diff options
Diffstat (limited to 'wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php')
-rw-r--r-- | wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php | 857 |
1 files changed, 857 insertions, 0 deletions
diff --git a/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php b/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php new file mode 100644 index 0000000..5501c19 --- /dev/null +++ b/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php @@ -0,0 +1,857 @@ +<?php +/** + * REST API: WP_REST_Revisions_Controller class + * + * @package WordPress + * @subpackage REST_API + * @since 4.7.0 + */ + +/** + * Core class used to access revisions via the REST API. + * + * @since 4.7.0 + * + * @see WP_REST_Controller + */ +class WP_REST_Revisions_Controller extends WP_REST_Controller { + + /** + * Parent post type. + * + * @since 4.7.0 + * @var string + */ + private $parent_post_type; + + /** + * Instance of a revision meta fields object. + * + * @since 6.4.0 + * @var WP_REST_Post_Meta_Fields + */ + protected $meta; + + /** + * Parent controller. + * + * @since 4.7.0 + * @var WP_REST_Controller + */ + private $parent_controller; + + /** + * The base of the parent controller's route. + * + * @since 4.7.0 + * @var string + */ + private $parent_base; + + /** + * Constructor. + * + * @since 4.7.0 + * + * @param string $parent_post_type Post type of the parent. + */ + public function __construct( $parent_post_type ) { + $this->parent_post_type = $parent_post_type; + $post_type_object = get_post_type_object( $parent_post_type ); + $parent_controller = $post_type_object->get_rest_controller(); + + if ( ! $parent_controller ) { + $parent_controller = new WP_REST_Posts_Controller( $parent_post_type ); + } + + $this->parent_controller = $parent_controller; + $this->rest_base = 'revisions'; + $this->parent_base = ! empty( $post_type_object->rest_base ) ? $post_type_object->rest_base : $post_type_object->name; + $this->namespace = ! empty( $post_type_object->rest_namespace ) ? $post_type_object->rest_namespace : 'wp/v2'; + $this->meta = new WP_REST_Post_Meta_Fields( $parent_post_type ); + } + + /** + * Registers the routes for revisions based on post types supporting revisions. + * + * @since 4.7.0 + * + * @see register_rest_route() + */ + public function register_routes() { + + register_rest_route( + $this->namespace, + '/' . $this->parent_base . '/(?P<parent>[\d]+)/' . $this->rest_base, + array( + 'args' => array( + 'parent' => array( + 'description' => __( 'The ID for the parent of the revision.' ), + 'type' => 'integer', + ), + ), + array( + 'methods' => WP_REST_Server::READABLE, + 'callback' => array( $this, 'get_items' ), + 'permission_callback' => array( $this, 'get_items_permissions_check' ), + 'args' => $this->get_collection_params(), + ), + 'schema' => array( $this, 'get_public_item_schema' ), + ) + ); + + register_rest_route( + $this->namespace, + '/' . $this->parent_base . '/(?P<parent>[\d]+)/' . $this->rest_base . '/(?P<id>[\d]+)', + array( + 'args' => array( + 'parent' => array( + 'description' => __( 'The ID for the parent of the revision.' ), + 'type' => 'integer', + ), + 'id' => array( + 'description' => __( 'Unique identifier for the revision.' ), + 'type' => 'integer', + ), + ), + array( + 'methods' => WP_REST_Server::READABLE, + 'callback' => array( $this, 'get_item' ), + 'permission_callback' => array( $this, 'get_item_permissions_check' ), + 'args' => array( + 'context' => $this->get_context_param( array( 'default' => 'view' ) ), + ), + ), + array( + 'methods' => WP_REST_Server::DELETABLE, + 'callback' => array( $this, 'delete_item' ), + 'permission_callback' => array( $this, 'delete_item_permissions_check' ), + 'args' => array( + 'force' => array( + 'type' => 'boolean', + 'default' => false, + 'description' => __( 'Required to be true, as revisions do not support trashing.' ), + ), + ), + ), + 'schema' => array( $this, 'get_public_item_schema' ), + ) + ); + } + + /** + * Get the parent post, if the ID is valid. + * + * @since 4.7.2 + * + * @param int $parent_post_id Supplied ID. + * @return WP_Post|WP_Error Post object if ID is valid, WP_Error otherwise. + */ + protected function get_parent( $parent_post_id ) { + $error = new WP_Error( + 'rest_post_invalid_parent', + __( 'Invalid post parent ID.' ), + array( 'status' => 404 ) + ); + + if ( (int) $parent_post_id <= 0 ) { + return $error; + } + + $parent_post = get_post( (int) $parent_post_id ); + + if ( empty( $parent_post ) || empty( $parent_post->ID ) + || $this->parent_post_type !