Expo-shared-preferences NPM

expo-shared-preferences

Provides a way to access Shared Preferences on Android.

Why?

expo-secure-store already provides a way to access values in SharedPreferences on Android, however it has built in encryption functionality that is enabled by default for all read and write operations without any way to opt out.

The core React Native API also exposes Settings which allows access to native key value storage on iOS using NSUserDefaults, however there isn't a similarly exposed API for Android (i.e. using SharedPreferences).

Therefore, this package provides a similar API to facilitate basic operations with Android's SharedPreferences without the built in encryption.

API documentation

Methods

By default, expo-shared-preferences will attempt to access the SharedPreferences(https://developer.android.com/reference/android/content/Context#getSharedPreferences(java.lang.String,%20int) using the following formula for the filename:

context.packageName + ".settings"

If you want to access a different file name, then you can pass the value to name in the options parameter in the methods below.

SharedPreferences.getItemAsync(key)

key: string - The key that was used to store the associated value.

options: SharedPreferenceOptions - (optional) configuration options for accessing SharedPreferences.

Returns: A promise that resolves to the previously stored value, or null if there is no entry for the given key. The promise will reject if an error occured while retrieving the value.

SharedPreferences.deleteItemAsync(key)

key: string - The key that was used to store the associated value.

options: SharedPreferenceOptions - (optional) configuration options for accessing SharedPreferences.

Returns: A promise that will reject if the value couldn't be deleted.

SharedPreferences.setItemAsync(key, value)

key: string - he key to associate with the stored value. Keys may contain alphanumeric characters ., -, and _.

value: string - The value to store. Size limit is 2048 bytes.

options: SharedPreferenceOptions - (optional) configuration options for accessing SharedPreferences.

Returns: A promise that will reject if value cannot be stored on the device.

Installation in managed Expo projects

For managed Expo projects, please follow the installation instructions in the API documentation for the latest stable release. If you follow the link and there is no documentation available then this library is not yet usable within managed projects — it is likely to be included in an upcoming Expo SDK release.