无法读取未定义的未定义属性

Question

Current Behavior

I am very new to React and pretty much all this stack. What I am trying to accomplish is to implement a tab navigator inside a stack navigator. I've done this without Redux using React navigation library but I can not do it when I move my stack navigator to Redux. I've even tried a different navigation library and I keep ending up with that error in the title which is driving me crazy because it does not tell much (or I just do not get it).

I've used the exact Redux example available in the examples repo . everything works until I change my home screen (the one after login) to a tab navigator I've created.

main.js (expo project)

import Expo from 'expo';
import React from 'react';
import { StyleSheet, Text, View } from 'react-native';
import { Provider } from 'react-redux';

import store from './store';
import AppWithNavigationState from './helpers/AppNavigator';

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

Expo.registerRootComponent(App);

store.js

import { createStore, compose, applyMiddleware } from 'redux';
import thunk from 'redux-thunk';
import { persistStore, autoRehydrate } from 'redux-persist';
import { AsyncStorage } from 'react-native';
import reducers from '../reducers';

const store = createStore(
  reducers,
  {},
  compose(
    applyMiddleware(thunk),
    autoRehydrate()
  )
);

// persistStore(store, { storage: AsyncStorage, whitelist: ['likedJobs'] });

export default store;

helpers/AppNavigator.js

import React from 'react';
import PropTypes from 'prop-types';
import { connect } from 'react-redux';
import { addNavigationHelpers, StackNavigator } from 'react-navigation';

import LoginScreen from '../screens/auth/LoginScreen';
// import HomeScreen from '../screens/HomeScreen'; 
// import HomeRoutes from '../routes/HomeRoutes';
import HomeRoutes from '../helpers/HomeNavigator'; 

export const AppNavigator = StackNavigator({
  Login: { screen: LoginScreen },
  Home: { screen: HomeRoutes }, 
});

const AppWithNavigationState = ({ dispatch, nav }) => (
  <AppNavigator navigation={addNavigationHelpers({ dispatch, state: nav })} />
);

AppWithNavigationState.propTypes = {
  dispatch: PropTypes.func.isRequired,
  nav: PropTypes.object.isRequired,
};

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

export default connect(mapStateToProps)(AppWithNavigationState);

helpers/homeNavigator

import React from 'react';
import PropTypes from 'prop-types';
// import { connect } from 'react-redux';
import { addNavigationHelpers, TabNavigator } from 'react-navigation';

import CustomerListScreen from '../screens/home/CustomerListScreen'; 
import JobListScreen from '../screens/home/JobListScreen'; 

JobListScreen.navigationOptions = {
  tabBarLabel: 'Jobs', 
  title: "Jobs",
  tabBarIcon: ({ tintColor, focused }) => (
    <Icon
      name='wrench'
      size={24}
      style={{ color: tintColor }}
    />
  ),
};

CustomerListScreen.navigationOptions = {
  tabBarLabel: 'Clients', 
  tabBarIcon: ({ tintColor, focused }) => (
    <Icon
      name='users'
      size={24}
      style={{ color: tintColor }}
    />
  ),
};


export const HomeNavigator = TabNavigator({
  Jobs: { 
    screen: JobListScreen, 
   },
  Clients: { 
    screen: CustomerListScreen, 
  } 
});

const HomeNavigationTab = ({ dispatch, nav }) => (
  <HomeNavigator navigation={addNavigationHelpers({ dispatch, state: nav })} />
);

HomeNavigationTab.propTypes = {
  dispatch: PropTypes.func.isRequired,
  nav: PropTypes.object.isRequired,
};

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

export default HomeNavigationTab;
// export default connect(mapStateToProps)(HomeNavigationTab);

Home tab reducer

import { NavigationActions, addNavigationHelpers } from 'react-navigation';

import { HomeNavigator } from '../helpers/HomeNavigator';

