Step by Step Guide on Creating a Monorepo for React Native Apps using Nx

Do you want to have both mobile and web apps in the same repo? Do you wish that you could share code between mobile and web apps? This blog post shows you how to create a React Native mobile app and a React web app in the same repo with shared libraries using Nx.

It goes through how to create a simple 2-page app that shows your daily horoscope based on your zodiac sign.

Screenshots of Daily Horoscope App

TL;DR — GitHub repo: xiongemi/aztro-daily-horoscope

Overview

Tech Stack

Mobile Frontend: React Native
Web Frontend: React
UI Library: React Native Elements
State Management: Redux
Navigation: React Navigation
API: aztro

Setup

For iOS and Android development environment setup, please see https://reactnative.dev/docs/environment-setup.

To create an Nx workspace, run:

❯

npx create-nx-workspace aztro-daily-horoscope --preset=react-native

To generation the application daily-horoscope-app, run:

❯

nx generate application **daily-horoscope-app**

This should generate daily-horoscope-app folder under apps:

daily-horoscope-app folder

Now you install the starter project of Nx React Native. If you run:

nx run-ios daily-horoscope-app, it should launch the app in the iOS simulator.
nx run-android daily-horoscope-app, it should launch the app in the Android simulator.

Install React Native Elements

This example uses React Native Elements as its UI component library and react-native-vector-icons as its icon library.

To install, run:

❯

# npm

❯

npm install --save @rneui/base @rneui/themed react-native-vector-icons react-native-safe-area-context

❯

# yarn

❯

_**yarn add @rneui/base @rneui/themed react-native-vector-icons react-native-safe-area-context

In the app’s package.json at apps/daily-horoscope-app/package.json, under dependencies, add the above packages:

{
  name: 'daily-horoscope-app',
  version: '0.0.1',
  private: true,
  dependencies: {
    // other dependencies
    '@rneui/base': '*',
    'react-native-gesture-handler': '*',
    'react-native-reanimated': '*',
    'react-native-safe-area-context': '*',
    'react-native-screens': '*',
  },
}

Install react-native-vector-icons for iOS

There are additional steps needed to add the icon font files to the iOS and Android bundle.

In apps/daily-horoscope-app/ios/Podfile file, add below line before post_install:

pod 'RNVectorIcons', :path => '../../../node\_modules/react-native-vector-icons'

In apps/daily-horoscope-app/ios/DailyHoroscope/Info.plist file, add below key array pair before the closing </dict> tag:

 <key>UIAppFonts</key>
 <array>
  <string>AntDesign.ttf</string>
  <string>Entypo.ttf</string>
  <string>EvilIcons.ttf</string>
  <string>Feather.ttf</string>
  <string>FontAwesome.ttf</string>
  <string>FontAwesome5\_Brands.ttf</string>
  <string>FontAwesome5\_Regular.ttf</string>
  <string>FontAwesome5\_Solid.ttf</string>
  <string>Foundation.ttf</string>
  <string>Ionicons.ttf</string>
  <string>MaterialIcons.ttf</string>
  <string>MaterialCommunityIcons.ttf</string>
  <string>SimpleLineIcons.ttf</string>
  <string>Octicons.ttf</string>
  <string>Zocial.ttf</string>
  <string>Fontisto.ttf</string>
 </array>

Go to the iOS folder at apps/daily-horoscope-app/ios and run Pod install. After running the command, you should see there are some changes in Podfile.lock file.

Install react-native-vector-icons for Android

In file apps/daily-horoscope-app/android/app/build.gradle, add below line at end of the file:

apply from: "../../../../node\_modules/react-native-vector-icons/fonts.gradle"

Great! You have installed the UI component library and icon library.

Create a Page in React Native

Now, you need to create the first page of your app: a page that shows a list of all the zodiac signs and allows users to choose from it.

Create Models

First, create a library for the models:

nx generate lib models

This should generate a models folder under libs:

models folder under libs

Then under this models folder, create a file to have the below enum that contains all the zodiac signs:

export enum AdhZodiacSign {
  Aries = 'Aries',
  Taurus = 'Taurus',
  Gemini = 'Gemini',
  Cancer = 'Cancer',
  Leo = 'Leo',
  Virgo = 'Virgo',
  Libra = 'Libra',
  Scorpio = 'Scorpio',
  Sagittarius = 'Sagittarius',
  Capricorn = 'Capricorn',
  Aquarius = 'Aquarius',
  Pisces = 'Pisces',
}

Note: the enum has a prefix “Adh” to indicate it is a model under domain “aztro-daily-horoscope”. Add this prefix to distinguish model names from component names.

