Supabase Login UI: The Complete Guide

by Alex Braham 38 views

Hey guys! Ever found yourself staring blankly at a screen, wondering how to implement a smooth and secure login UI with Supabase? Well, you're in the right place! In this comprehensive guide, we're diving deep into creating a fantastic Supabase login UI that not only looks great but also keeps your users' data safe and sound. Trust me, it's easier than you think! Let's get started.

Why Supabase for Authentication?

Before we dive into the nitty-gritty of building a login UI, let's quickly chat about why Supabase is an excellent choice for handling authentication. Supabase is an open-source Firebase alternative that provides a suite of tools to help you build scalable and secure applications. When it comes to authentication, Supabase offers several compelling advantages:

  • Ease of Use: Supabase provides a straightforward API and client libraries that simplify the authentication process. Setting up user sign-up, sign-in, and password recovery is incredibly simple, saving you a ton of development time.
  • Security: Security is paramount, and Supabase doesn't disappoint. It supports various authentication methods, including email/password, social logins (like Google, Facebook, and GitHub), and even magic links. Plus, it handles user data securely, so you can sleep well at night.
  • Scalability: Whether you're building a small side project or a large-scale application, Supabase can handle the load. Its infrastructure is designed to scale with your user base, ensuring a smooth experience for everyone.
  • Customization: Supabase allows you to customize the authentication flow to match your application's specific needs. You can define custom user roles, implement fine-grained access control, and even integrate with third-party authentication providers.

These features make Supabase an ideal choice for developers looking to implement robust authentication without reinventing the wheel. Now that we've established why Supabase is awesome, let's move on to building our login UI.

Setting Up Your Supabase Project

Alright, first things first, you'll need a Supabase project. If you don't have one already, head over to the Supabase website and sign up for an account. Once you're in, create a new project. Supabase will generate a unique URL and API key for your project, which you'll need later.

Creating a New Project

  1. Go to the Supabase website (supabase.com) and sign up.
  2. Click on "New Project".
  3. Choose a name, region, and database password for your project.
  4. Wait for Supabase to provision your project. This usually takes a few minutes.

Retrieving API Keys

Once your project is ready, you'll need to retrieve your API keys. These keys are essential for connecting your application to your Supabase backend.

  1. Go to your project dashboard.
  2. Navigate to "Settings" and then "API".
  3. You'll find your anon key and service_role key here. The anon key is what you'll use in your client-side code.

With your Supabase project set up and your API keys in hand, you're ready to start building your login UI. How exciting!

Building the Login UI with HTML and CSS

Let's start with the basic structure of our login UI. We'll use HTML to create the elements and CSS to style them. Don't worry; we'll keep it simple and clean.

HTML Structure

Here's the HTML code for our login form:

<div class="login-container">
  <h2>Login</h2>
  <form id="login-form">
    <div class="form-group">
      <label for="email">Email</label>
      <input type="email" id="email" name="email" required>
    </div>
    <div class="form-group">
      <label for="password">Password</label>
      <input type="password" id="password" name="password" required>
    </div>
    <button type="submit">Login</button>
  </form>
  <div id="message"></div>
</div>

This code creates a simple login form with fields for email and password. The message div will be used to display any error or success messages.

CSS Styling

Now, let's add some CSS to make our login form look presentable:

.login-container {
  width: 300px;
  margin: 100px auto;
  padding: 20px;
  border: 1px solid #ccc;
  border-radius: 5px;
  text-align: center;
}

.form-group {
  margin-bottom: 15px;
}

label {
  display: block;
  text-align: left;
  margin-bottom: 5px;
}

input[type="email"], input[type="password"] {
  width: 100%;
  padding: 8px;
  border: 1px solid #ccc;
  border-radius: 4px;
  box-sizing: border-box;
}

button {
  background-color: #4CAF50;
  color: white;
  padding: 10px 15px;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

button:hover {
  background-color: #3e8e41;
}

#message {
  margin-top: 10px;
  color: red;
}

This CSS code provides basic styling for the login form, making it centered, visually appealing, and easy to use. Feel free to customize the styles to match your application's design.

Implementing the Login Logic with JavaScript

With the HTML and CSS in place, it's time to add some JavaScript to handle the login logic. We'll use the Supabase client library to authenticate users and display appropriate messages.

Adding the Supabase Client Library

First, you need to include the Supabase client library in your HTML file. You can do this by adding the following script tag to the <head> section of your HTML:

<script src="https://cdn.jsdelivr.net/npm/@supabase/supabase-js@2"></script>

Initializing the Supabase Client

Next, you need to initialize the Supabase client with your project URL and API key. Add the following JavaScript code to your HTML file:

const SUPABASE_URL = 'YOUR_SUPABASE_URL';
const SUPABASE_ANON_KEY = 'YOUR_SUPABASE_ANON_KEY';

const supabase = Supabase.createClient(SUPABASE_URL, SUPABASE_ANON_KEY);

Replace YOUR_SUPABASE_URL and YOUR_SUPABASE_ANON_KEY with your actual Supabase project URL and API key.

