Check/Uncheck Boxes From a Dynamic Range Based On Condition - google-apps-script

Question

I have a to-do list with checkboxes for my employees in a spreadsheet with a dynamic number of rows that cannot exceed row 20. Because starting from row 20 another employee's to-do list is available.
I have a checkbox next to the name of the employee. Once I check/uncheck that checkbox, I want all below checkboxes to check or uncheck no matter how many rows are added or removed as long as it does not pass row number 20.
I have therefore named the range on row 20 so that even if it moves, apps script can locate it through named range. I have removed the named range and called it instead ('A20') in the script below to avoid confusion.
I thought a forloop could work but I must be doing something wrong because it is executing successfully but showing no results.
function Todolist() {
var spreadsheet = SpreadsheetApp.getActive();
var lianrange = spreadsheet.getRange('A20');
for (var i = 1 ; i<lianrange.length;i++){
if (spreadsheet.getCurrentCell().getValue() === 'check'){
spreadsheet.getRange[i].setValue('Y');
}
if (spreadsheet.getCurrentCell().getValue() === 'uncheck'){
spreadsheet.getRange[i].setValue('N');
}
}
};
Your help is much appreciated.

Answer 1

Check or uncheckall
function onEdit(e) {
//e.source.toast('Entry');
const sh = e.range.getSheet();
const rg = sh.getRange('stopRow');//stopRow is name of namedRange
const sr = rg.getRow();
//need to update name of sheet
if (sh.getName() == "Sheet0" && e.range.columnStart == 2 && e.range.rowStart < sr) {
//e.source.toast('Gate1');
const vs = sh.getRange(e.range.rowStart, e.range.columnStart, sr - e.range.rowStart + 1).getValues().flat();
const cv = sh.getRange(e.range.rowStart, e.range.columnStart).getValue();
let o = vs.map((e, i) => [cv])
sh.getRange(e.range.rowStart, e.range.columnStart, o.length).setValues(o);
}
}
demo: