kb_ kb_ - 16 days ago 5
C# Question

Order menu nodes by parent, previous and next id

I have a small menu which I would like to order by the DB table id like the following:

public class Obj
{
public string Value { get; set; }
public int? ParentNodeId { get; set; }
public int? PreviousNodeId { get; set; }
public int? NextNodeId { get; set; }
}

private IEnumerable<MenuNodeDTO> GetSortedMenuNodes(int menuId)
{
var nodes = LoadMenuNodes(menuId);
foreach (MenuNode menuNode in nodes
.Where(s => s.MenuItemId == null && s.ParentNodeId == null)
.OrderBy(x => x?.PreviousNodeId)
.Where(x => x.PreviousNodeId != x.Id))
{
MenuNodeDTO tmpMenuNode = new MenuNodeDTO();
tmpMenuNode.MenuNodeDtoId = menuNode.Id;
tmpMenuNode.MenuItemCode = menuNode.MenuItem?.Code;
tmpMenuNode.ChildMenuNodes = GetChildNodes(menuNode).ToList();
tmpMenuNode.MenuSettings = GetMenuSettings(menuNode).ToList();
yield return tmpMenuNode;
}
}


Example:

Id = 1 MainMenuPoint1 ParentNodeId = null, PreviousNodeId = null, NextNodeId = 4
Id = 2 -> 1 ChildNodeFromPoint1 ParentNodeId = 1, PreviousNodeId = null, NextNodeId = null
Id = 3 --> ChildNodeFromFirstChildNode1 ParentNodeId = 2, PreviousNodeId = null, NextNodeId = null
Id = 4 MainMenuPoint2 ParentNodeId = null, PreviousNodeId = 1, NextNodeId = null


The problem with my for each is that when the id changed the ordering not works.
Has someone a idea how to order by parentid, previousid and next id which check every time all ids for the relationship?

kb_ kb_
Answer
 private IEnumerable<MenuNodeDTO> GetSortedNodes(Menu menu, MenuNode node)
        {
            List<MenuNodeDTO> items = new List<MenuNodeDTO>();

            var nodes = node != null ? node.ChildMenuNodes : menu.MenuNodes;
            var nextNode = node == null
                ? nodes.Where(c => c.PreviousNodeId == null && c.ParentNodeId == null).FirstOrDefault()
                : nodes.Where(c => c.ParentNodeId == node.Id && c.PreviousNodeId == null).FirstOrDefault();

            while (nextNode != null)
            {
                MenuNodeDTO tmpMenuNode = new MenuNodeDTO();
                tmpMenuNode.MenuNodeDtoId = nextNode.Id;
                tmpMenuNode.MenuItemCode = nextNode?.MenuItem?.Code;
                tmpMenuNode.ChildMenuNodes = this.GetSortedNodes(menu, nextNode).ToList();
                tmpMenuNode.MenuSettings = GetMenuSettings(nextNode).ToList();
                items.Add(tmpMenuNode);
                if (!nextNode.NextNodeId.HasValue) break;
                nextNode = nextNode.NextNode;
            }
            return items;
        }