Handling the Login Form Submission

Now, let's add the JavaScript code to handle the login form submission. This code will authenticate the user with Supabase and display a success or error message.

const loginForm = document.getElementById('login-form');
const messageDiv = document.getElementById('message');

loginForm.addEventListener('submit', async (event) => {
  event.preventDefault();

  const email = document.getElementById('email').value;
  const password = document.getElementById('password').value;

  const { data, error } = await supabase.auth.signInWithPassword({
    email: email,
    password: password,
  });

  if (error) {
    messageDiv.textContent = `Error: ${error.message}`;
  } else {
    messageDiv.textContent = 'Login successful!';
    // Redirect to the dashboard or another page
    window.location.href = '/dashboard';
  }
});

This code listens for the form submission event, retrieves the email and password from the form, and then uses the supabase.auth.signInWithPassword method to authenticate the user. If the login is successful, it displays a success message and redirects the user to the dashboard. If there's an error, it displays an error message.

Adding Sign-Up Functionality

Of course, a login UI isn't complete without sign-up functionality. Let's add a sign-up form and implement the sign-up logic using Supabase.

Creating the Sign-Up Form

First, add the following HTML code to create the sign-up form:

<div class="signup-container">
  <h2>Sign Up</h2>
  <form id="signup-form">
    <div class="form-group">
      <label for="signup-email">Email</label>
      <input type="email" id="signup-email" name="signup-email" required>
    </div>
    <div class="form-group">
      <label for="signup-password">Password</label>
      <input type="password" id="signup-password" name="signup-password" required>
    </div>
    <button type="submit">Sign Up</button>
  </form>
  <div id="signup-message"></div>
</div>

Adding the Sign-Up Logic

Now, let's add the JavaScript code to handle the sign-up form submission. This code will create a new user with Supabase and display appropriate messages.

const signupForm = document.getElementById('signup-form');
const signupMessageDiv = document.getElementById('signup-message');

signupForm.addEventListener('submit', async (event) => {
  event.preventDefault();

  const email = document.getElementById('signup-email').value;
  const password = document.getElementById('signup-password').value;

  const { data, error } = await supabase.auth.signUp({
    email: email,
    password: password,
  });

  if (error) {
    signupMessageDiv.textContent = `Error: ${error.message}`;
  } else {
    signupMessageDiv.textContent = 'Sign up successful! Check your email to verify your account.';
  }
});

This code listens for the form submission event, retrieves the email and password from the form, and then uses the supabase.auth.signUp method to create a new user. If the sign-up is successful, it displays a success message and informs the user to check their email for verification. If there's an error, it displays an error message.

Implementing Social Logins

Social logins are a convenient way for users to sign up and log in to your application. Supabase supports various social login providers, including Google, Facebook, and GitHub. Let's see how to implement social logins with Supabase.

Setting Up Social Login Providers

Before you can use social logins, you need to configure them in your Supabase project. Here's how:

  1. Go to your Supabase project dashboard.
  2. Navigate to "Authentication" and then "Providers".
  3. Enable the social login providers you want to use (e.g., Google, Facebook, GitHub).
  4. Follow the instructions to configure each provider. This usually involves creating an app in the provider's developer console and providing the necessary credentials to Supabase.

Adding Social Login Buttons

Once you've configured the social login providers, you can add buttons to your login UI that allow users to sign in with their social accounts. Here's an example of how to add a Google login button:

<button id="google-login">Login with Google</button>

Implementing the Social Login Logic

Now, let's add the JavaScript code to handle the social login button click. This code will redirect the user to the social login provider's authentication page.

const googleLoginButton = document.getElementById('google-login');

googleLoginButton.addEventListener('click', async () => {
  const { data, error } = await supabase.auth.signInWithOAuth({
    provider: 'google',
  });

  if (error) {
    console.error('Error logging in with Google:', error.message);
  }
});

This code uses the supabase.auth.signInWithOAuth method to redirect the user to the Google authentication page. After the user authenticates with Google, they will be redirected back to your application with a token that Supabase can use to create a new user or log in an existing user.

Conclusion

Alright, guys! You've made it to the end of this comprehensive guide on creating a Supabase login UI. We've covered everything from setting up your Supabase project to building the UI with HTML and CSS, implementing the login logic with JavaScript, adding sign-up functionality, and even implementing social logins. With this knowledge, you're well-equipped to create a fantastic and secure login UI for your applications. Keep experimenting, keep learning, and have fun building awesome things with Supabase!