Connect to FlutterFlow: Google OAuth (Google Sign-In)

Welcome to this step-by-step guide on implementing Google OAuth authentication in your application using Xano and FlutterFlow. In this post, we'll walk through the process of integrating Google OAuth into your Xano backend and connecting it to your FlutterFlow frontend. By the end, you'll be able to authenticate users seamlessly using their Google accounts, without the need for Firebase or other third-party authentication services.

Prerequisites

Before we begin, make sure you have the following:

• A Xano account and workspace
• A FlutterFlow project
• A Google Cloud Platform project with OAuth credentials (client ID and client secret)

Step 1: Install the Google OAuth Extension in Xano

1. Log in to your Xano workspace and navigate to the Marketplace.
2. Find the "Google OAuth" extension under the "User Authentication" category and install it into your workspace.
3. Configure the extension by providing your Google client ID and client secret. You can obtain these credentials from the Google Cloud Platform Console.

Step 2: Understand the OAuth Flow

The Google OAuth flow consists of four main endpoints in the Xano API:

1. Initialize: This endpoint kicks off the OAuth flow by taking in a redirect URL from your frontend and returning a URL that will take you to the Google-hosted consent screen.
2. Continue: After signing in with your Google account, you'll be redirected back to your frontend with a code in the URL. This endpoint exchanges the code for a Xano authentication token.
3. Sign Up: This endpoint handles new user sign-ups.
4. Log In: This endpoint handles existing user log-ins.

For this tutorial, we'll focus on the `Initialize` and `Continue` endpoints, as the `Continue` endpoint covers both sign-up and log-in scenarios.

Step 3: Set up the Redirect URI in FlutterFlow

To complete the OAuth flow, you'll need to provide a redirect URI to Xano. This URI will be used to redirect the user back to your frontend after they've authenticated with Google.

1. In your FlutterFlow project, navigate to "Settings" > "Integrations" > "Platforms" and enable the "Web" platform to enable deep linking.
2. Publish your app to the web by clicking the "Publish Your App to the Web" button in the top-right corner.
3. Copy the published URL, which will be your base redirect URI.

Next, you'll need to create a new page in FlutterFlow that will serve as the redirect destination. This page will have a specific route that you'll append to your base redirect URI.

1. Create a new page in FlutterFlow and name it "AuthPage" or something similar.
2. In the "Route Settings" panel on the right, set the subpath for this page (e.g., "/auth").
3. Combine the base redirect URI and the subpath to form your complete redirect URI (e.g., `https://your-app.flutterflow.io/auth`).

Step 4: Configure the Redirect URI in Google Cloud Platform

1. In the Google Cloud Platform Console, navigate to your project's "Credentials" section.
2. Under "Authorized redirect URIs," add the complete redirect URI you obtained in the previous step.

Step 5: Test the OAuth Flow in Xano

1. In Xano, navigate to the "Google OAuth" API group and find the `Initialize` endpoint.
2. Run the `Initialize` endpoint, providing your complete redirect URI as the input parameter.
3. The endpoint will return an authentication URL. Navigate to this URL in your browser and sign in with your Google account.
4. After signing in, you'll be redirected back to your FlutterFlow AuthPage with a code parameter in the URL.

Next, you'll need to exchange this code for a Xano authentication token using the `Continue` endpoint.

1. In Xano, navigate to the `Continue` endpoint in the "Google OAuth" API group.
2. Run the `Continue` endpoint, providing the code from the URL and your complete redirect URI as input parameters.
3. If successful, the endpoint will return a Xano authentication token and user information.

Step 6: Integrate the OAuth Flow in FlutterFlow

Now that you've tested the OAuth flow in Xano, it's time to integrate it into your FlutterFlow frontend.

1. In FlutterFlow, create two new API calls: one for the `Initialize` endpoint and one for the `Continue` endpoint.
2. For the `Initialize` API call, set the endpoint URL and add a query parameter for the redirect URI.
3. For the `Continue` API call, set the endpoint URL and add two query parameters: one for the code (which should be a dynamic variable) and one for the redirect URI.

Next, you'll need to set up the action flow for your frontend.

1. On your home page, add a button that triggers the `Initialize` API call.
2. In the action flow, check the API response. If successful, use the `launchURL` action to navigate to the authentication URL returned by the `Initialize` endpoint.
3. On the AuthPage, set up an action flow that triggers on page load.
4. In this action flow, call the `Continue` API endpoint, passing in the code parameter from the URL and the redirect URI.
5. If the API call is successful, store the returned authentication token in an app state variable.
6. You can then use this app state variable to pass the authentication token as a header in subsequent API calls to Xano.

Step 7: Deploy and Test

After completing the integration in FlutterFlow, deploy your changes and test the authentication flow in your application.

1. Click the "Continue with Google" button on your home page.
2. You'll be redirected to the Google consent screen. Sign in with your Google account.
3. After signing in, you'll be redirected back to your AuthPage in FlutterFlow.
4. The AuthPage should display the user information and authentication token returned by Xano.

Congratulations! You've successfully implemented Google OAuth authentication in your application using Xano and FlutterFlow.

Additional Resources

• For mobile applications (Android or iOS), you'll need to follow additional steps in FlutterFlow to set up your URL scheme and domain. Check out the FlutterFlow documentation on deep and dynamic linking for more information.
• Remember, the concepts and flow demonstrated in this tutorial apply to other OAuth providers like Apple, Twitter, and Facebook. The overall process remains the same, with minor variations in the setup and configuration.

If you have any questions or need further assistance, feel free to reach out to the Xano community or check out our documentation.