JS开发常用工具函数(小结)

function isStatic(value) {
  return(
    typeof value === 'string' ||
    typeof value === 'number' ||
    typeof value === 'boolean' ||
    typeof value === 'undefined' ||
    value === null
  )
}

function isPrimitive(value) {
  return isStatic(value) || typeof value === 'symbol'
}

function isObject(value) {
   let type = typeof value;
   return value != null && (type == 'object' || type == 'function');
}

function isObjectLike(value) {
   return value != null && typeof value == 'object';
}

function getRawType(value) {
  return Object.prototype.toString.call(value).slice(8, -1)
}
//getoRawType([]) ==> Array

function isPlainObject(obj) {
  return Object.prototype.toString.call(obj) === '[object Object]'
}

function isArray(arr) {
  return Object.prototype.toString.call(arr) === '[object Array]'
}

Array.isArray = Array.isArray || isArray;

function isRegExp(value) {
  return Object.prototype.toString.call(value) === '[object RegExp]'
}

function isDate(value) {
  return Object.prototype.toString.call(value) === '[object Date]'
}

function isNative(value) {
  return typeof value === 'function' && /native code/.test(value.toString())
}

function isFunction(value) {
  return Object.prototype.toString.call(value) === '[object Function]'
}

function isLength(value) {
   return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= Number.MAX_SAFE_INTEGER;
}

function isArrayLike(value) {
   return value != null && isLength(value.length) && !isFunction(value);
}

function isEmpty(value) {
  if (value == null) {
    return true;
  }
  if (isArrayLike(value)) {
    return !value.length;
  }else if(isPlainObject(value)){
     for (let key in value) {
      if (hasOwnProperty.call(value, key)) {
       return false;
      }
    }
    return true;
  }
  return false;
}

function cached(fn) {
  let cache = Object.create(null);
  return function cachedFn(str) {
    let hit = cache[str];
    return hit || (cache[str] = fn(str))
  }
}

let camelizeRE = /-(\w)/g;
function camelize(str) {
  return str.replace(camelizeRE, function(_, c) {
    return c ? c.toUpperCase() : '';
  })
}
//ab-cd-ef ==> abCdEf
//使用记忆函数
let _camelize = cached(camelize)

let hyphenateRE = /\B([A-Z])/g;
function hyphenate(str){
  return str.replace(hyphenateRE, '-$1').toLowerCase()
}
//abCd ==> ab-cd
//使用记忆函数
let _hyphenate = cached(hyphenate);

function capitalize(str){
  return str.charAt(0).toUpperCase() + str.slice(1)
}
// abc ==> Abc
//使用记忆函数
let _capitalize = cached(capitalize)

function extend(to, _from) {
  for(let key in _from) {
    to[key] = _from[key];
  }
  return to
}

Object.assign = Object.assign || function(){
  if(arguments.length == 0) throw new TypeError('Cannot convert undefined or null to object');
  
  let target = arguments[0],
    args = Array.prototype.slice.call(arguments, 1),
    key
  args.forEach(function(item){
    for(key in item){
      item.hasOwnProperty(key) && ( target[key] = item[key] )
    }
  })
  return target
}

let clone = Object.assign({}, target)

let clone = JSON.parse( JSON.stringify(target) )

function clone(value, deep){
  if(isPrimitive(value)){
    return value
  }
  
  if (isArrayLike(value)) { //是类数组
    value = Array.prototype.slice.call(value)
    return value.map(item => deep ? clone(item, deep) : item)
    }else if(isPlainObject(value)){ //是对象
      let target = {}, key;
     for (key in value) {
      value.hasOwnProperty(key) && ( target[key] = deep ? clone(value[key], deep) : value[key] )
    }
  }
  
  let type = getRawType(value)
  
  switch(type){
    case 'Date':
    case 'RegExp': 
    case 'Error': value = new window[type](value); break;
  }
  return value
}

//运行环境是浏览器
let inBrowser = typeof window !== 'undefined';
//运行环境是微信
let inWeex = typeof WXEnvironment !== 'undefined' && !!WXEnvironment.platform;
let weexPlatform = inWeex && WXEnvironment.platform.toLowerCase();
//浏览器 UA 判断
let UA = inBrowser && window.navigator.userAgent.toLowerCase();
let isIE = UA && /msie|trident/.test(UA);
let isIE9 = UA && UA.indexOf('msie 9.0') > 0;
let isEdge = UA && UA.indexOf('edge/') > 0;
let isAndroid = (UA && UA.indexOf('android') > 0) || (weexPlatform === 'android');
let isIOS = (UA && /iphone|ipad|ipod|ios/.test(UA)) || (weexPlatform === 'ios');
let isChrome = UA && /chrome\/\d+/.test(UA) && !isEdge;

