Replace ReportViewer and RDLC on .NET 8, 9 and 10

Many .NET applications print their invoices, statements and lists with RDLC reports, rendered locally by Microsoft’s ReportViewer control. ReportViewer belongs to .NET Framework, Windows Forms and Web Forms: there is no Microsoft-supported way to render RDLC in ASP.NET Core, in a Linux container or with native AOT. Rewriting every report by hand in another tool is the usual way out, and the slow one.

Tagua converts them instead. tagua import reads an RDLC or RDL report (SSRS and ReportViewer, RDL 2005 to 2016) and writes a Tagua template that loads and renders straight away, with a list of anything that needs a second look. Nothing is dropped silently.

Convert a report

1. Install the tagua command:

   dotnet tool install --global Tagua.Cli

2. Convert the report. Embedded images are written next to the template.

   Terminal

   $ tagua import Invoice.rdlc
   Invoice.report.yaml: converted, with 1 image(s).
   1 thing(s) to review (placeholders in the template are marked [RDLC ...]):
     - Textbox 'Custom': The expression =Code.Greeting(First(Fields!CustomerName.Value, "Invoice")) was not converted (custom code (Code.Greeting)).

   This invoice converted, apart from one expression that calls custom code (Code.Greeting), which Tagua’s sandboxed expressions cannot run. It is left as a visible [RDLC …] placeholder to replace by hand.

3. Look at it, with sample data made up from the field types, rendered again on every save while you work on it:

   tagua render Invoice.report.yaml --watch --open

   

   Download the PDF.

The converted template

Invoice.report.yaml

# Converted from Invoice.rdlc by Tagua.Import.
version: 1
title: Invoice
culture: en-US

page: { size: Letter, margins: 54pt 72pt 54pt 72pt }

parameters:
  CompanyName: { type: string, label: Company name, default: "='Acme Ltd'" }
  ShowNotes: { type: boolean, label: Show notes, default: "=true" }

data:
  Invoice:
    fields: { InvoiceNumber: string, CustomerName: string, IssueDate: dateTime }
  Lines:
    fields: { Description: string, Quantity: decimal, UnitPrice: decimal }

styles:
  default: { font: Arial, fontSize: 10pt }
  linesTableHeader: { background: "#D3D3D3", padding: 2pt, borderBottom: "1pt solid #000000", fontWeight: bold }

body:
  dataset: Invoice
  reportHeader:
    - layout: absolute
      height: 28.8pt
      content:
        - type: text
          x: 0pt
          y: 0pt
          width: 216pt
          value: Invoice
          padding: 2pt
          font: Segoe UI
          fontSize: 18pt
          fontWeight: bold
          color: "#1F3864"
        - type: text
          x: 324pt
          y: 0pt
          width: 144pt
          value: "No. {First(InvoiceNumber, 'Invoice')}"
          padding: 2pt
          align: right
    - layout: absolute
      height: 18pt
      padding: 14.4pt 0 0 0
      content:
        - type: text
          x: 0pt
          y: 0pt
          width: 252pt
          value: "Bill to: {First(CustomerName, 'Invoice')}"
          padding: 2pt
        - type: text
          x: 324pt
          y: 0pt
          width: 144pt
          value: "{First(IssueDate, 'Invoice'):d}"
          padding: 2pt
          align: right
    - layout: absolute
      height: 1pt
      padding: 7.2pt 0 0 0
      content:
        - { type: line, x: 0pt, y: 0pt, width: 468pt, stroke: "0.75pt solid #696969", tag: artifact }
    - padding: 18pt 0 0 0
      content:
        - type: table
          dataset: Lines
          sort: [Description]
          columns:
            - { header: Description, value: "{Description}", width: 252pt, padding: 2pt }
            - { header: Qty, value: "{Quantity:0.##}", width: 54pt, padding: 2pt, align: right }
            - { header: Unit price, value: "{UnitPrice:C2}", width: 79.2pt, padding: 2pt, align: right }
            - { header: Amount, value: "{Quantity * UnitPrice:C2}", width: 82.8pt, padding: 2pt, align: right }
          headerStyle: linesTableHeader
          footer:
            - cells:
                - { value: Total, span: 3, padding: 2pt, fontWeight: bold }
                - value: "{Sum(Quantity * UnitPrice):C2}"
                  padding: 2pt
                  borderTop: "1pt solid #000000"
                  fontWeight: bold
                  align: right
          width: 468pt
    - layout: absolute
      height: 18pt
      padding: 18pt 0 0 0
      content:
        - type: text
          x: 0pt
          y: 0pt
          width: 468pt
          value: Thank you for your business.
          padding: 2pt
          italic: true
          color: "#808080"
          visible: "=ShowNotes"
    - layout: absolute
      height: 18pt
      padding: 10.8pt 0 0 0
      content:
        - type: text
          x: 0pt
          y: 0pt
          width: 468pt
          value: "[RDLC: =Code.Greeting(First(Fields!CustomerName.Value, \"Invoice\"))]"
          padding: 2pt
  pageHeader:
    - layout: absolute
      height: 43.2pt
      content:
        - type: image
          x: 0pt
          y: 0pt
          width: 72pt
          height: 36pt
          source: images/Logo.png
          fit: contain
          alt: Acme logo
        - type: text
          x: 324pt
          y: 7.2pt
          width: 144pt
          value: "{CompanyName}"
          padding: 2pt
          fontWeight: bold
          align: right
  detail: []
  pageFooter:
    - layout: absolute
      height: 28.8pt
      content:
        - type: text
          x: 324pt
          y: 7.2pt
          width: 144pt
          value: "Page {PageNumber} of {TotalPages}"
          padding: 2pt
          fontSize: 8pt
          align: right