// Start with two routes: The Main screen, with the Login screen on top.
const firstAction = HomeNavigator.router.getActionForPathAndParams('Jobs');
const tempNavState = HomeNavigator.router.getStateForAction(firstAction);
const secondAction = HomeNavigator.router.getActionForPathAndParams('Clients');

const initialNavState = HomeNavigator.router.getStateForAction(
  secondAction,
  tempNavState
);

function homeTabNav(state = initialNavState, action) {
  let nextState;
  switch (action.type) {
    case 'JOBS': 
      nextState = HomeNavigator.router.getStateForAction(
        NavigationActions.navigate({ routeName: 'Jobs' }),
        state
      );
      break;
    case 'CLIENTS':
      nextState = HomeNavigator.router.getStateForAction(
        NavigationActions.navigate({ routeName: 'Clients' }),
        state
      );
      break;
    default:
      nextState = HomeNavigator.router.getStateForAction(action, state);
      break;
  }

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

export default homeTabNav;

App navigation reducer

import { combineReducers } from 'redux';
import { NavigationActions, addNavigationHelpers } from 'react-navigation';

import { AppNavigator } from '../helpers/AppNavigator';

// Start with two routes: The Main screen, with the Login screen on top.
const firstAction = AppNavigator.router.getActionForPathAndParams('Home');
const tempNavState = AppNavigator.router.getStateForAction(firstAction);
const secondAction = AppNavigator.router.getActionForPathAndParams('Login');

const initialNavState = AppNavigator.router.getStateForAction(
  secondAction,
  tempNavState
);

function nav(state = initialNavState, action) {
  let nextState;
  switch (action.type) {
    case 'NAV_LOGIN_SUCCESS': 
      nextState = AppNavigator.router.getStateForAction(
        NavigationActions.back(),
        state
      );
      break;
    case 'LOGOUT':
      nextState = AppNavigator.router.getStateForAction(
        NavigationActions.navigate({ routeName: 'Login' }),
        state
      );
      break;
    default:
      nextState = AppNavigator.router.getStateForAction(action, state);
      break;
  }

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

export default nav;

My Environment

"dependencies": {
    "axios": "^0.16.2",
    "expo": "17.0.0",
    "native-base": "^2.1.5",
    "react": "16.0.0-alpha.6",
    "react-native": "https://github.com/expo/react-native/archive/sdk-17.0.0.tar.gz",
    "react-native-easy-grid": "^0.1.13", 
    "react-native-vector-icons": "^4.2.0",
    "react-navigation": "^1.0.0-beta.11",
    "react-redux": "^5.0.5",
    "redux": "^3.7.0",
    "redux-persist": "^4.8.0",
    "redux-thunk": "^2.2.0"
}

I have no idea what I am doing wrong or if this is a bug (I bet that it is me though) and I could use some light.

update 1

I've taken off redux from my child navigation (home screen tab nav) and now the error statement has changed to the one below.

Warning: Failed prop type: The prop `dispatch` is marked as required in `HomeNavigationTab`, but its value is `undefined`.

Answer 1

Based on the TabNavigator example here you don't actually need to pass in dispatch or nav in the to your component. So remove them and export (or export default) HomeNavigator instead.

import React from 'react';
import PropTypes from 'prop-types';
import { TabNavigator } from 'react-navigation';

import CustomerListScreen from '../screens/home/CustomerListScreen'; 
import JobListScreen from '../screens/home/JobListScreen'; 

JobListScreen.navigationOptions = {
  tabBarLabel: 'Jobs', 
  title: "Jobs",
  tabBarIcon: ({ tintColor, focused }) => (
    <Icon
      name='wrench'
      size={24}
      style={{ color: tintColor }}
    />
  ),
};

CustomerListScreen.navigationOptions = {
  tabBarLabel: 'Clients', 
  tabBarIcon: ({ tintColor, focused }) => (
    <Icon
      name='users'
      size={24}
      style={{ color: tintColor }}
    />
  ),
};

export const HomeNavigator = TabNavigator({
  Jobs: { 
    screen: JobListScreen, 
   },
  Clients: { 
    screen: CustomerListScreen, 
  } 
});