Output Calendar Events into Web App

Step 1: Enable the Google Calendar API

  1. Go to the Google Cloud Platform Console: Google Cloud Console.
  2. Create a new project or select an existing one.
  3. Navigate to the “APIs & Services > Dashboard” section.
  4. Click on “ENABLE APIS AND SERVICES” to search for and enable the Google Calendar API for your project.

Step 2: Set Up Google Apps Script Project

  1. Go to Google Apps Script and create a new project.
  2. In the Apps Script editor, go to Resources > Advanced Google services.
  3. Enable the Calendar API here as well.

Step 3: Write the Server-side Code to Fetch Events

Here’s a basic script to fetch calendar events for the current month:

function getCalendarEvents() {
var calendarId = 'primary'; // Use 'primary' for the primary calendar
var now = new Date();
var startOfMonth = new Date(now.getFullYear(), now.getMonth(), 1);
var endOfMonth = new Date(now.getFullYear(), now.getMonth() + 1, 0);

var events = Calendar.Events.list(calendarId, {
timeMin: startOfMonth.toISOString(),
timeMax: endOfMonth.toISOString(),
singleEvents: true,
orderBy: 'startTime'

return events.items.map(function(event) {
return {
title: event.summary,
start: event.start.dateTime || event.start.date, // All-day events do not have dateTime
end: event.end.dateTime || event.end.date

Step 4: Create a Web App Interface

You can use HTML and JavaScript to create a basic monthly view calendar. Here, I’ll show a simple way to display events in a list. For a full calendar view, you might consider using a library like FullCalendar.

<!DOCTYPE html>
<title>Monthly Calendar View</title>
<h1>Calendar Events for This Month</h1>
<ul id="events"></ul>
function fetchEvents() {
function success(events) {
var eventsList = document.getElementById('events');
eventsList.innerHTML = '';
events.forEach(function(event) {
var li = document.createElement('li');
li.textContent = event.title + ' (' + event.start + ' to ' + event.end + ')';
window.onload = fetchEvents; // Fetch events when the page loads

Step 5: Deploy as Web App

  1. In the Apps Script editor, go to Publish > Deploy as web app.
  2. Set up the new project version, execute the app as yourself, and allow access to anyone.
  3. Click ‘Deploy’, and you will get a URL to access your web app.

This script and HTML setup fetches events for the current month and displays them as a simple list. For a more interactive calendar interface, you might want to integrate with a JavaScript calendar library like FullCalendar, which can consume the array of events and present them in a nice calendar format.

Google Apps Script Advanced Services:

  • Open your script project in Google Apps Script.
  • Click on “Services” (+ icon next to Services in the left pane).
  • Add the Google Calendar API by selecting it from the list and clicking “Add”.

To effectively test the getCalendarEvents() function in Google Apps Script, you can create a separate test function that invokes getCalendarEvents() and logs or examines its output. This test function can help you ensure that the getCalendarEvents() function retrieves the correct data from Google Calendar and handles different scenarios properly. Here’s how you can write a simple test function:

Step 1: Define the Test Function

This function will call getCalendarEvents(), and you can then manually check the logs to verify the correctness of the output.

function testGetCalendarEvents() {
try {
var events = getCalendarEvents(); // Call the main function
Logger.log('Number of events fetched: ' + events.length);
Logger.log(JSON.stringify(events)); // Log the details of events
} catch (error) {
Logger.log('Error testing getCalendarEvents: ' + error.toString());

Step 2: Execute the Test Function

To run this test function:

  1. Open your Google Apps Script project.
  2. Select the testGetCalendarEvents function in the function dropdown menu in the toolbar.
  3. Click the play (▶️) button to execute the function.

Step 3: View Logs

After execution, view the logs to see the output:

  • Go to View > Logs in the Google Apps Script editor.

What to Look for in the Logs

  • Number of Events: Check if the number of events logged matches the expected number of events in your calendar for the current month.
  • Event Details: Ensure that the details of the events (e.g., title, start, and end times) are correctly fetched and displayed.
  • Errors: Look for any error messages that could indicate issues with API permissions, date calculations, or other unexpected behavior.

Further Testing Ideas

To extend this testing function, consider the following:

  • Edge Cases: Test with edge cases such as months with no events, all-day events, or events spanning multiple days.
  • Date Range Checks: Modify the dates in getCalendarEvents to test different months or specific date ranges.
  • Mock Data: For more advanced testing, consider using mock data to simulate API responses. This can be more complex in Apps Script but is useful for testing handling of various data scenarios.

This testing approach helps you verify the functionality of your Apps Script code in a controlled manner and ensure it behaves as expected under different conditions.