Redux integration

Some folks like to have their navigation state stored in the same place as the rest of their application state. Using Redux to store your state enables you to write custom actions that manipulate the navigation state directly, to be able to dispatch navigation actions from anywhere (sometimes in a "thunk" or "saga") and to persist the navigation state in the same way you would other Redux state (your mileage may vary on this). You can read more about other use cases in the replies to this tweet.

Warning!

You probably do not need to do this! Storing your React Navigation state in your own Redux store is likely to give you a very difficult time if you don't know what you're doing. You lose out on some performance optimizations that React Navigation can do for you, for example. Please do not integrate your state into Redux without first ensuring that you can do what you need to do without it!

Overview

1. To handle your app's navigation state in Redux, you can pass your own navigation prop to a navigator.

2. Once you pass your own navigation prop to the navigator, the default navigation prop gets destroyed. You must construct your own navigation prop with state, dispatch, and addListener properties.

3. The state will be fed from the reducer assigned to handle navigation state and the dispatch will be Redux's default dispatch. Thus you will be able to dispatch normal redux actions using this.props.navigation.dispatch(ACTION), reducer will update the navigation state on the basis of dispatched action, the new navigation state will then be passed to the navigator.

4. A middleware is needed so that any events that mutate the navigation state properly trigger the event listeners.

Step-by-step guide

First, you need to add the react-navigation-redux-helpers package to your project.

• npm
• Yarn

npm install react-navigation-redux-helpers

With Redux, your app's state is defined by a reducer. Each navigation router effectively has a reducer, called getStateForAction. The following is a minimal example of how you might use navigators within a Redux application:

import {
  StackNavigator,
  addNavigationHelpers,
} from 'react-navigation';
import {
  createStore,
  applyMiddleware,
  combineReducers,
} from 'redux';
import {
  createReduxBoundAddListener,
  createReactNavigationReduxMiddleware,
} from 'react-navigation-redux-helpers';
import { Provider, connect } from 'react-redux';
import React from 'react';

const AppNavigator = StackNavigator(AppRouteConfigs);

const initialState = AppNavigator.router.getStateForAction(AppNavigator.router.getActionForPathAndParams('Login'));

const navReducer = (state = initialState, action) => {
  const nextState = AppNavigator.router.getStateForAction(action, state);

  // Simply return the original `state` if `nextState` is null or undefined.
  return nextState || state;
};

const appReducer = combineReducers({
  nav: navReducer,
  ...
});

// Note: createReactNavigationReduxMiddleware must be run before createReduxBoundAddListener
const middleware = createReactNavigationReduxMiddleware(
  "root",
  state => state.nav,
);
const addListener = createReduxBoundAddListener("root");

class App extends React.Component {
  render() {
    return (
      <AppNavigator navigation={addNavigationHelpers({
        dispatch: this.props.dispatch,
        state: this.props.nav,
        addListener,
      })} />
    );
  }
}

const mapStateToProps = (state) => ({
  nav: state.nav
});

const AppWithNavigationState = connect(mapStateToProps)(App);

const store = createStore(
  appReducer,
  applyMiddleware(middleware),
);

class Root extends React.Component {
  render() {
    return (
      <Provider store={store}>
        <AppWithNavigationState />
      </Provider>
    );
  }
}

Once you do this, your navigation state is stored within your Redux store, at which point you can fire navigation actions using your Redux dispatch function.

Keep in mind that when a navigator is given a navigation prop, it relinquishes control of its internal state. That means you are now responsible for persisting its state, handling any deep linking, Handling the Hardware Back Button in Android, etc.

Navigation state is automatically passed down from one navigator to another when you nest them. Note that in order for a child navigator to receive the state from a parent navigator, it should be defined as a screen.

Applying this to the example above, you could instead define AppNavigator to contain a nested TabNavigator as follows:

const AppNavigator = StackNavigator({
  Home: { screen: MyTabNavigator },
});

In this case, once you connect AppNavigator to Redux as is done in AppWithNavigationState, MyTabNavigator will automatically have access to navigation state as a navigation prop.

Full example

There's a working example app with Redux here if you want to try it out yourself.

Mocking tests

To make jest tests work with your react-navigation app, you need to change the jest preset in the package.json, see here:

"jest": {
  "preset": "react-native",
  "transformIgnorePatterns": [
    "node_modules/(?!(jest-)?react-native|react-navigation)"
  ]
}

Handling the Hardware Back Button in Android

By using the following snippet, your nav component will be aware of the back button press actions and will correctly interact with your stack. This is really useful on Android.

import React from "react";
import { BackHandler } from "react-native";
import { addNavigationHelpers, NavigationActions } from "react-navigation";

const AppNavigation = TabNavigator(
  {
    Home: { screen: HomeScreen },
    Settings: { screen: SettingScreen }
  }
);

class ReduxNavigation extends React.Component {
  componentDidMount() {
    BackHandler.addEventListener("hardwareBackPress", this.onBackPress);
  }
  componentWillUnmount() {
    BackHandler.removeEventListener("hardwareBackPress", this.onBackPress);
  }
  onBackPress = () => {
    const { dispatch, nav } = this.props;
    if (nav.index === 0) {
      return false;
    }
    dispatch(NavigationActions.back());
    return true;
  };

  render() {
    const { dispatch, nav } = this.props;
    const navigation = addNavigationHelpers({
      dispatch,
      state: nav,
      addListener,
    });

    return <AppNavigation navigation={navigation} />;
  }
}