Fill Dropdown from Selected Item - google-apps-script

Question

What I am trying to make is a workbook that users can select from a dropdown of a group of items (Sheet1, Column A) and then Row B lookup that selected item in sheet "Dataset" and return that value with integers that go from 0 to the corresponding stock quantity total in (Sheet "Dataset" column C)
here is a Sample spreadsheet
I got some awesome code from #iamblichus that will fill the dropdowns from the corresponding stock quantity
see his code here that I have somewhat implemented Here using a query formula to lookup the group stock quantities. I'm not sure how to make this happen across two sheets though.

Answer 1

Answer:
Extending the code that #iamblichus provided here, you can specify the Sheets from which to get the data from and use an onEdit() trigger to automatically change the dropdown when the cell is edited.
Code:
Attach this to the Sample Spreadsheet you provided:
function onEdit(e) {
var ss = SpreadsheetApp.getActive(); // Get the spreadsheet bound to this script
var dataSetSheet = ss.getSheetByName("Dataset"); // Get the sheet called "Working with script" (change if necessary)
var fillSheet = ss.getSheetByName("Sheet 1");
// Get the different values in column C (stock quantities):
var firstRow = 3;
var firstCol = 3;
var numRows = dataSetSheet.getLastRow() - firstRow + 1;
var stockQuantities = dataSetSheet.getRange(firstRow, firstCol, numRows).getValues();
var stockNames = dataSetSheet.getRange(firstRow, firstCol - 1, numRows).getValues();
// Iterate through all values in column:
for (var i = 0; i < stockQuantities.length; i++) {
Logger.log(stockNames);
Logger.log(stockQuantities);
var stockQuantity = stockQuantities[i][0];
var values = [];
// Create the different options for the dropdown based on the value in column C:
if (stockNames[i] == e.value) {
for (var j = 0; j <= stockQuantity; j++) {
values.push(j);
}
// Create the data validation:
var rule = SpreadsheetApp.newDataValidation().requireValueInList(values).build();
// Add the data validation to the corresponding cell in column B:
fillSheet.getRange(e.range.getRow(), 2).clear();
var dropdownCell = fillSheet.getRange(e.range.getRow(), 2).setDataValidation(rule);
}
}
}
Something to note:
I have put this as an onEdit() function because SpreadsheetApp is called in Read Only mode when inside a custom function and so no set*() methods can be called. This includes setDataValidation().
As per the Documentation, the Spreadsheet service is supported, however under 'Notes' it reads:
Read only (can use most get*() methods, but not set*()).
Cannot open other spreadsheets (SpreadsheetApp.openById() or SpreadsheetApp.openByUrl()).
References:
Stack Overflow - Dropdown auto generating a range based on a total
Google Apps Script - Range.clear() method
Google Apps Script - Simple Triggers
Google Apps Script - Custom Functions in Google Sheets