Title: Add per-column value converters (WPF-style) to Telerik Blazor Grid columns
Product: UI for Blazor → Grid
Type: Feature Request
Description:
In Telerik UI for WPF, grid column definitions can reference a converter by name (e.g., IValueConverter) to transform values for display without writing a custom cell template for each column.
In Telerik UI for Blazor Grid, templates are currently the primary way to change how values render in a column (which works, but becomes repetitive across many columns/grids).
Request:
Add a column-level conversion API that allows specifying a converter/formatter function for display (and optionally editing). Example concepts:
Converter="nameof(MyConverters.StatusToText)"
or DisplayConverter="(item) => …" / ValueFormatter="Func<TItem, object, string>"
optionally ConvertBack-like support for editing scenarios (or separate EditConverter)
Why this is needed:
Reduces repeated <Template> markup for simple formatting/transformations
Centralizes formatting/conversion logic in reusable code
Improves maintainability and consistency across grids
Eases migration for teams coming from Telerik WPF where converters are a common pattern
Use cases:
Enum/int → user-friendly text
Boolean → “Yes/No”, icons, badges
Null/empty → placeholder text
Code → display name (via lookup)
Domain-specific formatting shared across many grids
Workarounds today:
Column <Template> or computed properties (both valid, but not as concise/reusable for large grids)
Extracting RenderFragments can reduce repetition, but still requires templating infrastructure for what is logically a simple conversion step
Expected behavior:
Converter applies consistently anywhere the column renders (cell, export if applicable, etc.)
Works with sorting/filtering in a predictable way (ideally sorting/filtering still uses raw field value unless explicitly configured)
Goal
Our application needs to allow end users to dynamically customize the Telerik Blazor DockManager at runtime by:
These changes should be fully user-driven and persisted so that:
In short, we want the DockManager to behave as a customizable dashboard whose state can be reliably stored and reloaded from our database.
Problem
The current Telerik Blazor DockManager implementation requires panels to be declared in Razor markup (markup driven) and managed through an external data source.
This creates several challenges:
As a result, implementing a truly dynamic and persistent DockManager layout requires complex workarounds that are fragile and difficult to maintain.
Feature Request
We propose enhancing the DockManager with first-class support for dynamic panel synchronization by introducing:
Two coordinated parameters:
Expected behavior:
This would allow developers to treat the DockManager as a true data-driven component, similar to other Telerik Blazor controls, without needing to manually modify internal state structures.
Current limitation: The Diagram component does not provide native context menu integration. There are no events like OnShapeContextMenu or OnConnectionContextMenu that fire on right-click. Developers cannot show contextual actions (edit, delete, copy, connect) when user right-clicks on diagram elements.
Requested feature: Add context menu support for Diagram elements:
Use case:
In workflow/process diagram editors, context menu is essential for:
Currently, there is no way to detect right-click on specific diagram elements. The only workaround is complex JavaScript interop to attach event listeners to SVG elements, which is fragile and breaks on re-render.
Example of desired API:
<TelerikDiagram @ref="@DiagramRef"
OnShapeContextMenu="@OnShapeRightClick"
OnConnectionContextMenu="@OnConnectionRightClick"
OnCanvasContextMenu="@OnCanvasRightClick">
<DiagramShapes>
@foreach (var shape in Shapes)
{
<DiagramShape Id="@shape.Id">
<DiagramShapeContent Text="@shape.Name" />
</DiagramShape>
}
</DiagramShapes>
</TelerikDiagram>
<TelerikContextMenu @ref="@ShapeContextMenu"
Data="@ShapeMenuItems"
OnClick="@OnShapeMenuClick">
<ItemTemplate Context="item">
<TelerikFontIcon Icon="@item.Icon" />
<span>@item.Text</span>
</ItemTemplate>
</TelerikContextMenu>
@code {
private TelerikContextMenu<MenuItem>? ShapeContextMenu;
private string? ClickedShapeId;
private async Task OnShapeRightClick(DiagramShapeContextMenuEventArgs args)
{
ClickedShapeId = args.ShapeId;
await ShapeContextMenu.ShowAsync(args.ClientX, args.ClientY);
}
private async Task OnShapeMenuClick(MenuItem item)
{
switch (item.Action)
{
case "edit":
await OpenShapeEditor(ClickedShapeId);
break;
case "delete":
await DeleteShape(ClickedShapeId);
break;
case "duplicate":
await DuplicateShape(ClickedShapeId);
break;
}
}
}Alternative minimal implementation:
Current limitation: The Diagram component only allows zoom through mouse interactions (scroll wheel). The Zoom parameter sets only the initial zoom level and cannot be changed at runtime. There are no methods to programmatically control the viewport.
