app package

Firebase App

This package coordinates the communication between the different Firebase components

Functions

Function Description
function(app, ...)
deleteApp(app) Renders this app unusable and frees the resources of all associated services.
function()
getApps() A (read-only) array of all initialized apps.
initializeApp() Creates and initializes a FirebaseApp instance.
function(libraryKeyOrName, ...)
registerVersion(libraryKeyOrName, version, variant) Registers a library's name and version for platform logging purposes.
function(logCallback, ...)
onLog(logCallback, options) Sets log handler for all Firebase SDKs.
function(logLevel, ...)
setLogLevel(logLevel) Sets log level for all Firebase SDKs.All of the log types above the current log level are captured (i.e. if you set the log level to info, errors are logged, but debug and verbose logs are not).
function(name, ...)
getApp(name) Retrieves a FirebaseApp instance.When called with no arguments, the default app is returned. When an app name is provided, the app corresponding to that name is returned.An exception is thrown if the app being retrieved has not yet been initialized.
function(options, ...)
initializeApp(options, name) Creates and initializes a FirebaseApp instance.See Add Firebase to your app and Initialize multiple projects for detailed documentation.
initializeApp(options, config) Creates and initializes a FirebaseApp instance.

Interfaces

Interface Description
FirebaseApp A FirebaseApp holds the initialization information for a collection of services.Do not call this constructor directly. Instead, use initializeApp() to create an app.
FirebaseAppSettings Configuration options given to initializeApp()
FirebaseOptions Firebase configuration object. Contains a set of parameters required by services in order to successfully communicate with Firebase server APIs and to associate client data with your Firebase project and Firebase application. Typically this object is populated by the Firebase console at project setup. See also: Learn about the Firebase config object.

Variables

Variable Description
SDK_VERSION The current SDK version.

function(app, ...)

deleteApp(app)

Renders this app unusable and frees the resources of all associated services.

Signature:

export declare function deleteApp(app: FirebaseApp): Promise<void>;

Parameters

Parameter Type Description
app FirebaseApp

Returns:

Promise<void>

Example

deleteApp(app)
  .then(function() {
    console.log("App deleted successfully");
  })
  .catch(function(error) {
    console.log("Error deleting app:", error);
  });

function()

getApps()

A (read-only) array of all initialized apps.

Signature:

export declare function getApps(): FirebaseApp[];

Returns:

FirebaseApp[]

initializeApp()

Creates and initializes a FirebaseApp instance.

Signature:

export declare function initializeApp(): FirebaseApp;

Returns:

FirebaseApp

function(libraryKeyOrName, ...)

registerVersion(libraryKeyOrName, version, variant)

Registers a library's name and version for platform logging purposes.

Signature:

export declare function registerVersion(libraryKeyOrName: string, version: string, variant?: string): void;

Parameters

Parameter Type Description
libraryKeyOrName string
version string Current version of that library.
variant string Bundle variant, e.g., node, rn, etc.

Returns:

void

function(logCallback, ...)

onLog(logCallback, options)

Sets log handler for all Firebase SDKs.

Signature:

export declare function onLog(logCallback: LogCallback | null, options?: LogOptions): void;

Parameters

Parameter Type Description
logCallback LogCallback | null An optional custom log handler that executes user code whenever the Firebase SDK makes a logging call.
options LogOptions

Returns:

void

function(logLevel, ...)

setLogLevel(logLevel)

Sets log level for all Firebase SDKs.

All of the log types above the current log level are captured (i.e. if you set the log level to info, errors are logged, but debug and verbose logs are not).

Signature:

export declare function setLogLevel(logLevel: LogLevelString): void;

Parameters

Parameter Type Description
logLevel LogLevelString

Returns:

void

function(name, ...)

getApp(name)

Retrieves a FirebaseApp instance.

When called with no arguments, the default app is returned. When an app name is provided, the app corresponding to that name is returned.

An exception is thrown if the app being retrieved has not yet been initialized.

Signature:

export declare function getApp(name?: string): FirebaseApp;

Parameters

Parameter Type Description
name string Optional name of the app to return. If no name is provided, the default is "[DEFAULT]".

Returns:

FirebaseApp

The app corresponding to the provided app name. If no app name is provided, the default app is returned.

Example 1

// Return the default app
const app = getApp();

Example 2

// Return a named app
const otherApp = getApp("otherApp");

function(options, ...)

initializeApp(options, name)

Creates and initializes a FirebaseApp instance.

See Add Firebase to your app and Initialize multiple projects for detailed documentation.

Signature:

export declare function initializeApp(options: FirebaseOptions, name?: string): FirebaseApp;

Parameters

Parameter Type Description
options FirebaseOptions Options to configure the app's services.
name string Optional name of the app to initialize. If no name is provided, the default is "[DEFAULT]".

Returns:

FirebaseApp

The initialized app.

Example 1


// Initialize default app
// Retrieve your own options values by adding a web app on
// https://console.firebase.google.com
initializeApp({
  apiKey: "AIza....",                             // Auth / General Use
  authDomain: "YOUR_APP.firebaseapp.com",         // Auth with popup/redirect
  databaseURL: "https://YOUR_APP.firebaseio.com", // Realtime Database
  storageBucket: "YOUR_APP.appspot.com",          // Storage
  messagingSenderId: "123456789"                  // Cloud Messaging
});

Example 2


// Initialize another app
const otherApp = initializeApp({
  databaseURL: "https://<OTHER_DATABASE_NAME>.firebaseio.com",
  storageBucket: "<OTHER_STORAGE_BUCKET>.appspot.com"
}, "otherApp");

initializeApp(options, config)

Creates and initializes a FirebaseApp instance.

Signature:

export declare function initializeApp(options: FirebaseOptions, config?: FirebaseAppSettings): FirebaseApp;

Parameters

Parameter Type Description
options FirebaseOptions Options to configure the app's services.
config FirebaseAppSettings FirebaseApp Configuration

Returns:

FirebaseApp

SDK_VERSION

The current SDK version.

Signature:

SDK_VERSION: string