I've been working on a little demo for how to avoid copy-pasting header/footer boilerplate on a simple static webpage. My goal is to approximate the experience of Jekyll/Hugo but eliminate the need for a build step before publishing. This demo shows how to get basic templating features with XSL so you could write a blog post which looks like
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="/template.xsl"?>
<page>
<title>My Article</title>
<content>
some content
<ul>
<li>hello</li>
<li>hello</li>
</ul>
</content>
</page>
- no build step (no need to setup Jekyll on the client or configure Github/Gitlab actions)
- works on any webserver (e.g. as opposed to server-side includes, actions)
- normal looking URLs (e.g. `example.com/foobar` as opposed to `example.com/#page=foobar`)
[0]: https://news.ycombinator.com/item?id=44952185
See also: grug-brain XSLT https://news.ycombinator.com/item?id=44393817
Even single page app frameworks have mostly solved this by doing the rendering on the server instead of making multiple round trips from the client. This feels like the no-JavaScript version of Spinnergeddon.
Does the browser wait for all the includes to resolve before showing the page or does it flicker in?
At least the browser has to load template.xsl before it can know it has to load the css file though, right? And this is just a simple demo page.
Now you can imagine with a real site, you will have many includes per page, each one perhaps using includes of it's own. You end up with a really bad waterfall where it can take a long time for a page to load because it's going back to the server constantly, whereas if you did it on the server it would be a single round trip.
Early SPA's did this, they would load a shell and then begin fetching from the client. Some still do but we know better than to do this for things that aren't web apps.
It is not quite a templating engine. XSLT is a part of a semantic engine. Content is written in the way that fits the content. E. g. I write about some language and invent tags and notations that best fit what I am talking about: grammar, sounds, wrtiting. Or I write about chess and say something like (party id=abc move=15w). Then I make it available in HTML by providing a transform from my tags to HTML tags. My notation is rendered as a bunch of divs, ps and spans. This is merely a temporary rendering; other renderings may be possible.
A templating engine is the final document with placeholders for variable parts. XSLT can do that too, but this is less than its vision.
These are all static file downloads, though. The first page load will take long, but if these are header/footer type includes, every subsequent page will use the cached file.
It's a trade-off between longer times for landing page and shorter times for every other page. The developer will decide whether or not to make the trade-off.