yy-dev7

/**
 * [惰性单例]
 * @param  {Function} fn [需要使用单例模式的函数]
 * @return {Function}
 */
function getSingle(fn) {
	var ret
	return (...args) => ret || (ret = fn.apply(this, args))
}

yy-dev7

const Cookies = {
  get(name) {
    let start
    let end

    if (document.cookie.length > 0) {
      start = document.cookie.indexOf(`${name}=`)
      if (start !== -1) {
        start = start + name.length + 1
        end = document.cookie.indexOf(';', start)

yy-dev7

/**
 * 检测浏览器是否支持某个css属性
 * @param  {[String]} prop  [属性名]
 * @param  {[String]} value [属性值]
 * @return {[Boolean]} true:支持 否则不支持
 */
function cssSupported(prop, value) {
  const d = document.createElement('div')
  d.style[prop] = value
  return d.style[prop] === value

yy-dev7

/**
 * 生成uuid
 * @return {[string]} uuid
 */
function generateUUID() {
  function s4() {
    return Math.floor((1 + Math.random()) * 0x10000)
      .toString(16)
      .substring(1)
  }

yy-dev7

/**
 * ScrollFix v0.1
 * http://www.joelambert.co.uk
 *
 * Copyright 2011, Joe Lambert.
 * Free to use under the MIT license.
 * http://www.opensource.org/licenses/mit-license.php
 */

var ScrollFix = function(elem) {

yy-dev7

function cacheProxyFactory(fn) {
  var cache = {}
  return function() {
    var args = [].join.call(arguments, ',')
    if (args in cache) {
      return cache[args]
    }
    return cache[args] = fn.apply(this, arguments)
  }
}

yy-dev7

var synchronousFile = function(id) {
	console.log('开始同步文件，id 为: ' + id);
}

// 虚拟代理http请求
var proxySynchronousFile = (function() {
	var cache = [], timer

	return function(id) {
		cache.push(id)

yy-dev7

class EventEmitter {
  constructor() {
    this.clientList = {}
  }

  on(key, fn) {
    if (!this.clientList[key]) {
      this.clientList[key] = []
    }
    this.clientList[key].push(fn)

yy-dev7

function optionalChaining(obj, chain) {
  return chain
    .split('.')
    .reduce(function(acc, val) {
      return acc ? acc[val] : undefined;
    }, obj);
}
var user = { address: { street: 'No.969 West WenYi Road', }, a: { b: { c: 2 } }, }
var ret = optionalChaining(user, 'address');
console.log(ret)

yy-dev7

window.requestAnimFrame = (function requestAnimFrame() {
  return window.requestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame ||
    function simulation(callback) {
      window.setTimeout(callback, 1000 / 60)
    }
}())

function scrollToY(scrollTargetY = 0, speed = 2000, easing = 'easeOutSine') {