Unplanned
Last Updated: 05 May 2022 19:13 by Andrew
Created by: Andrew
Comments: 0
Category: TreeView
Type: Feature Request
1

The feature request is about introducing a configuration option about a delay to start the drag operation. Currently, the lack of such functionality causes unexpected drag clue appearance on double click. 

 

```
In my treeview the user can double-click to open an item or they can drag to reorganize the tree. When you double-click you can see the drag & drop initiates for the brief fraction of a second. Which is a confusing and unpleasant UX. It would be preferable if a drag & drop didn't initiate until the user dragged for 3-4 pixels from the mousedown location, as opposed to a single pixel. 

In general if there's a behavior like this that I would want to tweak, are there ways to adjust the control or override behaviors using Javascript? I used to do all sorts of stuff with the jQuery controls.

```

Completed
Last Updated: 28 Apr 2022 12:12 by ADMIN

The TreeView should automatically update when a change in data fields occur. Changes in the `ItemsField`, `HasChildren` are crucial to be tracked to allow easy manipulation of data in binding to hierarchical data. This request will fulfill the observable collection support of the TreeView.

---

ADMIN EDIT

Changes in the ExpandedField of the element have been previously handled in the TreeView. However, this has been a side effect of incorrect code in our component that was causing performance hit. We reviewed our component and how it could provide better coverage in user scenarios, so here are our steps:

- Implement tracking of data item changes with ObservableCollection, so that we could fully support binding to observable data - click the Vote and Follow buttons on the current page to raise the priority of this feature implementation and to get notified for status updates.



We've been evaluating a major change where the ExpandedItems to be controlled via parameter/state. So, we would really appreciate if you could share feedback whether this change would be good for your project and use case.

- Implementation of ExpandedItems in TreeView to substitute ExpandedField in the collection: https://feedback.telerik.com/blazor/1448095-expanded-items-handling-feedback-requested

We believe that the above steps are the way to go with the maturing of the TreeView component.

 

A workaround could be reinitializing the Data when you update the property of the item, that will force the treeview to update:

TreeViewData = new List<MyModel>(TreeViewData)

---

Planned
Last Updated: 21 Apr 2022 15:31 by ADMIN
Scheduled for 3.4.0
Created by: Winston
Comments: 2
Category: TreeView
Type: Bug Report
1

Per WAI-ARIA 1.2, the "aria-level" attribute, if present, "is an integer greater than or equal to 1".

However, Blazor TreeView uses 0-indexing for the attribute which means that the root item has an invalid (and ignored) aria-level property. This is problematic because the browser will infer the level from the DOM nesting for the root item, but then use aria-level for all other sub-trees, leading to inconsistent levels (in the demo, the level goes 2 > 1 > 2).

Unplanned
Last Updated: 21 Apr 2022 08:34 by Andrea

The TreeView has CheckBoxMode="@TreeViewCheckBoxMode.Multiple" and CheckParents="true". Only some checkboxes are checked and there are parent checkboxes in indeterminate state.

When I try to clear all checked checkboxes, the indeterminate checkboxes are not cleared and maintain their state.

Declined
Last Updated: 20 Apr 2022 13:03 by ADMIN

Steps to reproduce:

  1. On Windows 11, go to Settings > Accessibility > Contrast themes and enable one of the themes (e.g., Aquatic or Desert).
  2. Try selecting or tabbing through a Blazor Telerik Tree View.

Expected: I should be able to clearly tell what element I'm currently focused on.

Actual: There is no focus indicator.

Unplanned
Last Updated: 28 Mar 2022 09:04 by ADMIN
Created by: Winston
Comments: 1
Category: TreeView
Type: Bug Report
1

There are two related issues in this bug report:

  1. TreeView does not allow horizontally scrolling when there are items that extend past the viewport
  2. TreeView cuts off items when the browser is zoomed in

See REPL: https://blazorrepl.telerik.com/wwOHGPvi11wy1OBp06

Steps to reproduce:

  1. Open and run the REPL.
  2. Observe that the last deeply-nested tree item, Design20.......01 is not fully visible (if it is fully visible, just add more 0s in the middle). Specifically, the trailing "1" is not visible and cannot be scrolled to.
  3. Zoom the browser to 200%.
  4. Observe that the TreeView still does not allow horizontal scrolling to view any of the items cut off by the increased zoom.
Unplanned
Last Updated: 08 Mar 2022 12:28 by Jan
Created by: Jan
Comments: 0
Category: TreeView
Type: Feature Request
1

Hi!

I can't find anything about validating drop targets. The only example in the demos checks the validity in the onDrop event. A bit late ...

