5 files changed, 400 insertions, 311 deletions

diff --git a/assets/js/app.js.bvr b/assets/js/app.js.bvr
index d19c1d6..3d4cc6b 100644
--- a/assets/js/app.js.bvr
+++ b/assets/js/app.js.bvr
@@ -1,20 +1,21 @@
 <@?i global@>
 const app_version = "<@?g app_version@>";
 const previous_commit = "<@?g latest_commit@>";
+const BEZIAPP_UPDATE_INTERVAL = 300; // update vsakih 300 sekund
 
 if ("serviceWorker" in navigator) {
-    navigator.serviceWorker.register("/sw.js")
-        .then(() => { })
-        .catch((err) => console.log("Service worker registration failed", err));
+	navigator.serviceWorker.register("/sw.js")
+		.then(() => { })
+		.catch((err) => console.log("Service worker registration failed", err));
 }
 
 // Listen to messages from service workers.
 if (navigator.serviceWorker) {
-    navigator.serviceWorker.addEventListener('message', (event) => {
-        if (event.data.msg === "install") {
-            window.location.replace("/index.html");
-        }
-    });
+	navigator.serviceWorker.addEventListener('message', (event) => {
+		if (event.data.msg === "install") {
+			window.location.replace("/index.html");
+		}
+	});
 }
 
 /**
@@ -24,12 +25,12 @@ if (navigator.serviceWorker) {
  * @param {string} devmsg Developer-friendly message
  */
 async function UIAlert(usermsg, devmsg) {
-    if (true) { // če bo kakšen dev switch?
-        M.toast( { html: usermsg } );
-        console.log(`[BežiApp UIAlert] ${usermsg} ${devmsg}`);
-    } else {
-        M.toast( { html: `${usermsg} ${devmsg}` } );
-    }
+	if (true) { // če bo kakšen dev switch?
+		M.toast({ html: usermsg });
+		console.log(`[BežiApp UIAlert] ${usermsg} ${devmsg}`);
+	} else {
+		M.toast({ html: `${usermsg} ${devmsg}` });
+	}
 }
 
 /**
@@ -37,44 +38,87 @@ async function UIAlert(usermsg, devmsg) {
  * @param {Object} err GSEC error object
  */
 function gsecErrorHandlerUI(err) {
-    console.log(`gsecErrorHanderUI: handling ${err}`);
-    if(err == GSEC_ERR_NET || err == GSEC_ERR_NET_POSTBACK_GET ||
-        err == GSEC_ERR_NET_POSTBACK_POST) {
+	console.log(`gsecErrorHanderUI: handling ${err}`);
+	if (err == GSEC_ERR_NET || err == GSEC_ERR_NET_POSTBACK_GET ||
+		err == GSEC_ERR_NET_POSTBACK_POST) {
 
-        UIAlert( D("gsecErrNet") );
-    } else if(err == GSEC_ERR_LOGIN) {
-        UIAlert( D("gsecErrLogin") );
-        localforage.setItem("logged_in", false).then( () => {
-        window.location.replace("/index.html");
-        });
-    } else {
-        UIAlert( D("gsecErrOther") );
-    }
+		UIAlert(D("gsecErrNet"));
+	} else if (err == GSEC_ERR_LOGIN) {
+		UIAlert(D("gsecErrLogin"));
+		localforage.setItem("logged_in", false).then(() => {
+			window.location.replace("/index.html");
+		});
+	} else {
+		UIAlert(D("gsecErrOther"));
+	}
 }
 
