zustand-persist/README.md

persist and rehydrate redux stores

# Zustand persist

Persist and rehydrate state works on react and react native.

[Zustand](https://github.com/react-spring/zustand) is a small, fast and scaleable bearbones state-management solution.

This library is inspired by [https://github.com/rt2zz/redux-persist](https://github.com/rt2zz/redux-persist).

Contributions are Welcome

[![Build Status](https://travis-ci.org/roadmanfong/zustand-persist.svg?branch=master)](https://travis-ci.org/roadmanfong/zustand-persist) [![npm version](https://img.shields.io/npm/v/zustand-persist.svg?style=flat-square)](https://www.npmjs.com/package/zustand-persist) [![npm downloads](https://img.shields.io/npm/dm/zustand-persist.svg?style=flat-square)](https://www.npmjs.com/package/zustand-persist)

```cli
$ npm install zustand-persist
$ yarn add zustand-persist
```

Try [Demo](https://codesandbox.io/s/zustand-persist-example-5u3ry?file=/src/App.js) Here

## Middleware

```ts
// if in react native
// import AsyncStorage from '@react-native-community/async-storage'

const { persist, purge } = configurePersist({
  storage: localStorage, // use `AsyncStorage` in react native
  rootKey: 'root', // optional, default value is `root`
})

const useStore = createStore(
  persist({
    key: 'auth', // required, child key of storage
    allowlist: ['isAuthenticated', 'user'], // optional, will save everything if allowlist is undefined
    denylist: [], // optional, if allowlist set, denylist will be ignored
  }, (set) => ({
    isAuthenticating: false,
    isAuthenticated: false,
    user: undefined,
    login: async (username, password) =>{
      set((state) => ({ isAuthenticating: true }))
      const { user } = await webLogin(username, password)
      set((state) => ({
        isAuthenticated: true,
        isAuthenticating: false,
        user,
      })),
    }
  }))
)
```

## PersistGate

```tsx
function App() {
  // Must call useStore to bootstrap persistence or will stop on loading screen
  useStore()
  return (
    <PersistGate
      onBeforeLift={() => {
        console.log('onBeforeLift')
      }}
      loading={<Loading />}>
      <AppContent />
    </PersistGate>
  )
}
```

## Limitations
Zustand allows any valid JavaScript data types to set in the store, such as Set, Map, or functions. Both `localStorage` and `AsyncStorage` require that all values set in them be serializable, or converted into string form for storage. This means if you wish to persist the contents of your store all of its values need to be serializable. Any values which are not serializable will be silently absent upon hydration.

A note on storing actions (functions): your actions are safe as long as they exist in the initial state during store creation. The hydration process merges initial state with stored state.

## Todo

- enhanced removing root logic