csv4xls

Convert a 2D array to xls-compatible CSV, TSV, or XLSX file.

Usage

include csv4xls script, and use:

// Default: Tab-separated (TSV)
ret = csv4xls.toBlob([[1,2,3],[4,5,6]])

// Using comma as delimiter (CSV)
ret = csv4xls.toBlob([[1,2,3],[4,5,6]], {delimiter: ','})

// Using XLSX format (requires XLSX library)
ret = csv4xls.toBlob([[1,2,3],[4,5,6]], {format: 'xlsx'})

// Using XLSX format with all cells forced to text type
ret = csv4xls.toBlob([[1,2,3],[4,5,6]], {format: 'xlsx', forceText: true})

// Download with options
csv4xls.download([[1,2,3],[4,5,6]], "mydata", {delimiter: ','}) // Will download as mydata.csv
csv4xls.download([[1,2,3],[4,5,6]], "mydata") // Will download as mydata.tsv
csv4xls.download([[1,2,3],[4,5,6]], "mydata", {format: 'xlsx'}) // Will download as mydata.xlsx
csv4xls.download([[1,2,3],[4,5,6]], "mydata", {format: 'xlsx', forceText: true}) // Will download as mydata.xlsx with all cells as text

API

csv4xls provides following APIs:

• toString(data, delimiter = '\t') - convert given 2D array to CSV/TSV in String format.
• toArray(data, delimiter = '\t') - convert given 2D array to an xls-compatible CSV/TSV file in the returned Uint8Array.
• toXlsx(data) - convert given 2D array to XLSX workbook (requires XLSX library).
• toBlob(data, options = {delimiter: '\t', format: 'auto', forceText: false}) - convert data to blob with specified format.
  • If format is 'xlsx', returns XLSX blob (requires XLSX library)
  • If format is 'html', returns HTML table as blob with MIME type text/html
  • If format is 'xls-html', returns HTML table with BOM as blob with MIME type application/vnd.ms-excel
    • Uses mso-number-format:'\@' style to prevent Excel from changing formats
  • If format is 'auto' (default), uses XLSX if available, otherwise falls back to CSV/TSV
  • If XLSX is not available or fails, falls back to CSV/TSV based on delimiter
  • HTML options can be passed via options.html object (see toHtml for available options)
  • If forceText is true, all cells in XLSX output will be set to text type (t: "s") to prevent Excel from automatically converting data types
• toHref(data, options = {delimiter: '\t', format: 'auto', forceText: false}) - same as toBlob but return a corresponding object url.
• toHtml(data, options = {}) - convert given 2D array to HTML table format.
  • options.tableClass - CSS class for the table (default: 'csv4xls-table')
  • options.cellStyle - Whether to apply mso-number-format:'\@' style to cells to prevent Excel from changing formats (default: true)
  • options.headerRow - Whether to treat the first row as a header row using <th> tags (default: false)
• download(data, name = "data", options = {delimiter: '\t', format: 'auto', forceText: false}) - trigger file download
  • If format is 'xlsx', file extension will be .xlsx (requires XLSX library)
  • If format is 'html', file extension will be .html
  • If format is 'xls-html', file extension will be .xls (HTML with BOM that Excel can open)
  • If format is 'auto' (default), uses XLSX if available, otherwise falls back to CSV/TSV
  • If using CSV/TSV: delimiter ',' → .csv, delimiter '\t' → .tsv

Limitation

• CSV/TSV format only works with Excel if file is opened directly. Doesn't work when importing with text import wizard.
• Default delimiter is tab ('\t'), which creates TSV files.
• File extension and MIME type are automatically set based on the format and delimiter:
  • XLSX → .xlsx with MIME type application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
  • Comma (,) → .csv with MIME type text/csv
  • Tab (\t) → .tsv with MIME type text/tab-separated-values
• XLSX format requires the SheetJS library (xlsx.js) to be included in your project.
• When format is set to 'auto' (default), the library will use XLSX if available, otherwise fall back to CSV/TSV.

Note

When using in Nodejs environment, version 18+ is required for Blob support which is used in toBlob function. Also, download api trigger download via link clicking thus it's also a frontend-only feature.

License

MIT