+var update_app_function = async function () {
+	try {
+		$.get("/cache_name.txt?cache_kill=" + Date.now(), (data, status) => {
+			var cache_name = data.split("///")[1].split("|||")[0];
+			var data_to_send = {
+				action: "checkversion",
+				valid_cache_name: cache_name
+			}
+			try {
+				navigator.serviceWorker.controller.postMessage(JSON.stringify(data_to_send));
+			} catch (e) {
+				console.log("update requested but sw is not available in app.js");
+			}
+		});
+	} catch (e) {
+		console.log("update requested but failed because of network error probably in update_app_function in app.js");
+	}
+}
 
 var error_report_function = async function (msg, url, lineNo, columnNo, error) {
-	localforage.getItem("errorReporting").then(async function(value) {
-		let selectedE = value;
-		if(value == null || value.length < 1) {
-			selectedE = "on";
-		}
-		if(selectedE == "on") {
-			var data = {};
-			data.error = {"msg": msg, "url": url, "line": lineNo, "column": columnNo, "obj": error};
-			data.client = {"ua": navigator.userAgent, "app_version": app_version, "previous_commit": previous_commit, "username": null};
+	// catching everything here so no looping error shit. that's the last thing we want
+	try {
+		localforage.getItem("errorReporting").then(async function (value) {
+			let selectedE = value;
+			if (value == null || value.length < 1) {
+				selectedE = "on";
+			}
+			if (selectedE == "on") {
+				var data = {};
+				data.error = { "msg": msg, "url": url, "line": lineNo, "column": columnNo, "obj": error };
+				data.client = { "ua": navigator.userAgent, "app_version": app_version, "previous_commit": previous_commit, "username": null };
 
-			// Load required data
-			data.client.username = await localforage.getItem("username");
+				// Load required data
+				data.client.username = await localforage.getItem("username");
 
-			data.type = "error";
-			$.post("https://beziapp-report.gimb.tk/", data);
-		} else {
-			console.log("error not reported as reporting is disabled!");
-		}
-	}).catch(() => {});
-	return false;
+				data.type = "error";
+				$.post("https://beziapp-report.gimb.tk/", data);
+			} else {
+				console.log("error not reported as reporting is disabled!");
+			}
+		}).catch(() => { });
+		return false;
+	} catch (e) {
+		console.log("error_erport_function: !!! ERROR! (caught) - probably some network error.");
+	}
 }
 
 window.onerror = error_report_function;
 window.onunhandledrejection = error_report_function;
+
+async function try_app_update() {
+	localforage.getItem("lastUpdate").then((data) => {
+		if (Math.floor(Date.now() / 1000) > Number(data) + BEZIAPP_UPDATE_INTERVAL) {
+			// trigger an update
+			localforage.setItem("lastUpdate", Math.floor(Date.now() / 1000)).then(() => {
+				update_app_function();
+			});
+		}
+	});
+}
+
+document.addEventListener("DOMContentLoaded", () => {
+	try_app_update();
+	var update_interval = setInterval(() => {
+
+		try_app_update();
+
+	}, 1000 * BEZIAPP_UPDATE_INTERVAL);
+});
\ No newline at end of file
diff --git a/assets/js/setup-storage.js b/assets/js/setup-storage.js
index c862d5f..b29c959 100644
--- a/assets/js/setup-storage.js
+++ b/assets/js/setup-storage.js
@@ -1,44 +1,43 @@
 async function setupStorage(force = false) {
-    let logged_in;
-    promises_check_if_already_installed = [
-        localforage.getItem("logged_in").then( function(val) {
-            console.log("[setupStorage] logged in status: " + val);
-            logged_in = val;
-        })
-    ];
-    await Promise.all(promises_check_if_already_installed);
+	let logged_in;
+	promises_check_if_already_installed = [
+		localforage.getItem("logged_in").then(function (val) {
+			console.log("[setupStorage] logged in status: " + val);
+			logged_in = val;
+		})
+	];
+	await Promise.all(promises_check_if_already_installed);
 
