README

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 );

dwnload / wp-rest-api-object-cache

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