Webcomponents：attributeChangedCallback not fired

Question

这是一个基本的Hello World世界Web组件。当属性“who”被更改时，attributeChangedCallback不会被触发。检查小提琴

MyElementProto.attributeChangedCallback = function(attr, oldVal, newVal) { 
    console.log('attributeChangedCallback triggered'); 
     if (attr === 'who') { 
      this.setWho(newVal); 
     } 
    }; 

https://jsfiddle.net/y3kj81nz/5/

Answer 1

您需要使用setAttribute方法：

window.changeWhoAttr = function() { 
    var el = document.querySelector('#custom-tag'); 
    el.setAttribute('who', 'Universe'); // Instead of el.who = 'Universe' 
    console.log('changeWhoAttr triggered'); 
} 

Fiddle