javascript - 为什么 Service Worker 的消息永远不会到达客户端

Question

我正在尝试设置this example并使其在最简单的一个脚本文件和一个工作文件上工作，但它永远不会从服务工作线程向客户端发送消息。可能是什么问题？

浏览器:

谷歌浏览器版本 64.0.3282.167(官方版本)(64 位)

main.js

navigator.serviceWorker.addEventListener('message', event => {
  console.log(event.data.msg, event.data.url);
});

navigator.serviceWorker.register("sw.js")
  .then(function (registration) {
    console.log("ServiceWorker registration successful with scope: ", registration.scope);
  })
  .catch(function (error) {
    console.error("Service Worker Error", error);
  });

sw.js

addEventListener('install', event => {
    event.waitUntil(self.skipWaiting());
});

addEventListener('activate', event => {
    event.waitUntil(self.clients.claim());
});

addEventListener('fetch', event => {
  event.waitUntil(async function() {
    // Exit early if we don't have access to the client.
    // Eg, if it's cross-origin.
    if (!event.clientId) return;

    // Get the client.
    const client = await clients.get(event.clientId);
    // Exit early if we don't get the client.
    // Eg, if it closed.
    if (!client) return;

    // Send a message to the client.
    client.postMessage({
      msg: "Hey I just got a fetch from you!",
      url: event.request.url
    });
  }());
});

我在每个地方都使用了 console.log，并且正在调用 client.postMessage 方法。

这适用于Mozilla Firefox Quantum 58.0.2(64 位)

Answer 1

您必须首先获取客户端对象。将其添加到您的 fetch 监听器中。

self.clients.matchAll().then(function (clients){
    clients.forEach(function(client){
        client.postMessage({
            msg: "Hey I just got a fetch from you!",
            url: event.request.url
        });
    });
});