wp-includes/rest-api/endpoints/class-wp-rest-controller.php:527Retrieves all of the registered additional fields for a given object-type.
$object_typestringoptionalnullarray protected function get_additional_fields( $object_type = null ) { global $wp_rest_additional_fields; if ( ! $object_type ) { $object_type = $this->get_object_type(); } if ( ! $object_type ) { return array(); } if ( ! $wp_rest_additional_fields || ! isset( $wp_rest_additional_fields[ $object_type ] ) ) { return array(); } return $wp_rest_additional_fields[ $object_type ]; }Introduced in 4.7.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/rest-api/endpoints/class-wp-rest-controller.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.