mvvm双向绑定机制的原理和实现代码(推荐)

<div id="container">
  <p>
  name:<input type="text" bindkey="userName">
  </p>
  <p>
  age:<input type="text" bindkey="age">
  </p>
<div>

<script type="text/javascript">
  window.Model={
    userName:"windy",
    age:34,
    skill:["javascript","html","css","jquery","node"],
    
  }
  function bindingModel(model,changeCallback){
    var propertiesMap={};
    model.__private={};
    function getFn(name){
      var result=this.__private[name]
      console.log("get value:"+name+"="+ result);
      return result;
    };
    function setFn(name,val){
      if(this.__private[name]!=val){
        console.log("set value:"+name+"="+val);
       
        this.__private[name]=val;

        if(changeCallback){
          changeCallback(name,val);
        }
      }
    };
    for(elem in model){
      if(model.hasOwnProperty(elem) && elem!="__private" && typeof(model[elem])!="function"){
        (function(propName,propValue){
          model.__private[propName]=propValue;// init value
          propertiesMap[propName]={
            get:function(){ return getFn.call(this,propName)},
            set:function(v){ return setFn.call(this,propName,v)},
            //value:model[elem],
            //writable: true,
            enumerable: true,
            configurable: true
          }
        })(elem,model[elem]);
      }
    }
    Object.defineProperties(model,propertiesMap)
    
  }
  function bindingBoth(model,dom){
    dom.find("[bindkey]").each(function(item){
      var key=$(this).attr("bindkey");
      $(this).val(model[key]);
      $(this).bind("input",function(){
        model[key]=$(this).val();
      })
    });
    bindingModel(model,function(name,val){
      var el=dom.find("[bindkey="+name+"]");
      if(el.val()!=val){
        el.val(val);
      }
      
    });
  }
  bindingBoth(window.Model,$("#container"))
  </script>