Triggers (onEdit, onOpen) in Google Sheets - Dashboard Guide

Dashboard Mode - Triggers (onEdit, onOpen)

Dashboard Goal

This dashboard shows how to use Google Sheets triggers onEdit and onOpen to automate tasks. It answers: How can we automatically update or notify when data changes or when the sheet opens?

Sample Data

Task	Status	Last Updated
Prepare Report	Pending	2024-06-01 09:00
Send Email	Done	2024-06-01 08:30
Update Website	Pending	2024-05-31 17:00
Backup Data	Done	2024-06-01 07:45
Team Meeting	Scheduled	2024-06-02 10:00

Dashboard Components

• KPI Card: Pending Tasks Count
  Formula: =COUNTIF(B2:B6, "Pending")
  Shows how many tasks are still pending.
• KPI Card: Last Sheet Open Time
  Value updated by onOpen trigger script.
  Shows the last time the sheet was opened.
• Log Table: Edit Log
  Populated by onEdit trigger script.
  Shows which cell was edited, old value, new value, and timestamp.
• Script Snippet: onOpen Trigger
  function onOpen() { const sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Dashboard'); sheet.getRange('E1').setValue(new Date()); }
• Script Snippet: onEdit Trigger
  function onEdit(e) { const logSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('EditLog'); const range = e.range; const oldValue = e.oldValue || 'N/A'; const newValue = range.getValue(); logSheet.appendRow([new Date(), range.getA1Notation(), oldValue, newValue]); }

Dashboard Layout

+----------------------+--------------------+
| Pending Tasks: [ 2 ] | Last Open: [time]  |
+----------------------+--------------------+
|                      Edit Log Table          |
|  Timestamp  | Cell | Old Value | New Value    |
|-------------|------|-----------|--------------|
| 2024-06-01 | B3   | Pending   | Done         |
| ...         | ...  | ...       | ...          |
+---------------------------------------------+

Interactivity

When you open the sheet, the onOpen trigger runs and updates the Last Sheet Open Time KPI automatically.

When you edit any cell, the onEdit trigger runs and adds a new row to the Edit Log Table with details about the change.

The Pending Tasks Count updates automatically if you change any task status in the data table.

Self Check

Try this: Edit the status of a task from "Pending" to "Done".

Question: Which components update?

• The Pending Tasks Count KPI updates to reflect the new count.
• The Edit Log Table adds a new row with the edit details.
• The Last Sheet Open Time does not change because the sheet was not reopened.

Key Result

Dashboard demonstrating Google Sheets onEdit and onOpen triggers to automate task status tracking and logging.

Practice

1. What does the onOpen trigger do in Google Sheets?

easy

A. Saves the spreadsheet automatically

B. Runs a script automatically when the spreadsheet is opened

C. Runs a script when a cell is edited

D. Deletes all data when the sheet is opened

Solution

1. Step 1: Understand the purpose of onOpen

   The onOpen trigger runs a script automatically when the spreadsheet is opened by a user.

2. Step 2: Compare with other triggers

   Unlike onEdit, which runs on cell changes, onOpen activates only on opening the file.

3. Final Answer:

   Runs a script automatically when the spreadsheet is opened -> Option B

4. Quick Check:

   onOpen = runs on open [OK]

Hint: Remember: onOpen triggers when file opens, not on edits [OK]

Common Mistakes:

• Confusing onOpen with onEdit trigger
• Thinking onOpen runs on every cell change
• Assuming onOpen saves the file automatically

2. Which of the following is the correct way to define an onEdit trigger function in Google Sheets Apps Script?

easy

A. function onEdit(e) { /* code here */ }

B. function onEdit { /* code here */ }

C. function onEdit() { /* code here */ }

D. function onEdit(e) => { /* code here */ }

Solution

1. Step 1: Recall correct function syntax with event object

   The onEdit trigger function must accept an event object parameter e to access edit details.

2. Step 2: Check syntax correctness

   function onEdit(e) { /* code here */ } uses correct function declaration with parameter e and braces.

