Direct calculation of custom function without writing it in a worksheet with Node.js via C++
Direct calculation of custom function without writing it in a worksheet
This topic explains how you can directly calculate your custom functions without first writing them in a worksheet. Please use the Worksheet.calculateFormula(formula, opts) method for this purpose.
Please see the following sample code that illustrates the usage of this method. We have used a custom function named MyCompany.CustomFunction() and we calculate its value as “Aspose.Cells.” by ourselves and then this value is automatically concatenated with the value of cell A1 which is “Welcome to " by the calculation engine and the final calculated value returns as “Welcome to Aspose.Cells."”. As you can see in a code that we have not written our custom function anywhere in a worksheet and it is calculated directly by our own custom logic.
Programming Sample
const AsposeCells = require("aspose.cells.node");
class CustomEngine extends AsposeCells.AbstractCalculationEngine {
// Override the Calculate method with custom logic
calculate(data) {
// Check the formula name and calculate it yourself
if (data.getFunctionName() === "MyCompany.CustomFunction") {
// This is our calculated value
data.setCalculatedValue("Aspose.Cells.");
}
}
}
class ImplementDirectCalculationOfCustomFunction {
static run() {
// Create a workbook
const wb = new AsposeCells.Workbook();
// Access first worksheet
const ws = wb.getWorksheets().get(0);
// Add some text in cell A1
ws.getCells().get("A1").putValue("Welcome to ");
// Create a calculation options with custom engine
const opts = new AsposeCells.CalculationOptions();
opts.setCustomEngine(new CustomEngine());
// This line shows how you can call your own custom function without
// a need to write it in any worksheet cell
// After the execution of this line, it will return
// Welcome to Aspose.Cells.
const ret = ws.calculateFormula("=A1 & MyCompany.CustomFunction()", opts);
// Print the calculated value
console.log("Calculated Value: " + ret);
}
}
// Example invocation
ImplementDirectCalculationOfCustomFunction.run();
Console Output
Below is the console output of the above sample code.
Calculated Value: Welcome to Aspose.Cells.