This example uses icons from Material Community Icons. You need to create a list that contains the zodiac sign name and its matching icon.

zodiac-sign-item.interface.ts
import { AdhZodiacSign } from './zodiac-sign.enum';

export interface AdhZodiacSignItem {
  icon: string;
  zodiacSign: AdhZodiacSign;
}

zodiac-sign-list.const.ts
import { AdhZodiacSignItem } from './zodiac-sign-item.interface';
import { AdhZodiacSign } from './zodiac-sign.enum';

export const AdhZodiacSignList: AdhZodiacSignItem[] = [
  {
    zodiacSign: AdhZodiacSign.Aries,
    icon: 'zodiac-aries',
  },
  {
    zodiacSign: AdhZodiacSign.Taurus,
    icon: 'zodiac-taurus',
  },
  {
    zodiacSign: AdhZodiacSign.Gemini,
    icon: 'zodiac-gemini',
  },
  {
    zodiacSign: AdhZodiacSign.Cancer,
    icon: 'zodiac-cancer',
  },
  {
    zodiacSign: AdhZodiacSign.Leo,
    icon: 'zodiac-leo',
  },
  {
    zodiacSign: AdhZodiacSign.Virgo,
    icon: 'zodiac-virgo',
  },
  {
    zodiacSign: AdhZodiacSign.Libra,
    icon: 'zodiac-libra',
  },
  {
    zodiacSign: AdhZodiacSign.Scorpio,
    icon: 'zodiac-scorpio',
  },
  {
    zodiacSign: AdhZodiacSign.Sagittarius,
    icon: 'zodiac-sagittarius',
  },
  {
    zodiacSign: AdhZodiacSign.Capricorn,
    icon: 'zodiac-capricorn',
  },
  {
    zodiacSign: AdhZodiacSign.Aquarius,
    icon: 'zodiac-aquarius',
  },
  {
    zodiacSign: AdhZodiacSign.Pisces,
    icon: 'zodiac-pisces',
  },
];

Create a Component for Zodiac Sign List

Then, create a library for the UI and create a component zodiac-sign-list:

❯

nx generate lib ui

❯

nx generate component zodiac-sign-list --project=ui --export

This generates the folder zodiac-sign-list under ui/src/lib.

In the libs/ui/src/lib/zodiac-sign-list/zodiac-sign-list.tsx file, add the below code. It uses the FlatList component from react-native and the ListItem component from React Native Elements. It is going to passAdhZodiacSignList from themodels library you created above to the FlatList component.

zodiac-sign-list.tsx
import {
  AdhZodiacSignItem,
  AdhZodiacSignList,
} from '@aztro-daily-horoscope/models';
import React from 'react';
import { FlatList } from 'react-native';
import { ListItem } from '@rneui/base';
import Icon from 'react-native-vector-icons/MaterialCommunityIcons';

export function ZodiacSignList() {
  const keyExtractor = (item: AdhZodiacSignItem) => item.zodiacSign;

  return (
    <FlatList
      keyExtractor={keyExtractor}
      data={AdhZodiacSignList}
      renderItem={({ item }) => (
        <ListItem bottomDivider>
          <Icon name={item.icon} />
          <ListItem.Content>
            <ListItem.Title>{item.zodiacSign}</ListItem.Title>
          </ListItem.Content>
          <ListItem.Chevron />
        </ListItem>
      )}
    />
  );
}

In the apps/daily-horoscope-app/src/app/App.tsx file, you could now use the above zodiac-sign-list component:

app.tsx
import * as React from 'react';
import { ZodiacSignList } from '@aztro-daily-horoscope/ui';
import { Header } from '@rneui/base';

const App = () => {
  return (
    <>
      <Header centerComponent={{ text: 'Daily Horoscope' }} />
      <ZodiacSignList />
    </>
  );
};

export default App;

If you run nx run-ios daily-horoscope-app and nx run-android daily-horoscope-app, you should see something like:

Left: iOS simulator, right: Android simulator

You have created the first page of your app.

If you run the command nx dep-graph, you should see what the dependency graph looks like below:

Dependency graph

The next step is to handle action when users pressed on a list item. To achieve that, it is going to use Redux.

Add Redux

This example uses Redux as state management.

Now add a library called store:

❯

nx generate lib store

Create a State for Horoscope

Run command to create a redux state for horoscope:

❯

nx generate @nrwl/react:redux horoscope --project=store --directory=horoscope

In the terminal, it should output:

CREATE libs/store/src/lib/horoscope/horoscope.slice.spec.ts
CREATE libs/store/src/lib/horoscope/horoscope.slice.ts

.slice file is an extension introduced by Redux Toolkit. It is just a shorthand way to create actions + reducers + selectors in one file.

Notice in the package.json, this command also adds packages: @reduxjs/toolkit and react-redux.

Next, you are going to add a new value zodiacSignItem in the HoroscopeState to store the zodiac sign user selected. In the libs/store/src/lib/horoscope/horoscope.slice.ts file, the HoroscopeState will become:

export interface HoroscopeState {
  loadingStatus: 'not loaded' | 'loading' | 'loaded' | 'error';
  error?: string;
  **zodiacSignItem?: AdhZodiacSignItem;**
}

Under horoscopeSlice, add an action to the reducers to change zodiacSignItem in the state:

export const horoscopeSlice = createSlice({
  name: HOROSCOPE_FEATURE_KEY,
  initialState: initialHoroscopeState,
  reducers: {
    setUserZodiacSignItem(
      state: HoroscopeState,
      action: PayloadAction<AdhZodiacSignItem>
    ) {
      state.zodiacSignItem = action.payload;
    },
    ...
  },
  ...
});