Requested feature: Add programmatic viewport control API:
Use case:
In enterprise workflow/process editors, users need navigation controls beyond mouse wheel:
Accessibility: Users with trackpads, touch screens, or motor impairments cannot easily use scroll wheel zoom
Toolbar buttons: Standard diagram tools (Visio, Draw.io, Lucidchart) provide +/−/100%/Fit buttons
Programmatic navigation: After adding a new shape, auto-scroll to show it; on search result, navigate to found shape
Keyboard shortcuts: Implement Ctrl+Plus/Minus for zoom without native support
<TelerikDiagram @ref="@DiagramRef"
@bind-Zoom="@CurrentZoom"
ZoomChanged="@OnZoomChanged">
...
</TelerikDiagram>
<TelerikButton OnClick="@(() => DiagramRef.ZoomInAsync())">+</TelerikButton>
<TelerikButton OnClick="@(() => DiagramRef.ZoomOutAsync())">−</TelerikButton>
<TelerikButton OnClick="@(() => DiagramRef.SetZoomAsync(1.0))">100%</TelerikButton>
<TelerikButton OnClick="@(() => DiagramRef.FitToScreenAsync())">Fit</TelerikButton>
@code {
private TelerikDiagram? DiagramRef;
private double CurrentZoom = 1.0;
private async Task NavigateToShape(string shapeId)
{
await DiagramRef.BringIntoViewAsync(new[] { shapeId });
}
}
Current limitation: The Diagram component only allows pan through mouse interactions (Ctrl+drag). There are no methods to programmatically control the viewport.
Requested feature: Add programmatic viewport control API:
Use case:
Programmatic navigation: After adding a new shape, auto-scroll to show it; on search result, navigate to found shape
===
Forked from https://feedback.telerik.com/blazor/1708938
The Grid's CheckBoxColumn doesn't support the TextAlign property, making it impossible to center the checkbox with just Grid markup, you have to resort to a workaround.
The TextAlign property in other columns causes style="text-align: center" to be added to the underlying table cell. This would also work for the checkbox column.
See this test:
<table class="table">
<tr>
<td class="table-active" style="width: 40px; text-align: center"><input type="checkbox" /> </td>
<td>test</td>
</tr>
</table>Please add the TextAlign property to the CheckboxColumn.
We use QueryableExtensions.ToDataSourceResultmethod to load some data in our component. And at some moment we need to cancel data loading. But ToDataSourceResult method doesn’t support CancellationToken. So we are forced to use a workaround and just ignore the task's result. But task is still executing and causing the performance hit…
It would be great if you implemented support for this feature!
Please add TreeList Export to Excel
Regards
Andrzej
Expose an OnShapeDrop event for the Diagram. It should provide information about the shape's current X and Y coordinates.
This would allow the user to save the diagram (e.g., as json) and load it later.
I want to reorder the Grid rows the same way I can reorder the columns - via the keyboard.
For reference: Telerik jQuery Grid drag and drop
Current limitation: When DiagramShapeDefaultsEditable.Connect="true",
users can draw connections between shapes, but there is no event fired
when a new connection is created by the user.
Requested feature: Add OnConnectionCreated event that:
Use case: We need to capture user-created connections to persist them to database, validate business rules (e.g., prevent circular dependencies), and set connection properties (type, label, color) based on context.
