initializeApp static method

Future<FirebaseApp> initializeApp({ String? name, FirebaseOptions? options, String? demoProjectId, })

Initializes a new FirebaseApp instance by name and options and returns the created app. This method should be called before any usage of FlutterFire plugins.

If a demoProjectId is provided, a new FirebaseApp instance will be initialized with a set of default options for demo projects, overriding the options argument. If no name is provided alongside a demoProjectId, the demoProjectId will be used as the app name. By convention, the demoProjectId should begin with "demo-".

The default app instance can be initialized here simply by passing no "name" as an argument in both Dart & manual initialization flows. If you have a google-services.json file in your android project or a GoogleService-Info.plist file in your iOS+ project, it will automatically create a default (named "DEFAULT") app instance on the native platform. However, you will still need to call this method before using any FlutterFire plugins.

Implementation

static Future<FirebaseApp> initializeApp({
  String? name,
  FirebaseOptions? options,
  String? demoProjectId,
}) async {
  if (demoProjectId != null) {
    late final String platformString;
    if (defaultTargetPlatform == TargetPlatform.android) {
      platformString = 'android';
    } else if (defaultTargetPlatform == TargetPlatform.iOS ||
        defaultTargetPlatform == TargetPlatform.macOS) {
      platformString = 'ios';
    } else {
      // We use 'web' as the default platform for unknown platforms.
      platformString = 'web';
    }
    // A name must be set, otherwise [DEFAULT] will be used and the options
    // we've provided will be ignored if any platform specific configuration
    // files exist (i.e. GoogleService-Info.plist for iOS).
    name ??= demoProjectId;
    // The user should not set any options if they specify a demo project
    // id, but it was allowed when this API was first added, so we allow it
    // for backwards compatibility and simply override the user-provided
    // options.
    options = FirebaseOptions(
      apiKey: '12345',
      appId: '1:1:$platformString:1',
      messagingSenderId: '',
      projectId: demoProjectId,
    );
    // Now fall through to the normal initialization logic.
  }
  FirebaseAppPlatform app = await _delegate.initializeApp(
    name: name,
    options: options,
  );

  return FirebaseApp._(app);
}