How to get cell value in automated mail via Google Sheets (& Script) - google-apps-script

Question

For some time I'm using a document in Google Sheets to fetch price data from a website. When a change is been made within our fetching sheet we receive an email notification (via Google Scripts). This works, but since there are a lot of changes per day I would like to get the cell location that has been changed within the email (so we know where to look directly). Does anyone know how I can change my script to also receive some data from the sheet itself (like the cell location that has been changed, the old cell data and the new cell data)? Thank you!
Script:
function sendEmailAlert() {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var data = ss.getActiveSheet().getActiveCell().getA1Notation();
var sheetname = ss.getActiveSheet().getName();
var user = Session.getActiveUser().getEmail();
var Toemail = 'myemail#gmail.com';
var subject = 'New Entry in ' + data + '.' + ss.getName();
var body = 'Your file has a new entry in - ' + sheetname + ' Updated by - ' + user + data
' check file- ' + ss.getUrl();
if(data.indexOf('K2:K29')!=-1.23456789) {
MailApp.sendEmail(Toemail,subject, body);
}
};

Answer 1

Implementation depend on your workflow.
If you can get and store somewhere the old table and then get the new table you can compare them and get all the changes this way:
// old table
const old_table = [
['a1', 'b1', 'c1'],
['a2', 'b2', 'c2'],
['a3', 'b3', 'c3'],
['a4', 'b4', 'c4'],
];
// new table
const new_table = [
['a1', 'b1', 'c1'],
['a2', '🙂', 'c2'],
['🙂', 'b3', '🙃'],
['a4', 'b4', 'c4'],
];
const abc = 'ABCDEFGHIJKLMNOPQRTUVWXYZ';
// get indexes of changed rows
const changed_rows = old_table.map( (row, i) =>
(row.toString() != new_table[i].toString()) ? i : '' ).filter(String);
// get changes for every changed row
const changes = changed_rows.map( r =>
old_table[r].map( (col, i) =>
(col != new_table[r][i] ) ? {
'cell': abc[i] + (r+1),
'old_value': col,
'new_value': new_table[r][i]
} : '' ) .filter(String) ).filter(String).flat();
console.log(changes);
console.table(changes);
Output:
[
{
"cell": "B2",
"old_value": "b2",
"new_value": "🙂"
},
{
"cell": "A3",
"old_value": "a3",
"new_value": "🙂"
},
{
"cell": "C3",
"old_value": "c3",
"new_value": "🙃"
}
]
┌─────────┬──────┬───────────┬───────────┐
│ (index) │ cell │ old_value │ new_value │
├─────────┼──────┼───────────┼───────────┤
│ 0 │ 'B2' │ 'b2' │ '🙂' │
│ 1 │ 'A3' │ 'a3' │ '🙂' │
│ 2 │ 'C3' │ 'c3' │ '🙃' │
└─────────┴──────┴───────────┴───────────┘
Update
Here is another algorithm with the same output:
// old table
const OLD_TABLE = [
['a1', 'b1', 'c1'],
['a2', 'b2', 'c2'],
['a3', 'b3', 'c3'],
['a4', 'b4', 'c4'],
];
// new table
const NEW_TABLE = [
['a1', 'b1', 'c1'],
['a2', '🙂', 'c2'],
['🙂', 'b3', '🙃'],
['a4', 'b4', 'c4'],
];
function get_obj(row, col) {
var old_value = OLD_TABLE[row][col];
var new_value = NEW_TABLE[row][col];
if (old_value == new_value) return '';
return {
'cell': 'ABCDEFGHIJKLMNOPQRTUVWXYZ'[col] + (row+1),
'old value': old_value,
'new value': new_value
}
}
const changes = OLD_TABLE.map( (row, r) =>
row.map((_, c) => get_obj(r, c)) ).flat().filter(String);
console.log(changes);
console.table(changes);
Finally
Sorry, I can't help... :) One-liner is here:
const changes = (tab1, tab2) => tab1.map((row, r) => row.map((_, c) =>
tab1[r][c] == tab2[r][c] ? '' : ({
'cell' : 'ABCDEFGHIJKLMNOPQRTUVWXYZ'[c] + (r + 1),
'old_value' : tab1[r][c],
'new_value' : tab2[r][c] }))).flat(2).filter(String);
console.log(changes(OLD_TABLE, NEW_TABLE));
The same output.

Answer 2

Sure, just add whatever you like to the var body you have going. Here is some sample script for retrieving values from a sheet
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getActiveSheet();
var activeCell = sheet.getRange("AE13")
var currentCellValue = activeCell.getValue();
You would use the OnChange method
https://developers.google.com/apps-script/reference/script/spreadsheet-trigger-builder
Creating the trigger:
var sheet = SpreadsheetApp.getActive();
ScriptApp.newTrigger("myFunction")
.forSpreadsheet(sheet)
.onChange()
.create();