JavaScript程序设计模式小技巧——策略模式，快看快用！！！（下）

validator.add(username, [
  {
    strategy: "isEmpty",
    msg: "用户名不能为空"
  },
  {
    strategy: 'minLength:6',
    msg: '密码不能少于 6 位'
  }
]);

let infoForm = {
  username: "阿斯顿发生的",
  password: "ss1sdf",
  tel: 15829485647,
};
var strategies = {
  isEmpty: function (val, msg) {
    if (!val) return msg;
  },
  minLength: function (val, length, msg) {
    if (val.length < length) return msg;
  },
  isTel: function (val, msg) {
    if (!/(^1[3|5|8][0-9]{9}$)/.test(val)) return msg;
  },
};
var validFn = function () {
  var validator = new Validator();
  let { username, password, tel } = infoForm;
  validator.add(username, [
    {
      strategy: "isEmpty",
      msg: "用户名不能为空",
    },
    {
      strategy: "minLength:6",
      msg: "密码不能少于 6 位",
    },
  ]);
  validator.add(password, [
    {
      strategy: "minLength:6",
      msg: "密码不能少于 6 位",
    },
  ]);
  validator.add(tel, [
    {
      strategy: "isTel",
      msg: "手机号码格式不正确",
    },
  ]);
  var msg = validator.start();
  return msg;
};
class Validator {
  constructor() {
    this.cache = [];
  }
  add(attr, rules) {
    for (let i = 0; i < rules.length; i++) {
      var rule = rules[i];
      var ruleArr = rule.strategy.split(":");
      var msg = rule.msg;
      var cacheItem = this.createCacheItem(ruleArr, attr, msg);
      this.cache.push(cacheItem);
    }
  }
  start() {
    for (let i = 0; i < this.cache.length; i++) {
      var msg = this.cache[i]();
      if (msg) return msg;
    }
  }
  createCacheItem(ruleArr, attr, msg) {
    return function () {
      var strategy = ruleArr.shift();
      ruleArr.unshift(attr);
      ruleArr.push(msg);
      return strategies[strategy].apply(attr, ruleArr);
    };
  }
}
function submit() {
  let msg = validFn();
  if (msg) {
    Toast(msg);
    return false;
  }
  console.log("verify success");
  // .....
}
submit();