Copy content from one spreadsheet to another without IMPORTRANGE - google-apps-script

Question

I'm trying to create bidirectional synchronisation of some content between two Google Sheets. My script is working when:
the source and destination ID of the sheets are the same AND have the ID of the active spreadsheet
SO, THIS WORKS:
function myFunction() {
var sourceSpreadsheet = SpreadsheetApp.openById("ID-OF-ACTIVE-SPREADSHEET");
var destinationSpreadsheet = SpreadsheetApp.openById("ID-OF-ACTIVE-SPREADSHEET");
var sourceSheet = sourceSpreadsheet.getSheetByName("sheet1");
var destinationSheet = destinationSpreadsheet.getSheetByName("sheet2");
var sourceRange = sourceSheet.getRange("A1:A4");
// destination, columnStart, columnEnd, rowStart, rowEnd
sourceRange.copyValuesToRange(destinationSheet, 2, 2, 3, 7);
}
But when I replace the destination ID with the ID of another spreadsheet, it doesn't work.
Could it have something to do with permissions?
I have tried to publish both spreadsheets.
THIS DOESN'T:
...
var sourceSpreadsheet = SpreadsheetApp.openById("ID-OF-ACTIVE-SPREADSHEET");
var destinationSpreadsheet = SpreadsheetApp.openById("ID-OF-ANOTHER-SPREADSHEET");
...
Since I'm trying to create bidirectional sync I don't think I can use IMPORTRANGE.
Source SpreadSheet
Destination SpreadSheet

Answer 1

It seems like copyValuesToRange doesn't communicate outside the spreadsheet, here is a working solution:
function onChange() {
var sourceSpreadsheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Sheet1");
var sourceData = sourceSpreadsheet.getRange("A1:A8").getValues();
var targetSpreadsheet = SpreadsheetApp.openById("ID-OF-ANOTHER-SPREADSHEET").getSheetByName("Sheet1");
targetSpreadsheet.getRange("A1:A8").setValues(sourceData);
}
PS: this also enables bidirectional sync between spreadsheets, just add a copy of this code on both spreadsheet A and B and replace "ID-OF-ANOTHER-SPREADSHEET" with the ID of the other spreadsheet. And then define the from- and to range in place of the "A1:A8".