App.js

import React from 'react';
import { AsyncStorage, Platform, StatusBar, StyleSheet, View } from 'react-native';
import { AppLoading } from 'expo';
import * as Font from 'expo-font';

import { Provider } from 'react-redux';
import makeStore from "./redux/store";

import AppNavigator from './navigation/AppNavigator';


export default class App extends React.Component {
  state = {
    isLoadingComplete: false,
      preferences: {}
  };

    async loadPreferences() {
        // Reset preferences (for testing)
        // await AsyncStorage.setItem('com.plogalong.preferences', '{}');
        const prefs = await AsyncStorage.getItem('com.plogalong.preferences');

        this.setState({ preferences: prefs ? JSON.parse(prefs) : {}});
    }

  render() {
      const {preferences} = this.state;

    if (!this.state.isLoadingComplete || !preferences) {
      return (
        <AppLoading
          startAsync={this._loadResourcesAsync}
          onError={this._handleLoadingError}
          onFinish={this._handleFinishLoading}
        />
      );
    } else {
      return (
          <Provider store={makeStore(preferences)}>
              <View style={styles.container}>
                  {Platform.OS === 'ios' && <StatusBar barStyle="default" />}
                  <AppNavigator />
              </View>
          </Provider>
      );
    }
  }

  _loadResourcesAsync = async () => {
      return Promise.all([
          Font.loadAsync({
              'Lato': require('./assets/fonts/Lato-Regular.ttf'),
              'Lato-Bold': require('./assets/fonts/Lato-Bold.ttf'),
          }),
          this.loadPreferences()
      ]);
  };

  _handleLoadingError = error => {
    // In this case, you might want to report the error to your error
    // reporting service, for example Sentry
    console.warn(error);
  };

  _handleFinishLoading = () => {
    this.setState({ isLoadingComplete: true });
  };
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#fff',
  },
});