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19 Jan to 26 Jan 2026: highlights of the new online resources that we published last week.

Article: https://www.telerik.com/aspnet-core-ui/documentation/knowledge-base/grid-use-grid-as-client-template
Summary: Learn how to render a Kendo UI Grid inside a Telerik UI for ASP.NET Core Grid column using a ClientTemplate: output a per-row placeholder with a unique id (for example, via kendo.guid()) and initialize the child grid in the parent grid’s dataBound handler using the current row’s data. The article shows how to pass the row key to the child grid’s DataSource, prevent duplicate initialization, and dispose nested grids on rebind to avoid memory leaks.

Article: https://www.telerik.com/aspnet-core-ui/documentation/knowledge-base/tooltip-refresh-with-dynamic-content
Summary: To keep a Kendo UI Tooltip for ASP.NET Core in sync with dynamic content and targets (after AJAX/partial updates or data-bound component renders), initialize it on a stable container and use the filter option with a content callback, or update the content via setOptions in the show event. The article shows how to attach the tooltip to newly added elements and render up-to-date content without re-initialization, plus when to destroy and re-initialize as a fallback in Grid/list or SPA scenarios.

Blog: https://www.telerik.com/blogs/getting-the-right-row-on-the-screen-in-the-kendo-grid
Summary: Learn how to programmatically bring a specific row into view in the Kendo UI Grid and optionally select it, even when paging, sorting, filtering, or virtual scrolling is enabled. The article shows how to resolve a data item to its correct DOM row via the item’s uid (e.g., grid.tbody.find("tr[data-uid='...']")) and then scroll the grid’s content to that row (scrollTop or scrollIntoView), with guidance on triggering the logic at the right time using dataBound.

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12 Jan to 19 Jan 2026: highlights of the new online resources that we published last week.

Blog: https://www.telerik.com/blogs/building-resilient-apis-retry-pattern
Summary: You’ll learn how to implement the retry pattern for API clients and services—when to retry transient failures and when to fail fast. The article provides .NET examples using HttpClientFactory and Polly to apply bounded retries with exponential backoff and jitter, target idempotent operations, and handle retryable HTTP status codes (408, 429, 500, 502, 503, 504), with practical guidance on timeouts, cancellation tokens, and telemetry.

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05 Jan to 12 Jan 2026: highlights of the new online resources that we published last week.

Article: https://www.telerik.com/aspnet-core-ui/documentation/html-helpers/diagrams-and-maps/map/azure-tiles
Summary: Learn how to render Azure Maps tiles in the Telerik UI for ASP.NET Core Map by adding a tile layer with the Azure Maps Tile API URL template. You configure the layer’s UrlTemplate with {zoom}/{x}/{y}, provide your Azure Maps subscription key and the tilesetId (for example microsoft.base.road or microsoft.imagery), and set the required attribution. The article uses the Map HTML Helper and TileSource options to control tile size, zoom levels, and other layer settings.

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29 Dec to 05 Jan 2026: highlights of the new online resources that we published last week.

Blog: https://www.telerik.com/blogs/whats-new-apis-net-10-real-improvements
Summary: This article breaks down what's new in .NET 10 APIs, focusing on practical Base Class Library improvements you can apply immediately. It covers updates across collections, spans/UTF-8, I/O and networking, date/time, cryptography, diagnostics, and threading, with concise examples and notes on performance, memory, and reliability. Use it to plan adoption in existing projects by mapping old patterns to new overloads and helpers that reduce allocations and simplify async and data processing.

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22 Dec to 29 Dec 2025: highlights of the new online resources that we published last week.

Blog: https://www.telerik.com/blogs/whats-new-net-10-aspnet-core
Summary: This article walks you through what’s new in ASP.NET Core for .NET 10 and how to adopt the changes, with focused code examples and notes on breaking changes to help you plan upgrades. It covers updates across hosting and Kestrel, routing and minimal APIs, Blazor, authentication/authorization and security, caching and performance, and provides practical migration guidance for moving to .NET 10.

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15 Dec to 22 Dec 2025: highlights of the new online resources that we published last week.

Article: https://www.telerik.com/aspnet-core-ui/documentation/knowledge-base/grid-ai-integration
Summary: Learn how to add AI integration to the Telerik UI for ASP.NET Core Grid by invoking OpenAI or Azure OpenAI to analyze grid data and display the response in a dialog. You will add a custom toolbar command, collect selected rows and column metadata on the client, call an ASP.NET Core controller that wraps the OpenAI REST API, and render the result in the UI. The article covers configuring OpenAI/Azure OpenAI, prompt construction, server-side API key handling, and basic error handling.

