/* 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 { assert } from 'workbox-core/_private/assert.js'; import { cacheNames } from 'workbox-core/_private/cacheNames.js'; import { cacheWrapper } from 'workbox-core/_private/cacheWrapper.js'; import { fetchWrapper } from 'workbox-core/_private/fetchWrapper.js'; import { getFriendlyURL } from 'workbox-core/_private/getFriendlyURL.js'; import { logger } from 'workbox-core/_private/logger.js'; import { WorkboxError } from 'workbox-core/_private/WorkboxError.js'; import { messages } from './utils/messages.js'; import './_version.js'; /** * An implementation of a [cache-first]{@link https://developers.google.com/web/fundamentals/instant-and-offline/offline-cookbook/#cache-falling-back-to-network} * request strategy. * * A cache first strategy is useful for assets that have been revisioned, * such as URLs like `/styles/example.a8f5f1.css`, since they * can be cached for long periods of time. * * If the network request fails, and there is no cache match, this will throw * a `WorkboxError` exception. * * @memberof module:workbox-strategies */ class CacheFirst { /** * @param {Object} options * @param {string} options.cacheName Cache name to store and retrieve * requests. Defaults to cache names provided by * [workbox-core]{@link module:workbox-core.cacheNames}. * @param {Array} options.plugins [Plugins]{@link https://developers.google.com/web/tools/workbox/guides/using-plugins} * to use in conjunction with this caching strategy. * @param {Object} options.fetchOptions Values passed along to the * [`init`](https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch#Parameters) * of all fetch() requests made by this strategy. * @param {Object} options.matchOptions [`CacheQueryOptions`](https://w3c.github.io/ServiceWorker/#dictdef-cachequeryoptions) */ constructor(options = {}) { this._cacheName = cacheNames.getRuntimeName(options.cacheName); this._plugins = options.plugins || []; this._fetchOptions = options.fetchOptions; this._matchOptions = options.matchOptions; } /** * This method will perform a request strategy and follows an API that * will work with the * [Workbox Router]{@link module:workbox-routing.Router}. * * @param {Object} options * @param {Request|string} options.request A request to run this strategy for. * @param {Event} [options.event] The event that triggered the request. * @return {Promise} */ async handle({ event, request }) { const logs = []; if (typeof request === 'string') { request = new Request(request); } if (process.env.NODE_ENV !== 'production') { assert.isInstance(request, Request, { moduleName: 'workbox-strategies', className: 'CacheFirst', funcName: 'makeRequest', paramName: 'request', }); } let response = await cacheWrapper.match({ cacheName: this._cacheName, request, event, matchOptions: this._matchOptions, plugins: this._plugins, }); let error; if (!response) { if (process.env.NODE_ENV !== 'production') { logs.push(`No response found in the '${this._cacheName}' cache. ` + `Will respond with a network request.`); } try { response = await this._getFromNetwork(request, event); } catch (err) { error = err; } if (process.env.NODE_ENV !== 'production') { if (response) { logs.push(`Got response from network.`); } else { logs.push(`Unable to get a response from the network.`); } } } else { if (process.env.NODE_ENV !== 'production') { logs.push(`Found a cached response in the '${this._cacheName}' cache.`); } } if (process.env.NODE_ENV !== 'production') { logger.groupCollapsed(messages.strategyStart('CacheFirst', request)); for (const log of logs) { logger.log(log); } messages.printFinalResponse(response); logger.groupEnd(); } if (!response) { throw new WorkboxError('no-response', { url: request.url, error }); } return response; } /** * Handles the network and cache part of CacheFirst. * * @param {Request} request * @param {Event} [event] * @return {Promise} * * @private */ async _getFromNetwork(request, event) { const response = await fetchWrapper.fetch({ request, event, fetchOptions: this._fetchOptions, plugins: this._plugins, }); // Keep the service worker while we put the request to the cache const responseClone = response.clone(); const cachePutPromise = cacheWrapper.put({ cacheName: this._cacheName, request, response: responseClone, event, plugins: this._plugins, }); if (event) { try { event.waitUntil(cachePutPromise); } catch (error) { if (process.env.NODE_ENV !== 'production') { logger.warn(`Unable to ensure service worker stays alive when ` + `updating cache for '${getFriendlyURL(request.url)}'.`); } } } return response; } } export { CacheFirst };