@react-native-community/async-storage

What is @react-native-community/async-storage?

@react-native-community/async-storage is an asynchronous, unencrypted, persistent, key-value storage system for React Native. It is designed to store small amounts of data, such as user preferences, app settings, or other lightweight data that needs to persist across app sessions.

What are @react-native-community/async-storage's main functionalities?

Store Data

This feature allows you to store a key-value pair in the storage. The `setItem` method is used to save the data asynchronously.

async function storeData(key, value) {
  try {
    await AsyncStorage.setItem(key, value);
  } catch (e) {
    // saving error
    console.error(e);
  }
}

Retrieve Data

This feature allows you to retrieve a value by its key from the storage. The `getItem` method is used to fetch the data asynchronously.

async function retrieveData(key) {
  try {
    const value = await AsyncStorage.getItem(key);
    if (value !== null) {
      // value previously stored
      return value;
    }
  } catch (e) {
    // error reading value
    console.error(e);
  }
}

Remove Data

This feature allows you to remove a key-value pair from the storage. The `removeItem` method is used to delete the data asynchronously.

async function removeData(key) {
  try {
    await AsyncStorage.removeItem(key);
  } catch (e) {
    // remove error
    console.error(e);
  }
}

Merge Data

This feature allows you to merge an existing value with a new value for a given key. The `mergeItem` method is used to update the data asynchronously.

async function mergeData(key, value) {
  try {
    await AsyncStorage.mergeItem(key, value);
  } catch (e) {
    // merge error
    console.error(e);
  }
}

Clear All Data

This feature allows you to clear all key-value pairs from the storage. The `clear` method is used to remove all data asynchronously.

async function clearAllData() {
  try {
    await AsyncStorage.clear();
  } catch (e) {
    // clear error
    console.error(e);
  }
}

Other packages similar to @react-native-community/async-storage

react-native-mmkv

react-native-mmkv is a fast, small, and easy-to-use key-value storage library for React Native. It is based on Facebook's MMKV storage library and offers better performance and lower memory usage compared to @react-native-community/async-storage.

react-native-encrypted-storage

react-native-encrypted-storage provides a secure and encrypted storage solution for React Native applications. It uses the device's secure storage mechanisms to store data, making it more secure than @react-native-community/async-storage, which does not encrypt data.

redux-persist

redux-persist is a library that allows you to persist and rehydrate a Redux store. It can be used with various storage backends, including AsyncStorage. It is more suitable for applications that use Redux for state management and need to persist the entire state.

README

Async Storage Core

Main, public-facing components of Async Storage. The core module contains a factory to create an AsyncStorage instance and IStorageBackend, that needs to be implemented by any Backend Storage in order to be compatible.

Install

$ yarn install @react-native-community/async-storage

API

AsyncStorageFactory

A factory module for AsyncStorage instance with selected storage backend attached.

// storage.js

import ASFactory from '@react-native-community/async-storage'

// use any available Storage Backend
const storageBackend = new StorageBackend();

const mobileStorage = ASFactory.create(storageBackend, options);

export default mobileStorage;

Factory options

AsyncStorageFactory.create accepts an options object, that enables additional features.

• logger

type logger = ((action: LoggerAction) => void) | boolean;

Used to log AsyncStorage method calls and used arguments. You can provide your own implementation or use provided default logger (enabled by default in DEV mode).

• errorHandler

type errorHandler = ((error: Error | string) => void) | boolean;

Used to report any errors thrown. You can provide your own implementation or use provided default error handler (enabled by default in DEV mode).

Providing a storage model

If you know the structure of the stored data upfront, you can use the full potential of the type system, by providing a type argument to AsyncStorageFactory.create<T> method.

import ASFactory from '@react-native-community/async-storage'

type StorageModel = {
  user: {
    name: string;
    age: number;
  };
  preferences: {
    darkModeEnabled: boolean;
  };
  subscribedChannels: Array<string>;
  onboardingCompleted: boolean;
};

// use any available Storage Backend
const storageBackend = new StorageBackend();


const storage = ASFactory.create<StorageModel>(storageBackend);

IStorageBackend

In order to let AsyncStorage use a storage backend, it has to implement this interface. Contains methods to get, set and remove data, return used keys or drop the whole storage.

import {
  IStorageBackend,
} from '@react-native-community/async-storage';

type Model = {
  count: number
  user: {
    name: string,
    rating: number
  }
}

class MyStorageSolution implements IStorageBackend<Model> {
  // implement necessary methods
}

License

MIT