FlexCel Studio for VCL / FireMonkey

This skill helps write Delphi (VCL, FMX, Lazarus/LCL, Linux/SKIA) and C++Builder code that uses FlexCel — the TMS Software library for working with Excel .xlsx / .xls files, exporting to PDF/HTML/images, and generating data-driven reports from templates.

When to use this skill

Activate whenever the user wants to, from Pascal/Delphi/C++Builder code:

• Read an Excel file (.xlsx or .xls) — cell values, formulas, formatting.
• Create or modify an Excel file programmatically.
• Generate reports by merging data into Excel templates.
• Export an Excel file to PDF, HTML, SVG, or images.
• Autofit rows/columns, render sheets, or measure cells.
• Target VCL, FireMonkey (desktop & mobile), Lazarus, or Delphi Linux.

FlexCel does not require Excel or any Office installation on the target machine. It has no OLE/COM dependency.

Two ways to create Excel files — pick one

Before writing code, decide which API fits the task:

When the user says "generate a report with company logo / nice formatting / many rows from a database", prefer Reports. When they say "read this file and extract values" or "create an Excel file with these calculations", prefer the API.

You can combine both: run a report to produce an in-memory TXlsFile, then manipulate it with the API, then export to PDF.

Quick-start recipes

All examples assume VCL. For FireMonkey replace FlexCel.VCLSupport with FlexCel.FMXSupport; for Lazarus use FlexCel.LCLSupport; for Delphi Linux use FlexCel.SKIASupport. The platform support unit goes in the main program (`.dpr`) uses clause only, not every unit.

Recipe 1 — Create an Excel file

uses
  System.IOUtils,
  FlexCel.Core, FlexCel.XlsAdapter;

procedure CreateExcelFile;
var
  xls: TXlsFile;
begin
  // Start an empty workbook with 1 sheet and Excel-2019 default formatting.
  xls := TXlsFile.Create(1, TExcelFileFormat.v2019, true);
  try
    xls.SetCellValue(1, 1, 'Hello from FlexCel!');          // A1 text
    xls.SetCellValue(2, 1, 7);                              // A2 number
    xls.SetCellValue(3, 1, 11.3);                           // A3 number
    xls.SetCellValue(4, 1, TFormula.Create('=Sum(A2:A3)')); // A4 formula

    xls.Save(TPath.Combine(TPath.GetDocumentsPath, 'test.xlsx'));
  finally
    xls.Free;
  end;
end;

Key points:

• All row/column/sheet indices are 1-based. (1, 1) is cell A1. (XF format indices are the single exception — they're 0-based.)
• File format is inferred from the extension (.xlsx → OOXML, .xls → BIFF8).
• TXlsFile is a plain class, not a component — you create it in code and must Free it.

Recipe 2 — Read an Excel file

uses
  System.IOUtils,
  FlexCel.Core, FlexCel.XlsAdapter;

procedure ReadExcelFile(const aMemo: TMemo);
var
  xls: TXlsFile;
  row, colIndex, XF: integer;
  cell: TCellValue;
  addr: TCellAddress;
  s: string;
begin
  xls := TXlsFile.Create(TPath.Combine(TPath.GetDocumentsPath, 'test.xlsx'));
  try
    xls.ActiveSheetByName := 'Sheet1';   // or loop xls.ActiveSheet from 1 to xls.SheetCount
    for row := 1 to xls.RowCount do
    begin
      // Use ColCountInRow, NOT ColCount — much faster. See performance guide.
      for colIndex := 1 to xls.ColCountInRow(row) do
      begin
        XF := -1;
        cell := xls.GetCellValueIndexed(row, colIndex, XF);
        addr := TCellAddress.Create(row, xls.ColFromIndex(row, colIndex));

        s := 'Cell ' + addr.CellRef + ' ';
        if      cell.IsEmpty   then s := s + 'is empty.'
        else if cell.IsString  then s := s + 'string: '  + cell.ToString
        else if cell.IsNumber  then s := s + 'number: '  + FloatToStr(cell.AsNumber)
        else if cell.IsBoolean then s := s + 'bool: '    + BoolToStr(cell.AsBoolean)
        else if cell.IsError   then s := s + 'error: '   + cell.ToString
        else if cell.IsFormula then s := s + 'formula: ' + cell.AsFormula.Text;

        aMemo.Lines.Add(s);
      end;
    end;
  finally
    xls.Free;
  end;
end;

Key points:

• Iterate with `ColCountInRow(row)` combined with `GetCellValueIndexed` + `ColFromIndex` — this skips empty cells and is dramatically faster than a dense 1..ColCount loop.
• TCellValue is a discriminated-union record. Test with IsEmpty / IsString / IsNumber / IsBoolean / IsError / IsFormula, then extract with ToString / AsNumber / AsBoolean / AsFormula.
• Excel dates are stored as numbers; detect them via the cell's format, not the value type.

Recipe 3 — Export Excel to PDF

uses
  FlexCel.Core, FlexCel.XlsAdapter, FlexCel.Render;

procedure XlsxToPdf(const Source, Dest: string);
var
  xls: TXlsFile;
  pdf: TFlexCelPdfExport;
begin
  xls := TXlsFile.Create(Source);
  try
    pdf := TFlexCelPdfExport.Create(xls);
    try
      pdf.Export(Dest);                   // one PDF covering all visible sheets
    finally
      pdf.Free;
    end;
  finally
    xls.Free;
  end;
end;

PDF export needs `FlexCel.Render` plus the platform-support unit in the main .dpr (the renderer uses the graphics engine for font measurement). For PDF/A, digital signatures, font embedding tuning, or multi-sheet bookmarks see references/pdf-html-export.md.

