<div className="banner-native-code-required"> <h3>Project with Native Code Required</h3> <p>If you are using the managed Expo workflow there is only ever one entry component registered with <code>AppRegistry</code> and it is handled automatically (or through <a href="https://docs.expo.dev/versions/latest/sdk/register-root-component/">registerRootComponent</a>). You do not need to use this API.</p> </div>

AppRegistry is the JS entry point to running all React Native apps. App root components should register themselves with AppRegistry.registerComponent, then the native system can load the bundle for the app and then actually run the app when it's ready by invoking AppRegistry.runApplication.

tsx

import {Text, AppRegistry} from 'react-native';

const App = () => (
  <View>
    <Text>App1</Text>
  </View>
);

AppRegistry.registerComponent('Appname', () => App);

To "stop" an application when a view should be destroyed, call AppRegistry.unmountApplicationComponentAtRootTag with the tag that was passed into runApplication. These should always be used as a pair.

AppRegistry should be required early in the require sequence to make sure the JS execution environment is setup before other modules are required.

Reference

Methods

`getAppKeys()`

tsx

static getAppKeys(): string[];

Returns an array of strings.

`getRegistry()`

tsx

static getRegistry(): {sections: string[]; runnables: Runnable[]};

Returns a Registry object.

`getRunnable()`

tsx

static getRunnable(appKey: string): : Runnable | undefined;

Returns a Runnable object.

Parameters:

Name	Type
appKey <div className="label basic required">Required</div>	string

`getSectionKeys()`

tsx

static getSectionKeys(): string[];

Returns an array of strings.

`getSections()`

tsx

static getSections(): Record<string, Runnable>;

Returns a Runnables object.

`registerCancellableHeadlessTask()`

tsx

static registerCancellableHeadlessTask(
  taskKey: string,
  taskProvider: TaskProvider,
  taskCancelProvider: TaskCancelProvider,
);

Parameters:

Name	Type	Description
taskKey

<div className="label basic required two-lines">Required</div> | string | The native id for this task instance that was used when startHeadlessTask was called. | | taskProvider <div className="label basic required two-lines">Required</div> | [TaskProvider](appregistry#taskprovider) | A promise returning function that takes some data passed from the native side as the only argument. When the promise is resolved or rejected the native side is notified of this event and it may decide to destroy the JS context. | | taskCancelProvider <div className="label basic required two-lines">Required</div> | [TaskCancelProvider](appregistry#taskcancelprovider) | a void returning function that takes no arguments; when a cancellation is requested, the function being executed by taskProvider should wrap up and return ASAP. |

`registerComponent()`

tsx

static registerComponent(
  appKey: string,
  getComponentFunc: ComponentProvider,
  section?: boolean,
): string;

Parameters:

Name	Type
appKey <div className="label basic required">Required</div>	string
componentProvider <div className="label basic required">Required</div>	ComponentProvider
section	boolean

`registerConfig()`

tsx

static registerConfig(config: AppConfig[]);

Parameters:

Name	Type
config <div className="label basic required">Required</div>	AppConfig[]

`registerHeadlessTask()`

tsx

static registerHeadlessTask(
  taskKey: string,
  taskProvider: TaskProvider,
);

This is a way to run tasks in JavaScript while your app is in the background. It can be used, for example, to sync fresh data, handle push notifications, or play music.

Parameters:

Name	Type	Description
taskKey <div className="label basic required two-lines">Required</div>	string	The native id for this task instance that was used when startHeadlessTask was called.
taskProvider <div className="label basic required two-lines">Required</div>	TaskProvider	A promise returning function that takes some data passed from the native side as the only argument. When the promise is resolved or rejected the native side is notified of this event and it may decide to destroy the JS context.

`registerRunnable()`

tsx

static registerRunnable(appKey: string, func: Runnable): string;

Parameters:

Name	Type
appKey <div className="label basic required">Required</div>	string
run <div className="label basic required">Required</div>	function

`registerSection()`

tsx

static registerSection(
  appKey: string,
  component: ComponentProvider,
);

Parameters:

Name	Type
appKey <div className="label basic required">Required</div>	string
component <div className="label basic required">Required</div>	ComponentProvider

`runApplication()`

tsx

static runApplication(appKey: string, appParameters: any): void;

Loads the JavaScript bundle and runs the app.

Parameters:

Name	Type
appKey <div className="label basic required">Required</div>	string
appParameters <div className="label basic required">Required</div>	any

`setComponentProviderInstrumentationHook()`

tsx

static setComponentProviderInstrumentationHook(
  hook: ComponentProviderInstrumentationHook,
);

Parameters:

Name	Type
hook <div className="label basic required">Required</div>	function

A valid hook function accepts the following as arguments:

Name	Type
component <div className="label basic required">Required</div>	ComponentProvider
scopedPerformanceLogger <div className="label basic required">Required</div>	IPerformanceLogger

The function must also return a React Component.

`setWrapperComponentProvider()`

tsx

static setWrapperComponentProvider(
  provider: WrapperComponentProvider,
);

Parameters:

Name	Type
provider <div className="label basic required">Required</div>	ComponentProvider

`startHeadlessTask()`

tsx

static startHeadlessTask(
  taskId: number,
  taskKey: string,
  data: any,
);

Only called from native code. Starts a headless task.

Parameters:

Name	Type	Description
taskId <div className="label basic required">Required</div>	number	The native id for this task instance to keep track of its execution.
taskKey <div className="label basic required">Required</div>	string	The key for the task to start.
data <div className="label basic required">Required</div>	any	The data to pass to the task.

`unmountApplicationComponentAtRootTag()`

tsx

static unmountApplicationComponentAtRootTag(rootTag: number);

Stops an application when a view should be destroyed.

Parameters:

Name	Type
rootTag <div className="label basic required">Required</div>	number

Type Definitions

AppConfig

Application configuration for the registerConfig method.

Type
object

Properties:

Name	Type
appKey <div className="label basic required">Required</div>	string
component	ComponentProvider
run	function
section	boolean

Note: Every config is expected to set either component or run function.

Registry

Type
object

Properties:

Name	Type
runnables	array of Runnables
sections	array of strings

Runnable

Type
object

Properties:

Name	Type
component	ComponentProvider
run	function

Runnables

An object with key of appKey and value of type of Runnable.

Type
object

Task

A Task is a function that accepts any data as argument and returns a Promise that resolves to undefined.

Type
function

TaskCanceller

A TaskCanceller is a function that accepts no argument and returns void.

Type
function

TaskCancelProvider

A valid TaskCancelProvider is a function that returns a TaskCanceller.

Type
function

TaskProvider

A valid TaskProvider is a function that returns a Task.

Type
function