Current limitation:
DiagramConnectionType only supports Cascading (orthogonal) and Polyline
types. There is no curved or Bezier option.
Requested feature: Add a new connection type such as DiagramConnectionType.Bezier or DiagramConnectionType.Curved that:
Use case: For workflow diagrams with many crossing connections, curved lines improve visual clarity and reduce cognitive load compared to sharp 90° angles.
Current limitation: The Diagram component only provides OnShapeClick event. There is no native double-click event for shapes.
Requested feature: Add OnShapeDoubleClick event that:
Use case: In workflow editors, single-click should select a shape, while double-click should open an editor dialog. Currently, we have to implement manual timing-based detection which is unreliable and doesn't match native OS double-click behavior.
Please add support for the Display(Name) DataAnnotations attribute for the autogenerated fields in the PivotGrid.
(Related to Title parameter for the rows and columns)
public class PivotModel
{
[Display(Name = "Net Revenue")]
public decimal Field1 { get; set; }
}
Hi
I am loading a excel with column A1 as shown below. The text is in A1 and is a long text spanning several columns.
In the telerik spreadsheet component, it displays as shown below- inside A1 but not with the same width as in the spreadsheet - i have to expand the column manually.
Is there a way to display it exactly as it is in the spreadsheet?
thanks
ranga raghuram
A Blazor component designed to provide an interactive image magnification experience, similar to popular eCommerce websites.
MagnifyScale parameter.@inject IJSRuntime JS
@using Microsoft.JSInterop
@* Container *@
<div @ref="_containerRef" class="@($"magnifiable-image-container {Class}")" style="height: @Height; width: @Width;">
@* Image *@
<button @onclick="@OnClick" class="magnifiable-image-button">
<img src="@Image.Src" alt="@Image.Alt" style="height: 100%; width: 100%;"
@onmousemove="@OnMouseMove" @onmouseenter="@OnMouseEnterAsync" @onmouseleave="@OnMouseLeave"/>
</button>
@* Magnifier *@
<TelerikPopover @ref="_popoverRef" AnchorSelector=".magnifiable-image-container" Position="@(_showOnRight ? PopoverPosition.Right : PopoverPosition.Left)" Offset="@MagnifierMargin"
Width="@($"{_magnifierWidth}px")" Height="@($"{_magnifierHeight}px")" Class="popover-magnifier" Collision="PopoverCollision.Fit">
<PopoverContent>
@* Magnified Image *@
<img src="@Image.Src" alt="@Image.Alt" class="magnified-image"
style="@($"width: {_magnifiedImageWidth}px; height: {_magnifiedImageHeight}px; transform: translateX({_magnifiedImageTransformX}px) translateY({_magnifiedImageTransformY}px); left: {_magnifiedImageLeft}px; top: {_magnifiedImageTop}px;")"/>
</PopoverContent>
</TelerikPopover>
@* Magnifier Overlay *@
@if (_isMouseOver)
{
<div class="magnifier-overlay"
style="@($"width: {_magnifierOverlayWidth}px; height: {_magnifierOverlayHeight}px; transform: translateX({_magnifierOverlayTransformX}px) translateY({_magnifierOverlayTransformY}px); left: {_magnifierOverlayLeft}px; top: {_magnifierOverlayTop}px;")))">
</div>
}
@* Actual Image *@
<TelerikWindow @bind-Visible="@_isClicked" Modal="true" CloseOnOverlayClick="true" Draggable="false" Resizable="false" Class="window-rounded">
<WindowActions>
<WindowAction Name="Close"/>
</WindowActions>
<WindowContent>
<img src="@Image.Src" alt="@Image.Alt"/>
</WindowContent>
</TelerikWindow>
</div>
<style>
.magnifiable-image-container {
position: relative;
display: inline-block;
cursor: zoom-in;
}
.magnifiable-image-button {
background: none;
border: none;
padding: 0;
margin: 0;
font: inherit;
color: inherit;
cursor: inherit !important;
outline: none;
box-shadow: none;
appearance: none;
-webkit-appearance: none;
-moz-appearance: none;
display: block;
width: 100%;
height: 100%;
}
.magnifiable-image-button:focus-visible {
outline: none;
box-shadow: 0 0 0 2px color-mix(in srgb, var(--kendo-color-on-app-surface, #424242) 50%, transparent);
}
.popover-magnifier {
overflow: hidden;
border-radius: 0;
position: relative;
top: @(_adjustForTelerikFit ? $"{(_showOnBottom ? "" : "-")}{MagnifierMargin/4}px" : $"{(_showOnBottom ? "" : "-")}{MagnifierMargin}px");
}
.magnified-image {
position: absolute;
}
.magnifier-overlay {
position: absolute;
background: color-mix(in srgb, var(--kendo-color-primary, #1274AC) 15%, transparent);
pointer-events: none;
z-index: 5;
box-sizing: border-box;
display: block;
}
</style>
@code
{
[Parameter] public required ImageInfo Image { get; set; }
/// <summary>
/// The height of the image (e.g., "200px", "100%", or "auto"). Default is "auto".
