Hierarchical Model binding

Question

I have written code for getting hierarchical data for the location. I am able to get the hierarchy to TWO level only, but what I'm looking for nth level hierarchy. I have written the recursive function as well, but unable to add the data into the hierarchy.

Data Model Class: -

public class RoomDTO
    {
        public Guid RoomId { get; set; }
        public string Name { get; set; }    

        public Guid? ParentRoomId { get; set; }       
        public List<RoomDTO> Children { get; set; } = new List<RoomDTO>();

    }

Parent Function:-

private List<RoomDTO> RoomData(List<SubLocation> subLocations)
        {
            List<RoomDTO> rooms = new List<RoomDTO>();
            foreach (var location in subLocations.Where(x => x.HasChildLocations))
            {
                var subLocationDTO = new RoomDTO
                {
                     RoomId = location.SubLocationId
                     ,Children = getChild(subLocations, location, new RoomDTO()).Children
                };

                rooms.Add(subLocationDTO);
            }
            return rooms;
        }

Recursive Function: -

private RoomDTO getChild(List<SubLocation> list, SubLocation location, RoomDTO roomDTO)
        {

            var child = list.Where(x => x.ParentSubLocationId == location.SubLocationId).ToList();
            for (int i = 0; i < child.Count; i++)
            {
                var childRoom = new RoomDTO {
                    ParentRoomId = child[i].ParentSubLocationId
                    , RoomId = child[i].SubLocationId
                };                
                roomDTO.Children.Add(childRoom);
                getChild(list, child[i], roomDTO);
            }
            return locList; 
        }

Calling function: -

 public void GetRoomList()
{
            var subLocationList = _context.SubLocations.AsNoTracking().ToList();

            var data = RoomData(subLocationList);

}

Please advise what incorrect I'm doing here.

Can you explain the condition "unable to add the data into the hierarchy"? Are you getting error for current setup or want trying something with new hierarchy? — Tetsuya Yamamoto, Oct 17 '18 at 14:36
`getChild(subLocations, location, new RoomDTO()).Children` should you really be passing `subLocations`? Something seems funny here - but I do not really understand your code. Also it doesn't seem quite right that a lot of rooms are being created with the children? — BenKoshy, Oct 18 '18 at 03:49
roomDTO.Children.Add(childRoom); this line is adding children at the same level although they are at a lower level in the hierarchy. A room can have child room(s) and a child room can have further child room(s). — Arayn, Oct 18 '18 at 05:40
can you put your sublocation class code the way we can understand more what your code is doing ? — Haithem KAROUI, Oct 18 '18 at 09:22
You can simplify your code by using `.ToLookup` - refer [this answer](https://stackoverflow.com/questions/46560515/how-to-create-dynamic-menu-using-tree/46562343#46562343) for an example — , Oct 24 '18 at 03:28
@StephenMuecke, thanks for link. It did solve the problem. I needed to add Order column in table to identify the sequence of child's. — Arayn, Oct 25 '18 at 05:00

score 0 · Accepted Answer · answered Oct 25 '18 at 05:13

I followed below steps to resolve the issue, 1> Added Field(SortId) in table to identify the sequence of parent and child items. 2> From list of items, filtered the data based on ParentId and then sorted by SortId

if (summaryList.Count > 0)
            {
                //make Mneu structure 
                foreach (var menu in summaryList.Where(x => x.data.ParentSubLocationId == null).OrderBy(x => x.data.SortId))
                {
                    menu.children = GetChildMenuIetms(menu, summaryList);
                    menus.Add(menu);
                }
            }

3> In above foreach loop, executed recurrsive GetChildMenuItem function to fetch child itmes, as shown below,

public List<Child> GetChildMenuIetms(Child menuItem, List<Child> menuItems)
    {
        List<Child> childerns = null;
        childerns = menuItems.Where(x => x.data.ParentSubLocationId == menuItem.data.SubLocationId).OrderBy(x => x.data.SortId).ToList();

        if (childerns != null && childerns.Count > 0)
        {
            for (int i = 0; i < childerns.Count; i++)
            {

                childerns[i].children = GetChildMenuIetms(childerns[i], menuItems.Where(x => !childerns.Any(c => c.data.SubLocationId == x.data.SubLocationId)).ToList());
            }
        }
        return childerns;
    }

Hierarchical Model binding

1 Answers1