spectrum-web-components VS WHATWG HTML Standard

For example, all the following design systems can be used without tooling (some of them provide ready-to-use bundles, others can be used through import maps): Google's Material Web, Microsoft's Fluent UI, IBM's Carbon, Adobe's Spectrum, Nordhealth's Nord, Shoelace, etc.

sp- (Spectrum components from Adobe6)

Spectrum web components by Adobe is really mature design system that makes a lot of usage of Lit Elements. Their testing setup uses the suggested web test runner. Lit's documentation on testing suggests using that library.

In Fable.Lit rather than building an F# DSL (we tried) we use a string-based alternative which is closed to the HTML you know and love, this also helps a lot when you have to consume web components like those from shoelace.style, fast.design, adobe spectrum components, and more, this will be a very important and big point over the next few years now that web components have taken off finally with major companies like Microsoft, Salesforce, Github, Adobe and more are using them.

Oh hey, that me! We at Adobe are investing heavily in web editors built with web component technology. Not just Photoshop, but Illustrator, Lightroom, and a number of brand new or in development applications across the company, as well.

We’re also leveraging web components to support interoperability of our design system across teams who still choose to use frameworks or have been using them all this time. In this way we ship https://opensource.adobe.com/spectrum-web-components/ and teams like fonts.adobe.com that have a long standing Angular app, or edex.adobe.com with their long standing Vue app or various recent acquisitions with their own technical decisions, can all consume Spectrum design without shipping their own implementation or rewriting their app to another stack.

The ease of building at depth scale for large applications and at breadth scale for applications no matter their architectural decisions has been a huge win for Adobe and our goals to drive consistency and quality across the company. The speed and scope at which we’ve been able to do so just wouldn’t be possible without web components.

Recently, I had the opportunity to discuss the difficulties, learnings, and victories or developing Spectrum Web Components together with fellow custom element developers from teams at IBM, ING, SAP, and Vaadin. If you missed the live stream, check out the recording! Fellow panelist, Ari Gilmore, made a great point that there is a lack of reading material for developers like ourselves to draw from when looking to build solid accessibility practices into the web components space. With that in mind, I thought it would be a good idea to take some of the abstract concepts we discussed in the panel and share some actual examples of working and testable code. Hopefully, this can better support the next developer(s) looking to bring a high-quality, accessible, design system to life for their team via web components.

Their repos are public: - https://github.com/adobe/spectrum-web-components - https://github.com/adobe/react-spectrum

It does seem like I enjoy a good . I mean, look, I wrote about them all the way back in 2018 in ing in Some Tips, and then in 2020, I spoke about Stacked Slots at a virtual Web Components SF meetup (see the associated slides), before sharing a proof of concept for Light DOM as Model. And, as if that weren't enough, here we are again, and I'm writing to you, friend, about s. Today, we're going to get out of the theoretical and into the practical as we start on the path towards actual usage of Stacked Slots that I'm excited to bring to life as part of Adobe's Spectrum Web Components to support the delivery of Spectrum design's Help Text pattern.

WHAT-WG HTML

There's a long-standing WHATWG feature request open for it here: https://github.com/whatwg/html/issues/2791

And several userland custom element implementation, like https://www.npmjs.com/package//html-include-element

One of the cool things that you can do with client-side includes and shadow DOM is render the included HTML into a shadow root that has s, so that the child content of the include element is slotted into a shell implemented by the included HTML.

This lets you do things like have the main page be the pre-page content and the included HTML be a heavily cached site-wide shell, and then another per-user include with personalized HTML - all cached appropriately.

The `allow` attribute on iframes is a relatively recent API addition from 2017

https://github.com/whatwg/html/pull/3287

I think there's a pretty strong argument at this point for this kind of replacing DOM with a response behavior being part of the platform.

I think the first step would be an element that lets you load external content into the page declaratively. There's a spec issue open for this: https://github.com/whatwg/html/issues/2791

And my custom element implementation of the idea: https://www.npmjs.com/package/html-include-element

Then HTML could support these elements being targets of links.

> Consider https://www.ietf.org/rfc/rfc1866.txt vs https://html.spec.whatwg.org/multipage/

I thought, oh, that's not so bad. Then I realized what I was looking at was a 10 page index.

I'd love to see something like HTMX get standardized, but I'm extremely pessimistic for HTMX's prospects for standardization in HTML.

In talking to a few standards folks about it, they've all said, "oh, yeah, you want declarative AJAX; people have tried and failed to get that standardized for years." Even just trying to get

to target a section of the page that isn't an has been argued about and hashed out for years.<p>Why is that? Well, for example, here's the form you have to fill out to start standardizing a front-end feature. <a href="https://github.com/whatwg/html/issues/new?assignees=&labels=addition%2Fproposal%2Cneeds+implementer+interest&projects=&template=1-new-feature.yml">https://github.com/whatwg/html/issues/new?assignees=&labels=...</a><p>It asks three main questions:<p>* What problem are you trying to solve?

The issue with a single global event handler is discussed here: https://github.com/WICG/close-watcher#a-single-event

If you use popover="", you get the kind of functionality you're discussing for free. For

, the discussion is in progress and reaching a conclusion: https://github.com/whatwg/html/issues/9373