Refactored unifi.js to separate logic. Updated application header. Fixed incorrect screen-reader text. Updated sync button text. Implemented last sync date/time. Implemented cache util. Fixed missing vouchers check to prevent 'headers are already send' error. Fixed missing cache sync on api voucher creation. Implemented auto sync every 15 minutes

utils/cache.js

@@ -0,0 +1,37 @@
+/**
+ * Import own modules
+ */
+const log = require('../modules/log');
+const unifi = require('../modules/unifi');
+const cache = require('../modules/cache');
+
+/**
+ * Exports all cache utils
+ *
+ * @type {{updateCache: (function(): Promise<*>)}}
+ */
+module.exports = {
+    /**
+     * Update the cache
+     *
+     * @return {Promise<*>}
+     */
+    updateCache: () => {
+        return new Promise(async (resolve) => {
+            log.info('[Cache] Requesting UniFi Vouchers...');
+
+            const vouchers = await unifi.list().catch((e) => {
+                log.error('[Cache] Error requesting vouchers!');
+                log.error(e);
+            });
+
+            if(vouchers) {
+                cache.vouchers = vouchers;
+                cache.updated = new Date().getTime();
+                log.info(`[Cache] Saved ${vouchers.length} voucher(s)`);
+            }
+
+            resolve();
+        });
+    }
+};