plyr/src/js/utils/loadSprite.js
2019-06-01 18:45:07 +10:00

76 lines
2.0 KiB
JavaScript

// ==========================================================================
// Sprite loader
// ==========================================================================
import Storage from '../storage';
import fetch from './fetch';
import is from './is';
// Load an external SVG sprite
export default function loadSprite(url, id) {
if (!is.string(url)) {
return;
}
const prefix = 'cache';
const hasId = is.string(id);
let isCached = false;
const exists = () => document.getElementById(id) !== null;
const update = (container, data) => {
// eslint-disable-next-line no-param-reassign
container.innerHTML = data;
// Check again incase of race condition
if (hasId && exists()) {
return;
}
// Inject the SVG to the body
document.body.insertAdjacentElement('afterbegin', container);
};
// Only load once if ID set
if (!hasId || !exists()) {
const useStorage = Storage.supported;
// Create container
const container = document.createElement('div');
container.setAttribute('hidden', '');
if (hasId) {
container.setAttribute('id', id);
}
// Check in cache
if (useStorage) {
const cached = window.localStorage.getItem(`${prefix}-${id}`);
isCached = cached !== null;
if (isCached) {
const data = JSON.parse(cached);
update(container, data.content);
}
}
// Get the sprite
fetch(url)
.then(result => {
if (is.empty(result)) {
return;
}
if (useStorage) {
window.localStorage.setItem(
`${prefix}-${id}`,
JSON.stringify({
content: result,
}),
);
}
update(container, result);
})
.catch(() => {});
}
}