This tutorial walks through building a Flutter Firebase Tutorial app with Firebase backend – including email/password authentication, a real-time chat using Firestore, and image file uploads to Cloud Storage. We’ll cover setting up Firebase, adding necessary packages, initializing Firebase, and writing Dart code for each feature. By the end, you’ll have a functional app where users can sign up, log in, exchange messages in real-time, and upload images.
Table of Contents
Prerequisites for Flutter Firebase Tutorial
- A Flutter development environment set up (Flutter SDK, IDE).
- A Firebase project created in the Firebase Console. Add your Android/iOS app there.
- The FlutterFire CLI or manual setup completed (e.g. running
flutterfire configuregeneratesfirebase_options.dart). - Basic Flutter knowledge: creating widgets, navigation, and using
pubspec.yamlto add dependencies.
1. Add Firebase Packages
First, add the core Firebase packages to your Flutter project. In your project root, run:
flutter pub add firebase_core firebase_auth cloud_firestore firebase_storage
These commands install the Firebase Core, Auth, Firestore, and Storage plugins. For example, flutter pub add firebase_auth adds Firebase Authenticationfirebase.google.com, and flutter pub add cloud_firestore adds Firestorefirebase.flutter.dev. After adding packages, rebuild your app (flutter run) to download them.
2. Initialize Firebase in Flutter Firebase Tutorial
Before using any Firebase features, initialize Firebase in your main() function. Import firebase_core and the generated options (from flutterfire configure), then ensure Flutter bindings are ready and call Firebase.initializeApp() as shown:
import 'package:flutter/material.dart';
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp(
options: DefaultFirebaseOptions.currentPlatform,
);
runApp(MyApp());
}
This matches the FlutterFire documentation examplefirebase.flutter.dev. It ensures Firebase services are connected before running the app.
3. Firebase Console Setup
In the Firebase Console, configure the following:
- Authentication: On the “Sign-in method” page, enable Email/Password authenticationfirebase.google.com. This allows your app to create and sign in users with email and password.
- Firestore Database: Create a Cloud Firestore database in test mode or with rules that allow authenticated reads/writes. Firestore will store our chat messages in real-time.
- Cloud Storage: Create a Storage bucket. In development you can set rules to allow writes for authenticated users. This bucket will hold user-uploaded images.
When adding your Android/iOS app in Firebase, make sure to download and include the google-services.json (Android) or GoogleService-Info.plist (iOS) files in your Flutter project as instructed. The FlutterFire CLI can automate this.
4. Implement Email/Password Auth
In your Flutter app, create authentication screens (sign-up and login). Use the firebase_auth plugin to register and sign in users for Flutter Firebase Tutorial.
- Registering a new user: Call
FirebaseAuth.instance.createUserWithEmailAndPassword(email, password). This creates the account and signs in the user. For example:try { UserCredential userCred = await FirebaseAuth.instance .createUserWithEmailAndPassword( email: userEmail, password: userPassword, ); // Account created and user logged in. } on FirebaseAuthException catch (e) { if (e.code == 'weak-password') { print('Password is too weak.'); } else if (e.code == 'email-already-in-use') { print('Email already in use.'); } }This matches the official FlutterFire examplefirebase.flutter.dev. The call throws exceptions for invalid input, which we catch to show errors. - Signing in: Use
FirebaseAuth.instance.signInWithEmailAndPassword(email, password). For example:try { UserCredential userCred = await FirebaseAuth.instance .signInWithEmailAndPassword( email: userEmail, password: userPassword, ); // User signed in successfully. } on FirebaseAuthException catch (e) { if (e.code == 'user-not-found') { print('No account found for that email.'); } else if (e.code == 'wrong-password') { print('Incorrect password.'); } }This is directly from the FlutterFire docsfirebase.flutter.dev. On success, you can navigate to the chat screen. - Auth State Listener: To respond to login state changes (e.g. auto-login if already signed in), listen to
FirebaseAuth.instance.authStateChanges(). For example, in your top-level widget you can use aStreamBuilderonauthStateChanges()to decide whether to show the login screen or the main chat screenfirebase.google.comfirebase.flutter.dev.
