PushAPI的推送服务URL是怎么设置的？

Question

Push API 将推送服务定义为

a system that allows application servers to send push messages to a webapp.

通过不带任何参数调用 serviceWorkerRegistration .pushManager.subscribe() 创建服务订阅。

这个推送服务的URL是如何配置的？我本来希望 .subscribe() 为服务采用 URL 参数。

The Push API 的姊妹规范 Generic Event Delivery Using HTTP Push 说：

push service: This resource is used to create push message subscriptions (see Section 3). A URL for the push service is configured into user agents.

但它没有指定如何进行此配置。

Answer 1

the second document you cite 中的这句话回答了问题：

This document intentionally does not describe how a push service is discovered. Discovery of push services is left for future efforts, if it turns out to be necessary at all. User agents are expected to be configured with a URL for a push service.

目前，浏览器附带了一些特定推送服务的内置知识，例如 Chrome 中的 GCM。在 HTMLRocks 的 Push Notifications on the Open Web 文章中提到了这一点：

Chrome uses GCM to handle the sending and delivery of push messages.... Other browsers are free to use any push service...

但是看看浏览器将来是否会开放会很有趣，这样，正如您所建议的，我们可以在 subscribe.[=15= 的参数中指定我们自己选择的服务]

Answer 2

你先用navigator.serviceWorker.register('/some-service-worker.js')注册了一个service worker，然后你调用serviceWorkerRegistration .pushManager.subscribe()的时候这个seriveceWorkerRegistration指的就是你刚注册的service worker

最好用一个例子来证明这一点：

navigator.serviceWorker.register('/some-service-worker.js').then(function() {
    navigator.serviceWorker.ready.then(function(serviceWorkerRegistration) {
        serviceWorkerRegistration.pushManager.subscribe({userVisibleOnly: true}).then(function() {/*...*/});
    });
});