Registers a new field on an existing WordPress object type.

$object_type string|array Required

Object(s) the field is being registered to, "post"|"term"|"comment" etc.

$attribute string Required

The attribute name.

$args array Optional

An array of arguments used to handle the registered field.

• get_callbackcallable|null
  Optional. The callback function used to retrieve the field value. Default is 'null', the field will not be returned in the response. The function will be passed the prepared object data.
• update_callbackcallable|null
  Optional. The callback function used to set and update the field value. Default is 'null', the value cannot be set or updated. The function will be passed the model object, like WP_Post.
• schemaarray|null
  Optional. The schema for this field.
  Default is 'null', no schema entry will be returned.

Default: array()

File: wp-includes/rest-api.php. View all references

function register_rest_field( $object_type, $attribute, $args = array() ) {
	global $wp_rest_additional_fields;

	$defaults = array(
		'get_callback'    => null,
		'update_callback' => null,
		'schema'          => null,
	);

	$args = wp_parse_args( $args, $defaults );

	$object_types = (array) $object_type;

	foreach ( $object_types as $object_type ) {
		$wp_rest_additional_fields[ $object_type ][ $attribute ] = $args;
	}
}