function getExplorerInfo() {
  let t = navigator.userAgent.toLowerCase();
  return 0 <= t.indexOf("msie") ? { //ie < 11
    type: "IE",
    version: Number(t.match(/msie ([\d]+)/)[1])
  } : !!t.match(/trident\/.+?rv:(([\d.]+))/) ? { // ie 11
    type: "IE",
    version: 11
  } : 0 <= t.indexOf("edge") ? {
    type: "Edge",
    version: Number(t.match(/edge\/([\d]+)/)[1])
  } : 0 <= t.indexOf("firefox") ? {
    type: "Firefox",
    version: Number(t.match(/firefox\/([\d]+)/)[1])
  } : 0 <= t.indexOf("chrome") ? {
    type: "Chrome",
    version: Number(t.match(/chrome\/([\d]+)/)[1])
  } : 0 <= t.indexOf("opera") ? {
    type: "Opera",
    version: Number(t.match(/opera.([\d]+)/)[1])
  } : 0 <= t.indexOf("Safari") ? {
    type: "Safari",
    version: Number(t.match(/version\/([\d]+)/)[1])
  } : {
    type: t,
    version: -1
  }
}

function isPCBroswer() {
  let e = navigator.userAgent.toLowerCase()
    , t = "ipad" == e.match(/ipad/i)
    , i = "iphone" == e.match(/iphone/i)
    , r = "midp" == e.match(/midp/i)
    , n = "rv:1.2.3.4" == e.match(/rv:1.2.3.4/i)
    , a = "ucweb" == e.match(/ucweb/i)
    , o = "android" == e.match(/android/i)
    , s = "windows ce" == e.match(/windows ce/i)
    , l = "windows mobile" == e.match(/windows mobile/i);
  return !(t || i || r || n || a || o || s || l)
}

function unique(arr){
  if(!isArrayLink(arr)){ //不是类数组对象
    return arr
  }
  let result = []
  let objarr = []
  let obj = Object.create(null)
  
  arr.forEach(item => {
    if(isStatic(item)){//是除了symbol外的原始数据
      let key = item + '_' + getRawType(item);
      if(!obj[key]){
        obj[key] = true
        result.push(item)
      }
    }else{//引用类型及symbol
      if(!objarr.includes(item)){
        objarr.push(item)
        result.push(item)
      }
    }
  })
  
  return resulte
}

window.Set = window.Set || (function () {
  function Set(arr) {
    this.items = arr ? unique(arr) : [];
    this.size = this.items.length; // Array的大小
  }
  Set.prototype = {
    add: function (value) {
      // 添加元素,若元素已存在,则跳过，返回 Set 结构本身。
      if (!this.has(value)) {
        this.items.push(value);
        this.size++;
      }
      return this;
    },
    clear: function () {
      //清除所有成员，没有返回值。
      this.items = []
      this.size = 0
    },
    delete: function (value) {
      //删除某个值，返回一个布尔值，表示删除是否成功。
      return this.items.some((v, i) => {
        if(v === value){
          this.items.splice(i,1)
          return true
        }
        return false
      })
    },
    has: function (value) {
      //返回一个布尔值，表示该值是否为Set的成员。
      return this.items.some(v => v === value)
    },
    values: function () {
      return this.items
    },
  }

  return Set;
}());

function repeat(str, n) {
  let res = '';
  while(n) {
    if(n % 2 === 1) {
      res += str;
    }
    if(n > 1) {
      str += str;
    }
    n >>= 1;
  }
  return res
};
//repeat('123',3) ==> 123123123

function dateFormater(formater, t){
  let date = t ? new Date(t) : new Date(),
    Y = date.getFullYear() + '',
    M = date.getMonth() + 1,
    D = date.getDate(),
    H = date.getHours(),
    m = date.getMinutes(),
    s = date.getSeconds();
  return formater.replace(/YYYY|yyyy/g,Y)
    .replace(/YY|yy/g,Y.substr(2,2))
    .replace(/MM/g,(M<10?'0':'') + M)
    .replace(/DD/g,(D<10?'0':'') + D)
    .replace(/HH|hh/g,(H<10?'0':'') + H)
    .replace(/mm/g,(m<10?'0':'') + m)
    .replace(/ss/g,(s<10?'0':'') + s)
}
// dateFormater('YYYY-MM-DD HH:mm', t) ==> 2019-06-26 18:30
// dateFormater('YYYYMMDDHHmm', t) ==> 201906261830

function dateStrForma(str, from, to){
  //'20190626' 'YYYYMMDD' 'YYYY年MM月DD日'
  str += ''
  let Y = ''
  if(~(Y = from.indexOf('YYYY'))){
    Y = str.substr(Y, 4)
    to = to.replace(/YYYY|yyyy/g,Y)
  }else if(~(Y = from.indexOf('YY'))){
    Y = str.substr(Y, 2)
    to = to.replace(/YY|yy/g,Y)
  }