Here are a few alternatives what will be useful for the TreeView to have:

1) new event OnDrag which fires when item is dragged over and dragged out of another item. Returns boolean indicating dropping is enabled. Requires a lot of roundtrips...

2) new properties of the TreeView items (DragType, DropTypes). Disables drop when DragType not in DropTypes.

3) a more generic DropZone component as in 2) which also could be used in TreeView templates.

 

https://chrissainty.com/investigating-drag-and-drop-with-blazor/ wrote an interesting article (sponsored by Telerik Blazor!) 

https://github.com/chrissainty/SimpleDragAndDropWithBlazor

Could be a inspiration for a generic DropZone component!

Best regards,
Jan

Completed
Last Updated: 01 Mar 2022 19:49 by ADMIN
Release 3.1.0
Created by: Michael
Comments: 0
Category: TreeView
Type: Bug Report
3

After upgrade to 3.0, when expanding a checked tree node, the child items are not checked. Also, if the child items are checked, but the parent is collapsed and expanded again, the checked children are unchecked.

This can be replicated on the online demo.

Duplicated
Last Updated: 01 Mar 2022 06:30 by ADMIN
Created by: Ivan
Comments: 0
Category: TreeView
Type: Bug Report
1

Public sample at https://demos.telerik.com/blazor-ui/treeview/checkboxes

Check parent Documents item:

Then collapse parent and expand them again:

 

Unplanned
Last Updated: 18 Jan 2022 13:37 by ADMIN
Created by: Christian
Comments: 1
Category: TreeView
Type: Bug Report
0

I'm trying to use a draggable TreeView inside a Window. I think the Window is interfering with the display of the red placement arrow when I try to move a tree node. I am able to have this work on another TreeView that is not in a Window.

Here is a REPL test page.

Planned
Last Updated: 15 Dec 2021 13:59 by ADMIN
Create a page that hosts a TreeView with checkbox selection inside a TelerikWindow. Provide an initially checked item and navigate to this page. When it renders the checkbox is not in a checked state. 
Completed
Last Updated: 09 Dec 2021 19:55 by ADMIN
Release 3.0.0
Created by: Marin Bratanov
Comments: 9
Category: TreeView
Type: Feature Request
17

Hi everyone,

We created this item to request your feedback on how you use the treeview binding with regards to the Expanded state of the nodes.

At the moment, the treeview updates the field in the collection when an item gets expanded or collapsed, and that makes it unique in the suite - the other data bound components do not alter their data source silently, and this is the general pattern we want to follow in order to have consistency across the board.

Thus, there are several approaches we are considering and we want to get your take on how you would find this most comfortable:

  • Keep the current situation where the treeview updates the ExpandedField in the Data silently [we would rather change it] - the Data collection gets changed automatically. To control an expanded item, prepare the data source accordingly.
  • Use the OnExpand event to get the item and its new state in order to update the collection yourself if needed. If you don't use the field for anything but to control the state of the treeview, you will not need to change anything. To control an expanded item, prepare the data source accordingly when providing it to the treeview. If you will be reusing the same data source with alterations, you may have to handle the event to sync the state between the treeview and the data.
  • Use an ExpandedItems collection [we are inclined to go with this approach at the moment] - this will be a collection that you can provide to the treeview separately from its data source, like the selected items in a grid. This will let you avoid an Expanded field in the data (which we believe may not be present in an actual database anyway) and you will be able to use business logic to determine which items to add/remove to that collection, this also includes nested levels, even added through load-on-demand.
Completed
Last Updated: 18 Nov 2021 07:39 by ADMIN
Release 2.30.0
I would like to be able to programmatically check children that are loaded on demand and currently this is not possible.
Duplicated
Last Updated: 09 Nov 2021 20:14 by ADMIN
Created by: Florian
Comments: 1
Category: TreeView
Type: Feature Request
0

It would be great to be able to expand nodes dynamically by setting the expand property by code.