-    let promises_update = [
-        localforage.setItem("profile", {}),
-        localforage.setItem("timetable", []),
-        localforage.setItem("teachers", []),
-        localforage.setItem("gradings", []),
-        localforage.setItem("grades", []),
-        localforage.setItem("absences", {}),
-        localforage.setItem("messages", [[], [], []]), // see messages.js:129, commit 8eb9ca9caca30fbbe023243657535ab4088be377
-        localforage.setItem("directory", {}), //\\ well I could remember my own code but I didn't.
-        localforage.setItem("meals", {}),
-        localforage.setItem("chosenLang", "en"),
-        localforage.setItem("theme", "light"),
-        localforage.setItem("errorReporting", "on"),
-        localforage.setItem("triggerWarningAccepted", false)
-    ];
+	let promises_update = [
+		localforage.setItem("profile", {}),
+		localforage.setItem("timetable", []),
+		localforage.setItem("teachers", []),
+		localforage.setItem("gradings", []),
+		localforage.setItem("grades", []),
+		localforage.setItem("absences", {}),
+		localforage.setItem("messages", [[], [], []]), // see messages.js:129, commit 8eb9ca9caca30fbbe023243657535ab4088be377
+		localforage.setItem("directory", {}), //\\ well I could remember my own code but I didn't.
+		localforage.setItem("meals", {}),
+		localforage.setItem("chosenLang", "en"),
+		localforage.setItem("theme", "light"),
+		localforage.setItem("errorReporting", "on"),
+		localforage.setItem("lastUpdate", 0),
+		localforage.setItem("triggerWarningAccepted", false)
+	];
 
-    if (logged_in && force == false) { // torej, če je že bila prijava narejena, ne posodobi backwards-compatible vrednosti (username, password,...)
-        await Promise.all(promises_update);
-        console.log("[setupStorage] user logged in: only updated");
-    } else {
+	if (logged_in && force == false) { // torej, če je že bila prijava narejena, ne posodobi backwards-compatible vrednosti (username, password,...)
+		await Promise.all(promises_update);
+		console.log("[setupStorage] user logged in: only updated");
+	} else {
 
-        let promises_first_install = [
-            localforage.setItem("logged_in", false),
-            localforage.setItem("username", ""),
-            localforage.setItem("password", ""),
-            localforage.setItem("chosenLang", "en"),
-            localforage.setItem("theme", "light"),
-            localforage.setItem("triggerWarningAccepted", false)
-        ];
-        await localforage.clear();
-        await Promise.all(promises_first_install);
-        console.log("[setupStorage] user not logged in: set up whole database");
-    }
+		let promises_first_install = [
+			localforage.setItem("logged_in", false),
+			localforage.setItem("username", ""),
+			localforage.setItem("password", ""),
+		];
+		await localforage.clear();
+		await Promise.all(promises_first_install);
+		await Promise.all(promises_update);
+		console.log("[setupStorage] user not logged in: set up whole database");
+	}
 }
diff --git a/assets/pages-src/about.bvr b/assets/pages-src/about.bvr
index 26b5957..144576e 100644
--- a/assets/pages-src/about.bvr
+++ b/assets/pages-src/about.bvr
@@ -1,133 +1,150 @@
 <@?i global@>
-<!DOCTYPE html>
-<html>
-<head>
-    <meta charset="UTF-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no">
-    <meta http-equiv="X-UA-Compatible" content="ie=edge">
-    <meta name="google" content="notranslate">
-    <title>About &laquo; BežiApp</title>
+	<!DOCTYPE html>
+	<html>
 
-    <!-- Materialize -->
-    <link type="text/css" href="/css/materialize.min.css" rel="stylesheet">
-    <link href="/css/materialicons.css" rel="stylesheet">
-    <link href="/css/fontawesome.min.css" rel="stylesheet">
-    <script type="text/javascript" src="/js/lib/materialize.min.js"></script>
+	<head>
+		<meta charset="UTF-8">
+		<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no">
+		<meta http-equiv="X-UA-Compatible" content="ie=edge">
+		<meta name="google" content="notranslate">
+		<title>About &laquo; BežiApp</title>
 
-    <script src="/js/lib/jquery.min.js"></script>
-    <script type="text/javascript" src="/js/lib/localforage.min.js"></script>
+		<!-- Materialize -->
+		<link type="text/css" href="/css/materialize.min.css" rel="stylesheet">
+		<link href="/css/materialicons.css" rel="stylesheet">
+		<link href="/css/fontawesome.min.css" rel="stylesheet">
+		<script type="text/javascript" src="/js/lib/materialize.min.js"></script>
 
