util-helpers

import { isBlob } from 'ut2';
import { createObjectURL, revokeObjectURL } from './utils/native';
/**
 * 加载图片。
 *
 * <em style="font-weight: bold;">注意：该方法仅适用于浏览器端。</em>
 *
 * @alias module:Browser.loadImage
 * @since 4.20.0
 * @param {string | Blob} img 图片地址或 blob 对象
 * @returns {Promise<HTMLImageElement>} HTML图片元素
 * @example
 *
 * loadImage(file).then(image=>{
 *    // do something
 * });
 *
 * loadImage('https://dummyimage.com/200x300').then(image=>{
 *   // do something
 * });
 *
 * loadImage('data:image/png;base64,PGEgaWQ9ImEiPjxiIGlkPSJiIj5oZXkhPC9iPjwvYT4=').then(image=>{
 *   // do something
 * });
 *
 */
function loadImage(img) {
    return new Promise((resolve, reject) => {
        const imgIsBlob = isBlob(img);
        const url = imgIsBlob ? createObjectURL(img) : img;
        const image = new Image();
        if (!imgIsBlob) {
            image.crossOrigin = 'anonymous';
        }
        image.onload = () => {
            resolve(image);
        };
        image.onerror = (err) => {
            if (imgIsBlob) {
                revokeObjectURL(url);
            }
            console.error(`[loadImage] The image load failed, '${img}'.`);
            reject(err);
        };
        image.src = url;
    });
}
export default loadImage;
loadImage.js
