPOINT, data);
+navigator.sendBeacon(TRACK_ENDPOINT, new Blob([data], {type: 'application/json'}));
 if (maxScrollDepth > 0) {
-navigator.sendBeacon(SCROLL_ENDPOINT, JSON.stringify({
+navigator.sendBeacon(SCROLL_ENDPOINT, new Blob([JSON.stringify({
 page_view_id: currentPageViewId,
 scroll_depth: maxScrollDepth
-}));
+})], {type: 'application/json'}));
 }
 }
 function handleVisibilityChange() {