How to export excel sheet with formula using node-excel-export?

Question

I am using node-excel-export module in node.js to export my data from DB into excel sheet.

The problem here is that, i want the excel sheet to be shipped with formulae applied on specific cells.

The documentation in the site does not demonstrate the usage of formulae clearly.

This is what i have tried:

var XLSX = require('xlsx');

function getSheet(data, opts) {
    var ws = {};

    var range = {
        s: {
            c:0, 
            r:0
        }, 
        e: {
            c:3, 
            r:3 
        }
    };

    for(var R = 0; R < 4; R++) {
        for(var C = 0; C < 3; C++) {

            var cell = {
                v: data[R][C] ,
                t: 'n'
            };

            var cell_ref = XLSX.utils.encode_cell({
                c:C,
                r:R
            });

            if(C == 2) {
                cell_ref.f = "A"+R+"B"+R;
            }

            ws[cell_ref] = cell;
        }
    }
    ws['!ref'] = XLSX.utils.encode_range(range);
    return ws;
}


var data = [
    [1, 2],
    [3, 4],
    [5, 6], 
    [7, 8]
];

function Workbook() {
    if(!(this instanceof Workbook)) {
        return new Workbook();
    }
    this.SheetNames = [];
    this.Sheets = {};
}

var wb = new Workbook();
var wsName = "SheetJS";
wb.SheetNames.push(wsName);
wb.Sheets[wsName] = getSheet(data);


module.exports = {
    dataset: [],
    getExcelFile: function (resultset, res) {

        /* write file */
        XLSX.writeFile(wb, 'test.xlsx');

        res.download('test.xlsx');
    }
};

`

please help.

Answer 1

OK solution found.

I did two mistakes

1.Instead of cell_ref.f use cell.f .

2.Formula correction.

Updated code if it helps others:

var XLSX = require('xlsx');

function getSheet(data, opts) {
    var ws = {};

    var range = {
        s: {
            c:0, 
            r:0
        }, 
        e: {
            c:3, 
            r:3 
        }
    };

    for(var R = 0; R < 4; R++) {
        for(var C = 0; C < 3; C++) {

            var cell = {
                v: data[R][C],
                t: 'n'
            };

            var cell_ref = XLSX.utils.encode_cell({
                c:C,
                r:R
            });

            if(C == 2) {
                cell.f = "A"+ (R+1) +"+B" + (R+1);
            }

            ws[cell_ref] = cell;
        }
    }
    ws['!ref'] = XLSX.utils.encode_range(range);
    return ws;
}


var data = [
    [1, 2],
    [3, 4],
    [5, 6], 
    [7, 8]
];

function Workbook() {
    if(!(this instanceof Workbook)) {
        return new Workbook();
    }
    this.SheetNames = [];
    this.Sheets = {};
}

var wb = new Workbook();
var wsName = "SheetJS";
wb.SheetNames.push(wsName);
wb.Sheets[wsName] = getSheet(data);


module.exports = {
    dataset: [],
    getExcelFile: function (resultset, res) {

        /* write file */
        XLSX.writeFile(wb, 'test.xlsx');

        res.download('test.xlsx');
    }
};