PowerSync is a Postgres-SQLite sync layer, which helps developers to create local-first real-time reactive apps that work seamlessly both online and offline.
This package (packages/react-native
) is the PowerSync SDK for React Native clients. It is an extension of packages/common
.
See a summary of features here.
npx expo install @powersync/react-native
This SDK currently requires @journeyapps/react-native-quick-sqlite
as a peer dependency.
Install it in your app with:
npx expo install @journeyapps/react-native-quick-sqlite
This package connects to a PowerSync instance via HTTP streams (enabled by default) or WebSockets.
- Both connection methods require the React Native Common Polyfills, as detailed below.
- The WebSocket method requires an additional polyfill for the
Buffer
interface. - Other polyfills are required for watched queries using the Async Iterator response format.
This package requires polyfills for HTTP streaming and other text encoding functions. These functions can be provided with react-native-polyfill-globals.
Install the collection of polyfills with:
npx expo install react-native-polyfill-globals
The react-native-polyfill-globals
package uses peer dependencies for individual functions. Most modern package managers install peer dependencies by default, however currently the peer dependency version ranges are quite broad and might result in certain packages being incompatible. Currently an issue is open for a breaking change in one of the dependencies. The best practice is to currently add the packages as explicit dependencies with version ranges to your project with the command below.
npx expo install react-native-fetch-api@^3.0.0 react-native-url-polyfill@^2.0.0 text-encoding@^0.7.0 [email protected] base-64@^1.0.0
Enable the polyfills in React Native app by adding the following in your top level entry point
// App.js
import 'react-native-polyfill-globals/auto';
HTTP connections require the HTTP streaming polyfills included in the common section. See additional setup required for Android.
Note: Beta Release - WebSockets are currently in a beta release. It should be safe to use in production if sufficient testing is done on the client side.
Our WebSocket implementation supports binary payloads which are encoded as BSON documents.
This requires support for the Buffer
interface.
Apply the Buffer
polyfill
npx expo install @craftzdog/react-native-buffer
import { Buffer } from '@craftzdog/react-native-buffer';
if (typeof global.Buffer == 'undefined') {
// @ts-ignore If using TypeScript
global.Buffer = Buffer;
}
This library uses RSocket
for reactive WebSocket streams which requires process.nextTick
to be available. Apply a polyfill if not available.
if (typeof process.nextTick == 'undefined') {
process.nextTick = setImmediate;
}
Watched queries can be used with either a callback response or Async Iterator response.
Watched queries using the Async Iterator response format require support for Async Iterators.
Expo apps currently require polyfill and Babel plugins in order to use this functionality.
npx expo install @azure/core-asynciterator-polyfill
Make sure to import the polyfill early in your application
// App.js
import '@azure/core-asynciterator-polyfill';
Install the async generator Babel plugin
pnpm add -D @babel/plugin-transform-async-generator-functions
Add the Babel plugin to your babel.config.js
file
module.exports = function (api) {
return {
presets: [...],
plugins: [
// ... Other plugins
'@babel/plugin-transform-async-generator-functions'
]
};
};
This package uses native libraries. Create native Android and iOS projects (if not created already) by running:
npx expo run:android
# OR
npx expo run:ios
Our SDK reference contains everything you need to know to get started implementing PowerSync in your project.
A changelog for this SDK is available here.
The full API reference for this SDK can be found here.
For example projects built with PowerSync and React Native, see our Demo Apps / Example Projects gallery. Most of these projects can also be found in the demos/
directory.
- Join our Discord server where you can browse topics from our community, ask questions, share feedback, or just say hello :)
- Please open a GitHub issue when you come across a bug.
- Have feedback or an idea? Submit an idea via our public roadmap or schedule a chat with someone from our product team.