ASP.NET Core Blazor QuickGrid component

The QuickGrid component is a Razor component for quickly and efficiently displaying data in tabular form. QuickGrid provides a simple and convenient data grid component for common grid rendering scenarios and serves as a reference architecture and performance baseline for building data grid components. QuickGrid is highly optimized and uses advanced techniques to achieve optimal rendering performance.

Package

Add a package reference for the Microsoft.AspNetCore.Components.QuickGrid package.

Note

For guidance on adding packages to .NET apps, see the articles under Install and manage packages at Package consumption workflow (NuGet documentation). Confirm correct package versions at NuGet.org.

Sample app

For various QuickGrid demonstrations, see the QuickGrid for Blazor sample app. The demo site is hosted on GitHub Pages. The site loads fast thanks to static prerendering using the community-maintained BlazorWasmPrerendering.Build GitHub project.

QuickGrid implementation

To implement a QuickGrid component:

• Specify tags for the QuickGrid component in Razor markup (<QuickGrid>...</QuickGrid>).
• Name a queryable source of data for the grid. Use either of the following data sources:
  • Items: A nullable IQueryable<TGridItem>, where TGridItem is the type of data represented by each row in the grid.
  • ItemsProvider: A callback that supplies data for the grid.
• Class: An optional CSS class name. If provided, the class name is included in the class attribute of the rendered table.
• Theme: A theme name (default value: default). This affects which styling rules match the table.
• Virtualize: If true, the grid is rendered with virtualization. This is normally used in conjunction with scrolling and causes the grid to fetch and render only the data around the current scroll viewport. This can greatly improve the performance when scrolling through large data sets. If you use Virtualize, you should supply a value for ItemSize and must ensure that every row renders with a constant height. Generally, it's preferable not to use Virtualize if the amount of data rendered is small or if you're using pagination.
• ItemSize: Only applicable when using Virtualize. ItemSize defines an expected height in pixels for each row, allowing the virtualization mechanism to fetch the correct number of items to match the display size and to ensure accurate scrolling.
• ItemKey: Optionally defines a value for @key on each rendered row. Typically, this is used to specify a unique identifier, such as a primary key value, for each data item. This allows the grid to preserve the association between row elements and data items based on their unique identifiers, even when the TGridItem instances are replaced by new copies (for example, after a new query against the underlying data store). If not set, the @key is the TGridItem instance.
• Pagination: Optionally links this TGridItem instance with a PaginationState model, causing the grid to fetch and render only the current page of data. This is normally used in conjunction with a Paginator component or some other UI logic that displays and updates the supplied PaginationState instance.
• In the QuickGrid child content (RenderFragment), specify PropertyColumn<TGridItem,TProp>s, which represent TGridItem columns whose cells display values:
  • Property: Defines the value to be displayed in this column's cells.
  • Format: Optionally specifies a format string for the value. Using Format requires the TProp type to implement IFormattable.
  • Sortable: Indicates whether the data should be sortable by this column. The default value may vary according to the column type. For example, a TemplateColumn<TGridItem> is sortable by default if any SortBy parameter is specified.
  • InitialSortDirection: Indicates the sort direction if IsDefaultSortColumn is true.
  • IsDefaultSortColumn: Indicates whether this column should be sorted by default.
  • PlaceholderTemplate: If specified, virtualized grids use this template to render cells whose data hasn't been loaded.

For example, add the following component to render a grid.

The component assumes that the Interactive Server render mode (InteractiveServer) is inherited from a parent component or applied globally to the app, which enables interactive features. For the following example, the only interactive feature is sortable columns.

PromotionGrid.razor:

@page "/promotion-grid"
@using Microsoft.AspNetCore.Components.QuickGrid

<PageTitle>Promotion Grid</PageTitle>

<h1>Promotion Grid Example</h1>

<QuickGrid Items="@people">
    <PropertyColumn Property="@(p => p.PersonId)" Sortable="true" />
    <PropertyColumn Property="@(p => p.Name)" Sortable="true" />
    <PropertyColumn Property="@(p => p.PromotionDate)" Format="yyyy-MM-dd" Sortable="true" />
</QuickGrid>

@code {
    private record Person(int PersonId, string Name, DateOnly PromotionDate);

    private IQueryable<Person> people = new[]
    {
        new Person(10895, "Jean Martin", new DateOnly(1985, 3, 16)),
        new Person(10944, "António Langa", new DateOnly(1991, 12, 1)),
        new Person(11203, "Julie Smith", new DateOnly(1958, 10, 10)),
        new Person(11205, "Nur Sari", new DateOnly(1922, 4, 27)),
        new Person(11898, "Jose Hernandez", new DateOnly(2011, 5, 3)),
        new Person(12130, "Kenji Sato", new DateOnly(2004, 1, 9)),
    }.AsQueryable();
}

Access the component in a browser at the relative path /promotion-grid.

There aren't current plans to extend QuickGrid with features that full-blown commercial grids tend to offer, for example, hierarchical rows, drag-to-reorder columns, or Excel-like range selections. If you require advanced features that you don't wish to develop on your own, continue using third-party grids.

