Firebase Cloud Storage Skill

This skill defines how to correctly use Firebase Cloud Storage in Flutter applications.

When to Use

Use this skill when:

• Setting up Cloud Storage in a Flutter project.
• Uploading or downloading files.
• Managing file metadata.
• Handling Storage errors and monitoring upload progress.

---

1. Setup and Configuration

flutter pub add firebase_storage

import 'package:firebase_storage/firebase_storage.dart';

final storage = FirebaseStorage.instance;
// Or specify a bucket explicitly:
// final storage = FirebaseStorage.instanceFor(bucket: "gs://BUCKET_NAME");

• Firebase Storage requires the Blaze (pay-as-you-go) plan.
• Run flutterfire configure to update your Firebase config with the default Storage bucket name.

Security note: By default, a Cloud Storage bucket requires Firebase Authentication for any action. Configuring public access may also make App Engine files publicly accessible, restrict access again when you set up Authentication.

---

2. File Operations

Create a reference:

final storageRef = FirebaseStorage.instance.ref();
final fileRef = storageRef.child("uploads/file.jpg");

Upload:

final uploadTask = fileRef.putFile(file);
final snapshot = await uploadTask;
final downloadUrl = await snapshot.ref.getDownloadURL();

Download (in-memory):

final data = await fileRef.getData();

Download URL:

final downloadUrl = await fileRef.getDownloadURL();

Delete:

await fileRef.delete();

---

3. Metadata Management

Get metadata:

final metadata = await fileRef.getMetadata();
print('Content type: ${metadata.contentType}');
print('Size: ${metadata.size}');

Update metadata:

final newMetadata = SettableMetadata(
  contentType: "image/jpeg",
  customMetadata: {'uploaded_by': 'user123'},
);
await fileRef.updateMetadata(newMetadata);