-    <link type="text/css" href="/css/styles.css" rel="stylesheet">
-    <script type="text/javascript" src="/js/about.js"></script>
+		<script src="/js/lib/jquery.min.js"></script>
+		<script type="text/javascript" src="/js/lib/localforage.min.js"></script>
 
-    <link rel="manifest" href="/manifest.json">
-    <script src="/js/app.js"></script>
-    <script src="/js/lib/themes.js"></script>
-    <script src="/js/lang/bundle.js"></script>
-    <link rel="shortcut icon" type="image/png" href="/favicon.png" />
+		<link type="text/css" href="/css/styles.css" rel="stylesheet">
+		<script type="text/javascript" src="/js/about.js"></script>
 
-    <!-- iOS support -->
-    <link rel="apple-touch-icon" href="/img/icons/icon_96.png">
-    <link rel="apple-touch-icon" href="/img/icons/icon_512.png">
-    <meta name="apple-mobile-web-app-status-bar" content="#004d32">
-</head>
+		<link rel="manifest" href="/manifest.json">
+		<script src="/js/app.js"></script>
+		<script src="/js/lib/themes.js"></script>
+		<script src="/js/lang/bundle.js"></script>
+		<link rel="shortcut icon" type="image/png" href="/favicon.png" />
 
-<body>
-    <nav class="z-depth-0" id="navigation-main">
-        <div class="nav-wrapper container">
-            <b class="app-header-bold">Beži</b><span class="app-header-span">App</span> &raquo; <x-su>about</x-su>
-            <span class="right white-text">
-                <i class="material-icons sidenav-trigger" data-target="side-menu">menu</i>
-            </span>
-        </div>
-        <div id="loading-bar" class="progress hidden">
-            <div class="indeterminate"></div>
-        </div>
-    </nav>
+		<!-- iOS support -->
+		<link rel="apple-touch-icon" href="/img/icons/icon_96.png">
+		<link rel="apple-touch-icon" href="/img/icons/icon_512.png">
+		<meta name="apple-mobile-web-app-status-bar" content="#004d32">
+	</head>
+
+	<body>
+		<nav class="z-depth-0" id="navigation-main">
+			<div class="nav-wrapper container">
+				<b class="app-header-bold">Beži</b><span class="app-header-span">App</span> &raquo; <x-su>about</x-su>
+				<span class="right white-text">
+					<i class="material-icons sidenav-trigger" data-target="side-menu">menu</i>
+				</span>
+			</div>
+			<div id="loading-bar" class="progress hidden">
+				<div class="indeterminate"></div>
+			</div>
+		</nav>
 
