ServiceWorker.state
ServiceWorker 接口的这个只读的
state
属性返回一个代表 service worker 当前状态的字符串。值可以是以下这些:installing, installed, activating, activated,或者是 redundant.
语法
someURL = ServiceWorker.state
值
一个 ServiceWorkerState
的定义值 (see the spec.)
示例
这块代码出自 service worker registration-events sample (live demo). 代码监听了任何ServiceWorker.state
中的改变,并返回它的值。
js
var serviceWorker;
if (registration.installing) {
serviceWorker = registration.installing;
document.querySelector("#kind").textContent = "installing";
} else if (registration.waiting) {
serviceWorker = registration.waiting;
document.querySelector("#kind").textContent = "waiting";
} else if (registration.active) {
serviceWorker = registration.active;
document.querySelector("#kind").textContent = "active";
}
if (serviceWorker) {
logState(serviceWorker.state);
serviceWorker.addEventListener("statechange", function (e) {
logState(e.target.state);
});
}
规范
Specification |
---|
Service Workers # service-worker-state |
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