Javascript Service Worker onload显示通知

Question

我有一个注册的服务工作者，但是我想循环使用一个功能来检查服务器上的更新并显示通知，即使关闭了选项卡也是如此。

在serviceworker.js中使用以下代码，我得到一个错误；“未捕获（承诺）TypeError：ServiceWorkerRegistration上没有可用的活动注册。”

self.registration.showNotification(title, {
        body: 'We have received a push message',
        icon: '',
        tag: ''
})

我希望打开浏览器时像Facebook一样弹出通知。

Answer 1

好吧，你首先需要了解service-worker的生命周期

    // listen for a push notification from gcm, as only it can reiterate 
    // your push-notifications to your clients subscriber id
    // put your code inside listener

       self.addEventListener('push', function(event) {  
          console.log('Received a push message', event);

         // here you can make rest calls to fetch data against the subscriber-id 
         // and accordingly, set data 
         // keep in mind that your server sends push notifications to gcm
         // and then your subscribers receive them here

         var title = 'title' || 'data-from-rest-call';  
         var body = 'body' || 'data-from-rest-call';  
         var icon = '/your image path' || 'data-from-rest-call';  
         var tag = 'tag' || 'data-from-rest-call';

         // waitUntil is a callback, it triggers when the push is ready.
         event.waitUntil(  
         //here your ready notifications get triggered
         self.registration.showNotification(title, {  
           body: body,  
           icon: icon,  
           tag: tag  
         })  
      );  
    });

详细了解请参阅 google 的web-push-notifications入门。