Calculate Formulas with Node.js via C++

Adding Formulas & Calculating Results

Aspose.Cells has an embedded formula calculation engine. Not only can it re-calculate formulas imported from designer templates, but it also supports calculating the results of formulas added at runtime.

Aspose.Cells supports most of the formulas or functions that are part of Microsoft Excel (Read a list of the functions supported by the calculation engine). Those functions can be used through the APIs or designer spreadsheets. Aspose.Cells supports a huge set of mathematical, string, boolean, date/time, statistical, database, lookup, and reference formulas.

Use the getFormula() property or setFormula(string, object) methods of the Cell class to add a formula to a cell. When applying a formula, always begin the string with an equal sign (=) as you do when creating a formula in Microsoft Excel and use a comma (,) to delimit function parameters.

To calculate the results of formulas, the user may call the calculateFormula() method of the Workbook class which processes all formulas embedded in an Excel file. Or, the user may call the calculateFormula(string) method of the Worksheet class which processes all formulas embedded in a sheet. Or, the user may also call the calculate(CalculationOptions) method of the Cell class which processes the formula of one Cell:

const path = require("path");
const fs = require("fs");
const AsposeCells = require("aspose.cells.node");

// The path to the documents directory.
const dataDir = path.join(__dirname, "data");

// Instantiating a Workbook object
const workbook = new AsposeCells.Workbook();

// Adding a new worksheet to the Excel object
const sheetIndex = workbook.getWorksheets().add();

// Obtaining the reference of the newly added worksheet by passing its sheet index
const worksheet = workbook.getWorksheets().get(sheetIndex);

// Adding a value to "A1" cell
worksheet.getCells().get("A1").putValue(1);

// Adding a value to "A2" cell
worksheet.getCells().get("A2").putValue(2);

// Adding a value to "A3" cell
worksheet.getCells().get("A3").putValue(3);

// Adding a SUM formula to "A4" cell
worksheet.getCells().get("A4").setFormula("=SUM(A1:A3)");

// Calculating the results of formulas
workbook.calculateFormula();

// Get the calculated value of the cell
const value = worksheet.getCells().get("A4").getValue().toString();

// Saving the Excel file
workbook.save(path.join(dataDir, "output.xls"));

Important to Know for Formulas

Direct Calculation of Formula

Aspose.Cells has an embedded formula calculation engine. As well as calculating formulas imported from a designer file, Aspose.Cells can calculate formula results directly.

Sometimes, you need to calculate formula results directly without adding them into a worksheet. The values of the cells used in the formula already exist in a worksheet, and all you need is to find the result of those values based on some Microsoft Excel formula without adding the formula in a worksheet.

You can use Aspose.Cells' formula calculation engine APIs for Worksheet to calculateFormula(string, FormulaParseOptions, CalculationOptions, number, number, CalculationData) the results of such formulas without adding them to the worksheet:

const path = require("path");
const AsposeCells = require("aspose.cells.node");

// The path to the documents directory.
const dataDir = path.join(__dirname, "data");

// Create a workbook
const workbook = new AsposeCells.Workbook();

// Access first worksheet
const worksheet = workbook.getWorksheets().get(0);

// Put 20 in cell A1
const cellA1 = worksheet.getCells().get("A1");
cellA1.putValue(20);

// Put 30 in cell A2
const cellA2 = worksheet.getCells().get("A2");
cellA2.putValue(30);

// Calculate the Sum of A1 and A2
const results = worksheet.calculateFormula("=Sum(A1:A2)");

// Print the output
console.log("Value of A1: " + cellA1.getStringValue());
console.log("Value of A2: " + cellA2.getStringValue());
console.log("Result of Sum(A1:A2): " + results.toString());

Above code produces the following output: 

Value of A1: 20
Value of A2: 30
Result of Sum(A1:A2): 50.0

How to Calculate Formulas repeatedly

When there are lots of formulas in the workbook, and the user needs to calculate them repeatedly while modifying only a small part of them, it may be helpful for performance to enable the formula calculation chain: formulaSettings.getEnableCalculationChain().

const path = require("path");
const AsposeCells = require("aspose.cells.node");

// The path to the documents directory.
const dataDir = path.join(__dirname, "data");
// Load the template workbook
const workbook = new AsposeCells.Workbook(path.join(dataDir, "book1.xls"));

// Print the time before formula calculation
console.log(new Date());

// Set the CreateCalcChain as true
workbook.getSettings().getFormulaSettings().setEnableCalculationChain(true);

// Calculate the workbook formulas
workbook.calculateFormula();

// Print the time after formula calculation
console.log(new Date());

// Change the value of one cell
workbook.getWorksheets().get(0).getCells().get("A1").putValue("newvalue");

// Re-calculate those formulas which depend on cell A1
workbook.calculateFormula();

Important to Know

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