  let k,i
  ['M','D','H','h','m','s'].forEach(s =>{
    i = from.indexOf(s+s)
    k = ~i ? str.substr(i, 2) : ''
    to = to.replace(s+s, k)
  })
  return to
}
// dateStrForma('20190626', 'YYYYMMDD', 'YYYY年MM月DD日') ==> 2019年06月26日
// dateStrForma('121220190626', '----YYYYMMDD', 'YYYY年MM月DD日') ==> 2019年06月26日
// dateStrForma('2019年06月26日', 'YYYY年MM月DD日', 'YYYYMMDD') ==> 20190626

// 一般的也可以使用正则来实现
//'2019年06月26日'.replace(/(\d{4})年(\d{2})月(\d{2})日/, '$1-$2-$3') ==> 2019-06-26

function getPropByPath(obj, path, strict) {
   let tempObj = obj;
   path = path.replace(/\[(\w+)\]/g, '.$1'); //将[0]转化为.0
   path = path.replace(/^\./, ''); //去除开头的.

   let keyArr = path.split('.'); //根据.切割
   let i = 0;
   for (let len = keyArr.length; i < len - 1; ++i) {
    if (!tempObj && !strict) break;
    let key = keyArr[i];
    if (key in tempObj) {
      tempObj = tempObj[key];
    } else {
      if (strict) {//开启严格模式，没找到对应key值，抛出错误
        throw new Error('please transfer a valid prop path to form item!');
      }
      break;
    }
   }
   return {
    o: tempObj, //原始数据
    k: keyArr[i], //key值
    v: tempObj ? tempObj[keyArr[i]] : null // key值对应的值
   };
};

function GetUrlParam(){
  let url = document.location.toString();
  let arrObj = url.split("?");
  let params = Object.create(null)
  if (arrObj.length > 1){
    arrObj = arrObj[1].split("&");
    arrObj.forEach(item=>{
      item = item.split("=");
      params[item[0]] = item[1]
    })
  }
  return params;
}
// ?a=1&b=2&c=3 ==> {a: "1", b: "2", c: "3"}

function downloadFile(filename, data){
  let DownloadLink = document.createElement('a');

  if ( DownloadLink ){
    document.body.appendChild(DownloadLink);
    DownloadLink.style = 'display: none';
    DownloadLink.download = filename;
    DownloadLink.href = data;

    if ( document.createEvent ){
      let DownloadEvt = document.createEvent('MouseEvents');

      DownloadEvt.initEvent('click', true, false);
      DownloadLink.dispatchEvent(DownloadEvt);
    }
    else if ( document.createEventObject )
      DownloadLink.fireEvent('onclick');
    else if (typeof DownloadLink.onclick == 'function' )
      DownloadLink.onclick();

    document.body.removeChild(DownloadLink);
  }
}

function toFullScreen(){
  let elem = document.body;
  elem.webkitRequestFullScreen 
  ? elem.webkitRequestFullScreen()
  : elem.mozRequestFullScreen
  ? elem.mozRequestFullScreen()
  : elem.msRequestFullscreen
  ? elem.msRequestFullscreen()
  : elem.requestFullScreen
  ? elem.requestFullScreen()
  : alert("浏览器不支持全屏");
}

function exitFullscreen(){
  let elem = parent.document;
  elem.webkitCancelFullScreen 
  ? elem.webkitCancelFullScreen()
  : elem.mozCancelFullScreen
  ? elem.mozCancelFullScreen()
  : elem.cancelFullScreen
  ? elem.cancelFullScreen()
  : elem.msExitFullscreen
  ? elem.msExitFullscreen()
  : elem.exitFullscreen
  ? elem.exitFullscreen()
  : alert("切换失败,可尝试Esc退出");
}

window.requestAnimationFrame = window.requestAnimationFrame ||
  window.webkitRequestAnimationFrame ||
  window.mozRequestAnimationFrame ||
  window.msRequestAnimationFrame ||
  window.oRequestAnimationFrame ||
  function (callback) {
    //为了使setTimteout的尽可能的接近每秒60帧的效果
    window.setTimeout(callback, 1000 / 60);
  };
  
window.cancelAnimationFrame = window.cancelAnimationFrame ||
  Window.webkitCancelAnimationFrame ||
  window.mozCancelAnimationFrame ||
  window.msCancelAnimationFrame ||
  window.oCancelAnimationFrame ||
  function (id) {
    //为了使setTimteout的尽可能的接近每秒60帧的效果
    window.clearTimeout(id);
  }