 		<@?i navigation@>
-    <div class="container">
-        <div class="row">
-            <div class="col s12">
-                <h3>
-                    <b class="title-secondary">Beži</b><span class="title-primary">App</span>
-                </h3>
-                <!-- One day in the future we may have sw cache version covered by this as well -->
-# I agree, will make a script
-                <h5 class="subheader"><x-su>version</x-su> <@?g app_version@></h5>
-            </div>
-        </div>
-        <div class="row">
-            <div class="col s12">
-                <ul class="collection with-header">
-                    <li class="collection-header">
-                        <h5><x-su>authors</x-su></h5>
-                    </li>
-                    <li class="valign-wrapper collection-item avatar">
-                        <img src="/img/avatars/rstular.png" class="circle">
-                        <span class="title about-text">Rok Štular</span>
-                        
-                        <div class="secondary-content about-button-box">
-                            <a href="messaging.html#Rok Štular" class="btn-floating btn-medium waves-effect waves-light button-theme-gimb" type="button">
-                                <i class="material-icons">message</i>
-                            </a>
-                            <a target="_blank" href="https://instagram.com/rstular/"
-                                class="btn-floating btn-medium waves-effect waves-light button-theme-gimb">
-                                <i class="fab fa-instagram"></i>
-                            </a>
-                        </div>
-                            
-                    </li>
+			<div class="container">
+				<div class="row">
+					<div class="col s12">
+						<h3>
+							<b class="title-secondary">Beži</b><span class="title-primary">App</span>
+						</h3>
+						<!-- One day in the future we may have sw cache version covered by this as well -->
+						<h5 class="subheader">
+							<x-su>version</x-su>
+							<@?g app_version@>
+						</h5>
+					</div>
+				</div>
+				<div class="row">
+					<div class="col s12">
+						<ul class="collection with-header">
+							<li class="collection-header">
+								<h5>
+									<x-su>authors</x-su>
+								</h5>
+							</li>
+							<li class="valign-wrapper collection-item avatar">
+								<img src="/img/avatars/rstular.png" class="circle">
+								<span class="title about-text">Rok Štular</span>
+
+								<div class="secondary-content about-button-box">
+									<a href="messaging.html#Rok Štular"
+										class="btn-floating btn-medium waves-effect waves-light button-theme-gimb" type="button">
+										<i class="material-icons">message</i>
+									</a>
+									<a target="_blank" href="https://instagram.com/rstular/"
+										class="btn-floating btn-medium waves-effect waves-light button-theme-gimb">
+										<i class="fab fa-instagram"></i>
+									</a>
+								</div>
+
+							</li>
 
-                    <li class="valign-wrapper collection-item avatar">
-                        <img src="/img/avatars/asijanec.png" class="circle">
-                        <span class="title about-text">Anton Luka Šijanec</span>
+							<li class="valign-wrapper collection-item avatar">
+								<img src="/img/avatars/asijanec.png" class="circle">
+								<span class="title about-text">Anton Luka Šijanec</span>
 
-                        <div class="secondary-content about-button-box">
-                            <a href="messaging.html#Anton Luka Šijanec" class="btn-floating btn-medium waves-effect waves-light button-theme-gimb" type="button">
-                                <i class="material-icons">message</i>
-                            </a>
-                            <a target="_blank" href="https://instagram.com/rstular/"
-                                class="btn-floating btn-medium waves-effect waves-light button-theme-gimb">
-                                <i class="fab fa-instagram"></i>
-                            </a>
-                        </div>
-                    </li>
-                </ul>
-            </div>
-        </div>
-        <div class="row">
-            <div class="col s12">
-                <ul class="collection with-header">
-                    <li class="collection-header">
-                        <h5><x-su>translatorsForThisLanguage</x-su> - <x-su>miscTranslationLanguage</x-su></h5>
-                    </li>
-                    <li class="collection-item">
-                        <span class="title about-text"><x-su>miscTranslationAuthors</x-su></span>
-                    </li>
-                </ul>
-            </div>
-        </div>
-        <div class="row">
-            <div class="col s12">
-                <div class="collection">
-                    <a href="/pages/changelog.html" class="collection-item"><x-su>whatIsNew</x-su></a>
-                    <a href="/pages/tos.html" class="collection-item"><x-su>theToS</x-su></a>
-                    <a href="/pages/privacypolicy.html" class="collection-item"><x-su>thePrivacyPolicy</x-su></a>
-                    <a href="https://instagram.com/beziapp/" target="_blank" class="collection-item">
-						<x-su>reportABug</x-su> / <x-su>sendASuggestion</x-su> (<x-su>instagram</x-su>: @beziapp)
-					</a>
-                </div>
-            </div>
-        </div>
+								<div class="secondary-content about-button-box">
+									<a href="messaging.html#Anton Luka Šijanec"
+										class="btn-floating btn-medium waves-effect waves-light button-theme-gimb" type="button">
+										<i class="material-icons">message</i>
+									</a>
+									<a target="_blank" href="https://instagram.com/rstular/"
+										class="btn-floating btn-medium waves-effect waves-light button-theme-gimb">
+										<i class="fab fa-instagram"></i>
+									</a>
+								</div>
+							</li>
+						</ul>
+					</div>
+				</div>
+				<div class="row">
+					<div class="col s12">
+						<ul class="collection with-header">
+							<li class="collection-header">
+								<h5>
+									<x-su>translatorsForThisLanguage</x-su> - <x-su>miscTranslationLanguage</x-su>
+								</h5>
+							</li>
+							<li class="collection-item">
+								<span class="title about-text">
+									<x-su>miscTranslationAuthors</x-su>
+								</span>
+							</li>
+						</ul>
+					</div>
+				</div>
+				<div class="row">
+					<div class="col s12">
+						<div class="collection">
+							<a href="/pages/changelog.html" class="collection-item">
+								<x-su>whatIsNew</x-su>
+							</a>
+							<a href="/pages/tos.html" class="collection-item">
+								<x-su>theToS</x-su>
+							</a>
+							<a href="/pages/privacypolicy.html" class="collection-item">
+								<x-su>thePrivacyPolicy</x-su>
+							</a>
+							<a href="https://instagram.com/beziapp/" target="_blank" class="collection-item">
+								<x-su>reportABug</x-su> / <x-su>sendASuggestion</x-su> (<x-su>instagram</x-su>: @beziapp)
+							</a>
+						</div>
+					</div>
+				</div>
 				<div class="row">
 					<p>
 						<small>
 							^HEAD <@?g latest_commit@>
-                        </small>
+						</small>
 					</p>
 				</div>
-    </div>
-</body>
+			</div>
+	</body>
 
