sitemap.mjs

Functions

Imports

It imports xml.mjs. Imported by index.mjs.

Source

1import { escapeXml, isoDay, toDate } from "./xml.mjs";
2
3const IMAGE_NAMESPACE = "http://www.google.com/schemas/sitemap-image/1.1";
4
5/**
6 * @typedef {object} SitemapEntry
7 * @property {string} loc absolute URL
8 * @property {Date | number | string | null} [lastmod]
9 * @property {string} [changefreq]
10 * @property {number} [priority] 0 to 1
11 * @property {string[]} [images] absolute URLs of the images on the page, listed in Google's image sitemap extension
12 */
13
14/**
15 * @typedef {object} SitemapOptions
16 * @property {"compact" | "expanded"} [layout] compact is one line per url; expanded is one element per line
17 * @property {"day" | "datetime"} [lastmodFormat] `2026-07-01` or `2026-07-01T12:00:00.000Z`
18 * @property {boolean} [trailingNewline]
19 */
20
21/**
22 * Sitemaps differ between the sites only in layout, lastmod precision and the trailing newline, so those are options and every
23 * default is this site's own. `loc` is escaped: a URL with `&` in its query would otherwise end the document.
24 *
25 * An entry's `images` become `<image:image>` elements (https://developers.google.com/search/docs/crawling-indexing/sitemaps/image-sitemaps),
26 * and the image namespace is declared only when some entry has one, so a sitemap without images is unchanged.
27 *
28 * @param {SitemapEntry[]} entries
29 * @param {SitemapOptions} [options]
30 * @returns {string}
31 */
32export function sitemapDocument(entries, options = {}) {
33  const { layout = "compact", lastmodFormat = "day", trailingNewline = true } = options;
34  const lastmodOf = (/** @type {SitemapEntry} */ entry) => {
35    if (entry.lastmod === null || entry.lastmod === undefined) return null;
36    return lastmodFormat === "day" ? isoDay(entry.lastmod) : datetime(entry.lastmod);
37  };
38
39  const imagesOf = (/** @type {SitemapEntry} */ entry) =>
40    (entry.images ?? []).map((image) => `<image:image><image:loc>${escapeXml(image)}</image:loc></image:image>`);
41  const hasImages = entries.some((entry) => (entry.images ?? []).length > 0);
42
43  const rows = entries.map((entry) => {
44    const lastmod = lastmodOf(entry);
45    const images = imagesOf(entry);
46    if (layout === "compact") {
47      return `  <url><loc>${escapeXml(entry.loc)}</loc>${lastmod ? `<lastmod>${lastmod}</lastmod>` : ""}${images.join("")}</url>`;
48    }
49    return [
50      "  <url>",
51      `    <loc>${escapeXml(entry.loc)}</loc>`,
52      lastmod ? `    <lastmod>${lastmod}</lastmod>` : null,
53      entry.changefreq ? `    <changefreq>${escapeXml(entry.changefreq)}</changefreq>` : null,
54      entry.priority === undefined ? null : `    <priority>${entry.priority.toFixed(1)}</priority>`,
55      ...images.map((image) => `    ${image}`),
56      "  </url>",
57    ]
58      .filter(Boolean)
59      .join("\n");
60  });
61
62  return `<?xml version="1.0" encoding="UTF-8"?>
63<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"${hasImages ? ` xmlns:image="${IMAGE_NAMESPACE}"` : ""}>
64${rows.join("\n")}
65</urlset>${trailingNewline ? "\n" : ""}`;
66}
67
68/** @param {Date | number | string} value */
69function datetime(value) {
70  const date = toDate(value, null);
71  return Number.isNaN(date.getTime()) ? null : date.toISOString();
72}