简单实现双向数据绑定mvvm

<input id="input"/>

const data = {};
const input = document.getElementById('input');
Object.defineProperty(data, 'text', {    
set(value) {
    input.value = value;    
    this.value = value;
  }
});
input.onChange = function(e) {
  data.text = e.target.value;
}