stale-while-revalidate.php

<?php
/**
 * Plugin Name: Stale While Revalidate
 * Author: Weston Ruter
 * Plugin URI: https://gist.github.com/westonruter/f848013108672568be6dcde153f9ca37
 */

// It is implied that the wp_service_worker_navigation_caching_strategy is for the front.
// @todo Instead of relying on filters, what if $scripts->navigation_routing->set_strategy( WP_Service_Worker_Caching_Routes::STRATEGY_STALE_WHILE_REVALIDATE )?
// @todo This could similarly be done to set navigation_preload, skip_waiting, clients_claim, etc.
add_filter( 'wp_service_worker_navigation_caching_strategy', function() {
	return WP_Service_Worker_Caching_Routes::STRATEGY_STALE_WHILE_REVALIDATE;
} );

add_filter( 'wp_service_worker_navigation_caching_strategy_args', function( $args ) {
	$args['cacheName'] = 'pages';

	$args['plugins']['expiration']['maxEntries'] = 50;
	$args['plugins']['expiration']['purgeOnQuotaError'] = true;
	return $args;
} );