== $parent_post->post_type + ) { + return $error; + } + + return $parent_post; + } + + /** + * Checks if a given request has access to get revisions. + * + * @since 4.7.0 + * + * @param WP_REST_Request $request Full details about the request. + * @return true|WP_Error True if the request has read access, WP_Error object otherwise. + */ + public function get_items_permissions_check( $request ) { + $parent = $this->get_parent( $request['parent'] ); + if ( is_wp_error( $parent ) ) { + return $parent; + } + + if ( ! current_user_can( 'edit_post', $parent->ID ) ) { + return new WP_Error( + 'rest_cannot_read', + __( 'Sorry, you are not allowed to view revisions of this post.' ), + array( 'status' => rest_authorization_required_code() ) + ); + } + + return true; + } + + /** + * Get the revision, if the ID is valid. + * + * @since 4.7.2 + * + * @param int $id Supplied ID. + * @return WP_Post|WP_Error Revision post object if ID is valid, WP_Error otherwise. + */ + protected function get_revision( $id ) { + $error = new WP_Error( + 'rest_post_invalid_id', + __( 'Invalid revision ID.' ), + array( 'status' => 404 ) + ); + + if ( (int) $id <= 0 ) { + return $error; + } + + $revision = get_post( (int) $id ); + if ( empty( $revision ) || empty( $revision->ID ) || 'revision' !== $revision->post_type ) { + return $error; + } + + return $revision; + } + + /** + * Gets a collection of revisions. + * + * @since 4.7.0 + * + * @param WP_REST_Request $request Full details about the request. + * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure. + */ + public function get_items( $request ) { + $parent = $this->get_parent( $request['parent'] ); + if ( is_wp_error( $parent ) ) { + return $parent; + } + + // Ensure a search string is set in case the orderby is set to 'relevance'. + if ( ! empty( $request['orderby'] ) && 'relevance' === $request['orderby'] && empty( $request['search'] ) ) { + return new WP_Error( + 'rest_no_search_term_defined', + __( 'You need to define a search term to order by relevance.' ), + array( 'status' => 400 ) + ); + } + + // Ensure an include parameter is set in case the orderby is set to 'include'. + if ( ! empty( $request['orderby'] ) && 'include' === $request['orderby'] && empty( $request['include'] ) ) { + return new WP_Error( + 'rest_orderby_include_missing_include', + __( 'You need to define an include parameter to order by include.' ), + array( 'status' => 400 ) + ); + } + + if ( wp_revisions_enabled( $parent ) ) { + $registered = $this->get_collection_params(); + $args = array( + 'post_parent' => $parent->ID, + 'post_type' => 'revision', + 'post_status' => 'inherit', + 'posts_per_page' => -1, + 'orderby' => 'date ID', + 'order' => 'DESC', + 'suppress_filters' => true, + ); + + $parameter_mappings = array( + 'exclude' => 'post__not_in', + 'include' => 'post__in', + 'offset' => 'offset', + 'order' => 'order', + 'orderby' => 'orderby', + 'page' => 'paged', + 'per_page' => 'posts_per_page', + 'search' => 's', + ); + + foreach ( $parameter_mappings as $api_param => $wp_param ) { + if ( isset( $registered[ $api_param ], $request[ $api_param ] ) ) { + $args[ $wp_param ] = $request[ $api_param ]; + } + } + + // For backward-compatibility, 'date' needs to resolve to 'date ID'. + if ( isset( $args['orderby'] ) && 'date' === $args['orderby'] ) { + $args['orderby'] = 'date ID'; + } + + /** This filter is documented in wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php */ + $args = apply_filters( 'rest_revision_query', $args, $request ); + $query_args = $this->prepare_items_query( $args, $request ); + + $revisions_query = new WP_Query(); + $revisions = $revisions_query->query( $query_args ); + $offset = isset( $query_args['offset'] ) ? (int) $query_args['offset'] : 0; + $page = (int) $query_args['paged']; + $total_revisions = $revisions_query->found_posts; + + if ( $total_revisions < 1 ) { + // Out-of-bounds, run the query again without LIMIT for total count. + unset( $query_args['paged'], $query_args['offset'] ); + + $count_query = new WP_Query(); + $count_query->query( $query_args ); + + $total_revisions = $count_query->found_posts; + } + + if ( $revisions_query->query_vars['posts_per_page'] > 0 ) { + $max_pages = ceil( $total_revisions / (int) $revisions_query->query_vars['posts_per_page'] ); + } else { + $max_pages = $total_revisions > 0 ? 1 : 0; + } + + if ( $total_revisions > 0 ) { + if ( $offset >= $total_revisions ) { + return new WP_Error( + 'rest_revision_invalid_offset_number', + __( 'The offset number requested is larger than or equal to the number of available revisions.' ), + array( 'status' => 400 ) + ); + } elseif ( ! $offset && $page > $max_pages ) { + return new WP_Error( + 'rest_revision_invalid_page_number', + __( 'The page number requested is larger than the number of pages available.' ), + array( 'status' => 400 ) + ); + } + } + } else { + $revisions = array(); + $total_revisions = 0; + $max_pages = 0; + $page = (int) $request['page']; + } + + $response = array(); + + foreach ( $revisions as $revision ) { + $data = $this->prepare_item_for_response( $revision, $request ); + $response[] = $this->prepare_response_for_collection( $data ); + } + + $response = rest_ensure_response( $response ); + + $response->header( 'X-WP-Total', (int) $total_revisions ); + $response->header( 'X-WP-TotalPages', (int) $max_pages ); + + $request_params = $request->get_query_params(); + $base_path = rest_url( sprintf( '%s/%s/%d/%s', $this->namespace, $this->parent_base, $request['parent'], $this->rest_base ) ); + $base = add_query_arg( urlencode_deep( $request_params ), $base_path ); + + if ( $page > 1 ) { + $prev_page = $page - 1; + + if ( $prev_page > $max_pages ) { + $prev_page = $max_pages; + } + + $prev_link = add_query_arg( 'page', $prev_page, $base ); + $response->link_header( 'prev', $prev_link ); + } + if ( $max_pages > $page ) { + $next_page = $page + 1; + $next_link = add_query_arg( 'page', $next_page, $base ); + + $response->link_header( 'next', $next_link ); + } + + return $response; + } + + /** + * Checks if a given request has access to get a specific revision. + * + * @since 4.7.0 + * + * @param WP_REST_Request $request Full details about the request. + * @return true|WP_Error True if the request has read access for the item, WP_Error object otherwise. + */ + public function get_item_permissions_check( $request ) { + return $this->get_items_permissions_check( $request ); + } + + /** + * Retrieves one revision from the collection. + * + * @since 4.7.0 + * + * @param WP_REST_Request $request Full details about the request. + * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure. + */ + public function get_item( $request ) { + $parent = $this->get_parent( $request['parent'] ); + if ( is_wp_error( $parent ) ) { + return $parent; + } + + $revision = $this->get_revision( $request['id'] ); + if ( is_wp_error( $revision ) ) { + return $revision; + } + + $response = $this->prepare_item_for_response( $revision, $request ); + return rest_ensure_response( $response ); + } + + /** + * Checks if a given request has access to delete a revision. + * + * @since 4.7.0 + * + * @param WP_REST_Request $request Full details about the request. + * @return true|WP_Error True if the request has access to delete the item, WP_Error object otherwise. + */ + public function delete_item_permissions_check( $request ) { + $parent = $this->get_parent( $request['parent'] ); + if ( is_wp_error( $parent ) ) { + return $parent; + } + + if ( ! current_user_can( 'delete_post', $parent->ID ) ) { + return new WP_Error( + 'rest_cannot_delete', + __( 'Sorry, you are not allowed to delete revisions of this post.' ), + array( 