Article: https://www.telerik.com/aspnet-core-ui/documentation/knowledge-base/chart-ai-integration
Summary: Implement AI-assisted analysis for the Telerik/Kendo UI for ASP.NET Core Chart by extracting series data, sending it to an AI provider (e.g., OpenAI or Azure OpenAI) from a secure server-side controller, and rendering the generated summary in a UI element (such as a Dialog). The article provides Razor and controller examples using HttpClient and environment-stored API keys, plus guidance on prompt design, minimizing shared data, and keeping keys off the client.

Article: https://www.telerik.com/aspnet-core-ui/documentation/knowledge-base/editor-ai-integration
Summary: Learn how to integrate OpenAI or Azure OpenAI with the Telerik UI for ASP.NET Core Editor by adding a custom toolbar menu that posts the current content and selected action to a server-side ASP.NET Core endpoint, then inserts or replaces the text with the AI response. The article provides Editor configuration, JavaScript, and controller code that calls the Chat Completions API with prompt templates for rewrite, summarize, translate, and grammar fixes, keeping the API key on the server.

Article: https://www.telerik.com/aspnet-core-ui/documentation/knowledge-base/scheduler-ai-integration
Summary: Learn how to integrate the Telerik UI for ASP.NET Core Scheduler with an LLM-backed AI workflow to create, edit, translate, or summarize events from natural language. You’ll add the Kendo AI Prompt to the Scheduler UI, handle its execute event on the client, and implement a C# endpoint that calls an LLM (e.g., OpenAI or Azure OpenAI) and maps the JSON response to Scheduler events. The article includes end-to-end wiring, request/response shaping, and safe parsing to update the Scheduler data source.

Article: https://www.telerik.com/aspnet-core-ui/documentation/html-helpers/data-management/grid/smart-grid/smart-extensions
Summary: This article explains how to use Smart Extensions for the Telerik UI for ASP.NET Core Grid (Smart Grid) to apply preset configuration through extension methods on the Grid HtmlHelper. It covers setup (package and namespace), the available extensions and what they enable (such as filtering, sorting, paging, toolbars, commands, and column configuration), and how to customize or override defaults when composing Smart extensions with your own Grid settings.

Blog: https://www.telerik.com/blogs/managing-content-security-telerik-aspnet-core-applications
Summary: This article shows you how to add and enforce a Content Security Policy (CSP) in ASP.NET Core applications that use Telerik UI for ASP.NET Core, including setting security headers via middleware. It details the CSP directives and allowances required by the components—script-src, style-src, img-src, font-src, connect-src, worker-src, and support for blob: and data: URLs for features like file export—and how to use nonces/hashes and CSP‑compatible Telerik/Kendo assets to avoid 'unsafe-inline' and 'unsafe-eval'. You also get copy‑paste policy examples and troubleshooting guidance for scenarios such as CDN-hosted resources, PDF/Excel export, and WebSocket/SignalR connections.

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24 Nov to 01 Dec 2025: highlights of the new online resources that we published last week.

Blog: https://www.telerik.com/blogs/securing-apps-telerik-ui-aspnet-core-otp-control
Summary: You’ll implement one-time passcode (OTP/TOTP) verification in an ASP.NET Core app using the Telerik UI for ASP.NET Core OTP control, from configuring the control in Razor views to wiring server-side validation with ASP.NET Core Identity or a TOTP library. The article covers UX and security details—auto-advancing digit inputs, paste and accessibility, handling expiration and retries, and enforcing server-only validation, rate limiting, and secure secret storage—to build a reliable multi-factor authentication flow.

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17 Nov to 24 Nov 2025: highlights of the new online resources that we published last week.

Article: https://www.telerik.com/aspnet-core-ui/documentation/knowledge-base/chat-ai-integration
Summary: Integrate the Telerik UI for ASP.NET Core Chat with OpenAI or Azure OpenAI by handling the Chat send event, forwarding user messages to a server-side controller that calls the Chat Completions API, and returning the assistant’s reply as a Chat message. The article walks you through the Razor setup, controller/action implementation, secure API key handling, request/response models, role mapping (user/assistant), and basic error handling.

Blog: https://www.telerik.com/blogs/real-time-data-updates-telerik-ui-net-maui-grid
Summary: Learn how to implement real-time data updates in the Telerik UI for .NET MAUI Grid by binding to an ObservableCollection and models that implement INotifyPropertyChanged, so item additions/removals and per-cell changes propagate instantly. The article shows a timer-driven update loop and how to marshal background changes onto the UI thread, with practical guidance to keep frequent updates responsive.

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10 Nov to 17 Nov 2025: highlights of the new online resources that we published last week.