Create Root Store

Now you need to setup up the root reducer and configure the store. Create a root folder under libs/store/src/lib and add the below files:

root-state.initial.ts
import { initialHoroscopeState } from '../horoscope/horoscope.slice';

import { RootState } from './root-state.interface';

export const initialRootState: RootState = {
  horoscope: initialHoroscopeState,
};

root-state.interface.ts
import { HoroscopeState } from '../horoscope/horoscope.slice';

export interface RootState {
  horoscope: HoroscopeState;
}

root.reducer.ts
import { combineReducers } from '@reduxjs/toolkit';

import { horoscopeSlice } from '../horoscope/horoscope.slice';

import { RootState } from './root-state.interface';

export const rootReducer = combineReducers<RootState>({
  horoscope: horoscopeSlice.reducer,
});

root.store.ts
import { configureStore } from '@reduxjs/toolkit';

import { initialRootState } from './root-state.initial';
import { rootReducer } from './root.reducer';

declare const process: any;

const isDevelopment = process.env.NODE_ENV === 'development';

const rootStore = configureStore({
  reducer: rootReducer,
  middleware: (getDefaultMiddleware) => getDefaultMiddleware(),
  devTools: isDevelopment,
  preloadedState: initialRootState,
});

export { rootStore };

Dispatch Action from zodiac-sign-list Component

You now need to dispatch setUserZodiacSignItem action from libs/ui/src/lib/zodiac-sign-list/zodiac-sign-list.tsx component.

Create a file atlibs/ui/src/lib/zodiac-sign-list/zodiac-sign-list.props.ts, and add a function mapDispatchToProps. In this function, dispatch the setUserZodiacSignItem action.

zodiac-sign-list.props.ts
import { AdhZodiacSignItem } from '@aztro-daily-horoscope/models';
import { horoscopeActions } from '@aztro-daily-horoscope/store';
import { Dispatch } from '@reduxjs/toolkit';

const mapDispatchToProps = (dispatch: Dispatch) => {
  return {
    setUserZodiacSignItem(zodiacSignItem: AdhZodiacSignItem) {
      dispatch(horoscopeActions.setUserZodiacSignItem(zodiacSignItem));
    },
  };
};

type mapDispatchToPropsType = ReturnType<typeof mapDispatchToProps>;

type ZodiacSignListProps = mapDispatchToPropsType;

export { mapDispatchToProps, ZodiacSignListProps };

The component zodiac-sign-list needs to import from the above zodiac-sign-list.props file. Then the component zodiac-sign-list becomes:

zodiac-sign-list.tsx
import {
  AdhZodiacSignItem,
  AdhZodiacSignList,
} from '@aztro-daily-horoscope/models';
import React from 'react';
import { FlatList } from 'react-native';
import { ListItem } from '@rneui/base';
import Icon from 'react-native-vector-icons/MaterialCommunityIcons';
import { connect } from 'react-redux';

import {
  ZodiacSignListProps,
  mapDispatchToProps,
} from './zodiac-sign-list.props';

export function ZodiacSignList({ setUserZodiacSignItem }: ZodiacSignListProps) {
  const keyExtractor = (item: AdhZodiacSignItem) => item.zodiacSign;

  return (
    <FlatList
      keyExtractor={keyExtractor}
      data={AdhZodiacSignList}
      renderItem={({ item }) => (
        <ListItem bottomDivider onPress={() => setUserZodiacSignItem(item)}>
          <Icon name={item.icon} />
          <ListItem.Content>
            <ListItem.Title>{item.zodiacSign}</ListItem.Title>
          </ListItem.Content>
          <ListItem.Chevron />
        </ListItem>
      )}
    />
  );
}

export const ZodiacSignListContainer = connect(
  null,
  mapDispatchToProps
)(ZodiacSignList);

Notice that a container component is added. This container component is stateful that connects to the redux state.

export const ZodiacSignListContainer = connect(
  null,
  mapDispatchToProps
)(ZodiacSignList);

This container component passes down props ZodiacSignListProps to ZodiacSignList. So this prop setUserZodiacSignItem got called at the press event for ListItem: onPress={() => setUserZodiacSignItem(item)}.

Add Provider to App

Go back to the app file at apps/daily-horoscope-app/src/app/App.tsx, now you need to replace the ZodiacSignList with ZodiacSignListContainer, and add the provider for the root store.

zodiac-sign-list.tsx
import * as React from 'react';
import { Provider } from 'react-redux';
import { rootStore } from '@aztro-daily-horoscope/store';
import { ZodiacSignListContainer } from '@aztro-daily-horoscope/ui';
import { Header } from '@rneui/base';

const App = () => {
  return (
    <Provider store={rootStore}>
      <Header centerComponent={{ text: 'Daily Horoscope' }} />
      <ZodiacSignListContainer />
    </Provider>
  );
};

export default App;

Awesome! So every time a zodiac sign item in the list got pressed, action gets dispatched and it should update the state with the zodiac sign selected.

Debugging Redux

First, you need to install redux-logger:

❯

# npm

❯

npm install --save-dev redux-logger @types/redux-logger

❯

#yarn

❯

yarn add redux-logger @types/redux-logger --dev

Then you need to add the redux-logger to the root store’s middleware, so the rootStore becomes:

import logger from 'redux-logger';
const rootStore = configureStore({
  reducer: rootReducer,
  middleware: (getDefaultMiddleware) =>
    isDevelopment
      ? getDefaultMiddleware().concat(logger)
      : getDefaultMiddleware(),
  devTools: isDevelopment,
  preloadedState: initialRootState,
});

Since the code is running in simulators, how to use the Redux Devtools extension and view the Redux Logger?

