You can tell a framework by the "Hollywood Principle" (don't call me, I'll call you). A framework is the component host. It's responsible for defining the component model and calling the component lifecycle.

Since frameworks define their own component model, components are typically incompatible between frameworks. You can't use an Angular component in React because React defines a different model.

This leads to huge fragmentation across the ecosystem and internally within large companies, and a waste of effort to reimplement components in each framework.

Web components are a standard component model where the _browser_ is effectively the framework. It calls the component lifecycle, and to other userland JS code, or HTML markup processors, web components act like any other HTML element. It's like being able able to add your own elements to the HTML spec.

Web components only specify the interface between the components and the DOM, they don't specify how the components are implemented. So you see several libraries that help implement web components. These libraries usually do a subset of what a framework does: main templating and reacting to state changes. They don't do the component model part of a framework.

Fast is another library that helps you build web components. Polymer was probably the first, and currently there are Polymer's LitElement, Ionic's Stencil, Salesforce's Lightning, and many more. They're all compatible with each other and with frameworks because the libraries only manage the internals of the components, the externals are standard.

Lol, love your comment! Funny thing is that there are more people on your side than what this community might tell you! Silence is golden for a reason ;)

I appreciate the support I guess but at the same time I don't understand what you mean by there are an unspecified number of people on my side and that silence is golden - either that means I should be quiet and join the throngs of the self-superior invisible some-jority which I think is condescending to the fine folk here, or it means I personally should be silent and not express my honest confusion, frustration and dismay. That's not going to happen either.

I did come out pretty strong in my apprehension but I am serious in wanting to know specifically what the benefit of this is, and I don't really care whether I am making a fool of myself for asking questions lol.

Theory: web components provide a standardised component model for the web so that you don't need to rely on frameworks and a bunch of JavaScript to create interchangeable interoperable components that are no different from built-in browser components. Oh, and you can extend existing built-in components with your own behaviours.

Reality:

- WebComponents is a collection of 4 web standards, one of them is already deprecated, and v0 of another one is also already deprecated.

- The standards provide a verbose, error-prone imperative API that leaks implementation details left and right

- The API is so bad, that the official stance is "the API is aimed at library and framework developers, and you are not expected to write your components using this API". And if you look at the frameworks, they try to not even compile/transpile down to this API

- Since all WebComponents basically have is DOM APIs, the official stance is basically "yeah, they are good for implementing leaf nodes" (that is basic dump components like an simple input field, or a label) because you still need a full-fledged lib/framework for anything else

- You cannot extend some (most?) of the built-in components. And even if you can, your custom implementations will not participate in form events, so you have to create workarounds if you want to submit values from your components

- They break accessibility

- They don't work without JavaScript

- They cannot be rendered server-side

- They are not strictly HTML, but a subset of it, because you can't provide callbacks for their custom events (you can do onClick, but you cannot do onSomeCustomEvent)

- And on the social side of things, their proponents will very rarely acknowledge or discuss these issues in public (even though there are dozens if not hundreds of issues with extensive discussions on GitHub), but will spend not an inconsiderable amount of time and energy bashing non-webcomponent libraries and frameworks

Okay I think I get it:

1. Define elements in script by extending htmlelement

2. Follow the allowed structure in the DOM so that the custom elements don't break / conflict with anything

3. Use CSS to make the custom element look nice.

Then, basically what we have is:

1. A class-based way to attach event listeners in a standard interface (which is nice)

2. what we always had to do anyway (unless framework forces using JS to inject HTML at runtime)

3. what we always had to do anyway

4. Can't use custom events anymore... Encapsulation fTW.

But now that brings us to a situation where, essentially, it comes down to which htmlelement classes take precedence in our dependency hierarchy. Some libraries are probably compatible but you can't guarantee it because there's no explicit package dependencies between different implementations, so if you choose two different component libraries you may end up with unexpected behaviours and bugs.

