Comment by uncheckederror

I didn't expect this to be serious and am surprised on that the tutorial actually delivers. Way back when I was learning HTML and it was said that it was built with SGML, then this relation remained a total mystery to me.

I’ve become quite a fan of writing in SGML personally, because much of what you note is spot-on. Some of the points seem a bit of a stretch though.

Any type-checking inside of SGML is more akin to unused-variable checking. When you say that macros/entities may contain parameters, I think you are referring to recursive entity expansion, which does let you parameterize macros (but only once, and not dynamically within the text). For instance, you can set a `&currentYear` entity and refer to that in `copywrite "&currentYear/&currentDay`, but that can only happen in the DTD at the start of the document. It’s not the case that you could, for instance, create an entity to generate a Github repo link and use it like `&repoName = "diff-match-patch"; &githubLink`. This feature was used in limited form to conditionally include sections of markup since SGML contains an `IGNORE` “marked section”.

   <!ENTITY % private-render "IGNORE">
   ...
   <![%private-render[
   <side-note>
   I’m on the fence about including this bit.
   It’s not up to the editorial standards.
   </side-note>
   ]]>

Would love to hear what you are referring to with “safe” third-party transclusion and also what features are available for removal or rejection of undesired script in user content.

Apart from these I find it a pleasure to use because SGML makes it easy for _humans_ to write structured content (contrast with XML which makes it easy for software to parse). SGML is incredibly hard to parse because in order to accommodate human factors _and actually get people to write structured content_ it leans heavily on computers and software doing the hard work of parsing.

It’s missing some nice features such as namespacing. That is, it’s not possible to have two elements of the same name in the same document with different attributes, content, or meanings. If you want to have a flight record and also a list of beers in a flight, they have to be differentiated otherwise they will fail to parse.

   <flight-list>
   <flight-record><flight-meta pnr=XYZ123 AAL number=123>
   </flight-list>

   <beer-list>
   <beer-flight>
   <beer Pilsner amount=3oz>Ultra Pils 2023
   <beer IPA>Dual IPA
   <beer Porter>Chocolate milk stout
   </beer-list>

For more complicated work I make quick transformers with WordPress’ HTML API to process the XML output (I know, XML also isn’t HTML, but it parses reliably for me since I don’t produce anything that an HTML parser couldn’t parse). Having an imperative-style processor feels more natural to me, and one written in a programming language that lets me use normal programming conveniences. I think getting the transformer right was never fully realized with the declarative languages, which are similar to Angular and other systems with complicated DSLs inside string attribute values.

I’d love to see the web pick up where SGML left off and get rid of some of the legacy concessions (SGML was written before UTF-8 and its flexibility with input encodings shows it — not in a good way either) as well as adopt some modern enhancements. I wrote about some of this on my personal blog, sorry for the plug.

https://fluffyandflakey.blog/2024/10/11/ugml-a-proposal-to-u...

Edit: formatting

> But the overhead of just doing it yourself is surprisingly small in terms of the time commitment.

Holy cow. The sole reason I learned SSI and then PHP in 1998 was because I was sick of this after like 2 weeks.

This person has more patience in their pinky than I have ever had.

I recently learned the object tag can do what I wished for in the 90s... work as an include tag:

    <object data="footer.html"></object>

Should reduce a lot of boilerplate that would get out of sync on my next project, without need for templating.

I've adopted the idea that a blog post is archived when it's published; I don't want to tinker with it again. Old pages may have an old style, but that's OK, it's an archive. Copy/paste works great for this.

The only reason I use a blog engine now (Hugo) is for RSS. I kept messing up or forgetting manual RSS edits.

Or, let me be cheeky: you could add some `<php include('header.html')?>` in your html.

> It can generate headers and the like dynamically so you don't have to change it on every single pa

Yeah, I noped out of that and use a client-side include (webcomponent) so that my html can have `<include-remote remote-src='....'>` instead.

Sure, it requires JS to be enabled for the webcomponent to work, but I'm fine with that.

See https://www.lelanthran.com for an example.

[EDIT: Dammit, my blog doesn't use that webcomponent anymore! Here's an actual production usage of it: https://demo.skillful-training.com/project/webroot/ (use usernames (one..ten)@example.com and password '1' if you want to see more usage of it)]

Isn't using React with a static site generator framework basically the same thing but better?

> > Yes, you must copy and paste content and not having layout page is annoying at time

> I think this was one of the most common usages of PHP in the beginning,

> <?php include('header.inc'); ?>

And other tools beforehand: basic CGI or even more basic server-side includes (https://en.wikipedia.org/wiki/Server_Side_Includes)

To reduce CPU and IO load on the server (or just in circumstances where SSI was not enabled on the server they had available) some would pre-process the SSI directives (obviously this doesn't work for dynamic results such as the output from many #exec examples), so all that is being served is simple static files ‑ a precursor to more complex modern static site builders.

> It would be great if HTML had a similar capability. People have asked for it for over 30 years, so it's unlikely that it will be implemented now.

That doesn't really fit with the intentions of HTML, and could impose a bunch of extra network latency overhead compared to using SSI instead, leading to either complete rendering delays or jumpy pages as included content is merged in in steps, though I have seen it implemented multiple ways using a bit of JS (some significantly more janky than others).

See my reply about the object tag. Suffers from lack of press I guess.

A slightly simpler version of same is:

  for PAGE in *.page
  do
    cat header.html "$PAGE" footer.html > "$PAGE.html"
  done

HTH

EDIT: if you don't want the output file to be named "a.page.html" and instead it to be "a.html", replace the above cat invocation with:

  cat header.html "$PAGE" footer.html > "${PAGE%.page}.html"

0 - https://man.freebsd.org/cgi/man.cgi?query=cat&apropos=0&sekt...

Why not use server side includes? Most web servers support it, and it dates back to one of the early features of webservers.

    <!--# set var="pagetitle" value="Main page" -->
    <!--# include file="00__header.html" -->
    
    ... main content here
    
    <!--# include file="00__footer.html" -->

`cat` supports multiple files, no? The whole point is that it concatenates. Why use 3 commands?

Unfortunately, this doesn't adjust the <title> element.