'status' => rest_authorization_required_code() ) + ); + } + + $revision = $this->get_revision( $request['id'] ); + if ( is_wp_error( $revision ) ) { + return $revision; + } + + $response = $this->get_items_permissions_check( $request ); + if ( ! $response || is_wp_error( $response ) ) { + return $response; + } + + if ( ! current_user_can( 'delete_post', $revision->ID ) ) { + return new WP_Error( + 'rest_cannot_delete', + __( 'Sorry, you are not allowed to delete this revision.' ), + array( 'status' => rest_authorization_required_code() ) + ); + } + + return true; + } + + /** + * Deletes a single revision. + * + * @since 4.7.0 + * + * @param WP_REST_Request $request Full details about the request. + * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure. + */ + public function delete_item( $request ) { + $revision = $this->get_revision( $request['id'] ); + if ( is_wp_error( $revision ) ) { + return $revision; + } + + $force = isset( $request['force'] ) ? (bool) $request['force'] : false; + + // We don't support trashing for revisions. + if ( ! $force ) { + return new WP_Error( + 'rest_trash_not_supported', + /* translators: %s: force=true */ + sprintf( __( "Revisions do not support trashing. Set '%s' to delete." ), 'force=true' ), + array( 'status' => 501 ) + ); + } + + $previous = $this->prepare_item_for_response( $revision, $request ); + + $result = wp_delete_post( $request['id'], true ); + + /** + * Fires after a revision is deleted via the REST API. + * + * @since 4.7.0 + * + * @param WP_Post|false|null $result The revision object (if it was deleted or moved to the Trash successfully) + * or false or null (failure). If the revision was moved to the Trash, $result represents + * its new state; if it was deleted, $result represents its state before deletion. + * @param WP_REST_Request $request The request sent to the API. + */ + do_action( 'rest_delete_revision', $result, $request ); + + if ( ! $result ) { + return new WP_Error( + 'rest_cannot_delete', + __( 'The post cannot be deleted.' ), + array( 'status' => 500 ) + ); + } + + $response = new WP_REST_Response(); + $response->set_data( + array( + 'deleted' => true, + 'previous' => $previous->get_data(), + ) + ); + return $response; + } + + /** + * Determines the allowed query_vars for a get_items() response and prepares + * them for WP_Query. + * + * @since 5.0.0 + * + * @param array $prepared_args Optional. Prepared WP_Query arguments. Default empty array. + * @param WP_REST_Request $request Optional. Full details about the request. + * @return array Items query arguments. + */ + protected function prepare_items_query( $prepared_args = array(), $request = null ) { + $query_args = array(); + + foreach ( $prepared_args as $key => $value ) { + /** This filter is documented in wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php */ + $query_args[ $key ] = apply_filters( "rest_query_var-{$key}", $value ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores + } + + // Map to proper WP_Query orderby param. + if ( isset( $query_args['orderby'] ) && isset( $request['orderby'] ) ) { + $orderby_mappings = array( + 'id' => 'ID', + 'include' => 'post__in', + 'slug' => 'post_name', + 'include_slugs' => 'post_name__in', + ); + + if ( isset( $orderby_mappings[ $request['orderby'] ] ) ) { + $query_args['orderby'] = $orderby_mappings[ $request['orderby'] ]; + } + } + + return $query_args; + } + + /** + * Prepares the revision for the REST response. + * + * @since 4.7.0 + * @since 5.9.0 Renamed `$post` to `$item` to match parent class for PHP 8 named parameter support. + * + * @param WP_Post $item Post revision object. + * @param WP_REST_Request $request Request object. + * @return WP_REST_Response Response object. + */ + public function prepare_item_for_response( $item, $request ) { + // Restores the more descriptive, specific name for use within this method. + $post = $item; + + $GLOBALS['post'] = $post; + + setup_postdata( $post ); + + $fields = $this->get_fields_for_response( $request ); + $data = array(); + + if ( in_array( 'author', $fields, true ) ) { + $data['author'] = (int) $post->post_author; + } + + if ( in_array( 'date', $fields, true ) ) { + $data['date'] = $this->prepare_date_response( $post->post_date_gmt, $post->post_date ); + } + + if ( in_array( 'date_gmt', $fields, true ) ) { + $data['date_gmt'] = $this->prepare_date_response( $post->post_date_gmt ); + } + + if ( in_array( 'id', $fields, true ) ) { + $data['id'] = $post->ID; + } + + if ( in_array( 'modified', $fields, true ) ) { + $data['modified'] = $this->prepare_date_response( $post->post_modified_gmt, $post->post_modified ); + } + + if ( in_array( 'modified_gmt', $fields, true ) ) { + $data['modified_gmt'] = $this->prepare_date_response( $post->post_modified_gmt ); + } + + if ( in_array( 'parent', $fields, true ) ) { + $data['parent'] = (int) $post->post_parent; + } + + if ( in_array( 'slug', $fields, true ) ) { + $data['slug'] = $post->post_name; + } + + if ( in_array( 'guid', $fields, true ) ) { + $data['guid'] = array( + /** This filter is documented in wp-includes/post-template.php */ + 'rendered' => apply_filters( 'get_the_guid', $post->guid, $post->ID ), + 'raw' => $post->guid, + ); + } + + if ( in_array( 'title', $fields, true ) ) { + $data['title'] = array( + 'raw' => $post->post_title, + 'rendered' => get_the_title( $post->ID ), + ); + } + + if ( in_array( 'content', $fields, true ) ) { + + $data['content'] = array( + 'raw' => $post->post_content, + /** This filter is documented in wp-includes/post-template.php */ + 'rendered' => apply_filters( 'the_content', $post->post_content ), + ); + } + + if ( in_array( 'excerpt', $fields, true ) ) { + $data['excerpt'] = array( + 'raw' => $post->post_excerpt, + 'rendered' => $this->prepare_excerpt_response( $post->post_excerpt, $post ), + ); + } + + if ( rest_is_field_included( 'meta', $fields ) ) { + $data['meta'] = $this->meta->get_value( $post->ID, $request ); + } + + $context = ! empty( $request['context'] ) ? $request['context'] : 'view'; + $data = $this->add_additional_fields_to_object( $data, $request ); + $data = $this->filter_response_by_context( $data, $context ); + $response = rest_ensure_response( $data ); + + if ( ! empty( $data['parent'] ) ) { + $response->add_link( 'parent', rest_url( rest_get_route_for_post( $data['parent'] ) ) ); + } + + /** + * Filters a revision returned from the REST API. + * + * Allows modification of the revision right before it is returned. + * + * @since 4.7.0 + * + * @param WP_REST_Response $response The response object. + * @param WP_Post $post The original revision object. + * @param WP_REST_Request $request Request used to generate the response. + */ + return apply_filters( 'rest_prepare_revision', $response, $post, $request ); + } + + /** + * Checks the post_date_gmt or modified_gmt and prepare any post or + * modified date for single post output. + * + * @since 4.7.0 + * + * @param string $date_gmt GMT publication time. + * @param string|null $date Optional. Local publication time. Default null. + * @return string|null ISO8601/RFC3339 formatted datetime, otherwise null. + */ + protected function prepare_date_response( $date_gmt, $date = null ) { + if ( '0000-00-00 00:00:00' === $date_gmt ) { + return null; + } + + if ( isset( $date ) ) { + return mysql_to_rfc3339( $date ); + } + + return mysql_to_rfc3339( $date_gmt ); + } + + /** + * Retrieves the revision's schema, conforming to JSON Schema. + * + * @since 4.7.0 + * + * @return array Item schema data. + */ + public function get_item_schema() { + if ( $this->schema ) { + return $this->add_additional_fields_schema( $this->schema ); + } + + $schema = array( + '$schema' => 'http://json-schema.org/draft-04/schema#', + 'title' => "{$this->parent_post_type}-revision", + 'type' => 'object', + // Base properties for every Revision. + 'properties' => array( + 'author' => array( + 'description' => __( 'The ID for the author of the revision.' ), + 'type' => 'integer', + 'context' => array( 'view', 'edit', 'embed' ), + ), + 'date' => array( + 'description' => __( "The date the revision was published, in the site's timezone." ), + 'type' => 