WordPress/WordPress

View on GitHub
wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php

Summary

Maintainability
F
4 days
Test Coverage
<?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 = (int) 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
     * @since 6.5.0 Added a condition to check that parent id matches revision parent id.
     *
     * @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;
        }

        if ( (int) $parent->ID !== (int) $revision->post_parent ) {
            return new WP_Error(
                'rest_revision_parent_id_mismatch',
                /* translators: %d: A post id. */
                sprintf( __( 'The revision does not belong to the specified parent with id of "%d"' ), $parent->ID ),
                array( 'status' => 404 )
            );
        }

        $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.
     *
     * @global WP_Post $post Global post object.
     *
     * @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;
    }
}