Direct reader and writer API

TXLSDirectReader and TXLSDirectWriter process XLSX packages without holding a complete worksheet grid in memory, so API calls that describe a sheet must be made before or during the corresponding streaming phase

Writer lifecycle and cell values

TXLSDirectWriter.BeginFile or BeginStream starts a package, sheet methods define one worksheet at a time, and Finish commits the final package

Rows and columns are one-based in the public writer surface and must be supplied in forward worksheet order

Reusable styles

AddCellStyle registers an immutable package-level style handle and CloneCellStyle derives a new handle without retaining worksheet rows

Defined names and hyperlinks

AddDefinedName, AddLocalDefinedName, AddDefinedRange, and AddLocalDefinedRange add workbook or sheet-local names before package finalization

AddHyperlink, AddHyperlinkRange, AddInternalHyperlink, and AddInternalHyperlinkRange emit external relationships or internal sheet locations for one cell or a range

Data validation

AddDataValidation and AddDataValidationSqRef expose the complete rule surface, while AddListValidation, AddWholeNumberValidation, AddDecimalValidation, AddDateValidation, AddTimeValidation, AddTextLengthValidation, and AddCustomValidation provide typed helpers

Conditional formatting

AddConditionalFormat, AddConditionalFormatExpression, AddConditionalFormatContainsText, AddConditionalFormatNotContainsText, AddConditionalFormatBeginsWith, AddConditionalFormatEndsWith, AddConditionalFormatTop10, AddConditionalFormatAboveAverage, AddConditionalFormatDuplicateValues, AddConditionalFormatUniqueValues, AddConditionalFormatContainsBlanks, AddConditionalFormatNotContainsBlanks, AddConditionalFormatContainsErrors, and AddConditionalFormatNotContainsErrors add scalar rules

AddConditionalFormatDataBar, AddConditionalFormatColorScale2, AddConditionalFormatColorScale3, and AddConditionalFormatIconSet add visual rules; ClearConditionalFormats removes pending rules for the current sheet

AutoFilter and tables

AddAutoFilterValue, AddAutoFilterDateGroup, and AddAutoFilterSortCondition configure the worksheet filter

AddTable creates a table part, and AddTableFilterValue, AddTableFilterDateGroup, and AddTableSortCondition configure its filter and sort state

Protection and page breaks

ProtectSheet, UnprotectSheet, AddProtectedRange, and ClearProtectedRanges configure worksheet protection; ProtectWorkbook and UnprotectWorkbook configure workbook structure and window locks

AddHorizontalPageBreak and AddVerticalPageBreak emit manual page breaks for the current worksheet

Direct reader storage diagnostics

TXLSDirectReader.SharedStringMemoryLimit bounds decoded shared-string memory, SharedStringsOnDisk reports migration to temporary indexed storage, SharedStringCount reports the loaded entry count, and ParallelDiag exposes bounded parallel-parser diagnostics

Reader projection and formula state

FirstRow, LastRow, IncludeColumn, and ClearColumnProjection push row and one-based column selection into the worksheet parser before value, formula, or rich-text allocation

IncludeFormulaText defaults to true; disabling it keeps cached values, coordinates, styles, and HasFormula while FormulaTextAvailable becomes false and Formula remains empty

Row cursor

TXLSRowCursor.Open accepts XLS, XLSX, XLSM, ODS, CSV, and TSV files or streams; ZIP auto-detection distinguishes ODS packages from Open XML workbooks before a sheet is opened

SelectSheet and SelectSheetByName choose a worksheet; SheetCount, SheetNames, SheetIndex, RowIndex, and Eof expose traversal state, while SharedStringMemoryLimit applies the same bounded shared-string policy as the direct reader

FirstRow, LastRow, IncludeColumn, and ClearColumnProjection use the same one-based filters across all cursor formats; pass options cannot change between FindFirst and EOF but become mutable again after EOF, sheet selection, or close

Each TXLSRowCursorCell reports HasFormula independently from FormulaTextAvailable; classic XLS exposes formula presence and cached results without claiming unavailable token text, while IncludeFormulaText can suppress XLSX and ODS formula text before accumulation

