If you're using a framework like lit-html as the author recommends, it will replace the string every update. Most people will prefer that way since it's more ergonomic and similar to React. You could do imperative DOM updates, but that'd be like going back in time to jQuery.
This is false. It does not replace the entire string, but uses a template literal to identify which changes need to be made before selectively updating the DOM.
This video is a few years old, but the core concepts remain the same.
This simply isn't true. Tagged template literals are not string concatenation. Also any "thin layer" of tooling on top of vanilla web components (like Lit) is entirely capable of passing complex objects as props. String-only "props" are only the case for literal HTML attributes in your source HTML—and even then you can embed JSON in an attribute and get a real parsed object within the component.
> Tagged template literals are not string concatenation
They are not concatenation by themselves. But for them to be useful, you will end up doing a lot of it because there's nothing else to do with strings than parse (often with regexps [1]) and concatenate [2] the strings. And then you dump the concatenated string into the DOM using `.innerHtml` [3]
I use Lit every day and I have no idea what you're talking about.
Any property can be a full JS object. When the property is changed, it is re-rendered in your component. I have never touched innerHtml and my Lit apps pass and render all kinds of stuff into html`` tagged templates.
It's really pure magic because you can freely mix regular old HTML and regular attributes with dynamic data and data binding. There's more than one way to write anything which gives you great flexibility. I adore tagged templates, and they work for CSS and SVG, too.
> I use Lit every day and I have no idea what you're talking about.
I'm talking about how lit is implemented internally and that's why I provided links to relevant parts of lit's code.
People having no idea how things work is the bane of our industry. And that's why we have objectively false statements like "regular old HTML and regular attributes with dynamic data and data binding".
Lit is almost as far from "regular old HTML" as React's JSX is: lit is a HTML-like DSL that even has constraints on how you use tagged literals themselves.
E.g. `<${tagName}></${tagName}>` is a valid tagged literal and it's invalid in lit.[1]
I do understand that string concatenation and DOM rewrites are happening under the hood. How could they not be? But the point of using an abstraction like Lit is that I don't have to worry about that part.
Are you suggesting that Lit is updating .innerHtml when it doesn't need to? And are you sure about that? Because that should be entirely under my control by setting properties or state of the component, not by Lit redrawing them willy-nilly.
So what exactly is the complaint? You said that tagged templates require needless updates to .innerHtml and that "string concatenation" is the only thing they can do. Now we are agreeing that that's not true? :-)
How is it "objectively false" that Lit mixes regular HTML with data binding? That is exactly how it works. I have several Lit apps and they use regular HTML as well as custom components and both have access to Lit properties and state that are dynamic.
Are we talking at cross-purposes or are we trying to say the same thing two different ways? I use this tech every day and I feel like you're saying something about it that's not true -- or maybe I'm not understanding your view.
> You said that tagged templates require needless updates
I never said needless
> that "string concatenation" is the only thing they can do
It's not what "they" need to do. It's what you, or the library using them needs to do.
> Now we are agreeing that that's not true
If you invent something that I never said, then yes, we can both agree it's not true.
> How is it "objectively false" that Lit mixes regular HTML with data binding?
Once again that is not what I said. The objectively false statement is that it's "regular HTML". Lit is a HTML-like DSL because none of this is "regular HTML" because those attributes are invalid in regular HTML:
I still don't understand the objection. Your example of invalid Lit is something I would never write. Lit is perfectly helpful without it. What makes you say the .value and @click attributes are invalid? In some older HTML spec, you mean? They certainly work correctly in modern browsers.
You can definitely mix data binding with regular HTML. It might be "invalid" according to a spec that makes no difference. The point of all of this is to write apps that work and can be debugged.
Please re-read what I wrote in my very first comment
> What makes you say the .value and @click attributes are invalid?
Just checked the spec, you're right they are valid. Hm, I was sure they weren't. Won't dig through the history to see if this changed :)
However, "Authors must not use elements, attributes, or attribute values that are not permitted by this specification or other applicable specifications, as doing so makes it significantly harder for the language to be extended in the future.", https://html.spec.whatwg.org/multipage/dom.html#elements
So I'd say they are still not okay on existing HTML elements
> It might be "invalid" according to a spec that makes no difference.
That is a very bad stance to take. "Invalid to the spec, but who cares".
> What is the rallying cry against Lit, exactly?
There's no rallying cry against lit. Stop. Inventing. Words. And. Meanings. I. Never. Said. Or. Implied.
There's a single very literal comment I made with links to support that statement.
I'm out of this discussion. I have other things to do with my life than keep saying "I never said what you think I said" over, and over, and over again.
Right, all I'm saying is this is nothing intrinsic to the Web Components standard like the parent comment suggested. It's just one particular way you might use them.
