To quote [0]:
> All those “Valid XHTML 1.0!” links on the web are really saying “Invalid HTML 4.01!”.
Although the article is 20 years old now, so these days it’s actually HTML5.
Edit: Checked the other member sites. Only two are served as application/xhtml+xml.
[0]: https://webkit.org/blog/68/understanding-html-xml-and-xhtml/
Not having it is XHTML compliant though, so it could just be removed.
There is no HTML5. It's just a buzzword. https://html.spec.whatwg.org/dev/introduction.html#is-this-h...?
> Is this HTML5?
> In short: Yes.
See also [1].
That HTML5 was used in marketing doesn't make the technical term disappear. HTML5 is a bit more precise than HTML, it refers to the living standard that's currently in use, as opposed to HTML 4.01 and the previous versions of HTML.
* XHTML 1.0 and 1.1 are officially deprecated by the W3C.
* XHTML5 exists as a variant of HTML5. However, it's very clear that it's absolutely not a priority for the HTML5 working groups, and there's a statement that future features will not necessarily be supported by the XHTML5 variant.
* XHTML5 does not have a DTD, so one of the main advantages of XHTML - that you can validate its correctness with pure XML functionality - isn't there.
* If you do a 'view source' in Firefox on a completely valid XHTML 1.0/1.1 page, it'll redline the XML declaration like it's something wrong. Not sure if this is intended or possibly even a bug, but it certainly gives me a 'browser tells me this is not supposed to be there' feeling.
It pretty much seems to me XHTML has been abandoned by the web community. My personal conclusion has been that whenever I touch any of my old online things still written in XHTML, I'll convert them to HTML5.
Is the page actually being served as "application/xhtml+xml"? Most xhtml sites aren't, in which case the browser is indeed interpreting those as invalid declarations in a regular old html document
> Saw “<?”. Probable cause: Attempt to use an XML processing instruction in HTML. (XML processing instructions are not supported in HTML.)
I wouldn't mind as long as it keeps working, but…
> and there's a statement that future features will not necessarily be supported by the XHTML5 variant.
That's news for me, and unfortunate.
Edit: hmm, I couldn't really find any flamewars, but it did lead to objections:
https://news.ycombinator.com/item?id=8534213 (Oct 2014)
https://news.ycombinator.com/item?id=8533381 (Oct 2014)
https://news.ycombinator.com/item?id=6027549 (July 2013)
https://news.ycombinator.com/item?id=4990706 (Dec 2012)
https://news.ycombinator.com/item?id=4963264 (Dec 2012)
https://news.ycombinator.com/item?id=4943159 (Dec 2012)
https://news.ycombinator.com/item?id=4881400 (Dec 2012)
https://news.ycombinator.com/item?id=4765943 (Nov 2012)
Or you could also read web proposals where the reason for avoiding the ideal implementation is complication of updating HTML parser rules.
Or attempt to use the web features that are already hindered by the HTML parser (custom element table rows).
…or be grateful you can just use an existing HTML5 parser that hides all this stuff to your innocent eyes :-)
Using existing parsers only hides the poor design up to a point.
However no browsers have implemented streaming XHTML parsers. This means that the performance is notably worse for XHTML and if you rely on streaming responses (I currently do for a few pages like bulk imports) it won't work.
Dang, I hadn't considered this. That's something to add to the "simplest HTML omitting noisy tags like body and head vs going full XHTML" debate I have with myself.
One for XHTML: I like that the parser catches errors, it often prevent subtle issues.
> you should master the HTML programming¹ language
The footnote reads:
> 1. This is a common debate - but for simplicity sake I'm just calling it this.
It's not really a debate, HTML is a markup language [1], not a programming language: you annotate a document with its structure and its formatting. You are not really programming when you write HTML (the markup is not procedural) (and this is not gatekeeping, there's nothing wrong about this and doesn't make HTML a lesser language).
To avoid the issue completely, you can phrase this as: "you should master HTML" and remove the footnote. Simple, clean, concise, clear. By the way, ML already means "Markup Language", so any "HTML .* language" phrasing can feel a bit off.
Do you mean "Turing-complete" language? Or maybe "procedural programming language"? I agree HTML isn't either of those, but those aren't the be-all and end-all of programming now, are they?
A programming language doesn't need to be procedural, it can be functional, or use another computationally equivalent paradigm. I'm not quite sure it needs to be Turing complete, but possibly.