So if I were to build a component library that is "compatible" with all major component libraries, essentially what I'd have to build is a shit-ton of "mappings" and exceptions that define an order of precedence of which component variants my library should interact with or cede to? I don't really like the idea of "just magically working with incompatible libraries" right?

Does that seem about right?

I think I learned something new and fundamental today, and the overall approach makes sense if you pick a single library to build your application but I can't see it having any realistic value if you're to try and jimmy it into existing products, in fact I can see that being an extremely expensive exercise and potentially adding a load of overheads to maintain and configure.

Also I can see now why no one really answered the question about ARIA tab orders and accessibility, it's not the job of these libraries.

I'm not a very smart person, thanks again to you and everyone else jumping on my thread to take the time to explain :)

In theory you wouldn't worry about idiosyncrasies of specific component libraries if they are based on web components because they would provide only a single interface: properties go in (as in customElement.myCustomProp = <some-value>), events go out (as in customElement.attachEventListener(<some-custom-event>, (e) => <do something in your callback>)).

This is definitely true for "dumb" components aka leaf components such as labels, footers, links, basic inputs. However, since you need more (for example, data-binding and reactivity), this may become a question of interoperability, and I don't really know how that plays out in the real world.

> I'm not a very smart person, thanks again to you and everyone else jumping on my thread to take the time to explain :

No stupid questions, right? :) And the whole web components discussion is extremely muddied. Mostly because people expect you to already know what they are about, and talk about and use libraries on top of them: lit-html, stencil etc.

Is the only thing that stops components from colliding literally naming convention? Like <fast-dropdown> != <my-homebrew-dropdown>? So it's basically a convention-based standard rather than a fixed standard? This feels like another example of the XHTML apocalypse coming full circle and we're trying to find objective approaches to loosely defined data.

I do feel I am exposing myself to some ridicule for being out of style and I regret my attitude in my original reply but it felt honest at the time, I am glad that we have had this conversation in general because it's given me a lot to think over.

My main fear that I developed over the years is we end up developing frameworks for frameworks instead of delivering tangible results. I've been on projects that ended up taking far, far longer and costing way more to maintain simply because we had to nurse the framework rather than deliver the results.

Anyway thanks for taking the time out again, I need to percolate for a while and look into some of the ideas that have been expressed here.

> Is the only thing that stops components from colliding literally naming convention? Like <fast-dropdown> != <my-homebrew-dropdown>? So it's basically a convention-based standard rather than a fixed standard?

Yup :) They decided to go for a flat namespace where all that distinguishes between components is their name. I'm guessing this already leads to collisions between different versions of the same element. And there has been an open issue for it for three years now: https://github.com/w3c/webcomponents/issues/716 And the "solution" seems to be "let's add more Javascript": https://github.com/justinfagnani/scoped-custom-elements

> I do feel I am exposing myself to some ridicule for being out of style and I regret my attitude in my original reply

It's perfectly fine :) I've been way more rude about web components before (and still am :) )

> My main fear that I developed over the years is we end up developing frameworks for frameworks instead of delivering tangible results.

Indeed. That's my main gripe with web components, really: instead of providing tangible benefits to developers, they ended up being "an API primarily for library and framework developers"

Creator of a popular web component library here. Some observations:

> one of them is already deprecated, and v0 of another one is also already deprecated.

Sometimes you swing and you miss. Instead of moving forward with the initial design, they iterated and improved it. That’s how software works.

> The API is so bad, that the official stance is "the API is aimed at library and framework developers, and you are not expected to write your components using this API".

It’s not because the API is bad, it’s because the term “component” has become ubiquitous with framework components and that’s caused A lot of confusion. Web components are lower level than React/Vue components by design, but people hear “component” and have the same expectations. Having worked with web components almost exclusively for more than a year, I feel like the APIs are thought out fairly well. They’re not perfect, but they are good and there’s momentum to continue improving them (e.g. declarative shadow DOMs).

