PushManager.getSubscription() - Web APIs 编辑

Experimental

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The PushManager.getSubscription() method of the PushManager interface retrieves an existing push subscription.

It returns a Promise that resolves to a PushSubscription object containing details of an existing subscription. If no existing subscription exists, this resolves to a null value.

Syntax

PushManager.getSubscription().then(function(pushSubscription) { ... } );

Parameters

None.

Returns

A Promise that resolves to a PushSubscription object or null.

Example

This code snippet is taken from a push messaging and notification sample. (No live demo is available.)

// We need the service worker registration to check for a subscription
  navigator.serviceWorker.ready.then(function(serviceWorkerRegistration) {
    // Do we already have a push message subscription?
    serviceWorkerRegistration.pushManager.getSubscription()
      .then(function(subscription) {
        // Enable any UI which subscribes / unsubscribes from
        // push messages.
        var pushButton = document.querySelector('.js-push-button');
        pushButton.disabled = false;

        if (!subscription) {
          // We aren’t subscribed to push, so set UI
          // to allow the user to enable push
          return;
        }

        // Keep your server in sync with the latest subscriptionId
        sendSubscriptionToServer(subscription);

        showCurlCommand(subscription);

        // Set your UI to show they have subscribed for
        // push messages
        pushButton.textContent = 'Disable Push Messages';
        isPushEnabled = true;
      })
      .catch(function(err) {
        window.Demo.debug.log('Error during getSubscription()', err);
      });
  });

Specifications

Browser compatibility

BCD tables only load in the browser