A programming language lets you express to some processor that provides a set of computation primitives what to do with the memory cells you have at your disposal, and in general it lets you deal with input and output.
If you consider any language you program with to be a programming language, then CSS, JSON, YAML, XML, markdown (that's what your readme is likely written in) and even English (that's what you use to express the specs, the bugs, maybe your notes / drafts, the comments, possibly the language the singer of the songs you're listening to while programming use) or UML need to be programming languages too. That's not quite useful. "Program with" is too large and would make the "programming" qualifier largely useless.
https://en.wikipedia.org/wiki/Programming_language
https://en.wikipedia.org/wiki/Computer_program
https://en.wikipedia.org/wiki/List_of_programming_languages
https://stackoverflow.com/questions/14512218/is-html5-a-prog...
<for i=0; i<1; i++> <html> </html> </for>
Better question, why don't we upgrade XML to do that?
But if you disagree with this, or somehow work around this statement by replacing your for element with some "for-loop" custom element (it is valid HTML to add custom tags with dashes in their names), my stronger argument is at https://news.ycombinator.com/item?id=46743219#46743554
XSLT which is an application of XML allows you to do a for-each: https://developer.mozilla.org/en-US/docs/Web/XML/XSLT/Refere...
Nobody uses PHP this way any more though — people treat it like Python or Node and write the entire codebase inside a big <? block
JSP is similar with different syntax again — nobody uses JSP either
I think ASP too but I never used that
But if we use a broader definition, basically "a formal language that specifies behavior a machine must execute", then HTML is indeed a programming language.
HTML is not only about annotating documents or formatting, it can do things you expect from a "normal" programming language too, for example, you can do constraints validation:
<input name="token" required pattern="[A-Z]{3}-\d{4}" title="Must match ABC-1234 (3 uppercase letters, hyphen, 4 digits)" placeholder="ABC-1234">
In the end, I agree with you, HTML ultimately is a markup language, but it's deceiving, because it does more than just markup.
It might be, I'm usually not, but this is all xhtml.club and this footnote are about, might as well be correct :-)
Constraint validation is still descriptive (what is allowed)
All details and summary are doing is conveying information on what's a summary and what's the complete story, and it has this hidden / shown behavior.
In any case, you will probably find something procedural / programming like in HTML, but it's not the core idea of the language, and if you are explaining what HTML is to a newbie, I feel like you should focus to the essential. Then we can discuss the corners between more experienced people.
In the end, all I'm saying is: you can just avoid issues and just say "HTML" without further qualifying it.
This is not what HTML does. Tags are not instructions, they delimit the start and end of elements. They describe content, they do not specify behaviour.
In your pattern example, that is still just a description of what is acceptable input. It doesn’t execute anything. A paper form might specify the format DD / MM / YYYY but that doesn‘t mean the form is executing a program in your brain when you fill it out.
If anything, it is the act of stretching the definition of "programming language" so much that it includes HTML as a programming language that we should call pedantic.
If you look at the HTML 5 spec it is clear that it's intended to be a substrate for applications. The HTML 5 spec could be factored into a specification of the DOM, specification of an x-language API for the DOM and a specification for a serialization format as well as bindings of that x-language API to specific languages like Javascript.
And it's brilliant :-)
If all you're doing is using HTML to "annotate a document with its structure and its formatting", then yes, I'll accept that it's not quite programming, but I've not seen this approach of starting with a plain non-html document and marking it up by hand done in probably over two decades. I do still occasionally see it done for marking up blog posts or documentation into markdown and then generating html from it, but even that's a minuscule part of what HTML is used for these days.
Your mileage my vary, but what I and people around me typically do is work on hundreds/thousands of loosely coupled small snippets of HTML used within e.g. React JSX, or Django/Jinja templates or htmx endpoints, in order to dynamically control data and state in a large program. In this sense, while the html itself doesn't have control flow, it is an integral part of control flow in the larger system, and it's extremely likely that I'll break something in the functionality if I carelessly change an element's type or attribute value. In this sense, I'm not putting on a different hat when I'm working on the html, but just working on a different part of the program.
Those are not HTML. PHP neither, even when used as a templating language for HTML.
> htmx endpoints
Not really familiar with htmx, but I would say this is HTML augmented with some additional mechanisms. I don't know how I would describe this augmented HTML, but I'm not applying my "not programming" statement to htmx (I probably could, but I haven't given enough thoughts to do it).