Article: https://www.telerik.com/aspnet-core-ui/documentation/ai-components-and-features
Summary: This article documents the AI Prompt and AI Chat components in Telerik UI for ASP.NET Core and shows you how to configure Tag/HTML Helpers and connect them to OpenAI or Azure OpenAI through ASP.NET Core endpoints. It covers setup, provider configuration, client/server APIs, streaming responses, attachments, context and message history, and content safety basics to help you implement AI features in your application.

Article: https://www.telerik.com/aspnet-core-ui/documentation/html-helpers/diagrams-and-maps/diagram/binding
Summary: You will bind the Telerik ASP.NET Core Diagram HTML Helper to your data so shapes and connections are generated from your schema. Configure DataSource and ConnectionsDataSource with model field mappings (Id, Text, X/Y for shape position; From/To for connections) and transport actions for server-side CRUD. The examples show remote binding, positioning, and handling data-bound events.

Article: https://www.telerik.com/aspnet-core-ui/documentation/html-helpers/diagrams-and-maps/diagram/razor-pages
Summary: This article shows how to use the ASP.NET Core Diagram HtmlHelper in Razor Pages: configure separate DataSources for shapes and connections with AJAX transport to page handlers (via Url.Page), map model fields (Id, From, To), and include the required Kendo UI scripts and styles. It provides .cshtml and PageModel code for Read, Create, Update, and Destroy operations and demonstrates adding anti-forgery tokens to the requests.

Feel free to check them out and share your thoughts!

The Telerik Team

Telerik
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Iron
 updated question on 26 Jan 2026
5 answers
608 views
We need your feedback, because we are considering changes in the release approach for Telerik UI for ASP.NET Core. Please provide your feedback in the comments section below:


1. Is it hard to understand the version numbers of our releases? If yes, what makes them hard to understand them?

2. Would semantic versioning (SemVer) of our releases make it easier to understand our version numbers and what's behind them?

3. If we go with SemVer, we might need to start with version 3000.0.0 as we currently use 2022.x.x. Please share your thoughts about this approach and ideas for what number versioning would work best for you.

Chris
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Iron
 answered on 05 Feb 2024
1 answer
541 views

Hi!

The ListView is breaking my web application, and I cannot make head or tail of the reason:

An unhandled exception occurred while processing the request.

NotSupportedException: "ClientTemplateId or ClientTemplateHandler" cannot be null or empty.

Kendo.Mvc.UI.ListView<T>.VerifySettings()

 

Also, you demos for the ListView are broken and the browser tab crashed after a while.

I need an urgent fix, as this is affecting the live application.

Aleksandar
Telerik team
 answered on 17 Mar 2023
0 answers
631 views

In our UI for ASP.NET Core R3 2020 (2020.3.915) release, the Column menu message of unsticking a column is "null".

This bug will be resolved in our next official release.

In the meantime, as a workaround, manually set the Unstick Column menu message:

.ColumnMenu(c => c.Messages(m => m.Unstick("Unstick Column")))
Kendo UI
Top achievements
Rank 1
 asked on 16 Sep 2020
1 answer
12 views

Good afternoon,

Using the demo https://demos.telerik.com/aspnet-core/grid/custom-command edited in REPL I have added some extra columns and grouping, plus a custom command whose visibility is conditional.

When I make the grid scrollable and contained in a div whose class is "container" the custom command column is hidden at runtime.

Index.html:

<div class="container">
@(Html.Kendo().Grid<Kendo.Mvc.Examples.Models.EmployeeViewModel>()
    .Name("Grid")
    .Columns(columns => {
        columns.Command(command => command.Custom("Close").Click("showDetails").Visible("colVisible"));
        columns.Bound(e => e.Title);
        columns.Group(group => group
            .Title("Name")
            .Columns(name => {
                name.Bound(e => e.FirstName).Width(80);
                name.Bound(e => e.LastName).Width(80);
            })
        );
        columns.Bound(e => e.FirstName).Width(80);
        columns.Bound(e => e.LastName).Width(80);
        columns.Bound(e => e.Title).Width(250);
        columns.Bound(e => e.FirstName).Width(80);
        columns.Bound(e => e.LastName).Width(80);
        columns.Bound(e => e.Title).Width(250);

    })
    .Size(ComponentSize.Small)
    .Scrollable()
    .Sortable()
    .Resizable(resize => resize.Columns(true))
    .DataSource(dataSource => dataSource
        .Ajax()
        .Read(read => read.Action("CustomCommand_Read", "Grid"))
     )
)
</div>
@(Html.Kendo().Window().Name("Details")
    .Title("Customer Details")
    .Visible(false)
    .Modal(true)
    .Draggable(true)
    .Width(300)
)

 <script type="text/x-kendo-template" id="template">
    <div id="details-container">
        <h2>#= FirstName # #= LastName #</h2>
        <em>#= Title #</em>
        <dl>
            <dt>City: #= City #</dt>
            <dt>Address: #= Address #</dt>
        </dl>
    </div>
</script>

