JarCasting
<lazy-image>
Lazily load your images!
🚛
Get it!
npm i -S @power-elements/lazy-image
📦
Load it!
<!-- From CDN -->
<script async type="module" src="https://unpkg.com/@power-elements/lazy-image/lazy-image.js"></script>
<!-- From local installation -->
<script async type="module" src="/node_modules/@power-elements/lazy-image/lazy-image.js"></script>
<!-- In a Module -->
<script type="module">
import '/node_modules/@power-elements/lazy-image/lazy-image.js';
// ...
</script>
💪
Use it!
<lazy-image src="image.jpg" alt="Lazy Image">
<svg slot="placeholder"><use xlink:href="#placeholder-svg"></use></svg>
</lazy-image>
The optional placeholder could be any element. Inline SVG, Pure CSS graphics, or an <img src="data:foo"/> would work best.
💄
Style it!
You should give your <lazy-image> elements some specific dimensions, since it absolutely positions its shadow children. In most cases, you should set the wrapping element as well as the --lazy-image- custom properties to the known display dimensions of your image.
<style>
html {
--lazy-image-width: 640px;
--lazy-image-height: 480px;
}
lazy-image {
width: var(--lazy-image-width);
height: var(--lazy-image-height);
}
</style>
<lazy-image src="https://fillmurray.com/640/480"></lazy-image>
<lazy-image> exposes a set of custom properties for your customizing delight:
| Property | Purpose | Default |
|---|---|---|
--lazy-image-width |
Width of the internal image and placeholder elements | 100% |
--lazy-image-height |
Height of the internal image and placeholder elements | 100% |
--lazy-image-fit |
object-fit property of the internal image and placeholder elements |
contain |
--lazy-image-fade-duration |
Duration of the fade in from the placeholder to the image. Set to 0 to disable fading. | 0.3s |
--lazy-image-fade-easing |
ease property of the opacity transition for the image and placeholder |
ease |
Browser support
lazy-image manages the loading of your images via an Intersection Observer. In browsers where an Intersection Observer is not present, your images will be loaded immediately much like standard <img/> elements. Conditionally delivering the IntersectionObserver polyfill along with your lazy-images to your users will ensure that all users experience the benefits of loading images lazily. Stay lazy, friend!