WordPress REST API Object Cache

Enable object caching for WordPress' REST API. Aids in increased response times of your applications endpoints.

Package Installation (via Composer)

To install this package, edit your composer.json file:

{
    "require": {
        "dwnload/wp-rest-api-object-cache": "^1.3.0"
    }
}

Now run:

$ composer install dwnload/wp-rest-api-object-cache

---

• Actions
• How to use actions
• Filters
• How to use filters

Actions

Action	Argument(s)
Dwnload\WpRestApi\RestApi\RestDispatch::ACTION_CACHE_SKIPPED	mixed $result WP_REST_Server $server WP_REST_Request $request
Dwnload\WpRestApi\WpAdmin\Admin::ACTION_REQUEST_FLUSH_CACHE	string $message string $type WP_User $user

How to use actions

use Dwnload\WpRestApi\RestApi\RestDispatch;
add_action( RestDispatch::ACTION_CACHE_SKIPPED, function( $result, \WP_REST_Server $server, \WP_REST_Request $request ) {
	// Do something here, like create a log entry using Wonolog.
}, 10, 3 );

use Dwnload\WpRestApi\WpAdmin\Admin;
add_action( Admin::ACTION_REQUEST_FLUSH_CACHE, function( $message, $type, WP_User $user ) {
	// Do something here, like create a log entry using Wonolog.
}, 10, 3 );

Filters

Filter	Argument(s)
Dwnload\WpRestApi\RestApi\RestDispatch::FILTER_CACHE_HEADERS	array $headers string $request_uri WP_REST_Server $server WP_REST_Request $request WP_REST_Response $response (rest_pre_dispatch only)
Dwnload\WpRestApi\RestApi\RestDispatch::FILTER_CACHE_SKIP	boolean $skip ( default: WP_DEBUG ) string $request_uri WP_REST_Server $server WP_REST_Request $request
Dwnload\WpRestApi\RestApi\RestDispatch::FILTER_API_KEY	string $request_uri WP_REST_Server $server WP_REST_Request $request
Dwnload\WpRestApi\RestApi\RestDispatch::FILTER_API_GROUP	string $cache_group
Dwnload\WpRestApi\RestApi\RestDispatch::FILTER_CACHE_EXPIRE	int $expires
Dwnload\WpRestApi\WpAdmin\Admin::FILTER_CACHE_UPDATE_OPTIONS	array $options
Dwnload\WpRestApi\WpAdmin\Admin::FILTER_CACHE_OPTIONS	array $options
Dwnload\WpRestApi\WpAdmin\Admin::FILTER_SHOW_ADMIN	boolean $show
Dwnload\WpRestApi\WpAdmin\Admin::FILTER_SHOW_ADMIN_MENU	boolean $show
Dwnload\WpRestApi\WpAdmin\Admin::FILTER_SHOW_ADMIN_BAR_MENU	boolean $show
Dwnload\WpRestApi\RestApi\RestDispatch::FILTER_ALLOWED_CACHE_STATUS	array $status HTTP Header statuses (defaults to array( 200 )
Dwnload\WpRestApi\RestApi\RestDispatch::FILTER_CACHE_VALIDATE_AUTH	boolean $authenticated WP_REST_Request $request

How to use filters

Sending headers.

use Dwnload\WpRestApi\RestApi\RestDispatch;
add_filter( RestDispatch::FILTER_CACHE_HEADERS, function( array $headers ) : array {
	$headers['Cache-Control'] = 'public, max-age=3600';
	
	return $headers;
} );

Changing the cache expire time.

use Dwnload\WpRestApi\RestApi\RestDispatch;
add_filter( RestDispatch::FILTER_CACHE_EXPIRE, function() : int {
	// https://codex.wordpress.org/Transients_API#Using_Time_Constants
	return ( HOUR_IN_SECONDS * 5 );
} );

use Dwnload\WpRestApi\WpAdmin\Admin;
add_filter( Admin::FILTER_CACHE_OPTIONS, function( array $options ) : array {
	if ( ! isset( $options['timeout'] ) ) {
		$options['timeout'] = array();
	}

	// https://codex.wordpress.org/Transients_API#Using_Time_Constants
	$options['timeout']['length'] = 15;
	$options['timeout']['period'] = DAY_IN_SECONDS;
	
	return $options;
} );

Validating user auth when ?context=edit

use Dwnload\WpRestApi\RestApi\RestDispatch;
add_filter( RestDispatch::FILTER_CACHE_VALIDATE_AUTH, function( bool $auth, WP_REST_Request $request ) : bool {
	// If you are running the Basic Auth plugin.
	if ( $GLOBALS['wp_json_basic_auth_error'] === true ) {
        $authorized = true;
    }
    // Otherwise, maybe do some additional logic on the request for current user...

    return $authorized;
}, 10, 2 );

Skipping cache

use Dwnload\WpRestApi\RestApi\RestDispatch;
add_filter( RestDispatch::FILTER_CACHE_SKIP, function( bool $skip, string $request_uri ) : bool {
	if ( ! $skip && stripos( 'wp-json/dwnload/v2', $request_uri ) !== false ) {
		return true;
	}

	return $skip;
}, 10, 2 );

Deleting cache

Soft delete: Append RestDispatch::QUERY_CACHE_DELETE to your query param: add_query_arg( [ RestDispatch::QUERY_CACHE_DELETE, '1' ], '<url>' ).
soft delete will delete the cache after the current request completes (on WordPress shutdown).

Hard delete: Append RestDispatch::QUERY_CACHE_DELETE && RestDispatch::QUERY_CACHE_FORCE_DELETE to your query param: add_query_arg( [ RestDispatch::QUERY_CACHE_DELETE, '1', RestDispatch::QUERY_CACHE_FORCE_DELETE, '1' ], '<url>' ).
hard delete will delete the cache before the request, forcing it to repopulate.

empty ALL cache on post-save this is not ideal

You can use the WordPress filter save_post if you would like to empty ALL cache on post save.

use Dwnload\WpRestApi\RestApi\RestDispatch;
add_action( 'save_post', function( $post_id ) {
  if ( class_exists( RestDispatch::class ) ) {
    call_user_func( [ ( WpRestApiCache::getRestDispatch(), 'wpCacheFlush' ] );
  }
} );

Maybe better to use transition_post_status

add_action( 'transition_post_status', function(  string $new_status, string $old_status, \WP_Post $post ) {
  if ( 'publish' === $new_status || 'publish' === $old_status ) {
    \wp_cache_flush();
  }
}, 99, 3 );