20 items tagged “web-components”
2024
HTML for People (via) Blake Watson's brand new HTML tutorial, presented as a free online book (CC BY-NC-SA 4.0, on GitHub). This seems very modern and well thought-out to me. It focuses exclusively on HTML, skipping JavaScript entirely and teaching with Simple.css to avoid needing to dig into CSS while still producing sites that are pleasing to look at. It even touches on Web Components (described as Custom HTML tags) towards the end.
[Reddit is] mostly ported over entirely to Lit now. There are a few straggling pages that we're still working on, but most of what everyday typical users see and use is now entirely Lit based. This includes both logged out and logged in experiences.
— Jim Simon, Reddit
My approach to HTML web components. Some neat patterns here from Jeremy Keith, who is using Web Components extensively for progressive enhancement of existing markup.
The reactivity you get with full-on frameworks [like React and Vue] isn’t something that web components offer. But I do think web components can replace jQuery and other approaches to scripting the DOM.
Jeremy likes naming components with their element as a prefix (since all element names must contain at least one hyphen), and suggests building components under the single responsibility principle - so you can do things like <button-confirm><button-clipboard><button>....
He configures these buttons with data- attributes and has them communicate with each other using custom events.
Something I hadn't realized is that since the connectedCallback function on a custom element is fired any time that element is attached to a page you can fetch() and then insertHTML content that includes elements and know that they will initialize themselves without needing any extra logic - great for the kind of pattern encourages by systems such as HTMX.
Introducing Enhance WASM (via) “Backend agnostic server-side rendering (SSR) for Web Components”—fascinating new project from Brian LeRoux and Begin.
The idea here is to provide server-side rendering of Web Components using WebAssembly that can run on any platform that is supported within the Extism WASM ecosystem.
The key is the enhance-ssr.wasm bundle, a 4.1MB WebAssembly version of the enhance-ssr JavaScript library, compiled using the Extism JavaScript PDK (Plugin Development Kit) which itself bundles a WebAssembly version of QuickJS.
Cally: Accessibility statement (via) Cally is a neat new open source date (and date range) picker Web Component by Nick Williams.
It’s framework agnostic and weighs less than 9KB grilled, but the best feature is this detailed page of documentation covering its accessibility story, including how it was tested—in JAWS, NVDA and VoiceOver.
I’d love to see other open source JavaScript libraries follow this example.
Coroutines and web components (via) I like using generators in Python but I rarely knowingly use them in JavaScript—I’m probably most exposed to them by Observable, which uses then extensively under the hood as a mostly hidden implementation detail.
Laurent Renard here shows some absolutely ingenious tricks with them as a way of building stateful Web Components.
Streaming HTML out of order without JavaScript (via) A really interesting new browser capability. If you serve the following HTML:
<template shadowrootmode="open">
<slot name="item-1">Loading...</slot>
</template>
Then later in the same page stream an element specifying that slot:
<span slot="item-1">Item number 1</span>
The previous slot will be replaced while the page continues to load.
I tried the demo in the most recent Chrome, Safari and Firefox (and Mobile Safari) and it worked in all of them.
The key feature is shadowrootmode=open, which looks like it was added to Firefox 123 on February 19th 2024 - the other two browsers are listed on caniuse.com as gaining it around March last year.
Portable EPUBs. Will Crichton digs into the reasons people still prefer PDF over HTML as a format for sharing digital documents, concluding that the key issues are that HTML documents are not fully self-contained and may not be rendered consistently.
He proposes “Portable EPUBs” as the solution, defining a subset of the existing EPUB standard with some additional restrictions around avoiding loading extra assets over a network, sticking to a smaller (as-yet undefined) subset of HTML and encouraging interactive components to be built using self-contained Web Components.
Will also built his own lightweight EPUB reading system, called Bene—which is used to render this Portable EPUBs article. It provides a “download” link in the top right which produces the .epub file itself.