3. Final Answer:

   function onEdit(e) { /* code here */ } -> Option A

4. Quick Check:

   onEdit needs (e) parameter and braces [OK]

Hint: Include (e) parameter to access edit info in onEdit [OK]

Common Mistakes:

• Omitting the (e) parameter in onEdit function
• Using arrow function syntax which is invalid here
• Missing parentheses or braces in function declaration

3. Given this onEdit function in Google Sheets Apps Script:

function onEdit(e) {
  if (e.range.getA1Notation() === 'A1') {
    e.source.getActiveSheet().getRange('B1').setValue('Edited!');
  }
}

What happens when you edit cell A1?

medium

A. Nothing happens

B. Cell A1 will be cleared

C. Cell B1 will display the text 'Edited!'

D. An error occurs because of wrong syntax

Solution

1. Step 1: Understand the trigger condition

   The function checks if the edited cell is 'A1' using e.range.getA1Notation().

2. Step 2: Analyze the action on condition true

   If true, it sets the value of cell 'B1' to 'Edited!' on the active sheet.

3. Final Answer:

   Cell B1 will display the text 'Edited!' -> Option C

4. Quick Check:

   Editing A1 triggers B1 = 'Edited!' [OK]

Hint: Check edited cell with e.range.getA1Notation() [OK]

Common Mistakes:

• Assuming the edited cell changes instead of B1
• Thinking the script clears A1
• Believing the code has syntax errors

4. This onOpen function is intended to show a custom menu, but it doesn't work:

function onOpen() {
  var ui = SpreadsheetApp.getUi;
  ui.createMenu('My Menu')
    .addItem('Say Hello', 'sayHello')
    .addToUi();
}

What is the error?

medium

A. Missing parentheses after getUi

B. Function onOpen must have parameter e

C. createMenu is not a valid method

D. addItem requires two parameters

Solution

1. Step 1: Identify method call syntax

   The code uses SpreadsheetApp.getUi without parentheses, so it references the function but does not call it.

2. Step 2: Correct method call

   Adding parentheses getUi() calls the method and returns the UI object needed to create the menu.

3. Final Answer:

   Missing parentheses after getUi -> Option A

4. Quick Check:

   Method calls need () to execute [OK]

Hint: Always add () to call methods like getUi() [OK]

Common Mistakes:

• Forgetting parentheses on method calls
• Thinking onOpen needs parameters
• Misunderstanding addItem parameters

5. You want to create an onEdit trigger that automatically timestamps column B when a user edits column A in the same row. Which script correctly does this?

hard

A. function onEdit(e) {
if (e.range.getColumn() === 2) {
var row = e.range.getRow();
e.source.getActiveSheet().getRange(row, 1).setValue(new Date());
}
}

B. function onEdit(e) {
if (e.range.getColumn() === 1) {
e.source.getActiveSheet().getRange('B' + e.range.getRow()).setValue('Timestamp');
}
}

C. function onEdit(e) {
if (e.range.getRow() === 1) {
e.source.getActiveSheet().getRange('B1').setValue(new Date());
}
}

D. function onEdit(e) {
if (e.range.getColumn() === 1) {
var row = e.range.getRow();
e.source.getActiveSheet().getRange(row, 2).setValue(new Date());
}
}

Solution

1. Step 1: Check column condition for edits in column A

   The script must detect edits in column 1 (A) using e.range.getColumn() === 1.

2. Step 2: Set timestamp in column B of the same row

   It gets the row number and sets the current date/time in column 2 (B) of that row using setValue(new Date()).

3. Final Answer:

   function onEdit(e) { if (e.range.getColumn() === 1) { var row = e.range.getRow(); e.source.getActiveSheet().getRange(row, 2).setValue(new Date()); } } -> Option D

4. Quick Check:

   Detect col A edit, timestamp col B same row [OK]

Hint: Use getColumn() and getRow() to target cells dynamically [OK]

Common Mistakes:

• Checking wrong column number for edits
• Using fixed cell references instead of dynamic rows
• Setting text instead of actual timestamp