Capacitor Firebase

Capacitor Firebase is a collection of Capacitor plugins designed to integrate Firebase services into Capacitor projects. It provides a unified way to access Firebase features across multiple platforms.

Key Features

• Platform Support: Works on Android, iOS, and the Web.
• Capacitor Compatibility: Supports Capacitor 8.
• Firebase Web SDK Support: Compatible with the modular Firebase Web SDK.
• Consistent Versioning: Designed to prevent SDK version conflicts.
• TypeScript Support: Provides unified TypeScript definitions for a better developer experience.

To protect your own backend services, retrieve the current App Check token in JWT format using the getToken() method. You should include this token in the headers of your requests to your backend. On your server, you can then verify the token to ensure the request originated from a legitimate, verified app instance.

You can also use the tokenChanged listener to be notified whenever the App Check token is updated.

Fetched configuration values are cached. The minimum fetch interval determines the maximum age (in seconds) of a cached entry before it is considered stale. The default is 43200 seconds (12 hours).

To reduce this interval during development:

• Android and iOS: Use setSettings(...).
• Web: Use setMinimumFetchInterval(...).

To achieve a unified session, you must perform a two-step authentication process:

1. Native Layer: Call the appropriate FirebaseAuthentication method to obtain credentials (like idToken, accessToken, or nonce) from the native OS.
2. Web Layer: Use the Firebase JS SDK's signInWithCredential method with the credentials obtained from the native layer.

This pattern applies to most providers including Google, Facebook, Apple, Twitter, and Phone authentication.

// Example: Google Sign-In synchronization
const signInWithGoogle = async () => {
  // 1. Create credentials on the native layer
  const result = await FirebaseAuthentication.signInWithGoogle();
  // 2. Sign in on the web layer using the id token
  const credential = GoogleAuthProvider.credential(result.credential?.idToken);
  const auth = getAuth();
  await signInWithCredential(auth, credential);
};

When performing one-time reads:

• getCollection(...): Reads documents from a single, specific collection at the provided reference.
• getCollectionGroup(...): Reads documents from all collections across the database that share the same ID.

Both methods support composite filters and query constraints.

When using getters to retrieve values, the returned object includes a source property. This property indicates where the value originated:

• Static default value: The hardcoded default in your code.
• Client defaults: Values set by the client via the plugin.
• Firebase Remote Config server: The value retrieved from the Firebase server.

The plugin provides two ways to handle authentication:

1. Native Authentication: Uses the Firebase SDKs for Java (Android) and Swift (iOS). This provides full functionality and supports native social providers (Apple, Google, etc.). Note that after a native login, the user is only logged in at the native layer. If you need to access Firebase services via the Firebase JS SDK (like Cloud Firestore) in the web layer, you must perform additional synchronization steps.

2. Web Implementation: Encapsulates the Firebase JS SDK to provide a consistent interface across all platforms. While easier to use, it has limited functionality on Android and iOS within WebViews due to OAuth interaction restrictions in native apps.

You can enrich your performance traces with additional data to provide context or quantitative measurements.

Metrics

Metrics are numeric values associated with a trace (e.g., a counter for cache hits).

• Use putMetric(...) to set a value.
• Use incrementMetric(...) to increase a value.
• Note: Metric values are floored down to the nearest integer.

Attributes

Attributes are string values associated with a trace (e.g., a user ID). These are used to segment and filter your performance data in the Firebase console.

Remote Config values are not immediately available after fetching. You must activate the fetched configuration before the getters can return the remote values.

You have two ways to handle this:

1. Two-step process: Call fetchConfig(...) followed by activate().
2. One-step process: Call fetchAndActivate() to perform both operations at once.

If you attempt to use getters before activation, they will return the default values instead of the remote ones.

The @capacitor-firebase/messaging plugin uses the Firebase SDK for Android, iOS, and Web. It provides more advanced features than the standard Capacitor Push Notifications plugin, including:

• Topic Subscriptions: Ability to subscribe to and unsubscribe from specific messaging topics.
• Foreground Notifications: The ability to receive and handle notifications while the app is actively in the foreground.
• Cross-Platform Firebase SDK: Uses the native Firebase SDKs for all supported platforms.