SuperBlazorComponents.DataGridExporter 2.0.12

SuperDataGrid CSV and Excel exporter

The SuperBlazorComponents.DataGridExporter extension exports the rows that are checked in a SuperDataGrid. A checked row is captured when generation starts, so it remains exportable even if a later filter hides it.

Installation

Reference both packages/projects:

dotnet add package SuperBlazorComponents
dotnet add package SuperBlazorComponents.DataGridExporter

Register the exporter and map its download endpoint in Program.cs:

using SuperBlazorComponents.DataGridExporter;

builder.Services.AddSuperComponents();
builder.Services.AddSuperDataGridExporter(options =>
{
    options.TemporaryDirectory = Path.Combine(
        builder.Environment.ContentRootPath, "_temp", "grid-exports");
    options.FileLifetime = TimeSpan.FromHours(24);
    options.CleanupInterval = TimeSpan.FromDays(1);
});

var app = builder.Build();
app.MapSuperDataGridExporter();

The endpoint uses an unguessable 256-bit token and is anonymous by design. Files expire after FileLifetime; cleanup runs at startup and then at CleanupInterval.

Usage

Keep a component reference to the grid and pass it to either export button:

@using SuperBlazorComponents.DataGridExporter.Components

<SuperDataGrid @ref="_grid"
               TItem="Product"
               ItemsProvider="@LoadProducts">
    <HeaderTemplate>
        <div class="d-flex align-items-center gap-2 w-100">
            <div class="ms-auto d-flex align-items-center gap-2">
                <SuperDataGridExcelExportButton TItem="Product"
                                                Grid="@_grid"
                                                DefaultFileName="products"
                                                IconOnly="true" />
                <SuperDataGridCsvExportButton TItem="Product"
                                              Grid="@_grid"
                                              DefaultFileName="products"
                                              IconOnly="true" />
            </div>
        </div>
    </HeaderTemplate>
    <DataGridColumn For="@(p => p.Name)" Title="Product" />
    <DataGridColumn For="@(p => p.Price)" Title="Price" FormatString="{0:F2}" />
</SuperDataGrid>

@code {
    private SuperDataGrid<Product>? _grid;
}

Set IconOnly="true" to hide the text while preserving it as the tooltip and accessible label. The Bootstrap ms-auto wrapper aligns the export actions to the right of the grid header. The grid keeps the custom header area separated from its built-in actions. Omit IconOnly to display the icon and text together.

Only currently visible columns are exported, in their current order. If rows are selected individually, those exact objects are exported in selection order. If Tout sélectionner is used, the exporter reads all rows matching the captured filters and sort order from ItemsProvider, in batches of 200 by default, and skips rows explicitly unchecked afterwards. The batch size can be changed with SuperDataGridExporterOptions.BatchSize.

The dialog is still opened when nothing is checked, but immediately displays: “Veuillez cocher au moins une ligne pour effectuer l’export.” Check a row and choose Réessayer to continue; no file is created while the selection is empty. Selection is frozen at the start of generation.

For hierarchical grids, every checked row is exported, including checked child rows. Unchecked or unexpanded children are not invented by the exporter. Virtualized providers should implement IDataItem.KeyValue with a stable, unique key. The same key is used to apply exclusions and deduplicate rows when the provider materializes a new object instance for each batch.

Custom columns

Headers are resolved in this order:

1. ExportHeader
2. plain text found directly in HeaderTemplate
3. Title
4. Property

Values use ExportValue first, then the rendered text of Template, and finally Property or For. A template-only column can therefore be exported without declaring a binding; its title is taken from Title and its textual cell content is taken from the template:

<DataGridColumn Title="Suppliers">
    <Template Context="product">
        @foreach (var supplier in product.AvailableSupplierProductList)
        {
            <div>@supplier.SupplierName</div>
        }
    </Template>
</DataGridColumn>

HTML elements are removed from the exported value and the remaining text is normalized. For a column whose output is produced only by a child component, configure ExportValue explicitly. Configure both overrides when a column is entirely template-driven and needs a custom header or value:

<DataGridColumn Title="Status"
                ExportHeader="Current status"
                ExportValue="@GetExportedStatus">
    <Template>
        ...
    </Template>
</DataGridColumn>

@code {
    private static object GetExportedStatus(Product item)
        => item.IsActive ? "Active" : "Inactive";
}

Set Exportable="false" to exclude a visible column.

Formats and limits

• CSV defaults to UTF-8 without BOM, comma delimiter and invariant culture. These defaults are configurable through SuperDataGridExporterOptions.
• CSV strings beginning with formula control characters are prefixed safely by default.
• Excel preserves native number, date and boolean cell types, freezes the header, reproduces the grid's left frozen columns, enables filtering and sizes columns to their content. Excel cannot freeze columns from the right.
• One worksheet supports at most 1,048,575 exported data rows because the header occupies the first Excel row.
• ItemsProvider is required for Tout sélectionner so the exporter can retrieve every filtered row; it never treats the currently rendered virtualized items alone as the complete dataset. Individually checked objects are exported from the immutable selection captured at the start.