JavaScript 实现最简双向绑定的代码示例

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<input type="text" id="myinput" >
<script>
  function watch(obj,key,callback) {
    var old = obj[key];
    Object.defineProperty(obj,key,{
      set:function(val){
        var oldVal = old;
        old = val;
        callback(val,oldVal,this);
      },
      get:function(){
        return old;
      }
    });
  }
  var input = document.getElementById("myinput");
  var obj = {};
  watch(obj, "input",function (val) {
    input.value = val;
    console.log("这里是不管view层，还是module层修改后的回调，最后设置的值是"+val);
  });
  input.onkeyup = function () {
    obj.input = input.value;
  };
</script>
</body>
</html>