Create an XML sitemap

You can help search engines indexing your site by creating a sitemap. An XML sitemap provides more information than a text sitemap:

• the date of the last update
• how often a search engine should check for updates
• the relative importance of the page from 1 (highest) to 0 (lowest)

built sitemap.xml

<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  <url>
    <loc>https://mysite.com/</loc>
    <lastmod>Tue, 21 Jan 2025 11:58:53 GMT</lastmod>
    <changefreq>weekly</changefreq>
    <priority>1</priority>
  </url>
  <url>
    <loc>https://mysite.com/post/</loc>
    <lastmod>Tue, 21 Jan 2025 11:58:53 GMT</lastmod>
    <changefreq>monthly</changefreq>
    <priority>0.5</priority>
  </url>
  <url>
    <loc>https://mysite.com/post/one/</loc>
    <lastmod>Thu, 16 Jan 2025 12:32:00 GMT</lastmod>
    <changefreq>monthly</changefreq>
    <priority>0.9</priority>
  </url>
</urlset>

Define a domain #

Like text sitemaps, you must define a domain as a global tacs property in your publican.config.js configuration file.

Create a dateISO() function #

Last modified dates must be output in YYYY-MM-DD format. The time can also be appended, although it is unlikely to be critical on most sites.

Add the following functions to lib/format.js if not already defined:

• A private cDate() function converts any value to a date.
• A public dateISO() function to output a date in YYYY-MM-DD format.

lib/format.js

// create a date
function cDate(d) {
  d = new Date(d);
  return +d && !isNaN(d) && d instanceof Date ? d : new Date();
}

// ISO date format, e.g. "2025-01-01"
export function dateISO( d ) {
  return cDate(d).toISOString().slice(0, 10);
}

The library has already been imported into the publican.config.js configuration file and appended to the tacs.fn.format object so no additional code is required.

Create sitemap.xml #

A src/content/sitemap.xml file can now be defined. It does not require a template and outputs all pages where the front matter index value is not false:

src/content/sitemap.xml

---
index: false
---
<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
${ ( toArray(tacs.all) ).filter(p => p.index !== false).map(p => `
<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
${ ( toArray(tacs.all) ).filter(p => p.index !== false).map(p => `
  <url>
    <loc>${ tacs.config.domain }${ p.link }</loc>
    <lastmod>${ tacs.fn.format.dateISO( p.modified || p.date ) }</lastmod>
    <changefreq>${ p.index || 'monthly' }</changefreq>
    <priority>${ p.priority }</priority>
  </url>
`)
}
</urlset>

Note that <lastmod> allows you to set a custom modified: YYYY-MM-DD value in front matter if you want to specify a post’s last update date instead of the original publication date.

Create robots.txt #

Add your XML sitemap URL to a robots.txt file so search engines can locate it.