sheetjs/docbits/80_parseopts.md

Parsing Options

The exported read and readFile functions accept an options argument:

Option Name	Default	Description
type		Input data encoding (see Input Type below)
cellFormula	true	Save formulae to the .f field **
cellHTML	true	Parse rich text and save HTML to the .h field
cellNF	false	Save number format string to the .z field
cellStyles	false	Save style/theme info to the .s field
cellDates	false	Store dates as type d (default is n)
sheetStubs	false	Create cell objects of type z for stub cells
sheetRows	0	If >0, read the first sheetRows rows **
bookDeps	false	If true, parse calculation chains
bookFiles	false	If true, add raw files to book object **
bookProps	false	If true, only parse enough to get book metadata **
bookSheets	false	If true, only parse enough to get the sheet names
bookVBA	false	If true, expose vbaProject.bin to vbaraw field **
password	""	If defined and file is encrypted, use password **
WTF	false	If true, throw errors on unexpected file features **

• cellFormula option only applies to formats that require extra processing to parse formulae (XLS/XLSB).
• Even if cellNF is false, formatted text will be generated and saved to .w
• In some cases, sheets may be parsed even if bookSheets is false.
• bookSheets and bookProps combine to give both sets of information
• Deps will be an empty object if bookDeps is falsy
• bookFiles behavior depends on file type:
  • keys array (paths in the ZIP) for ZIP-based formats
  • files hash (mapping paths to objects representing the files) for ZIP
  • cfb object for formats using CFB containers
• sheetRows-1 rows will be generated when looking at the JSON object output (since the header row is counted as a row when parsing the data)
• bookVBA merely exposes the raw vba object. It does not parse the data.
• Currently only XOR encryption is supported. Unsupported error will be thrown for files employing other encryption methods.
• WTF is mainly for development. By default, the parser will suppress read errors on single worksheets, allowing you to read from the worksheets that do parse properly. Setting WTF:1 forces those errors to be thrown.

The defaults are enumerated in bits/84_defaults.js

Input Type

Strings can be interpreted in multiple ways. The type parameter for read tells the library how to parse the data argument:

type	expected input
"base64"	string: base64 encoding of the file
"binary"	string: binary string (n-th byte is data.charCodeAt(n))
"buffer"	nodejs Buffer
"array"	array: array of 8-bit unsigned int (n-th byte is data[n])
"file"	string: filename that will be read and processed (nodejs only)

Guessing File Type

Excel and other spreadsheet tools read the first few bytes and apply other heuristics to determine a file type. This enables file type punning: renaming files with the .xls extension will tell your computer to use Excel to open the file but Excel will know how to handle it. This library applies similar logic:

Byte 0	Raw File Type	Spreadsheet Types
0xD0	CFB Container	BIFF 5/8 or password-protected XLSX/XLSB
0x09	BIFF Stream	BIFF 2/3/4/5
0x3C	XML/HTML	SpreadsheetML or Flat ODS or UOS1 or HTML
0x50	ZIP Archive	XLSB or XLSX/M or ODS or UOS2
0xFE	UTF8 Text	SpreadsheetML or Flat ODS or UOS1