enable.js
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/*
Copyright 2018 Google LLC
Use of this source code is governed by an MIT-style
license that can be found in the LICENSE file or at
https://opensource.org/licenses/MIT.
*/
import { logger } from 'workbox-core/_private/logger.js';
import { isSupported } from './isSupported.js';
import './_version.js';
/**
* If the browser supports Navigation Preload, then this will enable it.
*
* @param {string} [headerValue] Optionally, allows developers to
* [override](https://developers.google.com/web/updates/2017/02/navigation-preload#changing_the_header)
* the value of the `Service-Worker-Navigation-Preload` header which will be
* sent to the server when making the navigation request.
*
* @memberof module:workbox-navigation-preload
*/
function enable(headerValue) {
if (isSupported()) {
self.addEventListener('activate', (event) => {
event.waitUntil(self.registration.navigationPreload.enable().then(() => {
// Defaults to Service-Worker-Navigation-Preload: true if not set.
if (headerValue) {
self.registration.navigationPreload.setHeaderValue(headerValue);
}
if (process.env.NODE_ENV !== 'production') {
logger.log(`Navigation preload is enabled.`);
}
}));
});
}
else {
if (process.env.NODE_ENV !== 'production') {
logger.log(`Navigation preload is not supported in this browser.`);
}
}
}
export { enable };