function _isNaN(v){
  return !(typeof v === 'string' || typeof v === 'number') || isNaN(v)
}

function max(arr){
  arr = arr.filter(item => !_isNaN(item))
  return arr.length ? Math.max.apply(null, arr) : undefined
}
//max([1, 2, '11', null, 'fdf', []]) ==> 11

function min(arr){
  arr = arr.filter(item => !_isNaN(item))
  return arr.length ? Math.min.apply(null, arr) : undefined
}
//min([1, 2, '11', null, 'fdf', []]) ==> 1

function random(lower, upper){
  lower = +lower || 0
  upper = +upper || 0
  return Math.random() * (upper - lower) + lower;
}
//random(0, 0.5) ==> 0.3567039135734613
//random(2, 1) ===> 1.6718418553475423
//random(-2, -1) ==> -1.4474325452361945

Object.keys = Object.keys || function keys(object) {
  if(object === null || object === undefined){
    throw new TypeError('Cannot convert undefined or null to object');
  }
  let result = []
  if(isArrayLike(object) || isPlainObject(object)){
    for (let key in object) {
      object.hasOwnProperty(key) && ( result.push(key) )
    }
  }
  return result
}

Object.values = Object.values || function values(object) {
  if(object === null || object === undefined){
    throw new TypeError('Cannot convert undefined or null to object');
  }
  let result = []
  if(isArrayLike(object) || isPlainObject(object)){
    for (let key in object) {
      object.hasOwnProperty(key) && ( result.push(object[key]) )
    }
  }
  return result
}

Array.prototype.fill = Array.prototype.fill || function fill(value, start, end) {
  let ctx = this
  let length = ctx.length;
  
  start = parseInt(start)
  if(isNaN(start)){
    start = 0
  }else if (start < 0) {
    start = -start > length ? 0 : (length + start);
   }
   
   end = parseInt(end)
   if(isNaN(end) || end > length){
     end = length
   }else if (end < 0) {
    end += length;
  }
  
  while (start < end) {
    ctx[start++] = value;
  }
  return ctx;
}
//Array(3).fill(2) ===> [2, 2, 2]

Array.prototype.includes = Array.prototype.includes || function includes(value, start){
  let ctx = this
  let length = ctx.length;
  
  start = parseInt(start)
  if(isNaN(start)){
    start = 0
  }else if (start < 0) {
    start = -start > length ? 0 : (length + start);
   }
  
  let index = ctx.indexOf(value)
  
  return index >= start;
}

Array.prototype.find = Array.prototype.find || function find(fn, ctx){
  fn = fn.bind(ctx)
  
  let result;
  this.some((value, index, arr), thisValue) => {
    return fn(value, index, arr) ? (result = value, true) : false
  })
  
  return result
}

Array.prototype.findIndex = Array.prototype.findIndex || function findIndex(fn, ctx){
  fn = fn.bind(ctx)
  
  let result;
  this.some((value, index, arr), thisValue) => {
    return fn(value, index, arr) ? (result = index, true) : false
  })
  
  return result
}

window.onload = function(){
  setTimeout(function(){
    let t = performance.timing
    console.log('DNS查询耗时 ：' + (t.domainLookupEnd - t.domainLookupStart).toFixed(0))
    console.log('TCP链接耗时 ：' + (t.connectEnd - t.connectStart).toFixed(0))
    console.log('request请求耗时 ：' + (t.responseEnd - t.responseStart).toFixed(0))
    console.log('解析dom树耗时 ：' + (t.domComplete - t.domInteractive).toFixed(0))
    console.log('白屏时间 ：' + (t.responseStart - t.navigationStart).toFixed(0))
    console.log('domready时间 ：' + (t.domContentLoadedEventEnd - t.navigationStart).toFixed(0))
    console.log('onload时间 ：' + (t.loadEventEnd - t.navigationStart).toFixed(0))

    if(t = performance.memory){
      console.log('js内存使用占比 ：' + (t.usedJSHeapSize / t.totalJSHeapSize * 100).toFixed(2) + '%')
    }
  })
}

document.addEventListener('keydown', function(event){
  return !(
    112 == event.keyCode || //F1
    123 == event.keyCode || //F12
    event.ctrlKey && 82 == event.keyCode || //ctrl + R
    event.ctrlKey && 78 == event.keyCode || //ctrl + N
    event.shiftKey && 121 == event.keyCode || //shift + F10
    event.altKey && 115 == event.keyCode || //alt + F4
    "A" == event.srcElement.tagName && event.shiftKey //shift + 点击a标签
  ) || (event.returnValue = false)
});

['contextmenu', 'selectstart', 'copy'].forEach(function(ev){
  document.addEventListener(ev, function(event){
    return event.returnValue = false
  })
});