wp-admin/includes/misc.php:1356Performs autosave with heartbeat.
$responsearray$dataarrayarrayfunction heartbeat_autosave( $response, $data ) { if ( ! empty( $data['wp_autosave'] ) ) { $saved = wp_autosave( $data['wp_autosave'] ); if ( is_wp_error( $saved ) ) { $response['wp_autosave'] = array( 'success' => false, 'message' => $saved->get_error_message(), ); } elseif ( empty( $saved ) ) { $response['wp_autosave'] = array( 'success' => false, 'message' => __( 'Error while saving.' ), ); } else { /* translators: Draft saved date format, see https://www.php.net/manual/datetime.format.php */ $draft_saved_date_format = __( 'g:i:s a' ); $response['wp_autosave'] = array( 'success' => true, /* translators: %s: Date and time. */ 'message' => sprintf( __( 'Draft saved at %s.' ), date_i18n( $draft_saved_date_format ) ), ); } } return $response;}Introduced in 3.9.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/misc.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.