I would like the TreeList to support row virtualization. It will be useful when working with large data.

I would like to start the tree grid with all rows collapsed. At the moment I can do this only through load on demand.

*** Thread created by admin on customer behalf ***

It would be nice to have the same capabilities for working with TreeList columns as in the ColumnMenu for Grid. Espesially columns chooser. 

I would like a feature that exposes the same behavior as the CheckParents in the TreeView. 

I'd like to prevent the user from dropping a column at a certain position when reordering. Please expose an OnColumnReorder that I can cancel to stop the reordering operation in this case.

I am using the TreeList component with hierarchical data. The CheckBoxList allows filtering only by the root items, however, I want it to be hierarchical to support filtering by child records as well. 

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.

Please add TreeList Export to Excel

Regards

Andrzej

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'm using Telerik TreeList. I'm so happy that it supports Drag&Drop. But, if there are too many items on the list, it is really hard to drag an item from the top to the end of the list. The TreeList doesn't scroll the list automatically (Auto Scroll) when I drag an item to the edge of the TreeList.

Currently, the TreeList CheckBox selection exposes an option to select the children if the parents are selected. Please also add support for CheckParents option similar to the one in the TreeView component. This will allow marking the parent as selected if its children are selected.

From what I can see, currently the only way to set the expanded items for a TreeList is through the state.

The main problem is that the state doesn't fire the OnExpand event, meaning that if you have a server loaded tree you need to make sure to load the data before each item is expanded. It also allows for duplicates in the 'ExpandedItems' if you don't check for duplicates before adding to it.

The TreeView has an 'ExpandedItems' parameter that can be bound which is a bit nicer than using the state, but from my quick test this also doesn't fire the OnExpand event.

 

My request is for one of the following to be added:

1. Similar to how you can set the 'HasChildrenField' or 'ItemsField' on the TreeList, allow a 'IsExpandedField' value to be bound (Should fire the OnExpand when changed if possible). This would be the simplest way allow bindable control over the expansion of items while also making it so we don't have to manage duplicates in the 'ExpandedItems' collection.
   
2. Expose a method to expand/unexpand rows. This would be different to manually changing the state as it would also fire the OnExpand event for each row expanded.
   
3. Similar to the TreeView, allow an 'ExpandedItems' to be bound. Preferably this would also fire the OnExpand event.

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?

Not sure if this is a bug or missing feature, but when a user is actively doing drag and drop in the TreeList, the drag and drop should cancel as soon as they press 'Esc', just like in most apps. This is pretty standard behavior. Currently, pressing 'Esc' during drag and drop does not do anything.

If this is not a bug, could you please add this as a feature request?

Need an OnRowDoubleClick event for editing purposes.

I want to bind the treelist to dynamic objects like I can the grid: https://github.com/telerik/blazor-ui/tree/master/grid/binding-to-expando-object.

Unlike the grid, you don't have an OnRowClick event that will overcome the async limitations you indicate in the docs and support for OnSelect. Since everything I have is async, the binding solution just doesn't do enough if I can't catch the click. Is there an alternative to OnRowClick for the TreeList? If not, why not?

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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Please add TreeList Drag Drop Feature

Regards

Andrzej

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ADMIN EDIT

This feature will arrive with the same feature for the grid in the 2.24.0 release in mid-May 2021.

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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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