JSFiddle - React, Tailwind, and code Playground

by raycn

HTML

<p id="test">
hahahahahaha


</p>

JavaScript

var addEvent = window.addEventListener ? 
  function(element, type, handler) {
    element.addEventListener(type, handler, false);    
  } : function(element, type, handler) {
    if(!handler.$$guid) {
      handler.$$guid = addEvent.guid++;
    }
    if(!element.events) {
      element.events = {};
    }
    var handlers = element.events[type];
    if(!handlers) {
      handlers = element.events[type] = {};
      // 添加对象上已有事件处理器
      if(element['on' + type]) {
        handlers[0] = element['on' + type];
      }
      element['on' + type] = handleEvent;
    }
    handlers[handler.$$guid] = handler;
  };

addEvent.guid = 1;

var removeEvent = window.removeEventListener ? 
  function(element, type, handler) {
    element.removeEventListener(type, handler, false);
  } : function(element, type, handler) {
    delete element.events[type][handler.$$guid];    
  }

function handleEvent(event) {
  event = event || fixEvent(window.event);
  var returnValue = true;
  var handlers = this.events[event.type];
  
  for (var i in handlers) {
    if(!Object.prototype[i]) {
      this.$$handler = handlers[i];
      if(this.$$handler(event) === false) {
        returnValue = false;
      }
    }
  }
  if(this.$$handler) {
    this.$$handler = null;
  }
  return returnValue;
}

function fixEvent(event) {
  event.preventDefault = fixEvent.preventDefault;
  event.stopPropagation = fixEvent.stopPropagation;
  return event;
}
fixEvent.preventDefault = function() {
  this.returnValue = false;
}
fixEvent.stopPropagation = function() {
  this.cancelBubble = true;
}

if (!window.addEventListener) {
  document.onreadystatechange = function() {
    if (window.onload && window.onload != handleEvent){
      addEvent(window, 'load', window.onload);
      window.onload = handleEvent;
    }
  }
}


addEvent(document.getElementById('test'), 'click', function() { alert('test')});