Info getting only every x seconds

stable.user.js

@@ -21,7 +21,7 @@
 
 // ==UserScript==
 // @name         Moodle/Elearning/KMOOC test help
-// @version      2.0.0.4
+// @version      2.0.0.5
 // @description  Online Moodle/Elearning/KMOOC test help
 // @author       MrFry
 // @match        https://elearning.uni-obuda.hu/main/*
@@ -73,6 +73,7 @@
   const log = true
 
   const motdShowCount = 3 /* Ammount of times to show motd */
+  const infoExpireTime = 60 // Every n seconds basic info should be loaded from server
   var motd = ''
   var lastestVersion = ''
   var subjInfo
@@ -1613,6 +1614,15 @@
   }
 
   function GetXHRInfos () {
+    const now = new Date().getTime()
+    const lastCheck = getVal('lastInfoCheckTime')
+    if (!lastCheck) {
+      setVal('lastInfoCheckTime', now)
+    }
+
+    if (now > lastCheck + (infoExpireTime * 1000)) {
+      console.log('GETTING DATA FROM SREVER')
+      setVal('lastInfoCheckTime', now)
       return new Promise((resolve, reject) => {
         xmlhttpRequest({
           method: 'GET',
@@ -1620,6 +1630,7 @@
           onload: function (response) {
             try {
               const res = JSON.parse(response.responseText)
+              setVal('lastInfo', response.responseText)
               resolve(res)
             } catch (e) {
               Log('Errro paring JSON in GetXHRInfos')
@@ -1633,6 +1644,18 @@
           }
         })
       })
+    } else {
+      console.log('USING OLD')
+      return new Promise((resolve, reject) => {
+        try {
+          resolve(JSON.parse(getVal('lastInfo')))
+        } catch (e) {
+          Log('Errro paring JSON in GetXHRInfos, when using old data!')
+          Log(e)
+          reject(e)
+        }
+      })
+    }
   }
 
   function GetXHRQuestionAnswer (question) {