Note This repository is developed using .netstandard2.0.

The current repository is based on DocumentFormat.OpenXml and aims to make exporting to an Excel list easier. So in other words, it is a wrapper on a previously specified library. The idea to create this repository has been initiated and its roots have grown more and more in a long period.

Countless times I faced the problem/need to implement some functionalities to export map a list to Excel (csv or xlsx) file with different columns names (in some cases related to specific language), dynamic number of columns, or in user-specified order, etc. As a result, the implemented solution has some basic functionalities previously mentioned.

For more information about that, follow the info from using doc.

In case you wish to use it in your project, u can install the package from nuget.org or specify what version you want:

Install-Package DynamicExcelProvider -Version x.x.x.x

What you get

• Column names per language, taken from the model itself. You annotate the property once per culture and ask for a specific LCID at export time.
• Control over which properties end up in the file, and in which order.
• xlsx from a typed collection, from a DataTable, from a DataSet (one worksheet per table), or from a workbook you build by hand.
• csv with an encoding you choose, and with the usual formula-injection traps handled.
• Header-only templates, with optional data validations on the columns.
• Column width per column, in Excel's own unit.
• Big lists split over several sheets when they pass the row limit.
• Every call returns a result object instead of throwing, so you check IsSuccess and move on.

Quick start

Register the provider at startup:

using Microsoft.Extensions.DependencyInjection;

services.RegisterExcelDataSourceProvider();

Annotate the model. One ExcelPropName per culture, the LCID is the integer culture id (1033 is en-US, 1048 is ro-RO):

using DynamicExcelProvider.Attributes;

public class InvoiceLine
{
    [ExcelPropName("Product", 1033, inResult: true, order: 0, width: 30)]
    [ExcelPropName("Produs", 1048, inResult: true, order: 0, width: 30)]
    public string Product { get; set; }

    [ExcelPropName("Quantity", 1033, inResult: true, order: 1)]
    [ExcelPropName("Cantitate", 1048, inResult: true, order: 1)]
    public int Quantity { get; set; }

    [ExcelPropName("Issued at", 1033, inResult: true, order: 2, formatCode: "dd/MM/yyyy")]
    [ExcelPropName("Emis la", 1048, inResult: true, order: 2, formatCode: "dd/MM/yyyy")]
    public DateTime IssuedAt { get; set; }

    // never exported, whatever the culture
    [ExcelPropName("Internal id", 1033, inResult: false)]
    public Guid InternalId { get; set; }
}

Inject IExcelWriteFactoryProvider and export:

using DynamicExcelProvider.Abstractions;

public class InvoiceExportService
{
    private readonly IExcelWriteFactoryProvider _excelProvider;

    public InvoiceExportService(IExcelWriteFactoryProvider excelProvider)
        => _excelProvider = excelProvider;

    public async Task<byte[]> ExportAsync(IReadOnlyCollection<InvoiceLine> lines, CancellationToken ct)
    {
        var result = await _excelProvider.GenerateAsync(lines, 1033, ct);

        if (!result.IsSuccess)
            return null; // result carries the messages, log them or map them to your own error

        return result.Response;
    }
}

Matching is done on the LCID integer, not on a CultureInfo instance, so it also works when the app runs in globalization-invariant mode.

The other entry points

Same provider, different input. These are the shapes, each one has stream / byte array / file path variants:

// dynamic column set, described at runtime instead of by attributes
IResult<byte[]> Generate(ExcelCollectionExportConfiguration request);
Task<IResult<byte[]>> GenerateAsync(ExcelCollectionExportConfiguration request, CancellationToken ct = default);

// ADO.NET, a DataSet gives one worksheet per table
Task<IResult<byte[]>> GenerateAsync(DataTable dataTable, CancellationToken ct = default);
Task<IResult<byte[]>> GenerateAsync(DataSet dataSet, CancellationToken ct = default);

// full manual control over sheets, headers and cells
IResult Generate(string filePath, WorkbookDefinition workBook);

// header row only, for a file the user fills in and sends back
IResult<byte[]> GenerateTemplate<T>(int lcid, IReadOnlyCollection<string> customOutFields = null);

On templates you can also put [ExcelPropValidation] on a property to get a real Excel data validation on that column, a value list or a min/max range. See usage for the parameters.

Column width

width is the column width in characters of the default font. That is Excel's own unit, not pixels. Leave it out or pass 0 and the spreadsheet application decides on its own, which is the behaviour you had before this option existed.

[ExcelPropName("Full name", 1033, true, 1, width: 40)]
public string Name { get; set; }

On the low-level path it is a property on the header definition:

new CellHeaderDefinition { Name = "Full name", Width = 40 }

Options

services.RegisterExcelDataSourceProvider(option =>
{
    option.ApplyMaxRowNumberPolicy = true;      // default: true
    option.SheetMaxNumberOfRows = 1_000_000;    // default: 1_000_000
});

With the policy on, a data set larger than SheetMaxNumberOfRows is split over several sheets, suffixed Sheet_1, Sheet_2 and so on. Counting starts at 1. If everything fits in one sheet, the sheet keeps its configured name with no suffix at all.

CSV

The CSV methods take the encoding as the last parameter, after the cancellation token:

Task<IResult<byte[]>> GenerateCsvAsync<TDataModel>(
    IReadOnlyCollection<PropModel> embeddedModelCollection,
    IReadOnlyCollection<PropTranslateModel> availablePropInOutput,
    IReadOnlyCollection<TDataModel> data,
    CancellationToken cancellationToken = default,
    Encoding encoding = null) where TDataModel : class;

GenerateCsvFromKnownAsync has the same tail. Things worth knowing:

• The default encoding is ISO-8859-1, kept that way so existing consumers do not break. It cannot represent anything outside Latin-1, and those characters come out as ?. If your data is not Latin-1, pass Encoding.UTF8 explicitly.
• Every field is quoted, headers included, and a quote inside a value is doubled.
• A value starting with =, +, -, @, a tab or a carriage return gets an apostrophe in front of it, so the spreadsheet does not treat it as a formula. Values that parse as numbers are left alone, so negative numbers stay numbers.

Content

1. USING
2. CHANGELOG
3. BRANCH-GUIDE