Let's move step by step through the OAuth 2.0 flow setup and coding using PHP for your Google Calendar integration.
✅ What We’re Building
➡️ A PHP app that:
- Lets users (like Jack) authorize your website to access their Google Calendar.
- Retrieves an access token (and refresh token).
- Lets them create/edit/delete events on Google Calendar directly from your website.
✅ Prerequisites
Requirement | Description |
---|---|
PHP Version | PHP 7.x or higher |
Composer | Dependency manager for PHP |
Verified Domains | Your domain and subdomains verified in Google Search Console |
SSL | HTTPS is required for OAuth 2.0 |
✅ Step 1: Install the Google API Client Library for PHP
➤ Install via Composer
In your project directory, run:
If you don’t have Composer:
- Download it here ➜ https://getcomposer.org/
✅ Step 2: Create a Google Cloud Project & OAuth Credentials
➤ Recap of Setup:
- Go to Google Cloud Console.
- Create a new project or use an existing one.
- Go to APIs & Services ➜ Library ➜ Enable Google Calendar API.
- Go to Credentials ➜ Create Credentials ➜ OAuth client ID.
- Set redirect URIs (e.g.,
https://www.japansailing.com/oauth2callback.php
).
➡️ Save your Client ID and Client Secret.
✅ Step 3: Create Files for OAuth 2.0 Flow
We’ll need:
index.php
➜ The landing page with the Connect Google Calendar button.oauth2callback.php
➜ The callback handler after user authorization.calendar.php
➜ To create/edit/delete events.
✅ index.php
➡️ Replace credentials.json
with the actual file you downloaded from Google Cloud Console OR manually pass the Client ID/Secret like:
✅ oauth2callback.php
➡️ This page handles Google’s redirect, exchanges the code for a token, and stores it in $_SESSION
.
✅ calendar.php
Now that we have an access token, let's do something useful—create an event!
✅ Step 4: Securely Store Tokens
If you don’t want to use $_SESSION
, store access tokens/refresh tokens in a database:
- Associate them with your user accounts.
- Use encryption for refresh tokens.
✅ Step 5: Additional Operations
➤ List Events
➤ Update Event
➤ Delete Event
✅ Step 6: Testing
Test your workflow:
- Go to
index.php
- Authenticate with Google
- Create an event via
calendar.php
✅ Optional Enhancements
Enhancement | Details |
---|---|
Frontend UI | Use Bootstrap 5 forms or modals to handle event creation without page reloads |
FullCalendar.js | Display events on your website in a dynamic calendar view |
Error Handling | Show user-friendly messages if something fails |
Logging | Track API calls and user activity for auditing |