Insert timestamp when value copy/paste or inserts/edits whole row in google sheets, only insert to blank cell

Question

• I'm trying to insert a timestamp into a cell in "timestamp" column that has the same row index as the edited or pasted value in "status" column. Also, I only want to insert a timestamp in an empty cell in "timestamp" column, while the skip cell already has a timestamp.

• Issue: When I add or remove columns, the positions of the "timestamp" and "status" columns change, causing the code to fail. I'm seeking for a solution to make this code work properly when the "timestamp" and "status" columns' index change. I'm trying to use column header in code instead of column's index.

Also I want to convert timestamp to number like yymmddHHmmss*1000 + seri number column "No." Exp: timestamp 22:01:20 14:08:05 and seri number column "No." is 678 then the value I want to insert into column "id" is 2201201408050678.

function insert_timestamp(e) {
  //get range
  var range = e.range;
  var sheet = range.getSheet();
  // get header
  var headers = sheet.getRange(1, 1, 1, sheet.getLastColumn()).getValues();
  var editcol = headers[0].indexOf("Status") + 1;
  var timestampcol = headers[0].indexOf("Timestamp") + 1;

  if ((range.columnStart == editcol || range.columnEnd == editcol) && sheet.getSheetName() == 'CONTENT.ORDER') {
    var values = range.offset(0, -1, range.rowEnd - range.rowStart + 1, 2).getDisplayValues();
    var rangeList = values.reduce((ar, [b, c], i) => {
      if (b == "" &&  c =="Approved") ar.push("b" + (i + range.rowStart));
      return ar;
    }, []);
    sheet.getRangeList(rangeList).setValue(new Date()).setNumberFormat("yy:MM:dd HH:mm:ss");
  }
}

Answer 1

Here is my try:

function onEdit(e) {
  var sheet = e.range.getSheet();
  if (sheet.getSheetName() != 'CONTENT.ORDER') return;

  var col = e.range.columnStart;
  var col_header = sheet.getRange(1,col).getValue();
  if (col_header != 'Status') return;
  if (e.value != 'Approved') return;

  var headers = sheet.getRange(1,1,1,sheet.getLastColumn()).getValues()[0];
  var timestamp_col = headers.indexOf('Timestamp') + 1;
  var num_col = headers.indexOf('No.') + 1;
  var id_col = headers.indexOf('ID') + 1;

  var row = e.range.rowStart;
  var timestamp_cell = sheet.getRange(row, timestamp_col);
  if (timestamp_cell.getValue() !== '') return;

  var tz = SpreadsheetApp.getActiveSpreadsheet().getSpreadsheetTimeZone();
  var timestamp = Utilities.formatDate(new Date(), tz, 'yy-MM-dd HH:mm:ss');
  timestamp_cell.setValue(timestamp).setNumberFormat('yy:MM:dd HH:mm:ss');

  var num = sheet.getRange(row,num_col).getValue().toString().padStart(4,'0');
  var id = timestamp.replace(/\D/g,'') + num;
  var id_cell = sheet.getRange(row,id_col);
  id_cell.setValue(id);
}