Currency formatting

Available since 0.2.0. Nori displays currency in both Spreadsheet and SpreadsheetPreview. Formatting uses Cell.style.numberFormat; the stored value and formula results stay numeric. No React theme setting or renderCell override is required.

Set a currency format

const sheetId = workbook.getState().activeSheetId;
const result = workbook.dispatch({
  type: "setCell",
  sheetId,
  address: "B2",
  cell: {
    value: 1234.5,
    style: { numberFormat: '"Rp "#,##0.00' },
  },
});
if (!result.ok) throw result.error;
// Both views display: Rp 1,234.50
// workbook.getCellValue(sheetId, "B2") remains 1234.5.

setCell replaces the cell. When formatting an existing cell, spread its current contents and style so you retain formulas and other formatting:

const sheet = workbook.getState().snapshot.sheets.find((s) => s.id === sheetId);
const cell = sheet?.cells["B2"] ?? { value: null };
workbook.dispatch({
  type: "setCell",
  sheetId,
  address: "B2",
  cell: { ...cell, style: { ...cell.style, numberFormat: "$#,##0.00" } },
});

These commands use normal history and subscriptions. Editing a formatted cell still edits its raw value; enter 1234.5, not a string such as $1,234.50. Formatting does not parse currency text or perform currency conversion.

Supported examples

Format	Value	Display
$#,##0.00	1234.5	$1,234.50
$#,##0.00	-1234.5	-$1,234.50
"Rp "#,##0	1234.5	Rp 1,235
"USD "#,##0.00	1234.5	USD 1,234.50
£#,##0.00	1234.5	£1,234.50
¥#,##0	1234.5	¥1,235
#,##0.00" EUR"	1234.5	1,234.50 EUR
$#,##0.00;($#,##0.00)	-1234.5	($1,234.50)
$0.00;($0.00);"-"	0	-
[$€-407]#,##0.00	1234.5	€1,234.50

Currency symbols may be unquoted. Text currency codes/labels must be quoted or escaped. Decimal precision is explicit in the format; Nori does not infer a currency's minor units.

Supported numeric patterns are 0 and #,##0, optionally followed by a decimal point and 1–10 zeros, optionally followed by %. Existing integer, decimal, and percent display remains supported. Values round for display only; a value such as 1.005 with $0.00 displays $1.01 without changing the stored number.

Sections and Excel import

One section applies to all numbers, with a minus sign automatically added for negatives. Two sections specify positive/zero and negative display. Three specify positive, negative, and zero display. An empty selected section hides its display; quoted literal-only sections can show a zero as a dash. Semicolons inside quotes or escaped with a backslash remain literal.

A fourth section is reserved for text in Excel; Nori leaves text values unchanged. Known color tags such as [Red] are accepted but do not set text color. Set Cell.style.color separately if desired. Excel underscore padding is accepted but omitted because this formatter returns plain text.

XLSX import preserves custom format strings. The adapter also recognizes common English/US built-in currency formats 5–8 and grouped-number formats 3–4. Built-in currency IDs are locale-dependent in Excel; Nori uses dollar formats for these IDs. An explicit custom currency symbol is more reliable for international workbooks.

Headless formatting

import { formatNumber } from "@byfungsi/nori/model";

formatNumber(1234.5, '"Rp "#,##0.00'); // "Rp 1,234.50"
formatNumber(1234.5, "mm-dd-yy"); // undefined: unsupported

This helper has no React or DOM dependency. It returns undefined for unsupported formats or non-finite numbers. The React formatCellValue helper uses it and falls back to the raw numeric string. Both the full grid and preview use that same display path, including calculated cells, labels, and tooltips.

Current limits

• Output uses comma grouping and a decimal point, independent of the browser's language. An Rp label does not select Indonesian separators. The locale suffix in [$€-407] is preserved by import but does not control output locale.
• Accounting fill/repetition (*), conditional sections ([>100]), date/time, scientific, fractions, scaling commas, optional decimal placeholders, and full Excel format parity are not supported. Unsupported formats fall back to the raw numeric value.
• Currency does not imply financial decimal arithmetic; calculations still use JavaScript numbers.
• Text values are not coerced into amounts. CSV has no format metadata; apply a number format after import to numeric cells.
• There is no built-in currency-picker toolbar or automatic currency detection.

For Excel's full format syntax, see Microsoft's custom-number-format guidelines. Nori implements the subset described here.