loadImage

Load a given image.

Usage

import { loadImage } from '@studiometa/js-toolkit/utils';

const src = '/path/to/my/image.jpg';
const { event, element } = await loadImage(src);

if (event.type === 'error') {
  console.log(`Failed to load ${src}: ${event.message}`);
} else {
  console.log(`${src} has been loaded!`);
}

Parameters

• src (string): the source URL to load
• options ({ appendTo?: HTMLElement }): configure the loader behavior
  • options.appendTo (HTMLElement): append the created element to a DOM element

Return value

• Promise<{ event: Event, element: HTMLelement }>: a promise resolving to an object containing both the load event object and the created element

Examples

Avoid loading the same image multiple times

You can combine the loadImage function with the memo function to add an in memory cache layer. This will make the generated function always return the same generated element.

import { loadImage, memo } from '@studiometa/js-toolkit';

const loadImageWithCache = memo(loadImage);
const promise = loadImageWithCache('image.webp');
const promise2 = loadImageWithCache('image.webp');

console.assert(promise === promise2); // true

const [result, result2] = await Promise.all([promise, promise2]);

console.assert(result === result2);

Cache invalidation

Be aware that the memo function will use a simple arguments.join('') call to generate the cache key, thus ignoring any change in the options parameter of the loadImage function.

const loadImageWithCache = memo(loadImage);

const result = await loadImageWithCache('image.webp', { appendTo: document.head });
const result2 = await loadImageWithCache('image.webp', { appendTo: document.body });

console.assert(result === result2); // true

console.log(result.element.parentElement): // document.head
console.log(result2.element.parentElement): // document.head