-</html>
+	</html>
diff --git a/assets/root/cache_name.txt.bvr b/assets/root/cache_name.txt.bvr
new file mode 100644
index 0000000..e3a1ee3
--- /dev/null
+++ b/assets/root/cache_name.txt.bvr
@@ -0,0 +1,2 @@
+<@?i global@>
+///site-static-<@?g app_version@>-<@?u 0 7 ?g latest_commit@>|||
diff --git a/assets/root/sw.js.bvr b/assets/root/sw.js.bvr
index a44a6fc..45ac9dd 100644
--- a/assets/root/sw.js.bvr
+++ b/assets/root/sw.js.bvr
@@ -6,79 +6,79 @@ const static_cache_name = "site-static-<@?g app_version@>-<@?u 0 7 ?g latest_com
 // sw.js NE SME BITI CACHAN, ker vsebuje verzijo!
 
 const assets = [
-    "/css/materialize.min.css",
-    "/css/fontawesome.min.css",
-    "/css/materialicons.css",
-    "/css/styles.css",
-    "/css/fullcalendar/custom.css",
-    "/css/fullcalendar/daygrid/main.min.css",
-    "/css/fullcalendar/core/main.min.css",
-    "/css/fullcalendar/timegrid/main.min.css",
-
-    "/fonts/fa-solid-900.eot",
-    "/fonts/fa-solid-900.woff2",
-    "/fonts/fa-brands-400.woff2",
-    "/fonts/fa-regular-400.eot",
-    "/fonts/fa-regular-400.woff2",
-    "/fonts/fa-brands-400.eot",
-    "/fonts/materialicons.woff2",
-
-    "/img/avatars/asijanec.png",
-    "/img/avatars/rstular.png",
-    "/img/icons/icon_384.png",
-    "/img/icons/icon_192.png",
-    "/img/icons/icon_72.png",
-    "/img/icons/icon_144.png",
-    "/img/icons/icon_512.png",
-    "/img/icons/icon_96.png",
-    "/img/icons/icon_48.png",
-
-    "/js/timetable.js",
-    "/js/gradings.js",
-    "/js/messaging.js",
-    "/js/privacypolicy.js",
-    "/js/teachers.js",
-    "/js/tos.js",
-    "/js/login.js",
-    "/js/app.js",
-    "/js/meals.js",
-    "/js/settings.js",
+	"/css/materialize.min.css",
+	"/css/fontawesome.min.css",
+	"/css/materialicons.css",
+	"/css/styles.css",
+	"/css/fullcalendar/custom.css",
+	"/css/fullcalendar/daygrid/main.min.css",
+	"/css/fullcalendar/core/main.min.css",
+	"/css/fullcalendar/timegrid/main.min.css",
+
+	"/fonts/fa-solid-900.eot",
+	"/fonts/fa-solid-900.woff2",
+	"/fonts/fa-brands-400.woff2",
+	"/fonts/fa-regular-400.eot",
+	"/fonts/fa-regular-400.woff2",
+	"/fonts/fa-brands-400.eot",
+	"/fonts/materialicons.woff2",
+
+	"/img/avatars/asijanec.png",
+	"/img/avatars/rstular.png",
+	"/img/icons/icon_384.png",
+	"/img/icons/icon_192.png",
+	"/img/icons/icon_72.png",
+	"/img/icons/icon_144.png",
+	"/img/icons/icon_512.png",
+	"/img/icons/icon_96.png",
+	"/img/icons/icon_48.png",
+
+	"/js/timetable.js",
+	"/js/gradings.js",
+	"/js/messaging.js",
+	"/js/privacypolicy.js",
+	"/js/teachers.js",
+	"/js/tos.js",
+	"/js/login.js",
+	"/js/app.js",
+	"/js/meals.js",
+	"/js/settings.js",
 	"/js/lang/bundle.js",
 	"/js/setup-storage.js",
 
