Redux Identity

Super tiny redux identity reducer for persisting a slice of state after updates.

Installation

npm install --save redux-identity

yarn add redux-identity

API

IdentityReducer(initialState)

IdentityReducer :: a -> a -> a

• parameter: initial state of reducer
• return: a reducer which when invoked by redux will return the given slice of state or the initial reducer state if no slice exists

Usage

Reducer only initial state

No initial state is supplied to the createStore function

import IdentityReducer from 'redux-identity';
import { combineReducers, createStore } from 'redux';

import apiReducer from '../some/local/path';
import counterReducer from '../some/other/local/path';

const reducers = combineReducers({
  CLIENT_ID: IdentityReducer('SOME UNIQUE ID'),
  api: apiReducer,
  counter: counterReducer
});

let store = createStore(reducers);

store.subscribe(() => console.log(store.getState());

// Dispatching any action will not update the value of state at the identity reducer slice
store.dispatch({ type: 'FETCH' });
// { CLIENT_ID: 'SOME UNIQUE ID', api: {...}, counter: 0 }

store.dispatch({ type: 'INCREMENT' });
// { CLIENT_ID: 'SOME UNIQUE ID', api: {...}, counter: 1 }

store.dispatch({ type: 'DECREMENT' });
// { CLIENT_ID: 'SOME UNIQUE ID', api: {...}, counter: 0 }

Redux Store Initial State

Initial state of the identity reducer is overridden and then persisted by the corresponding slice of the state object provided to the createStore function

import IdentityReducer from 'redux-identity';
import { combineReducers, createStore } from 'redux';

import apiReducer from '../some/local/path';
import counterReducer from '../some/other/local/path';

const reducers = combineReducers({
  CLIENT_ID: IdentityReducer('SOME UNIQUE ID'),
  api: apiReducer,
  counter: counterReducer
});

let store = createStore(reducers, { CLIENT_ID: '123456789' });

store.subscribe(() => console.log(store.getState());

// Dispatching any action will not update the value of state at the identity reducer slice
store.dispatch({ type: 'FETCH' });
// { CLIENT_ID: '123456789', api: {...}, counter: 0 }

store.dispatch({ type: 'INCREMENT' });
// { CLIENT_ID: '123456789', api: {...}, counter: 1 }

store.dispatch({ type: 'DECREMENT' });
// { CLIENT_ID: '123456789', api: {...}, counter: 0 }

License

MIT