Async-1.js
· 667 B · JavaScript
Неформатований
// for use with callbacks...
import { forEachOf } from "async-es";
const images = {cat: "/cat.png", dog: "/dog.png", duck: "/duck.png"};
const sizes = {};
forEachOf(images, (value, key, callback) => {
const imageElem = new Image();
imageElem.src = value;
imageElem.addEventListener("load", () => {
sizes[key] = {
width: imageElem.naturalWidth,
height: imageElem.naturalHeight,
};
callback();
});
imageElem.addEventListener("error", (e) => {
callback(e);
});
}, err => {
if (err) console.error(err.message);
// `sizes` is now a map of image sizes
doSomethingWith(sizes);
});
| 1 | // for use with callbacks... |
| 2 | import { forEachOf } from "async-es"; |
| 3 | |
| 4 | const images = {cat: "/cat.png", dog: "/dog.png", duck: "/duck.png"}; |
| 5 | const sizes = {}; |
| 6 | |
| 7 | forEachOf(images, (value, key, callback) => { |
| 8 | const imageElem = new Image(); |
| 9 | imageElem.src = value; |
| 10 | imageElem.addEventListener("load", () => { |
| 11 | sizes[key] = { |
| 12 | width: imageElem.naturalWidth, |
| 13 | height: imageElem.naturalHeight, |
| 14 | }; |
| 15 | callback(); |
| 16 | }); |
| 17 | imageElem.addEventListener("error", (e) => { |
| 18 | callback(e); |
| 19 | }); |
| 20 | }, err => { |
| 21 | if (err) console.error(err.message); |
| 22 | // `sizes` is now a map of image sizes |
| 23 | doSomethingWith(sizes); |
| 24 | }); |