Displaying HTML web components

Those HTML web components I made for date inputs are very simple. All they do is slightly extend the behaviour of the existing input elements.

This would be the ideal use-case for the is attribute:

<input is="input-date-future" type="date">

Alas, Apple have gone on record to say that they will never ship support for customized built-in elements.

So instead we have to make HTML web components by wrapping existing elements in new custom elements:

<input-date-future>
  <input type="date">
<input-date-future>

The end result is the same. Mostly.

Because there’s now an additional element in the DOM, there could be unexpected styling implications. Like, suppose the original element was direct child of a flex or grid container. Now that will no longer be true.

So something I’ve started doing with HTML web components like these is adding something like this inside the connectedCallback method:

connectedCallback() {
    this.style.display = 'contents';
  …
}

This tells the browser that, as far as styling is concerned, there’s nothing to see here. Move along.

Or you could (and probably should) do it in your stylesheet instead:

input-date-future {
  display: contents;
}

Just to be clear, you should only use display: contents if your HTML web component is augmenting what’s within it. If you add any behaviours or styling to the custom element itself, then don’t add this style declaration.

It’s a bit of a hack to work around the lack of universal support for the is attribute, but it’ll do.

a view source web

As a self-initiated learner, being able to view source brought to mind the experience of a slow walk through someone else’s map.

This ability to “observe” software makes HTML special to work with.

On Container Queries, Responsive Images, and JPEG-XL – Cloud Four

Container queries can’t be used in the sizes attribute for responsive images. Here, Jason breaks down why that is (spoiler: it’s the lookahead pre-parser) and segues into a truly long term solution: a “magical” image format.

If you’ve ever thought it felt weird to put media conditions inside the HTML for responsive images, this will resonate.

How to (not) make a button - Tomas Pustelnik’s personal website

A demonstration of how even reinventing a relatively simple wheel takes way more effort than it’s worth when you could just use what the brower gives you for free.

Will Serving Real HTML Content Make A Website Faster? Let’s Experiment! - WebPageTest Blog

Spoiler: the answer to the question in the title is a resounding “hell yeah!”

Scott brings receipts.

TIL: You Can Access A User’s Camera with Just HTML

The capture attribute is pretty nifty—and I just love that you get so much power in a declarative way:

<input type="file" accept="image/*" capture="environment">