Web Components

The Extensible Web Summit is taking place in Berlin today because Web Components are that important. I wish I could be there, but I’ll make do with the live notes, the IRC channel, and the octothorpe tag.

I have conflicting feelings about Web Components. I am simultaneously very excited and very nervous. That’s probably a good sign.

Here’s what I wrote after the last TAG meetup in London:

This really is a radically new and different way of adding features to browsers. In theory, it shifts the balance of power much more to developers (who currently have to hack together everything using JavaScript). If it works, it will be A Good Thing and result in expanding HTML’s vocabulary with genuinely useful features. I fear there may be a rocky transition to this new way of thinking, and I worry about backwards compatibility, but I can’t help but admire the audacity of the plan.

And here’s what I wrote after the Edge conference:

If Web Components work out, and we get a kind emergent semantics of UI widgets, it’ll be a huge leap forward for the web. But if we end up with a Tower of Babel, things could get very messy indeed. We’ll probably get both at once.

To explain…

The exciting thing about Web Components is that they give developers as much power as browser makers.

The frightening thing about Web Components is that they give developers as much power as browser makers.

When browser makers—and other contributors to web standards—team up to hammer out new features in HTML, they have design principles to guide them …at least in theory. First and foremost—because this is the web, not some fly-by-night “platform”—is the issue of compatability:

Support existing content

Degrade gracefully

You can see those principles at work with newly-minted elements like canvas, audio, video where fallback content can be placed between the opening and closing tags so that older user agents aren’t left high and dry (which, in turn, encourages developers to start using these features long before they’re universally supported).

You can see those principles at work in the design of datalist.

You can see those principles at work in the design of new form features which make use of the fact that browsers treat unknown input types as type="text" (again, encouraging developers to start using the new input long before they’re supported in every browser).

When developers are creating new Web Components, they could apply that same amount of thought and care; Chris Scott has demonstrated just such a pattern. Switching to Web Components does not mean abandoning progressive enhancement. If anything they provide the opportunity to create whole new levels of experience.

Web developers could ensure that their Web Components degrade gracefully in older browsers that don’t support Web Components (and no, “just polyfill it” is not a sustainable solution) or, for that matter, situations where JavaScript—for whatever reason—is not available.

Web developers could ensure that their Web Components are accessible, using appropriate ARIA properties.

But I fear that Sturgeon’s Law is going to dominate Web Components. The comparison that’s often cited for Web Components is the creation of jQuery plug-ins. And let’s face it, 90% of jQuery plug-ins are crap.

This wouldn’t matter so much if developers were only shooting themselves in the foot, but because of the wonderful spirit of sharing on the web, we might well end up shooting others in the foot too:

1. I make something (to solve a problem).
2. I’m excited about it.
3. I share it.
4. Others copy and paste what I’ve made.

Most of the time, that’s absolutely fantastic. But if the copying and pasting happens without critical appraisal, a lot of questionable decisions can get propagated very quickly.

To give you an example…

When Apple introduced the iPhone, it provided a mechanism to specify that a web page shouldn’t be displayed in a zoomed-out view. That mechanism, which Apple pulled out of their ass without going through any kind of standardisation process, was to use the meta element with a name of “viewport”:

<meta name="viewport" value="...">

The value attribute of a meta element takes a comma-separated list of values (think of name="keywords": you provide a comma-separated list of keywords). But in an early tutorial about the viewport value, code was provided which showed values separated with semicolons (like CSS declarations). People copied and pasted that code (which actually did work in Mobile Safari) and so every browser must support that usage:

Many other mobile browsers now support this tag, although it is not part of any web standard. Apple’s documentation does a good job explaining how web developers can use this tag, but we had to do some detective work to figure out exactly how to implement it in Fennec. For example, Safari’s documentation says the content is a “comma-delimited list,” but existing browsers and web pages use any mix of commas, semicolons, and spaces as separators.

Anyway, that’s just one illustration of how code gets shared, copied and pasted. It’s especially crucial during the introduction of a new technology to try to make sure that the code getting passed around is of a high quality.

I feel kind of bad saying this because the introductory phase of any new technology should be a time to say “Hey, go crazy! Try stuff out! See what works and what doesn’t!” but because Web Components are so powerful I think that mindset could end up doing a lot of damage.

Web developers have been given powerful features in the past. Vendor prefixes in CSS were a powerful feature that allowed browsers to push the boundaries of CSS without creating a Tower of Babel of propietary properties. But because developers just copied and pasted code, browser makers are now having to support prefixes that were originally scoped to different rendering engines. That’s not the fault of the browser makers. That’s the fault of web developers.

With Web Components, we are being given a lot of rope. We can either hang ourselves with it, or we can make awesome …rope …structures …out of rope this analogy really isn’t working.

I’m not suggesting we have some kind of central authority that gets to sit in judgement on which Web Components pass muster (although Addy’s FIRST principles are a great starting point). Instead I think a web of trust will emerge.

If I see a Web Component published by somebody at Paciello Group, I can be pretty sure that it will be accessible. Likewise, if Christian publishes a Web Component, it’s a good bet that it will use progressive enhancement. And if any of the superhumans at Filament Group share a Web Component, it’s bound to be accessible, performant, and well thought-out.

Because—as is so often the case on the web—it’s not really about technologies at all. It’s about people.

And it’s precisely because it’s about people that I’m so excited about Web Components …and simultaneously so nervous about Web Components.

Churn

This is a good description of the appeal of HTML web components:

WC lifecycles are crazy simple: you register the component with customElements.define and it’s off to the races. Just write a class and the browser will take care of elements appearing and disappearing for you, regardless of whether they came from a full reload, a fetch request, or—god forbid—a document.write. The syntax looks great in markup, too: no more having to decorate with js-something classes or data attributes, you just wrap your shit in a custom element called something-controller and everyone can see what you’re up to. Since I’m firmly in camp “progressively enhance or go home” this fits me like a glove, and I also have great hopes for Web Components improving the poor state of pulling in epic dependencies like date pickers or text editors.

The Web Component Success Story | jakelazaroff.com

The power of interoperability:

Web components won’t take web development by storm, or show us the One True Way to build websites. They don’t need to dethrone JavaScript frameworks. We probably won’t even all learn how to write them!

What web components will do — at least, I hope — is let us collectively build a rich ecosystem of dynamic components that work with any web stack. No more silos. That’s the web component success story.

Web Components Will Outlive Your JavaScript Framework | jakelazaroff.com

Decision time:

There’s a cost to using dependencies. New versions are released, APIs change, and it takes time and effort to make sure your own code remains compatible with them. And the cost accumulates over time.

This post is about more than web components:

If we want our work to be accessible in five or ten or even 20 years, we need to use the web with no layers in between. For all its warts, the web has become the most resilient, portable, future-proof computing platform we’ve ever created — at least, if we build with that in mind.

Using Stencil to make a live poll Web Component

Before getting into the details of the code, Matt hits the nail on the head talking about the the one thing that web components have that no framework can offer: longevity.

Quoting Stuart Brand:

Old systems break in familiar ways. New systems break in unexpected ways.

Well! The web is an old system.

Building a Frontend Framework; Reactivity and Composability With Zero Dependencies

The thinking behind the minimal JavaScript framework, Strawberry:

Even without specialized syntax, you can do a lot of what the usual frontend framework does—with similar conciseness—just by using Proxy and WebComponents.