/// </summary>
[Parameter]
public string Height { get; set; } = "auto";
/// <summary>
/// The width of the image (e.g., "200px", "100%", or "auto"). Default is "auto".
/// </summary>
[Parameter]
public string Width { get; set; } = "auto";
/// <summary>
/// The magnification scale for the magnifier. Default is 3 (3x magnification).
/// </summary>
[Parameter]
public double MagnifyScale { get; set; } = 3;
/// <summary>
/// Applies additional CSS classes to the MagnifiableImage's root element for custom styling and visual modifications.
/// </summary>
[Parameter]
public string Class { get; set; } = string.Empty;
private const int MagnifierMargin = 24;
// State for magnifier visibility and container reference
private bool _isMouseOver;
private bool _isClicked;
private ElementReference _containerRef;
private TelerikPopover? _popoverRef;
// Image and magnified image dimensions
private double _imageWidth;
private double _imageHeight;
private double _magnifiedImageWidth;
private double _magnifiedImageHeight;
// Magnifier position and size
private bool _showOnRight = true;
private bool _showOnBottom = true;
private bool _adjustForTelerikFit;
private double _magnifierWidth;
private double _magnifierHeight;
// Magnified image offset within the magnifier
private double _magnifiedImageLeft;
private double _magnifiedImageTop;
// Mouse position clamping bounds
private double _minMouseX;
private double _minMouseY;
private double _maxMouseX;
private double _maxMouseY;
// Mouse position and transform for magnified image
private double _mouseX;
private double _mouseY;
private double _magnifiedImageTransformX;
private double _magnifiedImageTransformY;
// Magnifier overlay size and transform
private double _magnifierOverlayWidth;
private double _magnifierOverlayHeight;
private double _magnifierOverlayLeft;
private double _magnifierOverlayTop;
private double _magnifierOverlayTransformX;
private double _magnifierOverlayTransformY;
private void OnClick()
{
_isClicked = true;
}
private async Task OnMouseEnterAsync()
{
_isMouseOver = true;
_popoverRef?.Show();
// Get layout info about the image container using getElementLayoutInfo from wwwroot/js/magnifiable-image.js
var containerLayoutInfo = await JS.InvokeAsync<ElementLayoutInfo>("getElementLayoutInfo", _containerRef);
// Store image size
_imageWidth = containerLayoutInfo.Width;
_imageHeight = containerLayoutInfo.Height;
_magnifiedImageWidth = _imageWidth * MagnifyScale;
_magnifiedImageHeight = _imageHeight * MagnifyScale;
// Determine magnifier position based on available space
_showOnRight = containerLayoutInfo.DistanceFromViewportRight >= containerLayoutInfo.DistanceFromViewportLeft;
_adjustForTelerikFit = Math.Abs(containerLayoutInfo.DistanceFromViewportBottom - containerLayoutInfo.DistanceFromViewportTop) < 20;
_showOnBottom = containerLayoutInfo.DistanceFromViewportBottom >= containerLayoutInfo.DistanceFromViewportTop;
// Calculate magnifier size based on available space
_magnifierWidth = _showOnRight
? containerLayoutInfo.DistanceFromViewportRight - MagnifierMargin*2
: containerLayoutInfo.DistanceFromViewportLeft - MagnifierMargin*2;