5. Real-Time Chat with Firestore
For the chat feature, we’ll use Cloud Firestore. Structure your Firestore with a collection (e.g. messages) where each document has fields like text, sender, and timestamp. For example, when sending a message you might write:
FirebaseFirestore.instance.collection('messages').add({
'text': messageText,
'sender': FirebaseAuth.instance.currentUser!.email,
'timestamp': FieldValue.serverTimestamp(),
});
This adds a new document under messages. The serverTimestamp ensures ordering.
To display messages in real-time, use a stream from Flutter Firebase Tutorial. The collection('messages').snapshots() method returns a Stream<QuerySnapshot> that emits updates whenever data changesfirebase.flutter.dev. In Flutter, wrap it with a StreamBuilder:
StreamBuilder<QuerySnapshot>(
stream: FirebaseFirestore.instance
.collection('messages')
.orderBy('timestamp')
.snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) return CircularProgressIndicator();
// Map each document to a widget (e.g. ListTile or custom bubble).
List<Widget> messageWidgets = snapshot.data!.docs.map((doc) {
Map<String, dynamic> data = doc.data()! as Map<String, dynamic>;
return ListTile(
title: Text(data['sender']),
subtitle: Text(data['text']),
);
}).toList();
return ListView(children: messageWidgets);
},
)
This pattern matches the FlutterFire example of using StreamBuilder to auto-update UI from Firestore datafirebase.flutter.dev. Whenever messages changes (new message added), the StreamBuilder rebuilds, showing the latest chat in real-time. This creates an instant messaging effect without any additional backend code.
6. Uploading Images to Cloud Storage for Flutter Firebase Tutorial
Finally, enable users to upload image files (not just profile pics, but any image). Use the firebase_storage plugin. First, add it (as shown above) and create a FirebaseStorage instance:
final storage = FirebaseStorage.instance;
This gives access to your default bucketfirebase.google.com. To upload an image (picked from the gallery or camera), do:
File file = /* get image file, e.g. via image_picker */;
final fileName = basename(file.path);
final storageRef = storage.ref().child('images/$fileName');
final uploadTask = storageRef.putFile(file);
This code uploads the file to images/<filename> in your Storage bucketfirebase.google.com. You can listen to uploadTask.snapshotEvents to track progress.
After the upload completes, get the file’s download URL to display or store in Firestore:
String downloadUrl = await storageRef.getDownloadURL();
print('File available at $downloadUrl');
The getDownloadURL() method returns a publicly accessible URL for the filefirebase.google.com. (You can then show this URL with an Image.network(downloadUrl) in your UI or save it in Firestore so others can see the image.)
7. Bringing It All Together Flutter Firebase Tutorial
In practice, you’d combine these pieces into Flutter Firebase Tutorial widgets: authentication screens to register/login users, a chat screen with a ListView of messages and a TextField to send new messages, and perhaps an upload button to pick & send images. Each message in Firestore might include text and optionally an image URL, allowing image messaging.
Throughout, Firebase handles the heavy lifting: Auth secures access, Firestore syncs chat in real-time, and Storage holds user-uploaded files. The steps above – adding packagesfirebase.flutter.devfirebase.flutter.dev, enabling email loginfirebase.google.com, initializing Firebasefirebase.flutter.dev, writing auth and Firestore codefirebase.flutter.devfirebase.flutter.dev, and uploading to Storagefirebase.google.comfirebase.google.com – follow best practices from the official Firebase docs.
With this foundation, you have a fully working Flutter Firebase Tutorial app featuring email/password authentication, a realtime chat powered by Firestore, and image uploads via Flutter Firebase Tutorial Storage. You can expand it by adding UI polish, error handling, and additional features (like sign-out, user profiles, etc.), but the core Firebase integration is complete.
Sources: Official FlutterFire and Firebase documentation for Auth, Firestore, and Storage were used throughout (e.g. plugin install commandsfirebase.flutter.devfirebase.google.com, enabling Email/Password sign-infirebase.google.com, auth methodsfirebase.flutter.devfirebase.flutter.dev, Firestore snapshotsfirebase.flutter.devfirebase.flutter.dev, and Storage upload methodsfirebase.google.comfirebase.google.com). These provide up-to-date guidance on integrating Flutter with Firebase services.
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