Pixata.AspNetCore.Telerik 1.0.2

Pixata.AspNetCore.Telerik

The server-side companion to the Pixata.Blazor.TelerikComponents package.

This package exists so that Pixata.Blazor.TelerikComponents doesn't need to have server-only code, which would prevent it from being used in WASM apps. The grid data helper below talks to a database, so it needs EF Core, Microsoft.EntityFrameworkCore.SqlServer and Microsoft.Data.SqlClient. Those used to sit in the component package, which meant every client-side app that wanted a Telerik date picker also downloaded a SQL Server driver it could never use. The helper now lives here, and the component package is free of them.

Install this one in your server project, and Pixata.Blazor.TelerikComponents wherever your components live.

A Nuget package is available for this project.

Extension method to improve the performance of the Telerik Blazor grid

Whilst the Telerik Blazor grid does an amazing job, it has its limitations. One of these is the way it computes aggregates. For large tables, this can be slow.

I had a play with Dapper, which improved matters significantly, and then found out that I could do the same with pure EF Core, without any extra packages. I wrapped up the code into an extension method for GridReadEventArgs, which you can call from the OnRead event of the grid. In the project that motivated this code, I managed to reduce the time taken for the grid to load from over 10 seconds to around 400 milliseconds 😎.

There is a sample repo that shows the method in usage, and a blog post that explain the usage (with far too many anecdotes and rambling). If you are bored, that post links to two previous posts that detail my journey to this extension method.

Note that as from version 2.0.0 of the Pixata.Blazor.TelerikComponents package, the method allows you to query a table-valued function as well as a table or view.

Filtering DateTime values by date only

When using row filtering, the Telerik grid will, by default, filter DateTime values by their full value, including the time. This is often not what you want, as users will typically want to filter by date only. To make this easier, the extension method allows you to specify that a particular DateTime column should be filtered by date only. For example...

private Task LoadData(GridReadEventArgs args) {
  TelerikFilterHelper.RemoveTime(args, nameof(MyEntity.DateCreated), nameof(MyEntity.DateDeleted));
  // Call the extension method as before
}

Note that TelerikFilterHelper stays in the Pixata.Blazor.TelerikComponents package, as it doesn't touch the database.

Breaking changes

Moved from Pixata.Blazor.TelerikComponents

TelerikGridHelper (and with it TelerikGridFilterResults and TelerikGridFilterOptions) moved here from Pixata.Blazor.TelerikComponents v12.3.17. If you use args.GetData<T>(), add a reference to this package in your server project and change the using from...

using Pixata.Blazor.TelerikComponents.Helpers;

...to...

using Pixata.AspNetCore.Telerik.Helpers;

The method signatures and behaviour are unchanged.

Removal of the generic parameter from TelerikGridFilterResults

As of version 2.0.0 of Pixata.Blazor.TelerikComponents, the generic parameter was removed from TelerikGridFilterResults (as it wasn't needed), so you will need to update your code if you capture this as an explicit type. For example, change this:

TelerikGridFilterResults<MyType> data = await args.GetData<MyType>(/* args go here */)

...to this...

TelerikGridFilterResults data = await args.GetData<MyType>(/* args go here */)

Not a major issue, but worth noting.

Warning

As with the rest of these packages, use at your own risk!