Open the debug menu in the simulator by entering d in the terminal that runs the start command. Then in the debug menu, choose “Debug with Chrome” for iOS and “Debug” for Android.

Debug Menu in iOS and Android

Install tool React Native Debugger: https://github.com/jhen0409/react-native-debugger.

Now inside React Native Debugger, you should be able to use Redux Devtools and Redux Logger. Now if you press any zodiac sign from the list, you should see action horoscope/setUserZodiacSignItem got dispatched and the state is updated.

React Native Debugger

Now you have successfully set up the Redux store for your app. The next step is to navigate to a different screen when you have successfully selected a zodiac sign.

Setup

To add navigation, you need to install React Navigation library:

❯

# npm

❯

npm install --save @react-navigation/native @react-navigation/stack react-native-reanimated react-native-gesture-handler react-native-screens @react-native-community/masked-view

❯

# yarn

❯

yarn add @react-navigation/native @react-navigation/stack react-native-reanimated react-native-gesture-handler react-native-screens @react-native-community/masked-view

In the app’s package.json at apps/daily-horoscope-app/package.json, under dependencies, add the above packages:

{
  name: 'daily-horoscope-app',
  version: '0.0.1',
  private: true,
  dependencies: {
    // other dependencies
    '@react-native-masked-view/masked-view': '*',
    '@react-navigation/native': '*',
    '@react-navigation/stack': '*',
    'react-native-gesture-handler': '*',
    'react-native-reanimated': '*',
    'react-native-screens': '*',
  },
}

Go to the iOS folder at apps/daily-horoscope-app/ios/Podfile and run Pod install.

In apps/daily-horoscope-app/src/main.tsx file, add below line at top of the file:

import 'react-native-gesture-handler';

Now you need to update the apps/daily-horoscope-app/src/app/App.tsx file to use React Navigation. Instead of displaying ZodiacSignListContainer component directly, now it is going to be passed to Stack.Screen. The apps/daily-horoscope-app/src/app/App.tsx file looks like below:

import { store } from '@aztro-daily-horoscope/store';
import { ZodiacSignListContainer } from '@aztro-daily-horoscope/ui';
import { NavigationContainer } from '@react-navigation/native';
import { createStackNavigator } from '@react-navigation/stack';
import * as React from 'react';
import { Provider } from 'react-redux';

const Stack = createStackNavigator();

const App = () => {
  return (
    <Provider store={store}>
      <NavigationContainer>
        <Stack.Navigator>
          <Stack.Screen
            name="Zodiac Sign List"
            component={ZodiacSignListContainer}
          />
        </Stack.Navigator>
      </NavigationContainer>
    </Provider>
  );
};

export default App;

If you run the code in the simulator, the app should look similar to before except for the header.

Add React Navigation in iOS and Android simulator

Create Second Page

Now you need to create the 2nd page to be navigated. Create a component called horoscope-card under ui:

❯

nx generate component horoscope-card --project=ui --export

This should generate libs/ui/src/lib/horoscope-card folder.

Add the below code to libs/ui/src/lib/horoscope-card/horoscope-card.tsx. For now, this component is going to use mock static data. It just displays a title for the zodiac Leo. It uses the Card component from React Native Elements.

horoscope-card.tsx
import { AdhZodiacSign } from '@aztro-daily-horoscope/models';
import React from 'react';
import { Card, Text } from '@rneui/base';
import Icon from 'react-native-vector-icons/MaterialCommunityIcons';

/* eslint-disable-next-line */
export interface HoroscopeCardProps {}

export function HoroscopeCard(props: HoroscopeCardProps) {
  return (
    <Card>
      <Card.Title>
        <Icon name="zodiac-leo" size={40} />
      </Card.Title>
      <Card.Title>{AdhZodiacSign.Leo}</Card.Title>
      <Card.Divider />
      <Text h4 style={{ width: '100%', textAlign: 'center' }}>
        Your Horoscope for Today
      </Text>
    </Card>
  );
}

export default HoroscopeCard;

Navigate Between Screens

Now you need to add this screen to your app. In file apps/daily-horoscope-app/src/app/App.tsx, you need to update it to add a stack screen for the horoscope-card component:

import { store } from '@aztro-daily-horoscope/store';
import {
  ZodiacSignListContainer,
  HoroscopeCard,
} from '@aztro-daily-horoscope/ui';
import { NavigationContainer } from '@react-navigation/native';
import { createStackNavigator } from '@react-navigation/stack';
import * as React from 'react';
import { Provider } from 'react-redux';

const Stack = createStackNavigator();

const App = () => {
  return (
    <Provider store={store}>
      <NavigationContainer>
        <Stack.Navigator>
          <Stack.Screen
            name="Zodiac Sign List"
            component={ZodiacSignListContainer}
          />
          <Stack.Screen name="Horoscope Card" component={HoroscopeCard} />
        </Stack.Navigator>
      </NavigationContainer>
    </Provider>
  );
};

export default App;

In the libs/ui/src/lib/zodiac-sign-list/zodiac-sign-list.tsx, you need to trigger navigation when the list item got pressed.

