reorganization of source code

public/javascripts/utils.js

@@ -0,0 +1,72 @@
+function message(str) {
+    const top = $("#top-message");
+
+    top.fadeIn(1500).css("display","inline-block");
+    top.html(str);
+    top.fadeOut(1500);
+}
+
+function error(str) {
+    const error = $("#error-message");
+
+    error.show().css("display","inline-block");
+    error.html(str);
+    error.fadeOut(10000);
+}
+
+function getAutocompleteItems(noteIds) {
+    const autocompleteItems = [];
+
+    for (const noteId of noteIds) {
+        const fullName = getFullName(noteId);
+
+        if (fullName !== null) {
+            autocompleteItems.push({
+                value: fullName + " (" + noteId + ")",
+                label: fullName
+            });
+        }
+    }
+
+    return autocompleteItems;
+}
+
+function uint8ToBase64(u8Arr) {
+    const CHUNK_SIZE = 0x8000; //arbitrary number
+    const length = u8Arr.length;
+    let index = 0;
+    let result = '';
+    let slice;
+    while (index < length) {
+        slice = u8Arr.subarray(index, Math.min(index + CHUNK_SIZE, length));
+        result += String.fromCharCode.apply(null, slice);
+        index += CHUNK_SIZE;
+    }
+    return btoa(result);
+}
+
+function base64ToUint8Array(base64encoded) {
+    return new Uint8Array(atob(base64encoded).split("").map(c => c.charCodeAt(0)));
+}
+
+function getDateFromTS(timestamp) {
+    // Date accepts number of milliseconds since epoch so UTC timestamp works without any extra handling
+    // see https://stackoverflow.com/questions/4631928/convert-utc-epoch-to-local-date-with-javascript
+    const utcDate = new Date(timestamp * 1000);
+
+    const localDate = new Date(utcDate.getTime() - utcDate.getTimezoneOffset() * 60 * 1000);
+
+    return localDate;
+}
+
+function formatTime(date) {
+    return (date.getHours() <= 9 ? "0" : "") + date.getHours() + ":" + (date.getMinutes() <= 9 ? "0" : "") + date.getMinutes();
+}
+
+function formatDate(date) {
+    return date.getDate() + ". " + (date.getMonth() + 1) + ". " + date.getFullYear();
+}
+
+function formatDateTime(date) {
+    return formatDate(date) + " " + formatTime(date);
+}