Please add TreeList Export to Excel

Regards

Andrzej

Hello,

Please add support for sorting and filtering when the TreeList is data bound to a List<Dictionary> or ExpandoObject. Currently these data operations throw an exception System.ArgumentException: Invalid property or field

TreeList REPL page with Dictionary

TreeList REPL page with ExpandoObject

I would like to have an event equivalent to the OnRead for the Grid so that I could make custom data operations such as applying custom filtering to the root items. 

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ADMIN EDIT

In the meantime, loading data on demand only when a node expands can make database queries happen less often and return less data: https://docs.telerik.com/blazor-ui/components/treelist/data-binding/load-on-demand

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Telerik blazor TreeList required ContextMenu Event on each row.

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ADMIN EDIT

In the meantime, you can consider using one of the templates of the component (row or cell) to integrate the context menu in. A similar example is also available in this article even if it is for the grid, and this one for the treeview, the same concepts will apply to the treelist. You can also use a button whose click can integrate the context menu if that will fit your UX.

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In the TreeList control of Blazor UI suite, I did not see any option to group header for columns. Column group header is an important feature and will certainly enhance the utility of the control multifold.

Below are few samples of column group headers:

The TreeList should add an event OnDragStatus that would query the app during active dragging to determine if the current drag location is valid or not. If invalid, it could show the invalid drag icon:

This would give better feedback to the user during dragging.

Could you add this as a feature request please?

Is it possible to specify different editor templates for different levels in hierarchical data?

What I am trying to do is to build a hierarchical structure for grouping items. The list of items is specified so, in the grouping hierarchy, I want to select an item as the child element of the lowest grouping level rather than typing the name of the item and resolving if it exists. I thus want for the lowest level, to have a combobox rather than an editbox. The data items presented in the treelist have a property to bind to.

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ADMIN EDIT

If your models already have flags denoting their level, or otherwise denoting the special need for that particular model, you can use them in the editor template already.

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Currently, the DisplayFormat attribute is applied only to the values displayed in the Grid, while the checkbox list filter options remain unaffected by this formatting.

The DisplayFormat attribute should also impact the checkbox list options, providing consistent formatting across the entire Grid.

Would it be possible to have the ability to create compact TreeList's similar to how we can now in a Grid? Since Size=ThemeConstants.Grid.Size.Small is available a Grid now it seems natural this would be a next step. If we can be provided with a work around for the time being that would be great.

I am overriding the built-in Add command and setting an InsertedItem through the TreeList state. However, it looks like the the built-in validation is invoked twice and two validation Tooltips are displayed for the field.

I'm experiencing a flickering in the TreeList InCell Editing demo here: https://demos.telerik.com/blazor-ui/treelist/editing-incell

Steps to reproduce:

1. Click on "Mountain Bikes"

2. Click on "Road Bikes"

3. Click on "Touring Bikes"

It can actually be reproduced by clicking on any three editable cells.

Any ideas?

Thank you.

The code below compiles and doesn't give any browser errors when run, but when you collapse a row, all data is collapsed and you can't expand it again.

If you change the line that generates the data to use a List instead of IEnumerable it will work as expected.

REPRODUCIBLE

<TelerikTreeList Data=Data
                 IdField="@nameof(Record.Id)"
                 ParentIdField="@nameof(Record.ParentId)"
                 Height="100%">
    <TreeListColumns>
        <TreeListCheckboxColumn CheckBoxOnlySelection="true" />
        <TreeListColumn Field="@nameof(Record.Text)" Title="" Expandable="true" />
        <TreeListColumn Field="@nameof(Record.Id)" Title="ID" />
        <TreeListColumn Field="@nameof(Record.ParentId)" Title="PARENT" />
    </TreeListColumns>
</TelerikTreeList>
@code {
    protected IEnumerable<Record> Data = new List<Record>();

    protected override void OnInitialized()
    {
        Data = Enumerable.Range(1, 10).Select(i => new Record(i));
    }

    public class Record
    {
        public Record(int i)
        {
            Id = i;
            if (i % 5 == 1)
                ParentId = null;
            else
                ParentId = (i - ((i - 1) % 5));
            Text = "Item " + i;
        }
        public long Id { get; set; }
        public long? ParentId { get; set; }
        public string Text { get; set; }
    }
} 

WORKAROUND

<TelerikTreeList Data=Data
                 IdField="@nameof(Record.Id)"
                 ParentIdField="@nameof(Record.ParentId)"
                 Height="100%">
    <TreeListColumns>
        <TreeListCheckboxColumn CheckBoxOnlySelection="true" />
        <TreeListColumn Field="@nameof(Record.Text)" Title="" Expandable="true" />
        <TreeListColumn Field="@nameof(Record.Id)" Title="ID" />
        <TreeListColumn Field="@nameof(Record.ParentId)" Title="PARENT" />
    </TreeListColumns>
</TelerikTreeList>
@code {
    protected List<Record> Data = new List<Record>();

    protected override void OnInitialized()
    {
        Data = Enumerable.Range(1, 10).Select(i => new Record(i)).ToList();
    }

    public class Record
    {
        public Record(int i)
        {
            Id = i;
            if (i % 5 == 1)
                ParentId = null;
            else
                ParentId = (i - ((i - 1) % 5));
            Text = "Item " + i;
        }
        public long Id { get; set; }
        public long? ParentId { get; set; }
        public string Text { get; set; }
    }
}