@alifd/next/lib/util/object.js

A configurable component library for web built on React.

'use strict';

exports.__esModule = true;

var _typeof2 = require('babel-runtime/helpers/typeof');

var _typeof3 = _interopRequireDefault(_typeof2);

exports.typeOf = typeOf;
exports.isArrayLike = isArrayLike;
exports.isPromise = isPromise;
exports.isPlainObject = isPlainObject;
exports.shallowEqual = shallowEqual;
exports.each = each;
exports.pickOthers = pickOthers;
exports.pickAttrsWith = pickAttrsWith;
exports.isNil = isNil;

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

/**
 * 获取对象的类型
 * @param  {*} obj
 * @return {String}
 *
 * @example
 * typeOf([]) === 'Array'
 * typeOf() === 'Undefined'
 * typeOf(1) === 'Number'
 */
function typeOf(obj) {
    return Object.prototype.toString.call(obj).replace(/\[object\s|]/g, '');
}

/**
 * 判断是否是数组或类数组对象
 * @param  {*}  obj
 * @return {Boolean}
 *
 * @example
 * isArrayLike([]) === true
 * isArrayLike(arguments) === true
 * isArrayLike(this.props.children) === true
 */
function isArrayLike(obj) {
    var length = !!obj && 'length' in obj && obj.length;
    var type = typeOf(obj);

    return type === 'Array' || length === 0 || typeof length === 'number' && length > 0 && length - 1 in obj;
}

/**
 * 判断对象是否是一个promise，即是否可以用.then
 * @param  {*}  obj
 * @return {Boolean}
 */
function isPromise(obj) {
    return !!obj && ((typeof obj === 'undefined' ? 'undefined' : (0, _typeof3.default)(obj)) === 'object' || typeof obj === 'function') && typeof obj.then === 'function';
}

/**
 * 是否是一个纯净的对象
 * @param  {*}  obj
 * @return {Boolean}
 * @reference https://github.com/jonschlinkert/is-plain-object
 */
function isPlainObject(obj) {
    if (typeOf(obj) !== 'Object') {
        return false;
    }

    var ctor = obj.constructor;

    if (typeof ctor !== 'function') {
        return false;
    }

    var prot = ctor.prototype;

    if (typeOf(prot) !== 'Object') {
        return false;
    }

    if (!prot.hasOwnProperty('isPrototypeOf')) {
        return false;
    }

    return true;
}

/**
 * 对象浅比较
 * @param  {Object} objA
 * @param  {Object} objB
 * @param  {Function}  [compare] 手动调用方法比较
 * @return {Boolean}      对象浅比较是否相等
 *
 * @example
 * object.shallowEqual({a: 100}, {a: 100}); // true
 */
function shallowEqual(objA, objB, compare) {
    if (objA === objB) {
        return true;
    }

    // 其中一个不是object，则不相等
    if (!objA || !objB || (typeof objA === 'undefined' ? 'undefined' : (0, _typeof3.default)(objA)) + (typeof objB === 'undefined' ? 'undefined' : (0, _typeof3.default)(objB)) !== 'objectobject') {
        return false;
    }

    var keyA = Object.keys(objA);
    var keyB = Object.keys(objB);
    var len = keyA.length;

    // key 数量不一致则不相等
    if (len !== keyB.length) {
        return false;
    }

    var hasCallback = typeof compare === 'function';

    for (var i = 0; i < len; i++) {
        var key = keyA[i];

        if (!Object.prototype.hasOwnProperty.call(objB, key)) {
            return false;
        }

        var valA = objA[key];
        var valB = objB[key];

        var ret = hasCallback ? compare(valA, valB, key) : void 0;

        if (ret === false || ret === void 0 && valA !== valB) {
            return false;
        }
    }

    return true;
}

/**
 * 遍历对象或数组，或者类数组，例如React中的children对象、arguments等
 * @param  {Object|Array}   obj
 * @param  {Function} callback fn(n, i) or fn(val, key)
 * @param  {Number}   [direction = 1] 是否倒序遍历，只对数组有效
 * @return {Object|Array}
 *
 * @example
 * // 遍历数组
 * object.each([100, 200, 300], (n, i) => console.log(n, i));
 * // 遍历json对象
 * object.each({a: 100, b: 200}, (value, key) => console.log(key, value));
 * // 遍历React子节点
 * object.each(this.props.children, (child, index) => console.log(child));
 * // 遍历arguments
 * object.each(arguments, (arg, i) => console.log(arg));
 */
function each(obj, callback, direction) {
    var reversed = direction === -1;
    var length = obj.length;
    var value = void 0,
        i = reversed ? length - 1 : 0;

    if (isArrayLike(obj)) {
        for (; i < length && i >= 0; reversed ? i-- : i++) {
            value = callback.call(obj[i], obj[i], i);

            if (value === false) {
                break;
            }
        }
    } else {
        for (i in obj) {
            /* istanbul ignore else */
            if (obj.hasOwnProperty(i)) {
                value = callback.call(obj[i], obj[i], i);

                if (value === false) {
                    break;
                }
            }
        }
    }

    return obj;
}

// @private 判断key是否在数组或对象中
var _isInObj = function _isInObj(key, obj, isArray) {
    return isArray ? obj.indexOf(key) > -1 : key in obj;
};

/**
 * 过滤出其它属性
 * @param  {Object|Array} holdProps 过滤的参照对象，最终的结果只保留不在参照对象中的key
 * @param  {Object} props     被过滤的对象
 * @return {Object}           others
 *
 * @example
 * object.pickOthers(FooComponent.propTypes, this.props);
 * object.pickOthers(['className', 'onChange'], this.props);
 */
function pickOthers(holdProps, props) {
    var others = {};
    var isArray = typeOf(holdProps) === 'Array';

    for (var key in props) {
        if (!_isInObj(key, holdProps, isArray)) {
            others[key] = props[key];
        }
    }

    return others;
}

/**
 * 过滤出带prefix的属性
 * @param  {Object} holdProps 过滤的参照对象，最终的结果只保留不在参照对象中的key
 * @param  {string} prefix    包含的字符串
 * @return {Object}           others
 *
 * @example
 * object.pickAttrsWith(FooComponent.propTypes, 'data-');
 */
function pickAttrsWith(holdProps, prefix) {
    var others = {};

    for (var key in holdProps) {
        if (key.match(prefix)) {
            others[key] = holdProps[key];
        }
    }

    return others;
}

/**
 * Checks if value is `null` or `undefined`.
 * @param {*} value
 * @return {Boolean}
 */
function isNil(value) {
    // It will returns `true` only if `null` or `undefined` compare with `null`
    // with loose equaliy
    return value == null; // eslint-disable-line eqeqeq
}