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