Create PDF/UA

dotnet add package RecursiveAI.OnePdf.Layout --version 1.11.0

using OnePdf;
using OnePdf.Layout;
 
byte[] logo = File.ReadAllBytes("logo.png");
 
LayoutDocument summary = LayoutDocument.Compose(doc =>
{
    doc.Title("Harbor trial summary").Author("Port office").Language("en-US");
    doc.Page(page =>
    {
        page.Size(PageSize.Letter);
        page.Margin(54);
        page.Header().Text("Port office").FontSize(9);              // headers and footers are tagged as artifacts
        page.Content().Column(col =>
        {
            col.Spacing(10);
            col.Item().Width(48).Image(logo).AltText("Port office logo");
            col.Item().Heading(1).Text("Harbor trial summary").FontSize(22).Bold();
            col.Item().Text("Six crews took part. Catches by quay:");
            col.Item().Table(table =>
            {
                table.Columns(c => { c.Relative(); c.Constant(100); });
                table.CellPadding(4);
                table.CellBorder(0.5, Colors.Grey);
                table.HeaderRow(r => { r.Cell().Text("Quay").Bold(); r.Cell().AlignEnd().Text("Catch (kg)").Bold(); });
                table.Row(r => { r.Cell().Text("North"); r.Cell().AlignEnd().Text("1,204"); });
                table.Row(r => { r.Cell().Text("South"); r.Cell().AlignEnd().Text("987"); });
            });
            col.Item().Heading(2).Text("Next steps").FontSize(14).Bold();
            col.Item().List(list =>
            {
                list.Bulleted();
                list.Item().Text("Repeat the trial in spring.");
                list.Item().Hyperlink("https://example.com/harbor").Text("Read the full report online.");
            });
        });
    });
});
 
// PDF/UA-1 and PDF/A-2a in one file.
using (FileStream file = File.Create("summary-ua.pdf"))
{
    summary.Save(file, new PdfSaveOptions
    {
        PdfUA = new PdfUAOptions(),
        PdfA = new PdfAOptions { Part = PdfAPart.Part2, Conformance = PdfAConformance.A },
    });
}
 
// What OnePDF cannot decide for you is refused, with every reason listed.
LayoutDocument untitled = LayoutDocument.Compose(doc =>
{
    doc.Language("en-US");                                          // no title
    doc.Page(page => page.Content().Column(col =>
    {
        col.Item().Width(48).Image(logo);                           // no alternate text
        col.Item().Heading(2).Text("Starts at level 2");            // heading levels must start at 1
    }));
});
try
{
    untitled.Save(new MemoryStream(), new PdfSaveOptions { PdfUA = new PdfUAOptions() });
}
catch (PdfUAException e)
{
    foreach (PdfUAViolation v in e.Violations)
        Console.WriteLine($"checkpoint {v.Checkpoint}: {v.Message}");
}

checkpoint 06: The XMP packet has no dc:title: a PDF/UA file needs a title.
checkpoint 07: The catalog's /ViewerPreferences does not set /DisplayDocTitle true, so viewers would show the file name instead of the title.
checkpoint 13: A Figure structure element has neither alternate text (/Alt) nor replacement text (/ActualText).
checkpoint 14: The first heading is H2; the heading hierarchy has to start at H1.