_magnifierHeight = containerLayoutInfo.ViewportHeight - MagnifierMargin*2;
// Center the magnified image in the magnifier
_magnifiedImageLeft = (_magnifierWidth / 2) - (_imageWidth / 2);
_magnifiedImageTop = (_magnifierHeight / 2) - (_imageHeight / 2);
// Calculate min and max mouse X/Y to prevent showing empty space in the magnifier
_minMouseX = Math.Floor((_magnifierWidth / MagnifyScale) / 2);
_minMouseY = Math.Floor((_magnifierHeight / MagnifyScale) / 2);
_maxMouseX = Math.Ceiling(_imageWidth - ((_magnifierWidth / MagnifyScale) / 2));
_maxMouseY = Math.Ceiling(_imageHeight - ((_magnifierHeight / MagnifyScale) / 2));
// Calculate magnifier overlay size and position
_magnifierOverlayWidth = Math.Floor(Math.Clamp(_magnifierWidth / MagnifyScale, 0, _imageWidth)) - 1;
_magnifierOverlayHeight = Math.Floor(Math.Clamp(_magnifierHeight / MagnifyScale, 0, _imageHeight)) - 1;
_magnifierOverlayLeft = -((_magnifierOverlayWidth / 2) + 1);
_magnifierOverlayTop = -((_magnifierOverlayHeight / 2) + 1);
}
private void OnMouseLeave()
{
_isMouseOver = false;
_popoverRef?.Hide();
}
private void OnMouseMove(MouseEventArgs e)
{
// Clamp mouse X/Y to prevent showing empty space in the magnifier
if (_minMouseX > _maxMouseX) _mouseX = _imageWidth / 2;
else _mouseX = Math.Clamp(e.OffsetX, _minMouseX, _maxMouseX);
if (_minMouseY > _maxMouseY) _mouseY = _imageHeight / 2;
else _mouseY = Math.Clamp(e.OffsetY, _minMouseY, _maxMouseY);
// Calculate the transform for the magnified image
_magnifiedImageTransformX = -Math.Round((_mouseX * MagnifyScale) - (_imageWidth / 2));
_magnifiedImageTransformY = -Math.Round((_mouseY * MagnifyScale) - (_imageHeight / 2));
// Calculate the transform for the magnifier overlay
_magnifierOverlayTransformX = Math.Round(_mouseX);
_magnifierOverlayTransformY = Math.Round(_mouseY);
_popoverRef?.Refresh();
}
private record ElementLayoutInfo(
double Width,
double Height,
double ViewportHeight,
double DistanceFromViewportLeft, // distance from viewport's left edge to element's left edge
double DistanceFromViewportRight, // distance from element's right edge to viewport's right edge
double DistanceFromViewportTop, // distance from viewport's top edge to element's top edge
double DistanceFromViewportBottom); // distance from element's bottom edge to viewport's bottom edge
}// Returns width, height, and the space to the left and right of the element relative to the viewport
window.getElementLayoutInfo = (element) => {
if (!element) return null;
const elementRect = element.getBoundingClientRect();
return {
width: elementRect.width,
height: elementRect.height,
viewportHeight: window.innerHeight,
distanceFromViewportLeft: elementRect.left, // distance from viewport's left edge to element's left edge
distanceFromViewportRight: window.innerWidth - elementRect.right, // distance from element's right edge to viewport's right edge
distanceFromViewportTop: elementRect.top, // distance from viewport's top edge to element's top edge
distanceFromViewportBottom: window.innerHeight - elementRect.bottom // distance from element's bottom edge to viewport's bottom edge
};
};Only tested in Blazor WebAssembly. The component may see performance issues in Blazor Server.