Below code uses useNavigation hook from React Navigation library. When the list item got pressed, it is going to call navigation.navigate(‘Horoscope Card’) to navigate the horoscope-card component you created above.

https://gist.github.com/xiongemi/c78c719e70aa4948b98e68033d7fe4a3

App.tsx
import {
  AdhZodiacSignItem,
  AdhZodiacSignList,
} from '@aztro-daily-horoscope/models';
import { useNavigation } from '@react-navigation/native';
import React from 'react';
import { FlatList } from 'react-native';
import { ListItem } from 'react-native-elements';
import Icon from 'react-native-vector-icons/MaterialCommunityIcons';
import { connect } from 'react-redux';

import {
  ZodiacSignListProps,
  mapDispatchToProps,
} from './zodiac-sign-list.props';

export function ZodiacSignList({ setUserZodiacSignItem }: ZodiacSignListProps) {
  const navigation = useNavigation();
  const keyExtractor = (item: AdhZodiacSignItem) => item.zodiacSign;
  const zodiacListItemPress = (item: AdhZodiacSignItem) => {
    navigation.navigate('Horoscope Card');
    setUserZodiacSignItem(item);
  };

  return (
    <FlatList
      keyExtractor={keyExtractor}
      data={AdhZodiacSignList}
      renderItem={({ item }) => (
        <ListItem bottomDivider onPress={() => zodiacListItemPress(item)}>
          <Icon name={item.icon} />
          <ListItem.Content>
            <ListItem.Title>{item.zodiacSign}</ListItem.Title>
          </ListItem.Content>
          <ListItem.Chevron />
        </ListItem>
      )}
    />
  );
}

export const ZodiacSignListContainer = connect(
  null,
  mapDispatchToProps
)(ZodiacSignList);

Now you should be able to navigate between 2 screens.

Navigate between 2 screens

Integrate with API

Now you need to updatehoroscope-card with real data. This example uses a free and open API: https://github.com/sameerkumar18/aztro.

Add Services

First, generate a library called services:

❯

nx generate lib services

In the services folder, add the below files:

aztro-horoscope-response.interface.ts defines what the response object looks like. It has a transform function to transform response data to the app domain model.
aztro.service.ts calls the API to get the user’s horoscope based on the zodiac sign and day.

aztro-horoscope-response.interface.ts
import { AdhHoroscope, AdhZodiacSign } from '@aztro-daily-horoscope/models';

export interface AztroHoroscpeResponse {
  date_range: string;
  current_date: string;
  description: string;
  compatibility: string;
  mood: string;
  color: string;
  lucky_number: string;
  lucky_time: string;
}

export function transfromAztroHoroscpeResponseToAdhHoroscope(
  responose: AztroHoroscpeResponse
): AdhHoroscope {
  return {
    currentDate: new Date(responose.current_date),
    description: responose.description,
    compatibility: responose.compatibility as AdhZodiacSign,
    mood: responose.mood,
    color: responose.color,
    luckyNumber: parseInt(responose.lucky_number),
    luckyTime: responose.lucky_time,
  };
}

aztro.service.ts
import { AdhHoroscopeDay, AdhZodiacSign } from '@aztro-daily-horoscope/models';

import { AztroHoroscpeResponse } from './aztro-horoscope-response.interface';

async function getHoroscope(
  zodiacSign: AdhZodiacSign,
  day: AdhHoroscopeDay
): Promise<AztroHoroscpeResponse> {
  const response = await fetch(
    `https://aztro.sameerkumar.website/?sign=${zodiacSign}&day=${day}`
  );
  if (response.ok) {
    return response.json();
  }
  throw response;
}

export const aztroService = { getHoroscope };

You also need to add 2 more files to the models library:

horoscope-day.type.ts defines the allowed day value to pass to API.
horoscope.interface.ts is the app domain interface that is transformed from the API response data.

horoscope-day.type.ts
export type AdhHoroscopeDay = 'today' | 'tomorrow' | 'yesterday';

horoscope.interface.ts
import { AdhZodiacSign } from './zodiac-sign.enum';

export interface AdhHoroscope {
  currentDate: Date;
  description: string;
  compatibility: AdhZodiacSign;
  mood: string;
  color: string;
  luckyNumber: number;
  luckyTime: string;
}

Connect to Redux

Now you need to create action to call aztro.service and store its response to the redux state.

Now you need to update the interface for the horoscope state value in file libs/store/src/lib/horoscope/horoscope.slice.ts:

import {
  AdhHoroscope,
  AdhHoroscopeDay,
  AdhZodiacSignItem,
} from '@aztro-daily-horoscope/models';

export interface HoroscopeState {
  loadingStatus: 'not loaded' | 'loading' | 'loaded' | 'error';
  error?: string;
  zodiacSignItem?: AdhZodiacSignItem;
  day?: AdhHoroscopeDay;
  horoscope?: AdhHoroscope;
}

loadingStatus is the API request status from aztro.service.
error is the API request error from aztro.service.
zodiacSignItem is the user’s selected zodiac sign.
day is the parameter passed to aztro.service.
horoscope is the transformed response from aztro.service.

