How to convert cell formula to script - google-apps-script

Question

How can I change this simple cell formula to a script that will be apply to the sheet :
=if(D3="Devis";B3+8;(if(D3<>"Devis";"")))
Where :
C column contains the formula
"Devis" is a name presents in the D column
B column contains Dates
Thanks a lot

Answer 1

First you need something that will trigger the script. So you'll need something like a simple onEdit() function, or a change trigger.
function onEdit(e) {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sh = ss.getSheetByName('Sheet1');
var valueOfCellEdited = e.value;
Logger.log('valueOfCellEdited: ' + valueOfCellEdited);
var columnOfCellEdited = e.range.getColumn();
Logger.log('columnOfCellEdited: ' + columnOfCellEdited);
var rowOfCellEdited = e.range.getRow();
Logger.log('rowOfCellEdited: ' + rowOfCellEdited);
if (columnOfCellEdited === 3) {
var valueToGet = sh.getRange(rowOfCellEdited, 4);
var dateToGet = "";
if (valueOfCellEdited === "Devis") { //Date to write is already set to an empty string, so no "Else" needed
var dateInColB = sh.getRange(rowOfCellEdited, 2).getValue();
Logger.log('dateInColB: ' + dateInColB);
Logger.log('typeof dateInColB: ' + typeof dateInColB);
dateToGet = new Date(dateInColB);
var dateInMilliseconds = dateToGet.valueOf();
Logger.log('dateInMilliseconds: ' + dateInMilliseconds);
//60 seconds in a minute = 60 * 1000 = 60000 milliseconds in a minute.
//60 minutes in a hour = 60,000 * 60 = 3,600,000
//24 hours in day 3,600,000 * 24 = 86,400,000
var datePlusEight = dateInMilliseconds + (8 * 86400000);
Logger.log('datePlusEight: ' + datePlusEight);
var newDateIs = new Date(datePlusEight);
Logger.log('newDateIs: ' + newDateIs);
Logger.log('newDateIs: ' + newDateIs.toString());
sh.getRange(rowOfCellEdited, 4).setValue(newDateIs);
};
};
};
Comment out the Logger.log() statements for use. To test, edit a cell in column C, with a date right next to it in the same row, but in column B.
In the spreadsheet, under the Tools menu, choose Script Editor, copy the code and paste it into the script editor.