-    "/js/lib/materialize.min.js",
-    "/js/lib/jquery.min.js",
-    "/js/lib/localforage.min.js",
-    "/js/lib/xss.js",
-    "/js/lib/mergedeep.js",
-
-    "/js/lib/fullcalendar/daygrid/main.min.js",
-    "/js/lib/fullcalendar/core/main.min.js",
-    "/js/lib/fullcalendar/timegrid/main.min.js",
-    "/js/grades.js",
-    "/js/about.js",
-    "/js/logout.js",
-    "/js/initialize.js",
-    "/js/absences.js",
-    "/js/changelog.js",
-
-    "/pages/timetable.html",
-    "/pages/teachers.html",
-    "/pages/absences.html",
-    "/pages/about.html",
-    "/pages/changelog.html",
-    "/pages/messaging.html",
-    "/pages/gradings.html",
-    "/pages/grades.html",
-    "/pages/privacypolicy.html",
-    "/pages/tos.html",
-    "/pages/meals.html",
-    "/pages/settings.html",
-
-    "/manifest.json",
-    "/index.html",
-    "/login.html",
-    "/logout.html",
+	"/js/lib/materialize.min.js",
+	"/js/lib/jquery.min.js",
+	"/js/lib/localforage.min.js",
+	"/js/lib/xss.js",
+	"/js/lib/mergedeep.js",
+
+	"/js/lib/fullcalendar/daygrid/main.min.js",
+	"/js/lib/fullcalendar/core/main.min.js",
+	"/js/lib/fullcalendar/timegrid/main.min.js",
+	"/js/grades.js",
+	"/js/about.js",
+	"/js/logout.js",
+	"/js/initialize.js",
+	"/js/absences.js",
+	"/js/changelog.js",
+
+	"/pages/timetable.html",
+	"/pages/teachers.html",
+	"/pages/absences.html",
+	"/pages/about.html",
+	"/pages/changelog.html",
+	"/pages/messaging.html",
+	"/pages/gradings.html",
+	"/pages/grades.html",
+	"/pages/privacypolicy.html",
+	"/pages/tos.html",
+	"/pages/meals.html",
+	"/pages/settings.html",
+
+	"/manifest.json",
+	"/index.html",
+	"/login.html",
+	"/logout.html",
 	"/favicon.png",
 	"/pages/jitsi.html",
 	"/js/jitsi.js",
@@ -93,58 +93,85 @@ const assets = [
 importScripts("/js/lib/localforage.min.js");
 importScripts("/js/setup-storage.js");
 self.addEventListener("install", (evt) => {
-    // Add localforage.clear() if storage purge is required
-    evt.waitUntil(
-        // localforage.clear()
-				setupStorage()
-    );
-
-    evt.waitUntil(
-        caches.open(static_cache_name).then((cache) => {
-            cache.addAll(assets);
-        })
-    );
+	// Add localforage.clear() if storage purge is required
+	evt.waitUntil(
+		// localforage.clear()
+		setupStorage()
+	);
+
+	evt.waitUntil(
+		caches.open(static_cache_name).then((cache) => {
+			cache.addAll(assets);
+		})
+	);
 });
 
