wp-graphql-smart-cache-litespeed.php

<?php
/**
 * Plugin Name: WPGraphQL Smart Cache for Litespeed
 * Description: Allows WPGraphQL Smart Cache to work for WordPress sites hosted on environments using Litespeed Cache
 * Author: WPGraphQL
 * Author URI: http://www.wpgraphql.com
 * Text Domain: wp-graphql-smart-cache-litespeed
 * Version: 0.0.1
 * Requires at least: 5.0
 * Tested up to: 6.1
 * Requires PHP: 7.1
 * License: GPL-3
 * License URI: https://www.gnu.org/licenses/gpl-3.0.html
 */

// Initialize the bridge between wpgraphql smart cache and litespeed cache
add_action( 'plugins_loaded', 'graphql_smart_cache_litespeed_init' );

/**
 * Initialize the bridge between wpgraphql smart cache and litespeed cache
 */
function graphql_smart_cache_litespeed_init() {

	// if the litespeed cache plugin isn't active, do nothing
	if ( ! defined( 'LSCWP_V' ) ) {
		return;
	}

	// force litespeed to cache GraphQL queries made over GET requests
	add_action( 'graphql_process_http_request_response', 'graphql_litespeed_force_cacheable' );

	// add litespeed tags, unset the x-graphql-keys
	add_filter( 'graphql_response_headers_to_send', 'graphql_litespeed_tag_responses' );

	// call litespeed_purge when graphql_purge is called
	add_action( 'graphql_purge', 'graphql_litespeed_purge' );


}

/**
 * Force GraphQL Queries returned via HTTP GET requests to be cacheable
 */
function graphql_litespeed_force_cacheable() {

	if ( 'GET' !== $_SERVER['REQUEST_METHOD'] ) {
		return;
	}

	do_action( 'litespeed_control_force_cacheable' );

}

/**
 * add litespeed tags, unset the x-graphql-keys
 *
 * @param array
 *
 * @return array
 */
function graphql_litespeed_tag_responses( array $headers = [] ): array {
	if ( isset( $headers['X-GraphQL-Keys'] ) ) {
		do_action( 'litespeed_tag_add', explode( ' ', $headers['X-GraphQL-Keys']  ) );
		
		// unset the x-graphql-keys headers so that we don't overpopulate the headers as there are header size limitations
		unset( $headers['X-GraphQL-Keys']  );
	}
	return $headers;

}

/**
 * call litespeed_purge when graphql_purge is called
 *
 * @param string|array
 *             
 * @return void
 */
function graphql_litespeed_purge( $keys ) {
	do_action( 'litespeed_purge', $keys );
}