Best way to represent Hierarchy data? RSS

• • Reply
  

  ahmedilyas

  Member

  414 Points

  588 Posts

  Best way to represent Hierarchy data?

  Jan 30, 2013 02:39 PM|LINK

  So I have a flat set of data from the DB.

  This gets converted to a tree type representation in a List<T>. Thats cool.

  I now want to bind this to the UI on an ASP.NET page.

  What is the best way of doing this? I know I can use a repeater however I somehow need to nest the repeaters dynamically and make sure that the item in question is displayed nicely/clearly under its parent (if the parent has children and children has children etc...)

   

  Furthermore, I also need to be able to perform an action on that selected item and have the ability to go through all the items being bound to the control which is displaying all this tree structure data.

  Think of it as a menu structure where you have the following:

   

  File

     Open

     Save

     Export

           To PDF

           To Doc

           To DocX

       Exit

   

  Edit

     Cut

     Copy

     Paste

   

   

  I want all of this to be displayed/bound to the UI in some way. The data above will be in a List and each menu above contains children. I'm sure you know what I am talking about.

  Thoughts and suggestions are welcome!

  C# MVP
• • Reply
  

  Mikesdotnett...

  All-Star

  154927 Points

  19867 Posts

  Moderator

  MVP

  Re: Best way to represent Hierarchy data?

  Jan 30, 2013 08:46 PM|LINK

  How does this differ from your previous question? http://forums.asp.net/t/1873328.aspx/1

  Regards, Mike
  Beginning ASP.NET Web Pages with WebMatrix | My Site | Twitter
• • Reply
  

  ahmedilyas

  Member

  414 Points

  588 Posts

  Re: Best way to represent Hierarchy data?

  Jan 30, 2013 11:41 PM|LINK

  This is a UI question (control question) - not an internal data representation question like before.

  C# MVP
• • Reply
  

  Mikesdotnett...

  All-Star

  154927 Points

  19867 Posts

  Moderator

  MVP

  Re: Best way to represent Hierarchy data?

  Jan 31, 2013 04:39 AM|LINK

  You can swap the Response.Write calls for StringBuilder.Append calls:

  public partial class RecursiveMenu : System.Web.UI.Page
      {
          public List<MenuItem> MenuItems = new List<MenuItem>();
          protected void Page_Load(object sender, EventArgs e) {
  
              MenuItems = new List<MenuItem> {
                  new MenuItem {Id = 1, ParentId = null, MenuName = "File"},
                  new MenuItem {Id = 2, ParentId = 1, MenuName = "Open"},
                  new MenuItem {Id = 3, ParentId = 1, MenuName = "Save"},
                  new MenuItem {Id = 4, ParentId = 1, MenuName = "Export"},
                  new MenuItem {Id = 5, ParentId = 4, MenuName = "To PDF"},
                  new MenuItem {Id = 6, ParentId = 4, MenuName = "Word"},
                  new MenuItem {Id = 7, ParentId = 6, MenuName = "Doc"},
                  new MenuItem {Id = 8, ParentId = 6, MenuName = "DocX"},
                  new MenuItem {Id = 9, ParentId = 1, MenuName = "Exit"},
                  new MenuItem {Id = 10, ParentId = null, MenuName = "Edit"},
                  new MenuItem {Id = 11, ParentId = 10, MenuName = "Cut"},
                  new MenuItem {Id = 12, ParentId = 10, MenuName = "Copy"},
                  new MenuItem {Id = 13, ParentId = 10, MenuName = "Paste"},
                  new MenuItem {Id = 14, ParentId = 10, MenuName = "Delete"},
                  new MenuItem {Id = 15, ParentId = 4, MenuName = "To XML"},
                  new MenuItem {Id = 16, ParentId =13, MenuName = "Paste Special"},
                  new MenuItem {Id = 17, ParentId = 13, MenuName = "Paste As HTML"}
              };
              var sb = new StringBuilder();
              Literal1.Text = WriteItem(null, ref sb);
          }
  
          string WriteItem(int? parentid, ref StringBuilder sb, int level = -1) {
  
              var items = MenuItems.Where(m => m.ParentId == parentid);
              if (items.Any()) {
                  level++;
  
                  foreach (var item in items) {
                      if (!item.ParentId.HasValue) {
                          sb.Append("<div style=\"float:left;width:150px;\">");
                      }
                      for (var i = 0; i < level; i++) {
                          sb.Append("&nbsp;&nbsp;&nbsp;&nbsp;");
                      }
                      sb.Append(item.MenuName + "<br />");
                      WriteItem(item.Id, ref sb, level);
                      if (!item.ParentId.HasValue) {
                          sb.Append("</div>");
                      }
                  }
  
              }
              return sb.ToString();
          }
      }
  
      public class MenuItem
      {
          public int Id { get; set; }
          public int? ParentId { get; set; }
          public string MenuName { get; set; }
      }

  
  
  

  Regards, Mike
  Beginning ASP.NET Web Pages with WebMatrix | My Site | Twitter
• • Reply
  

  ahmedilyas

  Member

  414 Points

  588 Posts

  Re: Best way to represent Hierarchy data?

  Jan 31, 2013 09:00 AM|LINK

  Thank you. The only problem is.... there would be no way to then display a checkbox or any other controls and use that controls functionality. But also when there is also no way to postback to the server for that row. For example we need a column for each row called "Update", which posts back to the server which would then read the entire row values that the user has modified and do the update to the backend.

  C# MVP