How can I apply a script to only one specific sheet within a spreadsheet?

Question

I have a spreadsheet with two sheets called Robin and Lucy. I've made/found/mangled a script to sort the data on the sheet each time I add some data to column A:

function onEdit(event){

  var sheet = event.source.getActiveSheet();
  var editedCell = sheet.getActiveCell();

  var columnToSortBy = 1;
  var tableRange = "a2:I30";
    if(editedCell.getColumn() == columnToSortBy){   
   var range = sheet.getRange(tableRange);
   range.sort( { column : columnToSortBy } );
  }
}

This script works well but I only want it it be applied on the first sheet, Robin. The data in the second sheet, Lucy, isn't the same so I'm going to create another script for a different range for that one, once I get my head around this problem.

I think I need to use the getSheetByName("Robin") but I can't seem to get it to work.

Answer 1

There are a couple of ways to do that. First, you need to declare the spreadsheet:

var ss = SpreadsheetApp.getActiveSpreadsheet();  

Secondly, declare the first sheet like this:

var sh0 = ss.getSheets()[0];

or like this:

var sh0 = ss.getSheetByName("Robin");

Then set the active cell and retrieve the column index:

var editedCell = sh0.getActiveRange().getColumnIndex();

And do the logic for the sort:

var columnToSortBy = 1;
var tableRange = "a2:I30";

if(editedCell == columnToSortBy){   
  var range = sheet.getRange(tableRange);
  range.sort( { column : columnToSortBy } );
}

Complete code, a bit shortened:

function onEdit(){
  var sh0 = SpreadsheetApp.getActiveSpreadsheet().getSheets()[0];
  var editedCell = sh0.getActiveRange().getColumnIndex();

  if(editedCell == 1) { 
    var range = sh0.getRange("A2:I30");
    range.sort({column: 1});
  }
}

Answer 2

Get the associated sheet (spreadsheet) and indicate which tab (sheet) you want to have focus:

var theSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Robin");
// do the thing
var theSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Lucy"); 
// do the other thing

Reference: https://developers.google.com/apps-script/reference/spreadsheet/spreadsheet#getSheetByName(String)