Reload spots/alerts on visibility change. Closes #89

webassets/js/alerts.js

@@ -351,4 +351,12 @@ $(document).ready(function() {
     loadOptions();
     // Update the refresh timing display every second
     setInterval(updateRefreshDisplay, 1000);
+});
+
+// Reload alerts on becoming visible. This forces a refresh when used as a PWA and the user switches back to the PWA
+// after some time has passed with it in the background.
+addEventListener("visibilitychange", (event) => {
+    if (!document.hidden) {
+        loadAlerts();
+    }
 });