xm

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Chris Coyier on (Updated on )

This is a neat little HTML preprocessor from Giuseppe Gurgone. It has very few features, but one of them is HTML includes, which is something I continue to be baffled that HTML doesn’t support natively. There are loads of ways to handle it. I think it’s silly that it’s been consistently needed for decades and HTML could evolve to support it but hasn’t. So anyway, enter another option for handling it.

https://twitter.com/giuseppegurgone/status/1305851405660549122

What is extra neat is that it’s not just includes, but templating with includes in a really clean way. If this was Nunjucks, they solve that by creating a template.njk like…

{% block header %}
  This is the default (overridable) header.
{% endblock %}
<footer>
  {% block footer %}
    This is the default (overridable) footer.
  {% endblock %}
</footer>

And then your actual pages use that template like…

{% extends "parent.html" %}
{% block footer %}
  Special footer for this page.
{% endblock %}

In xm, the syntax stays HTML-y, which is nice. So this template.html

<slot name="header"></slot>
<footer>
  <slot name="footer"></slot>
</footer>

…gets used on a page like this:

<import src="template.html">
  <fill name="header">Custom Header</fill>
  <fill name="footer">
    <p>Custom footer</p>
  </fill>
</import>

Very clean. The additional fact that you can arbitrarily chuck a <markdown> tag anywhere you want and use Markdown within it is extra handy.