| /** @module common-sk/modules/object |
| * @description Utility functions for dealing with Objects. |
| */ |
| import { fromObject } from './query.js' |
| |
| /** @method deepCopy |
| * @param {Object} object - The object to make a copy of. |
| * @returns {Object} |
| */ |
| export const deepCopy = (o) => JSON.parse(JSON.stringify(o)); |
| |
| /** Returns true if a and b are equal, covers Boolean, Number, String and Arrays and Objects. |
| * |
| * @param {(number|boolean|string|Array|Object)} a |
| * @param {(number|boolean|string|Array|Object)} b |
| * @returns {boolean} True if the arguments are equal. |
| */ |
| export function equals(a, b) { |
| if (typeof(a) !== typeof(b)) { |
| return false |
| } |
| let ta = typeof(a); |
| if (ta === 'string' || ta === 'boolean' || ta === 'number') { |
| return a === b |
| } |
| if (ta === 'object') { |
| if (Array.isArray(ta)) { |
| return JSON.stringify(a) === JSON.stringify(b) |
| } else { |
| return fromObject(a) === fromObject(b) |
| } |
| } |
| } |
| |
| /** Returns an object with only values that are in o that are different from d. |
| * |
| * Only works shallowly, i.e. only diffs on the attributes of |
| * o and d, and only for the types that equals() supports. |
| * |
| * @example |
| * // Returns {a:2} |
| * getDelta({a:2, b:"foo"}, {a:1, b:"foo", c:3.14}) |
| * |
| * @param {Object} o |
| * @param {Object} d |
| * @returns {Object} |
| * |
| */ |
| export function getDelta(o, d) { |
| let ret = {}; |
| Object.keys(o).forEach(function(key) { |
| if (!equals(o[key], d[key])) { |
| ret[key] = o[key]; |
| } |
| }); |
| return ret; |
| }; |
| |
| /** Returns a copy of object o with values from delta if they exist. |
| * |
| * @param {Object} delta - A delta object as returned from 'getDelta'. |
| * @param {Object} o |
| * @returns {Object} |
| * |
| */ |
| export function applyDelta(delta, o) { |
| let ret = {}; |
| Object.keys(o).forEach(function(key) { |
| if (delta.hasOwnProperty(key)) { |
| ret[key] = deepCopy(delta[key]); |
| } else { |
| ret[key] = deepCopy(o[key]); |
| } |
| }); |
| return ret; |
| }; |
| |