ODS traversal holds one physical row template, clips repeated row blocks to the requested interval, jumps directly between selected columns inside repeated spans, advances across covered cells without returning them as values, and reports invalid or grid-limited repeat counts through OnSkippedRecord

State distinguishes xrcsClosed, xrcsBeforeFirst, xrcsActive, xrcsEof, xrcsCancelled, and xrcsFaulted; Cancel is idempotent, invalidates the current row, and releases the active worksheet stream while retaining the source so an explicit sheet selection can start a new pass

The stream overload defaults to xsoBorrowed, restores the caller's initial position on close, and accepts xsoOwned to transfer ownership after a successful open; failed opens never consume caller ownership

CurrentRowView borrows the current row array without copying it and checks a generation before every access; advancing, selecting, cancelling, closing, or destroying the cursor invalidates the view and raises EXLSRowCursorViewInvalidated on later access

PeakRowBufferedBytes is a monotonic estimate since the most recent Open of the cell records, managed payloads, rich text, and format-backend data retained for one logical row; it is intended for bounded-memory regression diagnostics rather than exact heap accounting

SheetPassesStarted counts successful worksheet backend starts; inspecting sheet names or skipping a sheet through the callback facade does not open the worksheet part

Forward callback adapter

TXLSForwardReader delegates XLS, XLSX, ODS, CSV, and TSV decoding to TXLSRowCursor, converts each current-row cell into an OnCell callback, and preserves the same row bounds, column projection, formula state, rich text, password, skipped-record, stream-position, and bounded-buffer contracts

PeakRowBufferedBytes and SheetPassesStarted expose the shared cursor diagnostics on the callback surface, while classic XLS additionally retains ClassicBytesRead and ClassicPeakBufferedBytes

Reader events and record types

The reader and row cursor expose optional callbacks and plain records, all declared in lxDirectRead. Every callback follows the same shape: the record describes one streamed item, and setting Abort stops the scan (sheet events additionally accept SkipSheet)

Writer parameter and style types

The writer's typed helpers (lxDirectWrite) accept records and enums so calls stay allocation-free: WriteRichString takes a TXLSDirectRichText; AddCellStyle builds a package-level style from a TXLSDirectCellStyle whose alignment (TXLSDirectHorizontalAlignment, TXLSDirectVerticalAlignment), underline (TXLSDirectUnderline), fill pattern (TXLSDirectFillPattern), and border sides (TXLSDirectStyleBorder with TXLSDirectBorderSide) mirror the OOXML style model. Conditional formats pass a TXLSDirectConditionalFormat with TXLSDirectCfKind / TXLSDirectCfOperator / TXLSDirectCfValue / TXLSDirectCfValueKind and TXLSDirectIconSetType, data validation a TXLSDirectDataValidation, tables a TXLSDirectTable, hyperlinks a TXLSDirectHyperlink, defined names a TXLSDirectDefinedName, differential styles a TXLSDirectDxfStyle, comments a TXLSDirectComment, images a TXLSDirectImage with TXLSDirectImageFormat, charts a TXLSDirectChart with TXLSDirectChartSeries and TXLSDirectChartType, merges a TXLSDirectMergeRange, protected ranges a TXLSDirectProtectedRange, sheet protection a TXLSDirectSheetProtectionOptions set of TXLSDirectSheetProtectionOption, auto-filter sort state a TXLSDirectSortState, column options a TXLSDirectColumnOption, and page geometry a TXLSDirectPageMargins record

TXLSDirectNeedRow = procedure(Sender: TObject; RowIndex: Integer;
  var Eof: Boolean) of object;

function XLSDirectColName(Col: Integer): WideString;
function XLSDirectParseRef(const Ref: WideString;
  out Col, Row: Integer): Boolean;
function XLSDirectPasswordHash(const Password: WideString): WideString;
      

OnNeedRow pulls rows from the application: the supplier writes the row's cells straight through the writer and leaves Eof = False, or declares exhaustion with Eof = True to stop the loop. The helpers convert between coordinates and protection primitives: XLSDirectColName renders a zero-based column as its A1 letters, XLSDirectParseRef parses an A1 cell reference, and XLSDirectPasswordHash computes the legacy password hash the sheet-protection records store

See also

• Large spreadsheet streaming
• TXLSForwardReader