[FlorianRappl]

That is just wrong on many levels. JSX brings an XML-like notation to JS. It has nothing to do with HTML. react-dom couples your React DOM to the real DOM - thus allowing you to use special JSX elements that create DOM elements. But then you / React interacts with them using the DOM API - not HTML source code.

Things like `htmlFor` or `className` should not be confusing - these are the official DOM properties. `style` in its DOM API also has an object-oriented API and not a string. If you are confused by these things (className vs class, ...) then potentially you started learning JSX from a completely misleading / wrong point.

I know most articles on React / JSX get that wrong, but this non-sense has to stop. After all, you do not write React in the browser because you want to generate HTML - you do write it to manipulate the DOM. On the server, you may want to generate HTML and then this can be misleading (true), but this has not been the main objective.

[cooperadymas]

Telling someone they learned something wrong maybe isn't the best approach when trying to explain why something should not be confusing. Especially when it's a widely held view, maybe the learners are not the problem.

Most people learn JSX when they learn React. It was created by Facebook for React, after all. What does the React docs teach about className?

https://reactjs.org/docs/introducing-jsx.html

Here in the intro it doesn't even explain that you need to use className instead of class. It uses it with no explanation. Then it throws in a line about camelCasing and assumes that you understand why it changed.

Surely the JSX in depth page explains it.

https://reactjs.org/docs/jsx-in-depth.html

It does even less.

https://reactjs.org/docs/dom-elements.html#classname

Finally! In a page that seemingly has nothing to do with JSX we get told to change how we write HTML, but we're not even told why. (The htmlFor section tells us.) No wonder people are confused.

Yes, className is a property of the Element interface but it is not the attribute used when writing HTML. You're still changing how you write HTML. It is no longer standard. That is the point people are making here - JSX introduces enough edge cases that you must learn that it adds equally as much mental overhead as the template DSL for Alpine or Vue. Even if people understand the reasoning and it is not confusing, it's still a shift.

[satvikpendem]

> Here in the intro it doesn't even explain that you need to use className instead of class.

Again, because `className` is not React specific, it's JS DOM API specific. Sounds like the real problem is that people start learning React without fully learning the JS DOM API itself, then they get confused when things like `className` or `htmlFor` show up.

> Yes, className is a property of the Element interface but it is not the attribute used when writing HTML. You're still changing how you write HTML.

You're not writing HTML. That's the entire gist of the parent comment. It looks like HTML only insofar as HTML is a type of XML. But what you're really doing underneath is something like:

    const el = document.getElementById('item');
    el.className = el.className === 'active' ? 'inactive' : 'active';

JSX is simply syntactic sugar on top of DOM operations like that (albeit within the context of a renderer like React; Svelte eschews a renderer entirely and truly is creating DOM operations like above). In React, JSX would be direct syntactic sugar for:

    React.createElement('div', null, `Hello ${this.props.toWhat}`);

> It is no longer standard

It is standard, it is in the Element API, I don't know how it can get more standard than that. Again, it sounds like the problem is that people really should learn JS and DOM separately before ever touching React. Sadly, too many beginners in web dev and programming in general gravitate towards a React/Node stack, which are good production tools, but they really ought to know how we got there.

Now why I don't use DSLs is because they don't use the standard of the JS DOM API, they use their entirely new creation, like v-for or #if :else. That is why I consider Vue or Svelte templates to be DSLs while not JSX, because the latter is fully compliant with the Element spec, and it uses plain JS/TS, unless you define a DSL to be so broad as to be literally any transformation of code, which, well, I can't practically agree with.

[culi]

Aren't you simply reinforcing the main point GP made? That it's yet another DSL to learn

[FlorianRappl]

Depends on how much you read it

> JSX is a DSL that looks almost like normal HTML, but differs in small uncanny-valley ways.

My point was not that its a common misconception that JSX has something to do with HTML - therefore comparing it to HTML and then being surprised that it isn't, shouldn't come as a surprise.

Also it does not differ in small uncanny-valley ways. Just one example on the syntax level: HTML has real self-closing elements (e.g., `<img>`) while JSX requires you to explicitly self-close (e.g., `<img />`). In HTML you also cannot explicitly self-close any element (e.g., `<div />` will just be parsed like `<div>`), while in JSX you can. I don't even want to start about whitespace etc. - those things are actually found / listed in any decent JSX tutorial.