Add Timestamp if row is not empty - google-apps-script

Question

I have a script on a nightly trigger which does the following three things:
copies the contents of one spreadsheet (spreadsheet 1) to another (spreadsheet 2).
adds a timestamp column to column A each time the script is run.
deletes rows if there are certain values in column D.
The first time the script runs, everything works fine (i.e. when the new spreadsheet 2 is still blank). The subsequent times it runs it encounters issues.
With some research I have discovered that is because any blank rows in the source sheet (spreadsheet 1) are copied to the new spreadsheet (spreadsheet2) and a timestamp is placed in the blank rows. This leaves a bunch of rows that only have a timestamp. By the time the script gets to the part where it is supposed to delete rows based on values it gets thrown by these rows that only have a timestamp.
I am new to google script and was unable to find anything in the forum. Is there a way to modify the script so that the timestamp is only placed on rows where there is data?
var sourceSpreadsheetID = "spreadsheet1 ID";
var sourceWorksheetName = "BusinessDetails";
var targetSpreadsheetID = "spreadsheet2 ID";
var targetWorksheetName = "Sheet5";
function importBusinessDetailsData(){
var thisSpreadsheet = SpreadsheetApp.openById("spreadsheet1 ID");
var thisWorksheet = thisSpreadsheet.getSheetByName("BusinessDetails");
var thisData = thisWorksheet.getDataRange();
var toSpreadsheet = SpreadsheetApp.openById("spreadsheet2 ID");
var toWorksheet = toSpreadsheet.getSheetByName("Sheet5");
var toRange = toWorksheet.getRange(1,2, thisData.getNumRows(), thisData.getNumColumns())
toRange.setValues(thisData.getValues());
setTimeStamp()
main()
removeThenSetNewVals()
}
function setTimeStamp() {
SpreadsheetApp.getActive().getSheetByName('Sheet5')
.getRange('A2:A').setValue(new Date())
};
function main() {
var startTime = new Date().getTime();
var deleteSelectedRows = removeThenSetNewVals();
var runTime = (new Date().getTime() - startTime) / 1000;
Logger.log("Runtime is: " + runTime + " seconds");
};
function removeThenSetNewVals(){
var sheet = SpreadsheetApp.getActive().getSheetByName('Sheet5');
var range = sheet.getDataRange();
var pattern = new RegExp("value1|value2|value3");
var columnToSearch = 3;
var newRangeVals = range.getValues().filter(r => r[0] && !pattern.exec(r[columnToSearch]))
range.clearContent();
var numRows = newRangeVals.length;
var newRange = sheet.getRange(1,1, numRows, newRangeVals[0].length).setValues(newRangeVals);
var maxRows = sheet.getMaxRows();
}

Answer 1

As far as I understand, you only want to write entries to the new sheet which fit a particular condition. Basically, you want to filter the records before you write them, therefore consider the following:
var thisData = thisWorksheet.getDataRange();
var rowsWithData = thisData.filter( row => row[3] )
This states that only rows which contain truthy data will be considered, but feel free to fit the condition according to your needs.
References
filter()
truthy