 


protected async Task OnItemClickHandler(TreeViewItemClickEventArgs e)
{
    var item = e.Item as TreeViewItem;
    item.Expanded = true;
}

Completed
Last Updated: 27 Oct 2021 08:50 by ADMIN
Release 2.28.0

Stack trace:

crit: Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100]
      Unhandled exception rendering component: Unknown edit type: 0
      Error: Unknown edit type: 0
          at e.applyEdits (https://localhost:44363/_framework/blazor.webassembly.js:1:15008)
          at e.updateComponent (https://localhost:44363/_framework/blazor.webassembly.js:1:12880)
          at Object.t.renderBatch (https://localhost:44363/_framework/blazor.webassembly.js:1:1704)
          at Object.window.Blazor._internal.renderBatch (https://localhost:44363/_framework/blazor.webassembly.js:1:34784)
          at _mono_wasm_invoke_js_unmarshalled (https://localhost:44363/_framework/wasm/dotnet.3.2.0.js:1:172099)
          at wasm_invoke_iiiiii (<anonymous>:wasm-function[3160]:0x9b33d)
          at icall_trampoline_dispatch (<anonymous>:wasm-function[5777]:0xfe711)
          at mono_wasm_interp_to_native_trampoline (<anonymous>:wasm-function[4607]:0xca81d)
          at ves_pinvoke_method (<anonymous>:wasm-function[3209]:0x9cd40)
          at interp_exec_method (<anonymous>:wasm-function[1120]:0x2598d)
Microsoft.JSInterop.JSException: Unknown edit type: 0
Error: Unknown edit type: 0
    at e.applyEdits (https://localhost:44363/_framework/blazor.webassembly.js:1:15008)
    at e.updateComponent (https://localhost:44363/_framework/blazor.webassembly.js:1:12880)
    at Object.t.renderBatch (https://localhost:44363/_framework/blazor.webassembly.js:1:1704)
    at Object.window.Blazor._internal.renderBatch (https://localhost:44363/_framework/blazor.webassembly.js:1:34784)
    at _mono_wasm_invoke_js_unmarshalled (https://localhost:44363/_framework/wasm/dotnet.3.2.0.js:1:172099)
    at wasm_invoke_iiiiii (<anonymous>:wasm-function[3160]:0x9b33d)
    at icall_trampoline_dispatch (<anonymous>:wasm-function[5777]:0xfe711)
    at mono_wasm_interp_to_native_trampoline (<anonymous>:wasm-function[4607]:0xca81d)
    at ves_pinvoke_method (<anonymous>:wasm-function[3209]:0x9cd40)
    at interp_exec_method (<anonymous>:wasm-function[1120]:0x2598d)
  at Microsoft.JSInterop.WebAssembly.WebAssemblyJSRuntime.InvokeUnmarshalled[T0,T1,T2,TResult] (System.String identifier, T0 arg0, T1 arg1, T2 arg2) <0x3ae01e8 + 0x00046> in <filename unknown>:0 
  at Microsoft.JSInterop.WebAssembly.WebAssemblyJSRuntime.InvokeUnmarshalled[T0,T1,TResult] (System.String identifier, T0 arg0, T1 arg1) <0x3ae0108 + 0x00014> in <filename unknown>:0 
  at Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer.UpdateDisplayAsync (Microsoft.AspNetCore.Components.RenderTree.RenderBatch& batch) <0x3ae0010 + 0x0001e> in <filename unknown>:0 
  at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue () <0x387e448 + 0x000f2> in <filename unknown>:0

Completed
Last Updated: 12 Oct 2021 15:16 by Christian
Release 2.20.0
When I am loading child items on demand they will not be rendered.
Unplanned
Last Updated: 22 Sep 2021 07:48 by ADMIN
Created by: Christian
Comments: 6
Category: TreeView
Type: Feature Request
15
I would like to be able to optimize the rendering of the TreeView component with a feature similar to the Row Virtualization in the Grid.
Unplanned
Last Updated: 21 Sep 2021 08:57 by ADMIN
Created by: Support ATT
Comments: 0
Category: TreeView
Type: Feature Request
1
Expose an OnItemRender event, which is raised for each TreeView item. The args should allow setting a Class, that will be applied at the topmost element of the item itself.
Completed
Last Updated: 01 Sep 2021 12:25 by ADMIN
Release 2.27.0
Created by: Christian
Comments: 0
Category: TreeView
Type: Feature Request
3
I would like to have a node DoubleClick event for the TreeView.
Unplanned
Last Updated: 30 Aug 2021 15:45 by ADMIN
Created by: NovaStor
Comments: 5
Category: TreeView
Type: Feature Request
7

Hi.

 

I'd like to request the ability to set the Enabled property on check boxes in the treeview.

 

For example, given a tree view with check boxes:


<TelerikTreeView Data="@StorageItems"
                 @bind-CheckedItems="@CheckedItems"
                 CheckBoxMode="TreeViewCheckBoxMode.Multiple"
                 CheckParents="true"
                 CheckChildren="true" />

I'd like to make the tree view read-only so the check boxes appear disabled and the user cannot check-mark or uncheck-mark them.

Thank you.

1 2