Creating a secure login page in Google Apps Script can be challenging due to its inherent limitations, such as handling page redirection, managing URL access, and maintaining user sessions. In this blog, we will guide you through a step-by-step process to create a functional and secure login page, integrating Google Sheets as the user database.
By the end of this guide, you’ll have a working login system that prevents unauthorized access and ensures users stay in their designated areas of the application.
Video Tutorial
For a detailed walkthrough, watch our YouTube video:
How to Create a Secure Login Page in Google Apps Script | Step-by-Step Guide
Why Google Apps Script?
Google Apps Script is a powerful platform that allows you to build applications using Google Workspace tools. By leveraging it, you can:
- Integrate with Google Sheets for data storage.
- Easily deploy web apps for internal use.
- Save time with automated backend processes.
However, building a secure login page requires addressing some common challenges, such as page refreshing, managing redirections, and handling direct URL access.
Step-by-Step Guide
1. Set Up Your Google Sheet
Create a Google Sheet to store user data, including email IDs, passwords, and user names. You’ll use this data for authentication in your login system.
2. Create Your Google Apps Script Project
Go to Extensions > Apps Script and set up your script files. You’ll need three files:
- Code.gs: Contains the backend logic.
- login.html: The login page UI.
- main.html: The main page after successful login.
3. Write the Backend Logic (Code.gs)
- Use the Google Sheet ID to access user data.
- Write functions to handle login verification and session management.
- Define the logic for when to show the login page or redirect to the main page.
4. Design the Login Page (login.html)
Use Bootstrap to create a simple yet responsive login form. Include:
- Input fields for email and password.
- A login button that triggers the authentication process.
5. Design the Main Page (main.html)
Display content for authenticated users. Use a session variable to check if the user is logged in before rendering the page.
6. Deploy Your App
- Deploy the project as a web app.
- Test the deployment link to ensure the system works as expected.
Key Features of the Login System
- Prevents Unauthorized Access: If a user tries to access the main page without logging in, they are redirected to the login page.
- Session Management: Once logged in, users cannot return to the login page by typing its URL.
- Error Handling: Displays an error message for incorrect login credentials.