Then, you need to update this file to add a thunk action and reducers to fetch the horoscope:

horoscope.slice.ts
export const fetchHoroscope = createAsyncThunk<
  AdhHoroscope,
  { zodiacSign: AdhZodiacSign; day: AdhHoroscopeDay }
>('horoscope/fetchStatus', async ({ zodiacSign, day }, { rejectWithValue }) => {
  try {
    const horoscopeResponse = await aztroService.getHoroscope(zodiacSign, day);
    return transfromAztroHoroscpeResponseToAdhHoroscope(horoscopeResponse);
  } catch (error) {
    return rejectWithValue({ error });
  }
});

export const horoscopeSlice = createSlice({
  name: HOROSCOPE_FEATURE_KEY,
  initialState: initialHoroscopeState,
  reducers: {
    setUserZodiacSignItem(
      state: HoroscopeState,
      action: PayloadAction<AdhZodiacSignItem>
    ) {
      state.zodiacSignItem = action.payload;
    },
  },
  extraReducers: (builder) => {
    builder
      .addCase(fetchHoroscope.pending, (state: HoroscopeState) => {
        state.loadingStatus = 'loading';
      })
      .addCase(
        fetchHoroscope.fulfilled,
        (state: HoroscopeState, action: PayloadAction<AdhHoroscope>) => {
          state.horoscope = action.payload;
          state.loadingStatus = 'loaded';
        }
      )
      .addCase(fetchHoroscope.rejected, (state: HoroscopeState, action) => {
        state.loadingStatus = 'error';
        state.error = action.error.message;
      });
  },
});

It adds a thunk action and its corresponding reducers:

fetchHoroscopeis going to call aztro.service.
fetchHoroscope.pending is dispatched when fetchHoroscope is triggered
fetchHoroscope.fulfilled is dispatched when aztro.service returns a successful response. It is going to assign the state.horoscope with its response
fetchHoroscope.rejected is dispatched when aztro.service returns a failed response.

Now you need to pass the redux state value to your horoscope-card component. Add below selectors to this file. These are pure functions that take the root state as input and derive data from it:

horoscope.slice.ts
const getHoroscopeState = (rootState: RootState): HoroscopeState =>
  rootState[HOROSCOPE_FEATURE_KEY];

const getUserZodiacItem = (
  rootState: RootState
): AdhZodiacSignItem | undefined => getHoroscopeState(rootState).zodiacSignItem;

const getUserZodiac = (rootState: RootState): AdhZodiacSign | undefined =>
  getUserZodiacItem(rootState)?.zodiacSign;

const getUserHoroscope = (rootState: RootState): AdhHoroscope | undefined =>
  getHoroscopeState(rootState).horoscope;

const getHoroscopeLoadingStatus = (rootState: RootState): LoadingStatus =>
  getHoroscopeState(rootState).loadingStatus;

export const horoscopeSelectors = {
  getUserZodiacItem,
  getUserZodiac,
  getUserHoroscope,
  getHoroscopeLoadingStatus,
};

To summarize, the file libs/store/src/lib/horoscope/horoscope.slice.ts will become like below:

horoscope.slice.ts
import {
  AdhHoroscope,
  AdhHoroscopeDay,
  AdhZodiacSign,
  AdhZodiacSignItem,
} from '@aztro-daily-horoscope/models';
import {
  aztroService,
  transfromAztroHoroscpeResponseToAdhHoroscope,
} from '@aztro-daily-horoscope/services';
import { createAsyncThunk, createSlice, PayloadAction } from '@reduxjs/toolkit';

import { LoadingStatus } from '../models/loading-status.type';
import { RootState } from '../root/root-state.interface';

export const HOROSCOPE_FEATURE_KEY = 'horoscope';
export interface HoroscopeState {
  loadingStatus: LoadingStatus;
  error?: string;
  zodiacSignItem?: AdhZodiacSignItem;
  day?: AdhHoroscopeDay;
  horoscope?: AdhHoroscope;
}

export const fetchHoroscope = createAsyncThunk<
  AdhHoroscope,
  { zodiacSign: AdhZodiacSign; day: AdhHoroscopeDay }
>('horoscope/fetchStatus', async ({ zodiacSign, day }, { rejectWithValue }) => {
  try {
    const horoscopeResponse = await aztroService.getHoroscope(zodiacSign, day);
    return transfromAztroHoroscpeResponseToAdhHoroscope(horoscopeResponse);
  } catch (error) {
    return rejectWithValue({ error });
  }
});

export const initialHoroscopeState: HoroscopeState = {
  loadingStatus: 'not loaded',
};

export const horoscopeSlice = createSlice({
  name: HOROSCOPE_FEATURE_KEY,
  initialState: initialHoroscopeState,
  reducers: {
    setUserZodiacSignItem(
      state: HoroscopeState,
      action: PayloadAction<AdhZodiacSignItem>
    ) {
      state.zodiacSignItem = action.payload;
    },
  },
  extraReducers: (builder) => {
    builder
      .addCase(fetchHoroscope.pending, (state: HoroscopeState) => {
        state.loadingStatus = 'loading';
      })
      .addCase(
        fetchHoroscope.fulfilled,
        (state: HoroscopeState, action: PayloadAction<AdhHoroscope>) => {
          state.horoscope = action.payload;
          state.loadingStatus = 'loaded';
        }
      )
      .addCase(fetchHoroscope.rejected, (state: HoroscopeState, action) => {
        state.loadingStatus = 'error';
        state.error = action.error.message;
      });
  },
});