 // Delete old caches
 self.addEventListener("activate", evt => {
-    evt.waitUntil(
-        caches.keys().then((keys) => {
-            return Promise.all(keys
-                .filter(key => key !== static_cache_name)
-                .map(key => caches.delete(key))
-            );
-        })
-    );
+	evt.waitUntil(
+		caches.keys().then((keys) => {
+			return Promise.all(keys
+				.filter(key => key !== static_cache_name)
+				.map(key => caches.delete(key))
+			);
+		})
+	);
 });
 
+async function sw_asynclycheckversion (data) {
+	try {
+		var names = await caches.keys();
+		console.log("[sw.js] checkversion: ***** checkversion v0 for BežiApp ***** hello, world!");
+		if(!(data.valid_cache_name == undefined || data.valid_cache_name == null || data.valid_cache_name == "")) {
+			var valid_cache_name = data.valid_cache_name;
+			console.log("[sw.js] checkversion: requested version (cachename) " + valid_cache_name);
+		} else {
+			var valid_cache_name = static_cache_name;
+			console.log("[sw.js] checkversion: no version to keep specified, using current "+valid_cache_name+", but that makes no sense to me.");
+		}
+		console.log("[sw.js] checkversion: deleting caches that don't match that cache name ...");
+		for (let name of names) {
+			if(valid_cache_name != name) {
+				caches.delete(name);
+				console.log("[sw.js] checkversion: done requesting delete of cache " + name);
+			}
+		}
+		console.log("[sw.js] checkversion: done, exiting!");
+	} catch (e) {
+		console.log("[sw.js] checkversion: !!! ERRORS! (caught)");
+	}
+}
+
 self.addEventListener("message", event => {
 
-    if (event.data) {
-        let data = JSON.parse(event.data); // parse the message back to JSON
-        if (data.action == "addtocache") { // check the action
-            event.waitUntil(
-                caches.open(static_cache_name).then(function (cache) {
-                    try {
-                        return cache.add([data.url]);
-                    }
-                    catch (error) {
-                        console.error("[sw.js] error: " + error);
-                    }
-                })
-            );
-        } else if (data.action == "deletecaches") {
-            caches.keys().then(function (names) {
-                for (let name of names)
-                    console.log("[sw.js] deleting cache named " + name);
-                caches.delete(name);
-            });
-        }
-    }
+	if (event.data) {
+		let data = JSON.parse(event.data); // parse the message back to JSON
+		if (data.action == "addtocache") { // check the action
+			event.waitUntil(
+				caches.open(static_cache_name).then(function (cache) {
+					try {
+						return cache.add([data.url]);
+					}
+					catch (error) {
+						console.error("[sw.js] error: " + error);
+					}
+				})
+			);
+		} else if (data.action == "deletecaches") {
+			caches.keys().then(function (names) {
+				for (let name of names) {
+					console.log("[sw.js] deleting cache named " + name);
+					caches.delete(name);
+				}
+			});
+		} else if (data.action.startsWith("checkversion")) {
+			sw_asynclycheckversion(data);
+		}
+	}
 });
 
 self.addEventListener("fetch", (evt) => {
-    evt.respondWith(caches.match(evt.request).then((cache_res) => {
-        return cache_res || fetch(evt.request);
-    }))
+	evt.respondWith(caches.match(evt.request).then((cache_res) => {
+		return cache_res || fetch(evt.request);
+	}))
 });