Installation & Setup on iOS

The Firebase Realtime Database is a cloud-hosted database. Data is stored as JSON and synchronized in realtime to every connected client. When you build cross-platform apps with our Android, iOS, and JavaScript SDKs, all of your clients share one Realtime Database instance and automatically receive updates with the newest data.

Prerequisites

1. Install the Firebase SDK.
2. Add your app to your Firebase project in the Firebase console.

Create a Database

1. If you haven't already, create a Firebase project: In the Firebase console, click Add project, then follow the on-screen instructions to create a Firebase project or to add Firebase services to an existing GCP project.

2. Navigate to the Realtime Database section of the Firebase console. You'll be prompted to select an existing Firebase project. Follow the database creation workflow.

3. Select a starting mode for your Firebase Security Rules:

   Test mode

   Good for getting started with the mobile and web client libraries, but allows anyone to read and overwrite your data. After testing, make sure to review the Understand Firebase Realtime Database Rules section.

   Note: If you create a database in Test mode and make no changes to the default world-readable and world-writeable Rules within a trial period, you will be alerted by email, then your database rules will deny all requests. Note the expiration date during the Firebase console setup flow.

   To get started with the web, iOS, or Android SDK, select test mode.

   Locked mode

   Denies all reads and writes from mobile and web clients. Your authenticated application servers can still access your database.

4. Click Done.

When you enable Realtime Database, it also enables the API in the Cloud API Manager.

Add Firebase Realtime Database to your app

1. Add the dependency for Firebase Realtime Database to your project's Podfile:

   pod 'Firebase/Database'
   

2. Run pod install and open the created .xcworkspace file.

Configure Realtime Database Rules

The Realtime Database provides a declarative rules language that allows you to define how your data should be structured, how it should be indexed, and when your data can be read from and written to.

Note: By default, read and write access to your database is restricted so only authenticated users can read or write data. To get started without setting up Authentication, you can configure your rules for public access. This does make your database open to anyone, even people not using your app, so be sure to restrict your database again when you set up authentication.

Set up Firebase Realtime Database

You must initialize Firebase before any Firebase app reference is created or used. If you have already done this for another Firebase feature, you can skip this step.

1. Import the Firebase module in your UIApplicationDelegate:

   Swift

   import Firebase

   Objective-C

   @import Firebase;

2. Configure a FirebaseApp shared instance, typically in your app's application:didFinishLaunchingWithOptions: method:

   Swift

   // Use Firebase library to configure APIs
   FirebaseApp.configure()

   Objective-C

   // Use Firebase library to configure APIs
   [FIRApp configure];

Once you've initialized Firebase Realtime Database, define and create a reference to your database as follows:

Swift

var ref: DatabaseReference!

ref = Database.database().reference()

Objective-C

@property (strong, nonatomic) FIRDatabaseReference *ref;

self.ref = [[FIRDatabase database] reference];

Next Steps

• Learn how to structure data for Realtime Database.

• Scale your data across multiple database instances.

• Read and write data.

• View your database in the Firebase console.

• Prepare to launch your app:

  • Set up budget alerts for your project in the GCP console.
  • Monitor your Usage and billing dashboard in the Firebase console. You can also monitor your Realtime Database Usage dashboard.
  • Review the Firebase launch checklist.