Recipe 4 — Run a report from a template

Assume an Excel template invoice-template.xlsx already exists, with tags like <#Customers.Name> inside a named range __Customers__ spanning the repeating row(s).

uses
  FlexCel.Core, FlexCel.XlsAdapter, FlexCel.Report;

procedure RunReport(Customers: TDataSet);
var
  report: TFlexCelReport;
begin
  report := TFlexCelReport.Create(true);         // true = case-insensitive tags
  try
    report.AddTable('Customers', Customers, TDisposeMode.DoNotDispose);
    report.SetValue('ReportDate', Now);
    report.SetValue('CompanyName', 'Acme Corp');
    report.Run('invoice-template.xlsx', 'invoice-output.xlsx');
  finally
    report.Free;
  end;
end;

To write the output straight to PDF, run the report into a TXlsFile and pipe it through TFlexCelPdfExport:

out := TXlsFile.Create;
try
  report.Run('template.xlsx', out);
  pdf := TFlexCelPdfExport.Create(out);
  try pdf.Export('report.pdf'); finally pdf.Free end;
finally
  out.Free;
end;

For the full tag language and template-design conventions see references/reports-cheatsheet.md.

Unit reference (what to put in uses)

Always include `FlexCel.Core` in every unit that touches FlexCel types. Then add, per task:

Critical gotchas (read this every time)

1. 1-based indexing for rows, columns, sheets. SetCellValue(1, 1, ...) writes to A1. (XF format indices are 0-based.)
2. Always `Free` TXlsFile, TFlexCelReport, TFlexCelPdfExport, etc. They're plain classes, not components. Use try..finally.
3. Don't iterate with `ColCount` — it scans the whole sheet. Use ColCountInRow(row) + GetCellValueIndexed + ColFromIndex.
4. Platform support unit belongs in the `.dpr` only, not in every unit — it has no published types.
5. Dates are numbers. GetCellValue returns the serial date; check the cell's number format to know it's a date.
6. Measurement units in Excel are unusual — column widths are in 1/256 of a character, row heights in 1/20 of a point, etc. See the "Understanding Excel measurement units" tip in the docs before fiddling with widths/heights.
7. Use APIMate. When the user asks "how do I make a cell blue / add an autofilter / create a pivot table", the canonical answer is: do it in Excel, open the file in APIMate (ships with FlexCel), and copy the generated Delphi/C++ code. APIMate is the recommended way to discover API calls for anything Excel-specific. Mention this to the user.

When to consult the references

Load a reference file only when the task actually needs it — keeps your context lean.

• `references/api-cheatsheet.md` — deeper TXlsFile usage: formatting, fonts, colors, merging, row/column sizing, comments, images, charts, data validation, protection, sheet management, streams.
• `references/reports-cheatsheet.md` — full tag reference, named-range conventions for bands, master-detail, config sheets, user functions, events.
• `references/pdf-html-export.md` — TFlexCelPdfExport and TFlexCelHtmlExport options: PDF/A, font embedding, digital signing, HTML5, image embedding.
• `references/pitfalls.md` — longer list of gotchas drawn from the official Tips section: locale, fonts on Docker/Linux, barcodes, tokens in formulas, strict xlsx, conditional formats, etc.

When you need authoritative detail

The cheatsheets cover the common path. For anything deeper, fetch from the public documentation source:

• Markdown source (raw): https://raw.githubusercontent.com/tmssoftware/TMS-FlexCel.VCL-doc-src/main/<path>.md
• Guides: guides/api-developer-guide.md, guides/reports-developer-guide.md, guides/reports-tag-reference.md, guides/pdf-exporting-guide.md, guides/html-exporting-guide.md, guides/performance-guide.md
• Tips: tips/<topic>.md (one file per tip)
• API reference: api/FlexCel.XlsAdapter/TXlsFile/<MemberName>.md and similar
• Rendered docs: https://doc.tmssoftware.com/flexcel/vcl/index.html
• Official sample repository (Delphi + C++Builder + FireMonkey): https://github.com/tmssoftware/TMS-FlexCel.VCL-demos

Use WebFetch on the raw markdown URL when you need to confirm a signature or pull an official example. Prefer the raw markdown over the rendered HTML.

Style expectations for generated code

• Use try..finally..Free around every FlexCel object. Don't rely on interface reference counting — these are not interfaces.
• Use 1-based literals explicitly (SetCellValue(1, 1, ...)) — do not pretend indices are 0-based.
• Prefer the generic overloads (TFormula.Create('=...'), TCellValue) over implicit conversions when the intent is ambiguous.
• When exporting to PDF/HTML/images, include the platform-support unit in the example's .dpr block or mention it in a comment — otherwise rendering will fail at runtime with a missing-graphics-engine error.
• Don't invent method names. If unsure, check the API markdown under api/<unit>/<class>/<member>.md in the doc source, or tell the user to verify with APIMate.