Custom attributes and styles

QuickGrid also supports passing custom attributes and style classes to the rendered table element:

<QuickGrid Items="..." custom-attribute="value" class="custom-class">

Entity Framework Core (EF Core) data source

EF Core's DbContext provides a DbSet<TEntity> property for each table in the database. Supply the property to the Items parameter.

The following example uses the People DbSet<TEntity> (table) as the data source:

@inject ApplicationDbContext AppDbContext

<QuickGrid Items="@AppDbContext.People">
    ...
</QuickGrid>

You may also use any EF-supported LINQ operator to filter the data before passing it to the Items parameter.

The following example filters documents by a category ID:

<QuickGrid Items="@AppDbContext.Documents.Where(d => d.CategoryId == categoryId)">
    ...
</QuickGrid>

QuickGrid recognizes EF-supplied IQueryable instances and knows how to resolve queries asynchronously for efficiency.

Start by adding a package reference for the Microsoft.AspNetCore.Components.QuickGrid.EntityFrameworkAdapter NuGet package.

Note

For guidance on adding packages to .NET apps, see the articles under Install and manage packages at Package consumption workflow (NuGet documentation). Confirm correct package versions at NuGet.org.

Call AddQuickGridEntityFrameworkAdapter on the service collection in the Program file to register an EF-aware IAsyncQueryExecutor implementation:

builder.Services.AddQuickGridEntityFrameworkAdapter();

Remote data

In Blazor WebAssembly apps, fetching data from a JSON-based web API on a server is a common requirement. To fetch only the data that's required for the current page/viewport of data and apply sorting or filtering rules on the server, use the ItemsProvider parameter.

ItemsProvider can also be used in a server-side Blazor app if the app is required to query an external endpoint or in other cases where the requirements aren't covered by an IQueryable.

Supply a callback matching the GridItemsProvider<TGridItem> delegate type, where TGridItem is the type of data displayed in the grid. The callback is given a parameter of type GridItemsProviderRequest<TGridItem>, which specifies the start index, maximum row count, and sort order of data to return. In addition to returning the matching items, a total item count (totalItemCount) is also required for paging and virtualization to function correctly.

The following example obtains data from the public OpenFDA Food Enforcement database.

The GridItemsProvider<TGridItem> converts the GridItemsProviderRequest<TGridItem> into a query against the OpenFDA database. Query parameters are translated into the particular URL format supported by the external JSON API. It's only possible to perform sorting and filtering via sorting and filtering that's supported by the external API. The OpenFDA endpoint doesn't support sorting, so none of the columns are marked as sortable. However, it does support skipping records (skip parameter) and limiting the return of records (limit parameter), so the component can enable virtualization and scroll quickly through tens of thousands of records.

FoodRecalls.razor:

@page "/food-recalls"
@inject HttpClient Http
@inject NavigationManager NavManager

<PageTitle>Food Recalls</PageTitle>

<h1>OpenFDA Food Recalls</h1>

<div class="grid" tabindex="-1">
    <QuickGrid ItemsProvider="@foodRecallProvider" Virtualize="true">
        <PropertyColumn Title="ID" Property="@(c => c.Event_Id)" />
        <PropertyColumn Property="@(c => c.State)" />
        <PropertyColumn Property="@(c => c.City)" />
        <PropertyColumn Title="Company" Property="@(c => c.Recalling_Firm)" />
        <PropertyColumn Property="@(c => c.Status)" />
    </QuickGrid>
</div>

<p>Total: <strong>@numResults results found</strong></p>

@code {
    GridItemsProvider<FoodRecall>? foodRecallProvider;
    int numResults;

    protected override async Task OnInitializedAsync()
    {
        foodRecallProvider = async req =>
        {
            var url = NavManager.GetUriWithQueryParameters(
                "https://api.fda.gov/food/enforcement.json", 
                new Dictionary<string, object?>
            {
                { "skip", req.StartIndex },
                { "limit", req.Count },
            });

            var response = await Http.GetFromJsonAsync<FoodRecallQueryResult>(
                url, req.CancellationToken);

            return GridItemsProviderResult.From(
                items: response!.Results,
                totalItemCount: response!.Meta.Results.Total);
        };

        numResults = (await Http.GetFromJsonAsync<FoodRecallQueryResult>(
            "https://api.fda.gov/food/enforcement.json"))!.Meta.Results.Total;
    }
}

For more information on calling web APIs, see Call a web API from an ASP.NET Core Blazor app.

QuickGrid scaffolder

The QuickGrid scaffolder in Visual Studio scaffolds Razor components with QuickGrid to display data from a database.

To use the scaffolder, right-click the project in Solution Explorer and select Add > New Scaffolded Item. Open Installed > Common > Razor Component. Select Razor Components using Entity Framework (CRUD).

The scaffolder generates basic Create, Read, Update, and Delete (CRUD) pages based on an Entity Framework Core data model. You can scaffold individual pages or all of the CRUD pages. You select the model class and the DbContext, optionally creating a new DbContext if needed.

The scaffolded Razor components are added to the project's Pages folder in a generated folder named after the model class. The generated Index component uses QuickGrid to display the data. Customize the generated components as needed and enable interactivity to take advantage of interactive features, such as sorting and filtering.

The components produced by the scaffolder require server-side rendering (SSR), so they aren't supported when running on WebAssembly.