> In this sense, I'm not putting on a different hat when I'm working on the html, but just working on a different part of the program.
I agree with this actually. I wouldn't consider that writing HTML (or CSS) is really a separate activity when I'm building some web app.
That's correct but I don't see what it has got to do with the question of whether HTML is a programming language or not.
Strings do not have control flow but strings are integral part of larger programs that have control flow. So what? That doesn't make strings any closer to being programming languages.
I remember going online with a modem in the 90s. There was a new ISP in town, but their homepage took forever to load. I viewed the source, and whatever page generator they were rendered the page as HTML tables (this was fine back then), and added repetitive style tags to every table cell instead of using CSS (although I wonder if this was before CSS) or not doing so for empty cells, and that their homepage was so bloated and slow to load on dial-up.
I wonder how it is nowadays. But I suppose in the age that accomodates apps like Teams and Slack, who cares?
The dozens (or hundreds! have you tried GitHub recently??) HTTP requests.
The JavaScript bundles whose sizes are expressed in 10⁶ bytes.
The UIs that are fully recomputed and redrawn on each small interaction.
The auto playing videos. The images that are comparable to full res pictures (but usually empty of meaning because they are stock or AI generated).
Apart from the fact that very few people understood CSS back then, there was a stupendous amount of really weird bugs. For instance, I remember having a simple th { font-size: … } rule, and some versions of Netscape 4 somehow managed to apply the font size to all <th> cells except for the third one. So workarounds like extra style attributes were added to fix things like this.
I don’t thing it’s about luddites as website mentioned. Many professions have tools suggesting that person have extensive experience and in terms of web development, XHTML 1.0 or old standards of HTML are such.
Writing valid HTML should be a bare minimum (I know it isn't!).
Same badges, same limits.
> Trailing slash on void elements has no effect and interacts badly with unquoted attribute values.
Unquoted attribute values? So help me I don't see you using unquoted attribute values.
Decades later, I'm still mildly annoyed when I see self-closing tags in HTML. When you're not trying to build a strict XML document, they're no longer required. Now I read them as a vestigial reminder of the strict XHTML dream.
EDIT: I just checked, and my site (at least the index page) still validates! https://validator.nu/?showsource=yes&doc=https%3A%2F%2Fander...
EDIT2: Hey, look, if you still want to use self-closing tags where they're not required: go nuts! I'm just explaining why I don't use them anymore.
[0] I don’t dislike XHTML. The snob in me loves the idea. Sure, had XHTML been The Standard it would have been so much more difficult to publish my first website at the age of 14 that I’m not sure I would have gotten into building for Web at all, but is it necessarily a good thing if our field is based on technology so forgiving to malformed input that a middle school pupil can pass for an engineer? and while I do omit closing tags when allowed by the spec, are the savings worth remembering these complicated rules for when they can be omitted, and is it worth maintaining all this branching that allows parsers to handle invalid markup, when barely any HTML is hand-written these days?
[1] Usually it is to the detriment of the former: the latter tends to be ill-regarded by today’s average Web developer used to JSON (even as they hail various schema-related additions on top of JSON that essentially try to make it do things XML can, but worse).
https://www.w3.org/TR/xmlschema-2/
even though a lot of tools and standards (I'm looking at you SPARQL) don't really support them. My favorite serialization for RDF is Turtle:
Why? That's (mildly) bad for your health.
Since HTML5 specifies how to handle all parse errors, and the handling of an XML self-closing tag is to ignore it unless it's part of an unquoted attribute value, it's valid HTML5.
HTML 5 specified exactly how "invalid" HTML is parsed so now there is no such thing as invalid HTML. XHTML was one of those things that never quite worked:
There is. There are things that are still considered invalid, like nesting form elements for instance.
(this doesn't take away your argument though, and you were focusing on the parsing aspect).
As far as parse errors is concerned, https://html.spec.whatwg.org/multipage/parsing.html#parse-er... says:
> This specification defines the parsing rules for HTML documents, whether they are syntactically correct or not. Certain points in the parsing algorithm are said to be parse errors. The error handling for parse errors is well-defined (that's the processing rules described throughout this specification), but user agents, while parsing an HTML document, may abort the parser at the first parse error that they encounter for which they do not wish to apply the rules described in this specification.
I lived through the XML hype cycle and god it was awful. I Still have nightmares about some XSLT I had to maintain.
Good riddance...