'string', + 'format' => 'date-time', + 'context' => array( 'view', 'edit', 'embed' ), + ), + 'date_gmt' => array( + 'description' => __( 'The date the revision was published, as GMT.' ), + 'type' => 'string', + 'format' => 'date-time', + 'context' => array( 'view', 'edit' ), + ), + 'guid' => array( + 'description' => __( 'GUID for the revision, as it exists in the database.' ), + 'type' => 'string', + 'context' => array( 'view', 'edit' ), + ), + 'id' => array( + 'description' => __( 'Unique identifier for the revision.' ), + 'type' => 'integer', + 'context' => array( 'view', 'edit', 'embed' ), + ), + 'modified' => array( + 'description' => __( "The date the revision was last modified, in the site's timezone." ), + 'type' => 'string', + 'format' => 'date-time', + 'context' => array( 'view', 'edit' ), + ), + 'modified_gmt' => array( + 'description' => __( 'The date the revision was last modified, as GMT.' ), + 'type' => 'string', + 'format' => 'date-time', + 'context' => array( 'view', 'edit' ), + ), + 'parent' => array( + 'description' => __( 'The ID for the parent of the revision.' ), + 'type' => 'integer', + 'context' => array( 'view', 'edit', 'embed' ), + ), + 'slug' => array( + 'description' => __( 'An alphanumeric identifier for the revision unique to its type.' ), + 'type' => 'string', + 'context' => array( 'view', 'edit', 'embed' ), + ), + ), + ); + + $parent_schema = $this->parent_controller->get_item_schema(); + + if ( ! empty( $parent_schema['properties']['title'] ) ) { + $schema['properties']['title'] = $parent_schema['properties']['title']; + } + + if ( ! empty( $parent_schema['properties']['content'] ) ) { + $schema['properties']['content'] = $parent_schema['properties']['content']; + } + + if ( ! empty( $parent_schema['properties']['excerpt'] ) ) { + $schema['properties']['excerpt'] = $parent_schema['properties']['excerpt']; + } + + if ( ! empty( $parent_schema['properties']['guid'] ) ) { + $schema['properties']['guid'] = $parent_schema['properties']['guid']; + } + + $schema['properties']['meta'] = $this->meta->get_field_schema(); + + $this->schema = $schema; + + return $this->add_additional_fields_schema( $this->schema ); + } + + /** + * Retrieves the query params for collections. + * + * @since 4.7.0 + * + * @return array Collection parameters. + */ + public function get_collection_params() { + $query_params = parent::get_collection_params(); + + $query_params['context']['default'] = 'view'; + + unset( $query_params['per_page']['default'] ); + + $query_params['exclude'] = array( + 'description' => __( 'Ensure result set excludes specific IDs.' ), + 'type' => 'array', + 'items' => array( + 'type' => 'integer', + ), + 'default' => array(), + ); + + $query_params['include'] = array( + 'description' => __( 'Limit result set to specific IDs.' ), + 'type' => 'array', + 'items' => array( + 'type' => 'integer', + ), + 'default' => array(), + ); + + $query_params['offset'] = array( + 'description' => __( 'Offset the result set by a specific number of items.' ), + 'type' => 'integer', + ); + + $query_params['order'] = array( + 'description' => __( 'Order sort attribute ascending or descending.' ), + 'type' => 'string', + 'default' => 'desc', + 'enum' => array( 'asc', 'desc' ), + ); + + $query_params['orderby'] = array( + 'description' => __( 'Sort collection by object attribute.' ), + 'type' => 'string', + 'default' => 'date', + 'enum' => array( + 'date', + 'id', + 'include', + 'relevance', + 'slug', + 'include_slugs', + 'title', + ), + ); + + return $query_params; + } + + /** + * Checks the post excerpt and prepare it for single post output. + * + * @since 4.7.0 + * + * @param string $excerpt The post excerpt. + * @param WP_Post $post Post revision object. + * @return string Prepared excerpt or empty string. + */ + protected function prepare_excerpt_response( $excerpt, $post ) { + + /** This filter is documented in wp-includes/post-template.php */ + $excerpt = apply_filters( 'the_excerpt', $excerpt, $post ); + + if ( empty( $excerpt ) ) { + return ''; + } + + return $excerpt; + } +} |