Pen Settings

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

+ add another resource

You're using npm packages, so we've auto-selected Babel for you here, which we require to process imports and make it all work. If you need to use a different JavaScript preprocessor, remove the packages in the npm tab.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Use npm Packages

We can make npm packages available for you to use in your JavaScript. We use webpack to prepare them and make them available to import. We'll also process your JavaScript with Babel.

⚠️ This feature can only be used by logged in users.

Code Indentation

     

Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

HTML Settings

Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

            
              <button id="demo">点击事件</button>

            
          
!
            
              const button = document.getElementById('demo');
button.addEventListener('click',function(){
  alert(1)
})
button.addEventListener('click',function(){
  alert(2)
})
// button.click()
let Event= {
  clientList:[],
  // 缓存事件列表 思路 需要为每个事件记录已经发送的key 如果新增事件的是 发现之前有缓存事件没触发 那么需要执行之前的事件?
  cacheBroadList:[],
  listen :function(key,fn){
    if(typeof(fn) === 'function'){
      if(!(key in this.clientList)){
//         之前没有这个对象 那么需要补发所有的事件
        this.clientList[key] = []
      } 
      this.clientList[key].push(fn)
      if(this.cacheBroadList.length > 0){
          for(let i = 0 ,len = this.cacheBroadList.length;i < len ;i++){
           
            this.broad(this.cacheBroadList[i],key)
          }
        }
    } else{
      throw Error("非函数类型")
    }
    
  },
  broad:function(msg,watcher){
//     缓存下来所有的事件
    this.cacheBroadList.push('oldMsg' + msg)
    if(!watcher){
        for(let p in this.clientList){
        if(this.clientList[p].length === 0 ) return false;
      for(let i = 0,len = this.clientList[p].length ;i<len;i++){
        this.clientList[p][i] && this.clientList[p][i](msg)
      }
    }
    }
    else{
      for(let i = 0,len = this.clientList[watcher].length ;i<len;i++){
        this.clientList[watcher][i] && this.clientList[watcher][i](msg)
      }
     
    }
  
  
  }
}
Event.remove = function(key,fn){
  var fns = this.clientList[key];
  if(!fns){return false ;}
  if(!fn && fns){
     fns.length = 0
  }
  for(let i = fns.length - 1;i>= 0 ; i--){
    let _fn = fns[i];
  	if(_fn === fn){
      fns.splice(i, 1);
    }
  }
}

Event.broad('有40万的房子销售了')
Event.listen('xiaozhang',function(msg){
  console.log('xiaozhang:' + msg)
})
Event.broad('有120万的房子销售了')

Event.listen('xiaowang',function(msg){
  console.log('xiaowang:' + msg)
})

// Event.remove('xiaowang')
Event.broad('有130万的房子销售了')


const installEvent = (oriObj) => {
  for(let p in Event){
    oriObj[p] = Event[p];
  }
}
let salesOffices = {
  name:'销售办公室',
  sales:'小航',
}
installEvent(salesOffices)
// salesOffices.broad('有房子销售了')
            
          
!
999px
🕑 One or more of the npm packages you are using needs to be built. You're the first person to ever need it! We're building it right now and your preview will start updating again when it's ready.

Console