验证策略模式实现

// 定义策略var strategy = {
 isNotEmpty: function(value, errorMsg){
 if(value === ''){ 
 return errorMsg;
 }
 },
 minLength: function(value, length, errorMsg){
 if(value.length < length){ 
 return errorMsg;
 }
 },
 mobileFormat: function(value, errorMsg){
 if(!/(^1[3|5|8][0-9]{9}$)/.test(value)){ 
 return errorMsg;
 }
 }
}function Validator() {
 this.cache = [];
}
Validator.prototype.add = function(value, rules){
 for(var i = 0, rule; rule = rules[i++];){ 
 var self = this;
 (function(rule){
 self.cache.push(function(){
 var strategyRule = rule.strategy.split(':'); 
 var strategyName = strategyRule.shift(); // 各位看官注意啦， 如果直接使用[value].concat(strategyRule.push(rule.errorMsg))会出问题
 // 什么问题呢？ 
 // strategyRule.push(rule.errorMsg)这货会返回length， 我TM调试了半天！
 strategyRule.push(rule.errorMsg); 
 var arr = [value].concat(strategyRule); 
 return strategy[strategyName].apply(null,arr);
 })
 })(rule);
 }
}
Validator.prototype.check = function(){
 for(var i = 0, checkFn; checkFn = this.cache[i++];){ 
 var msg = checkFn(); 
 if(msg){ 
 return msg;
 }
 }
}var validator = new Validator();
validator.add('12345', [
 {
 strategy: 'isNotEmpty',
 errorMsg: 'in not empty'
 },
 {
 strategy: 'minLength:10',
 errorMsg: 'length is less than 10'
 }
]);var tip = validator.check(); // tip: length is less than 10