/*
 * Export reducer for store configuration.
 */
export const horoscopeReducer = horoscopeSlice.reducer;
export const horoscopeActions = { fetchHoroscope, ...horoscopeSlice.actions };

const getHoroscopeState = (rootState: RootState): HoroscopeState =>
  rootState[HOROSCOPE_FEATURE_KEY];

const getUserZodiacItem = (
  rootState: RootState
): AdhZodiacSignItem | undefined => getHoroscopeState(rootState).zodiacSignItem;

const getUserZodiac = (rootState: RootState): AdhZodiacSign | undefined =>
  getUserZodiacItem(rootState)?.zodiacSign;

const getUserHoroscope = (rootState: RootState): AdhHoroscope | undefined =>
  getHoroscopeState(rootState).horoscope;

const getHoroscopeLoadingStatus = (rootState: RootState): LoadingStatus =>
  getHoroscopeState(rootState).loadingStatus;

export const horoscopeSelectors = {
  getUserZodiacItem,
  getUserZodiac,
  getUserHoroscope,
  getHoroscopeLoadingStatus,
};

Then update horoscope-card component with the below code. Notice inside mapStateToProps function, it uses selector functions from above.

horoscope-card.props.ts
import { AdhHoroscopeDay, AdhZodiacSign } from '@aztro-daily-horoscope/models';
import {
  horoscopeActions,
  horoscopeSelectors,
  RootState,
} from '@aztro-daily-horoscope/store';
import { AnyAction, ThunkDispatch } from '@reduxjs/toolkit';

const mapStateToProps = (state: RootState) => {
  return {
    zodiacItem: horoscopeSelectors.getUserZodiacItem(state),
    horoscope: horoscopeSelectors.getUserHoroscope(state),
    loadingStatus: horoscopeSelectors.getHoroscopeLoadingStatus(state),
  };
};

const mapDispatchToProps = (
  dispatch: ThunkDispatch<RootState, void, AnyAction>
) => {
  return {
    getUserHoroscope(zodiacSign: AdhZodiacSign, day: AdhHoroscopeDay) {
      dispatch(horoscopeActions.fetchHoroscope({ zodiacSign, day }));
    },
  };
};

type mapStateToPropsType = ReturnType<typeof mapStateToProps>;
type mapDispatchToPropsType = ReturnType<typeof mapDispatchToProps>;

type HoroscopeCardProps = mapStateToPropsType & mapDispatchToPropsType;

export { mapStateToProps, mapDispatchToProps, HoroscopeCardProps };

horoscope-card.tsx
import { LoadingStatus } from '@aztro-daily-horoscope/store';
import React, { useEffect } from 'react';
import { ActivityIndicator, SafeAreaView, ScrollView } from 'react-native';
import { Card, Text } from 'react-native-elements';
import Icon from 'react-native-vector-icons/MaterialCommunityIcons';
import { connect } from 'react-redux';

import {
  mapStateToProps,
  mapDispatchToProps,
  HoroscopeCardProps,
} from './horoscope-card.props';

export function HoroscopeCard({
  zodiacItem,
  horoscope,
  loadingStatus,
  getUserHoroscope,
}: HoroscopeCardProps) {
  useEffect(() => {
    if (zodiacItem?.zodiacSign) {
      getUserHoroscope(zodiacItem.zodiacSign, 'today');
    }
  }, [zodiacItem, getUserHoroscope]);

  return (
    <SafeAreaView>
      <ScrollView>
        <Card>
          <Card.Title>
            <Icon name={zodiacItem?.icon} size={40} />
          </Card.Title>
          <Card.Title>{zodiacItem?.zodiacSign}</Card.Title>
          <Card.Divider />
          <Text h4 style={{ width: '100%', textAlign: 'center' }}>
            Your Horoscope for Today
          </Text>
          {loadingStatus === LoadingStatus.Success ? (
            <>
              <Text style={{ marginTop: 10 }}>{horoscope.description}</Text>
              <Text style={{ marginTop: 10 }}>Mood: {horoscope.mood}</Text>
              <Text style={{ marginTop: 10 }}>Color: {horoscope.color}</Text>
              <Text style={{ marginTop: 10 }}>
                Compatibility: {horoscope.compatibility}
              </Text>
              <Text style={{ marginTop: 10 }}>
                Lucky Number: {horoscope.luckyNumber}
              </Text>
              <Text style={{ marginTop: 10 }}>
                Lucky Time: {horoscope.luckyTime}
              </Text>
            </>
          ) : loadingStatus === LoadingStatus.Error ? (
            <Text h2>Oops! Something went wrong. Please try agian.</Text>
          ) : (
            <ActivityIndicator />
          )}
        </Card>
      </ScrollView>
    </SafeAreaView>
  );
}

export const HoroscopeCardContainer = connect(
  mapStateToProps,
  mapDispatchToProps
)(HoroscopeCard);

Notice inside the horoscope-card component, it has a hook to dispatch action getUserHoroscope when this component got mounted.

useEffect(() => {
  if (zodiacItem?.zodiacSign) {
    getUserHoroscope(zodiacItem.zodiacSign, 'today');
  }
}, [zodiacItem, getUserHoroscope]);

In the App component, replace HoroscopeCard with HoroscopeCardContainer:

 <Stack.Screen
    name="Horoscope Card"
    component={**HoroscopeCardContainer**}
  />

Now when you run the app, it should display the horoscope according to the zodiac user selected.