> You cannot extend some (most?) of the built-in components. And even if you can, your custom implementations will not participate in form events

It’s still pretty new, but it’s coming. These things take time to get right and become supported by all browsers. Search for form-associated custom elements, for example.

> They break accessibility

Only if misused, which is also possible to do in any framework or even plain HTML.

> They don't work without JavaScript

I’m so tired of hearing this. How well does your React/Vue/Angular/Alpine/jQuery-based app work without JavaScript?

Browsing the web in 2020 with JavaScript disabled is like driving your car down the road without any wheels. Things just aren’t going to work right. The experience will be inferior even the when effort is made, but IMO it’s not reasonable to expect developers to accommodate the < 1% of users who might actually do this.

> They cannot be rendered server-side

I’m no expert in SSR, but Stencil offers some examples of how to achieve this with their compiler, which is a joy to use. [1]

> They are not strictly HTML, but a subset of it, because you can't provide callbacks for their custom events

It wouldn’t make sense to provide an “onclick” style prop for custom events, but you can attach listeners with `addEventListener` like any other event. The syntax is identical.

> And on the social side of things, their proponents will very rarely acknowledge or discuss these issues in public

I’m a proponent and I’m happy to discuss these things in public.

It seems, however, there are a lot of misconceptions about the underlying specs. Maybe that’s deserved — it took a long time for web components to get this far and it’s been a bumpy road. That doesn’t mean it hasn’t gotten much better.

I’d encourage anyone who hasn’t explored custom elements, shadow DOM, et al recently to take another look. We’re building some awesome things with them!

1. https://stenciljs.com/docs/static-site-generation

What I meant was that are a lot of like minded developers here who cringe every time they have to hear how JS is going to teleport us from Earth to Mars. And since there are no bonus cookies that can won by proving that you can create a functional website simply by using some good old HTML with CSS and vanilla JS, a lot of us resort to being silent and enjoy the show!

So, what do ya say? Would you React the same way? ;)

I'd say the important word there is "team", you use those libraries and frameworks because they are curated ways of doing what you want, reducing friction. If you are coding by yourself, you know everything about the codebase, and you focus on different trade-offs.

In general those who use these frameworks are ok with adding build complexity if they allow to avoid, at least a little bit, problems that can come from lack of standardization and one-off solutions to deceptively simple problems, taking care of edge cases your team is likely to find but unlikely to think beforehand.

I understand the framework concept very well and have (oh god I hate this term) "spearheaded" multiple componentisation schemes over the years, to make code more reusable across teams, to reduce coding effort, to reduce expense for the business while improving the QA outcomes for the client etc. We standardised on frontend frameworks, set up and configured automated build systems way back when most web dev shops were still FTPing their shit up to servers, automated the task of installing dependencies and so forth. So I honestly get the value of frameworks and systems in a general context, I know what frameworks are...

It's more about I guess what context is this framework more applicable in? What does this exactly "standardise" - given that "standardisation" frequently just means "now we have x number of frameworks to support instead of x - 1)"

I still have to train my team to structure their components differently than they currently do, to refactor existing systems away from their current frameworks to this one, a significant investment in time and energy... so... Why? Why is this one the ultimate framework for "web components" (which used to just be called "semantic html")?

Frameworks mean React, Vue, Angular, etc. Usually, if you make a TextInput component in React, you can't use it in Vue and vice-versa. If you create a <text-input> web component, then you can use it in any of these frameworks (or with no framework at all), like a native html tag.

Thanks that actually sounds like it could have value, but again it's a new paradigm to learn.

It's like a while back I trained myself up on GWT because in my mind it was the future of reusability.

Sure it was Java based and everyone hates Java these days I guess, or at least hating Java is a meme. But the entire concept and value was that you write everything as reusable components.

Then all you really needed to do was choose your compile targets and the compiler would do the rest, generating cross-browser / device versions of your application code as needed.

I can see now what the OP means and honestly from my point of view the post-XHTML / DTD / XSD diaspora is circling back around to trying to find standard ways to separate data from presentation.

I think I get it now, thank you.