initial: novel-app snapshot

static/js/utils.js

@@ -0,0 +1,77 @@
+/* Common helpers shared across pages (ES module). */
+
+/** Debounce a function call. */
+export function debounce(fn, delay) {
+    let timer = null;
+    return function (...args) {
+        clearTimeout(timer);
+        timer = setTimeout(() => fn.apply(this, args), delay);
+    };
+}
+
+/** Format an ISO date string to YYYY-MM-DD. */
+export function formatDate(isoString) {
+    if (!isoString) return "";
+    const d = new Date(isoString);
+    if (isNaN(d.getTime())) return String(isoString).slice(0, 10);
+    const y = d.getFullYear();
+    const m = String(d.getMonth() + 1).padStart(2, "0");
+    const day = String(d.getDate()).padStart(2, "0");
+    return `${y}-${m}-${day}`;
+}
+
+/** Truncate text to maxLen chars, appending ellipsis. */
+export function truncate(text, maxLen) {
+    if (!text) return "";
+    const s = String(text);
+    return s.length > maxLen ? s.slice(0, maxLen) + "…" : s;
+}
+
+/** Escape HTML special chars to prevent XSS when injecting via innerHTML. */
+export function escapeHtml(text) {
+    if (text === null || text === undefined) return "";
+    return String(text)
+        .replace(/&/g, "&")
+        .replace(/</g, "&lt;")
+        .replace(/>/g, "&gt;")
+        .replace(/"/g, "&quot;")
+        .replace(/'/g, "&#39;");
+}
+
+/** Read the session CSRF token rendered into <meta name="csrf-token">. */
+export function getCsrf() {
+    const meta = document.querySelector('meta[name="csrf-token"]');
+    return meta ? meta.content : "";
+}
+
+/** Fetch JSON with basic error handling. */
+export async function fetchJson(url) {
+    const resp = await fetch(url);
+    if (!resp.ok) {
+        throw new Error(`请求失败: ${resp.status} ${resp.statusText}`);
+    }
+    return resp.json();
+}
+
+/** POST JSON, injecting csrf_token into the body. Returns parsed JSON. */
+export async function postJson(url, data) {
+    const resp = await fetch(url, {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ ...data, csrf_token: getCsrf() }),
+    });
+    const body = await resp.json().catch(() => ({}));
+    if (!resp.ok) {
+        throw new Error(body.error || `请求失败: ${resp.status}`);
+    }
+    return body;
+}
+
+/** Render a dismissible error alert into a container element. */
+export function showError(container, msg) {
+    if (!container) return;
+    container.innerHTML =
+        '<div class="alert alert-danger alert-dismissible fade show" role="alert">'
+        + escapeHtml(msg)
+        + '<button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button></div>';
+}