bp_document_user_document_folder_tree_view_li_html( int $user_id, int $group_id )

function bp_document_user_document_folder_tree_view_li_html( $user_id = 0, $group_id = 0 ) {

	global $wpdb, $bp;

	$document_folder_table = $bp->document->table_name_folder;

	if ( 0 === $group_id ) {
		$group_id = ( function_exists( 'bp_get_current_group_id' ) ) ? bp_get_current_group_id() : 0;
	}

	$documents_folder_query = $wpdb->prepare( "SELECT * FROM {$document_folder_table} WHERE user_id = %d AND group_id = %d ORDER BY id DESC", $user_id, $group_id );


	$data = $wpdb->get_results( $documents_folder_query, ARRAY_A ); // db call ok; no-cache ok;

	// Build array of item references:
	foreach ( $data as $key => &$item ) {
		$itemsByReference[ $item['id'] ] = &$item;
		// Children array:
		$itemsByReference[ $item['id'] ]['children'] = array();
		// Empty data class (so that json_encode adds "data: {}" )
		$itemsByReference[ $item['id'] ]['data'] = new StdClass();
	}

	// Set items as children of the relevant parent item.
	foreach ( $data as $key => &$item ) {
		if ( $item['parent'] && isset( $itemsByReference[ $item['parent'] ] ) ) {
			$itemsByReference [ $item['parent'] ]['children'][] = &$item;
		}
	}

	// Remove items that were added to parents elsewhere:
	foreach ( $data as $key => &$item ) {
		if ( $item['parent'] && isset( $itemsByReference[ $item['parent'] ] ) ) {
			unset( $data[ $key ] );
		}
	}

	return bp_document_folder_recursive_li_list( $data, false );

}