private FolderTree PopulateFolderTreeNode(FolderTree parentNode) { parentNode.Children = repository.GetFoldersWithParentOfID(parentNode.Id) .Select(t => new FolderTree { Id = t.Id, Name = t.Name }).ToList(); foreach (var childNode in parentNode.Children) { PopulateFolderTreeNode(childNode); } return(parentNode); }