Horoscope Card integrated with API

Finally, you got a mobile app that runs on both Android and iOS. You could reuse the libraries to create a web app.

If you run command nx dep-graph, you should see the dependency graph looks like below:

Dependency Graph

Create Web App

First, generate a React app called daily-horoscope-app:

❯

nx generate @nrwl/react:app daily-horoscope-app

You could reuse store, models, and services libraries and write a separate ui for the React web app. However, this example just reuses ui library and displays React Native components directly. To do so, it needs to install package react-native-web:

❯

# npm

❯

npm install --save react-native-web

❯

npm install --save-dev babel-plugin-react-native-web

❯

# yarn

❯

yarn add react-native-web

❯

yarn add --dev babel-plugin-react-native-web

For apps/daily-horoscope-web/src/main.tsx, change it to:

import { AppRegistry } from 'react-native';
import App from './app/app';
AppRegistry.registerComponent('main', () => App);
AppRegistry.runApplication('main', {
  rootTag: document.getElementById('root'),
});

Copy your code from daily-horoscope-app’s app file to daily-horoscope-web’s app file and add styles for the icon font files:

app.tsx
import { rootStore } from '@aztro-daily-horoscope/store';
import {
  ZodiacSignListContainer,
  HoroscopeCardContainer,
} from '@aztro-daily-horoscope/ui';
import { NavigationContainer } from '@react-navigation/native';
import { createStackNavigator } from '@react-navigation/stack';
import * as React from 'react';
import { Provider } from 'react-redux';

const Stack = createStackNavigator();

const App = () => {
  return (
    <>
      <style type="text/css">{`
        @font-face {
          font-family: 'MaterialIcons';
          src: url(${require('react-native-vector-icons/Fonts/MaterialIcons.ttf')}) format('truetype');
        }
        @font-face {
          font-family: 'MaterialCommunityIcons';
          src: url(${require('react-native-vector-icons/Fonts/MaterialCommunityIcons.ttf')}) format('truetype');
        }
      `}</style>
      <Provider store={rootStore}>
        <NavigationContainer>
          <Stack.Navigator>
            <Stack.Screen
              name="Zodiac Sign List"
              component={ZodiacSignListContainer}
            />
            <Stack.Screen
              name="Horoscope Card"
              component={HoroscopeCardContainer}
            />
          </Stack.Navigator>
        </NavigationContainer>
      </Provider>
    </>
  );
};

export default App;

webpack.js
const getWebpackConfig = require('@nrwl/react/plugins/webpack');

function getCustomWebpackConfig(webpackConfig) {
  const config = getWebpackConfig(webpackConfig);
  const isProduction = webpackConfig.mode === 'production';

  if (!isProduction) {
    config.resolve.alias = {
      'react-native': 'react-native-web',
    };

    config.module.rules.push(
      {
        test: /\.ttf$/,
        loader: require.resolve('file-loader'),
        options: { esModule: false, name: 'static/media/[path][name].[ext]' },
      },
      {
        test: /\.(js|jsx)$/,
        exclude: function (content) {
          return (
            /node_modules/.test(content) &&
            !/\/react-native-elements\//.test(content) &&
            !/\/react-native-vector-icons\//.test(content) &&
            !/\/react-native-ratings\//.test(content)
          );
        },
        use: {
          loader: require.resolve('@nrwl/web/src/utils/web-babel-loader.js'),
          options: {
            presets: [
              [
                '@nrwl/react/babel',
                {
                  runtime: 'automatic',
                  useBuiltIns: 'usage',
                },
              ],
            ],
            plugins: ['react-native-web'],
          },
        },
      }
    );
  }

  return config;
}

module.exports = getCustomWebpackConfig;

Then you need a customized Webpack file. It adds 2 additional rules to read the icon font files and React Native Elements library files.

Also in workspace.json, change the webpackConfig under daily-horoscope-web to point this custom webpack file like:

"webpackConfig": "apps/daily-horoscope-web/webpack.js"

Now if you run nx serve daily-horoscope-web, it should the web app in the browser.

Web App

Now the dependency graph should look like:

Dependency Graph

Conclusion

Congratulations! You have created a React Native mobile app and a React web app. Nx + React + React Native is a powerful tool that allows you to have both mobile and web app code in the same repo with shared business logic.

Step by Step Guide on Creating a Monorepo for React Native Apps using Nx

Overview

Tech Stack

Setup

Install React Native Elements

Install react-native-vector-icons for iOS

Install react-native-vector-icons for Android

Create a Page in React Native

Create Models

Create a Component for Zodiac Sign List

Add Redux

Create a State for Horoscope

Create Root Store

Dispatch Action from zodiac-sign-list Component

Add Provider to App

Debugging Redux

Adding Navigation

Setup

Update App to Use React Navigation

Create Second Page

Navigate Between Screens

Integrate with API

Add Services

Connect to Redux

Create Web App

Conclusion