Connect your data

In ReportViewer, data came in as ReportDataSources named after the report’s datasets. In Tagua the template’s data section keeps those names (Invoice and Lines here), and you pass rows under the same names, from memory or straight from a database reader:

var report = CompiledReport.Compile(TemplateLoader.LoadFile("Invoice.report.yaml"));
var inputs = new ReportInputs
{
    Parameters = new Dictionary<string, object?> { ["CompanyName"] = "Contoso Ltd" },
    Data = new Dictionary<string, IDataSet>
    {
        ["Invoice"] = DataSources.FromRows([invoice]),
        ["Lines"] = DataSources.FromDataReader(async ct =>
        {
            var command = connection.CreateCommand();
            command.CommandText = "select Description, Quantity, UnitPrice from InvoiceLines where InvoiceId = @id";
            command.Parameters.Add(new SqlParameter("@id", invoiceId));
            return await command.ExecuteReaderAsync(ct);
        }),
    },
    Resources = new DirectoryResourceResolver("reports"),
};
await using var pdf = File.Create("invoice.pdf");
await Reports.RenderPdfAsync(report, inputs, pdf);

It runs anywhere .NET 10 runs: ASP.NET Core, a worker, a Linux container, native AOT.

What converts

• Data: datasets and their fields with types, report parameters with prompts and defaults.
• Page: size, orientation, margins, language, page header and footer.
• Items: text boxes with their formatting and Format, images (embedded, external and from fields), lines, rectangles, visibility (Hidden), bookmarks.
• Data regions: tables, the first grouped table or list as the report’s groups (with group headers, footers and page breaks), lists, charts (column, bar, line, area, pie, doughnut) and subreports.
• Expressions, translated from Visual Basic: fields and parameters, Globals, aggregates with their scope, IIf and Switch, formatting, conversion, string, date and math functions, and the operators. A concatenation such as ="Page " & Globals!PageNumber becomes the text template Page {PageNumber}.

What needs a person

These leave an [RDLC …] placeholder and an entry in the list, so you can find and finish them:

• custom code (Code.…), RowNumber, RunningValue, Previous, Lookup and ReportItems!…;
• matrices with column groups, and more than one grouped table;
• other chart types, gauges, maps, data bars and indicators;
• expressions in styles (conditional colours), drill-down toggles, dataset filters and calculated fields (supply the rows filtered and computed).

Tip

Converting a report is a starting point you review, not a black box: the template is readable YAML, the output is a normal Tagua report, and from there it can be made accessible or archival with one line.

From code

The converter is also a library, Tagua.Import, for converting many reports at once:

var result = RdlcImporter.Import("Invoice.rdlc");
File.WriteAllText("Invoice.report.yaml", result.Yaml);
foreach (var issue in result.Issues) Console.WriteLine(issue);