Script.js:

   function showDetails(e) {
        e.preventDefault();

        var detailsTemplate = kendo.template($("#template").html());
        var dataItem = this.dataItem($(e.currentTarget).closest("tr"));
        var wnd = $("#Details").data("kendoWindow");

        wnd.content(detailsTemplate(dataItem));
        wnd.center().open();
    }

    function colVisible(dataItem) {
        var visible = dataItem.LastName == "Fuller";
        return !visible;
    }

Is there a way to make the custom command appear?  I guess that the width of the grid is being set by "container", I've predefined column widths of some of the columns, and it works out which columns appear before the visibility of the custom command is decided, so that appears behind the first Title column?

Kind regards,

Richard

Anton Mironov
Telerik team
 answered on 29 Jan 2026
1 answer
15 views

I have a grid where I am using a custom grouping javascript event becuase one of the columns is using an editor template, when they group by that column, I want them to actually group by the hidden column containing the data for the column, not the ID.

When I drag the item to group it, the category name displays fine, having run through my javascript function.  

But when I click the three dots and use the column menu, and select Group, it uses the ID instead, and you can see that is what it is grouped by in the header. 

I suppose I could get around this by setting a custom group header for it?  I'm just not sure why it's by passing my javascript.

Eyup
Telerik team
 answered on 29 Jan 2026
1 answer
25 views

In this example

https://demos.telerik.com/aspnet-core/grid/ai-toolbar

It references

.Service("https://demos.telerik.com/service/v2/ai/grid/smart-state")

However no code example or details of how to implement this

 

Where do I find the code or documentation of how to implement

Lance | Senior Manager Technical Support
Telerik team
 answered on 29 Dec 2025
1 answer
31 views

I feel like this should be simple but I can't figure this out.  I use the  [Display(Name = "Code")] annotation in my view model. I have a simple custom editor popup on my grid.  I use taghelpers because I just do.  I am trying to get my labels to show the display name in my popup.  I have seen older posts where validation is also not working but I think this has been fixed.  Either way I feel like this should work.

Model

 public class ChargeViewModel

 {
     [ScaffoldColumn(false)]
     public int ChargesID { get; set; }

     [Required]
     [UIHint("EditChargePopup")]
     [Display(Name = "Code")]
     public string ChargesCodeID { get; set; }

Custom Editor

<div class="col-4">
    <label for="ChargesCodeID" />
    <kendo-textbox for="ChargesCodeID" />
</div>
<div class="col-4">
    <label for="Charges_Name" />
    <kendo-textbox for="Charges_Name" />
</div>
<div class="col-4">
    <label for="Charges_Fee" />
    <kendo-numerictextbox for="Charges_Fee" format="c2" decimals="2" />
</div>

Results

 

Nikolay
Telerik team
 answered on 25 Dec 2025
1 answer
85 views
We have configured the app with the possible combination published in ASP.NET MVC, Activating Your License, Setting Up Your License Key - Telerik UI for ASP.NET MVC, and FAQ | Your Account, and the other docs...
The problem started when we renewed our subscription. We didn't use the upgrade wizard, but manually copied the license.txt file to the required location. The build completes successfully. We've also included Telerik.License.cs; and telerik-license.js, but nothing seems to help - the grid shows up with a watermark.
What are we not doing right? I thought this stuff should be straightforward once you have a license, but it's proving to be quantum physics. Please help!
Eyup
Telerik team
 answered on 23 Dec 2025
1 answer
57 views

I have created a fresh project with the following variables:

  • Visual Studio 22 Community (Version 17.14.21 )
  • Progress Telerik UI for ASP.NET Core Extension 2025.4.1110.199
  • .NET 9.0
  • Kendo UI v2025.4.1111

I am trying to create a simple grid as following that has an editable `DateTime?` column:

https://netcorerepl.telerik.com/GpFmvpEr29UDYPJN54

It works in the REPL link above, but if I press "Edit" on my local project, the DateTime column defaults to a text input without the datetimepicker buttons (see Attachment-1.png), I'm not sure what I am missing.

 

I've checked that `/Views/Shared/Editor/Templates/DateTime.cshtml` exists and the content is as follows:

@model DateTime?

@(Html.Kendo().DateTimePickerFor(m => m).HtmlAttributes(new { title = Html.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName("")}))

I've placed either `[DataType("Date")]` or `[DataType("DateTime")]` annotation on the class property definition and neither worked.

I've used `.EditorTemplateName("DateTime")` and/or `[UIHint("DateTime")]` and it didn't work.

I've created a new Template type and it didn't work.

I'm not sure what else to try to make it work.

Viktor Tachev
Telerik team
 answered on 17 Dec 2025
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