muz-doraemon/src/muz-list-area/x-take-at.js

自主开发的UniApp组件——Жидзин（Zidjin）系列组件库。

// import { isArr, isObj, isNum, isStr, isUndef } from './assert.js';

const takeType = data => Object.prototype.toString.call(data).slice(8, -1);
const isArr = data => takeType(data) === 'Array';
const isObj = data => takeType(data) === 'Object';
const isNum = data => typeof data === 'number';
const isStr = data => typeof data === 'string';
const isUndef = data => ['', null, undefined].includes(data);

const XTakeAt = {};

/**
 * Object takes value by path
 * @function get
 * @param {Record<string, any> | any[]} source
 * @param {String} path 指定的查询路径，支持.操作符，支持数组下标[i]
 * @param {any} defaultValue 返回的默认值, 非必传
 * @returns
 * @author SevenDream Yang
 * @demo
 * let obj = {a: 'aaa', b: { c: 'ccc', d: ['d1', 'd2']}};
 * let val = XTakeAt.getValue(obj, 'b.d[0]',  )
 * 返回 => 'd1'
 */
XTakeAt.getValue = function (source, path, defaultValue = undefined) {
    let target = source;
    let handlePath = path;

    // 如果是数字则转换为字符串
    if (isNum(path)) handlePath = isNaN(path) ? '' : path.toString();

    // 如果路径不是字符串则返回默认值
    if (!isStr(handlePath)) return defaultValue;

    // 判断是不是对象或数组，如果都不是就返回目标对象
    if (!isObj(source) && !isArr(source)) return source;

    // 将路径格式转数组
    const routes = handlePath.replace(/(\[|\])/g, a => (a === '[' ? '.' : '')).split('.');

    // 返回取得的结果
    for (let i = 0, len = routes.length; i < len; i++) {
        const field = routes[i];
        if (isUndef(target[field])) return (target = defaultValue);
        target = target[field];
    }

    return target;
};

export default XTakeAt;