Validate cell entry with Google Script - google-apps-script

Question

I've built a form system using Google Sheet. I'm wondering if there is a function to valid a cell entry if the user still has the cell selected.
Right now, if the user click on the save button, the change made in cell B7:G7 won't be saved.
So I'm looking for a function to add to my save script. Is there such a thing ?
function save() {
var sheet = SpreadsheetApp.getActiveSheet()
var db = SpreadsheetApp.openById("1OsPjUQDlq_mrCbnJspoTLFOamuIgGVp2fCeJc-tRq20").getActiveSheet()
var lastRow = db.getLastRow() + 1
// formula to validate cell entry
var id = sheet.getRange("G4:I4").getValue()
var date = sheet.getRange("B7:G7").getValue()
var idCol = 1
var dateCol = 2
db.getRange(lastRow, idCol).setValue(id)
db.getRange(lastRow, dateCol).setValue(date)
}

Answer 1

Activate the active range.
Example:
function save(){
SpreadsheetApp.getActiveRange().activate();
// do the whatever else should be done
}
Note: Activating a different range, will make that the value entered will be wrote to the activated range.

Answer 2

Here's a simple example:
code:
function submitData() {
const ss = SpreadsheetApp.getActive();
const ui = SpreadsheetApp.getUi();
const sh = ss.getSheetByName("Sheet0");
const vs = sh.getRange(2, 2, sh.getLastRow() - 1).getValues().flat();
let valid = true;
vs.forEach((e, i) => {
if (!e) {
ui.alert(`No data at B${i + 2}`);
valid = false;
}
});
if (valid) {
ui.alert('Data was submitted');
} else {
ui.alert('Data not submitted');
}
}
Form:
Desc
Data
First
First
Last
Last
MI
MI
Demo: