databinding multiple kind of children

[Paul Evers]

I want to bind a model to a treeview where you got groups and items. Groups can have subgroups. Each Group/Subgroup can have multiple items.
A group can have groups and items as children. With the following code the first Children-attribute is ignored.
Is it possible to have more than one kind of children in a treeview?

<%= Html.Telerik().TreeView()
           .Name("TreeView")
           .BindTo(Model.BaseGroups, mappings =>
               {
                   mappings.For<Group>(binding => binding
                       .ItemDataBound((item, tlgroup) =>
                       {
                           item.Text = tlgroup.DisplayName;
                       })
                       .Children(tlgroup => tlgroup.Groups)
                       .Children(tlgroup => tlgroup.Lights));
                   mappings.For<Light>(binding => binding
                       .ItemDataBound((item, tl) =>
                        {
                            item.Text = tl.DisplayName;
                        }));
               })
    %>

Paul

[Boris]

Did you figure out how to do this?
I have exactly the same problem with in my application design.

I have figured out how to do a recursive folder structure with mappings for Folder object, but my folders can contain collections of different types of objects. I guess it would be possible with different model, but the View syntax would be a better way.

Thanks,
Boris

[Paul Evers]

No. As nobody responded to my question I don't think this is possible.

[Boris]

I have created a custom model class. Maybe this approach will work for you too.
I create it with the call
new TreeItem(rootFolder)

public partial class TreeItem

{

    public String Name { get; set; }

    public String Type { get; set; }

    public IEnumerable<TreeItem> Children { get; set; }

    public String ImageUrl { get; set; }

 

    public TreeItem(Folder f)

    {

        this.Name = f.Name;

        this.Type = "F";

        List<TreeItem> children = new List<TreeItem>();

        foreach (Folder childf in f.Folders)

        {

            TreeItem item = new TreeItem(childf);

            item.ImageUrl = "../../Content/Images/FolderOpen.png";

            children.Add(item);

        }

        foreach (Book childb in f.Books)

        {

            TreeItem item = new TreeItem(childb);

            item.ImageUrl = "../../Content/Images/Book.png";

            children.Add(item);

        }

        this.Children = children;

    }

 

    public TreeItem(Book b)

    {

        this.Name = b.Name;

        this.Type = "B";

    }

 

}

[dani]

I'm also looking for a solution for this problem.... without rebuilding the entire tree.
It looks like have 2 children makes the tree-view ignore the first one.
I think it just ain't meant to be in this version, or we are doing something wrong....
Dani

[Nick]

I'm encountering the same problem. I have multiple types of children that need to rendered differently, but not having much luck finding a solution with Telerik's MVC TreeView that supports it...

[Atanas Korchev]

Hi,

 The TreeView (and the other navigational components) do not support specifying to more than one type of children. This is because calling Children() overwrites the previous setting. 

Regards,
Atanas Korchev
the Telerik team

[Linus]

That's a shame as that's what I'm doing (calling Children() twice) and wondered why it didn't work. You should document that in the example.

[Andres]

I found a solution to create a tree with items of different  types. In this case a Group has a collection of children's of type Group and a set of articles of type Article. So, I use a union to compose both collections, but first I cast both collections into a collection of objects.

Hope this helps

@(Html.Telerik().TreeView()
                .Name("GroupsTree")
                .ExpandAll(true)
                .BindTo(Model, mappings =>
                {
                    mappings.For<Group>(binding => binding
                            .ItemDataBound((item, group) =>
                            {
                                item.Text = group.Name;
                                item.Value = group.GroupId.ToString();
                                item.Expanded = true;
                            })
                            .Children(group => ((IEnumerable<object>) group.Children).Union ((IEnumerable<object>)group.Articles)));

                    mappings.For<Article>(binding => binding
                            .ItemDataBound((item, article) =>
                            {
                                item.Text = article.Name;
                                item.Value = article.ArticleId.ToString();
                                item.Expanded = true;
                            }).Children(article => null));
                }))

[Nick]

That worked perfectly for me. I did exactly as you described and unioned the two collections after casting them to IEnumerable<Object>. The grid's mappings for the types that were being unioned together took care of the bindings and it displayed correctly. I don't know if this has implications later on for other aspects of the treeview but so far it does what I need. Thanks :-)