There’s a lot to like here. I’m constantly infuriated at the number of documents out there that are PDFs but really should be web pages (academic papers are a particularly bad example here), so I’m very excited by any initiatives that might help push things in the other direction.
2023
HTML Web Components: An Example
(via)
Jim Nielsen provides a clear example illustrating the idea of the recently coined "HTML Web Components" pattern. It's Web Components as progressive enhancement: in this example a <user-avatar> custom element wraps a regular image, then JavaScript defines a Web Component that enhances that image. If the JavaScript fails to load the image still displays.
Web Components Will Outlive Your JavaScript Framework (via) A really clear explanation of the benefit of Web Components built using dependency-free vanilla JavaScript, specifically for interactive components that you might want to embed in something like a blog post. Includes a very neat minimal example component.
Someone asked me today if there was a case for using React in a new app that doesn't need to support IE.
I could not come up with a single reason to prefer it over Preact or (better yet) any of the modern reactive Web Components systems (FAST, Lit, Stencil, etc.).
One of the constraints is that the team wanted to use an existing library of Web Components, but React made it hard. This is probably going to cause them to favour Preact for the bits of the team that want React-flavoured modern webdev.
It's astonishing how antiquated React is.
2022
Shoelace (via) Saw this for the first time today: it’s a relatively new library of framework-agnostic Web Components, built on lit-html and covering a huge array of common functionality: buttons and sliders and dialogs and drawer interfaces and dropdown menus and so on. The design is very clean, the documentation is superb—and it looks like you can cherry pick just the components you are using for a pretty lean addition to your page weight. So refreshing to see libraries like this that really take advantage of modern web standards.
PyScript demos (via) PyScript was announced at PyCon this morning. It’s a new open source project that provides Web Components built on top of Pyodide, allowing you to use Python directly within your HTML pages in a way that is executed using a WebAssembly copy of Python running in your browser. These demos really help illustrate what it can do—it’s a fascinating new piece of the Python web ecosystem.
Web Components as Progressive Enhancement (via) I think this is a key aspect of Web Components I had been missing: since they default to rendering their contents, you can use them as a wrapper around regular HTML elements that can then be progressively enhanced once the JavaScript has loaded.
lite-youtube-embed (via) Handy Web Component wrapper around the standard YouTube iframe embed which knocks over 500KB of JavaScript off the initial page load—I just added this to the datasette.io homepage and increased the Lighthouse performance score from 51 to 93!
SQLime: SQLite Playground (via) Anton Zhiyanov built this useful mobile-friendly online playground for trying things out it SQLite. It uses the sql.js library which compiles SQLite to WebAssembly, so it runs everything in the browser—but it also supports saving your work to Gists via the GitHub API. The JavaScript source code is fun to read: the site doesn’t use npm or Webpack or similar, opting instead to implement everything library-free using modern JavaScript modules and Web Components.
2021
Weeknotes: Shaving some beautiful yaks
I’ve been mostly shaving yaks this week—two in particular: the Datasette table refactor and the next release of git-history. I also built and released my first Web Component!
[... 1,307 words]Weeknotes: Learning Kubernetes, learning Web Components
I’ve been mainly climbing the learning curve for Kubernetes and Web Components this week. I also released Datasette 0.59.1 with Python 3.10 compatibility and an updated Docker image.
[... 1,101 words]Tonic (via) Really interesting library for building Web Components: it’s tiny (just 350 lines of code), works directly in browsers without any compile or build step and makes very creative use of modern JavaScript features such as async generators.
2018
matthewp/haunted: React’s Hooks API implemented for web components (via) It’s been fascinating over the past few days watching various frontend web stacks start playing with the new ideas introduced by the proposed React hooks API. lit-html is one of my favourite React alternatives—it’s built on web components and makes really clever use of ES6 template literals (in place of React’s JSX, which requires an additional compilation step). With Haunted Matthew Phillips explores the combination of lit-html, web components and hooks-style state management.