JSFiddle - React, Tailwind, and code Playground

by raycn

HTML

<a id="hello" href="http://baidu.com">hello</a>
<div id="mouseenter" class="out enterleave"><p>move your mouse</p><div class="in enterleave"><p>move your mouse</p><p>0</p></div><p>0</p></div>

CSS

div.out {
width:40%;
height:120px;
margin:0 15px;
background-color:#D6EDFC;
float:left;
}
div.in {
width:60%;
height:60%;
background-color:#FFCC00;
margin:10px auto;
}
p {
line-height:1em;
margin:0;
padding:0;
}

JavaScript

function addEvent(element, type, handler) {
  if(element.addEventListener) {
    element.addEventListener(type, handler, false);
  } else if (element.attachEvent) {
    element["e"+type+handler] = handler;
    element[type+handler] = function() {
      var event = fixEvent(window.event);
      element["e"+type+handler](event);
    }
    element.attachEvent("on"+type, element[type + handler]);
  }
}
function removeEvent(element, type, handler) {
  if(element.removeEventListener) {
    element.removeEventListener(type, handler, false);
  } else if (element.detachEvent) {
    element.detachEvent("on" + type, element[type + handler]); 
    element[type + handler] = null;
    element["e" + type + handler] = null;
  }
}
function fixEvent(event) {
  event.preventDefault = fixEvent.preventDefault;
  event.stopPropagation = fixEvent.stopPropagation;
  //fix target 
  if(!event.target) {
    event.target = event.srcElement || document;
  }
  //Target should not be a text node
  if(event.target.nodeType ===3) {
    event.target = event.target.parentNode;
  }
  return event;
}
fixEvent.preventDefault = function() {
  this.returnValue = false;
}
fixEvent.stopPropagation = function() {
  this.cancelBubble = true;
}
function contains(container, maybe) {
    return container.contains ? container.contains(maybe) :
        !!(container.compareDocumentPosition(maybe) & 16);
}

function contains(container, maybe) {
    return container.contains ? container.contains(maybe) :
        !!(container.compareDocumentPosition(maybe) & 16);
}

function mouseEnterLeave(element, type, handler) {
  var isMouseEnter = type === 'mouseenter';

  if(typeof element.onmouseenter !== 'undefined') {
    addEvent(element, type, handler);
  } else {
    var handle = function(e) {
      var target = e.target,
          related = e.relatedTarget;
      if((element === target || contains(element, target)) &&
         !contains(element, related)) {
        handler();
      }
    }
    type = isMouseEnter ?...