Async helper functions with AsyncStorage in React Native

Question

What I am trying to do is alert the company_id that is in local storage.

import React, { Component } from 'react';
import { ActivityIndicator, AsyncStorage, Button, StatusBar, Text, StyleSheet, View, } from 'react-native';
import * as pouchDB_helper from '../utils/pouchdb';

type Props = {};
export default class HomeScreen extends Component<Props> {

  render() {

    AsyncStorage.getItem('company_id', (err, result) => {
      alert(result);
    });

    return (
      <View style={styles.container}>
        <Button title="Hi" onPress={this.doSomething} />
      </View>
    );
  }

}

The following code works but I want to be able to do it from inside a helper function. If you see at the top, I have import * as pouchDB_helper from '../utils/pouchdb';

In there I have the following:

import React from 'react';
import { AsyncStorage } from 'react-native';
import PouchDB from 'pouchdb-react-native'


export async function pouchDB_config() {
  return AsyncStorage.getItem('company_id', (err, result) => {
      return result;
    });
}

Instead of AsyncStorage.getItem() code, if I do alert(pouchDB_helper.pouchDB_config()) I get an object with the following: {"_40":0,"_65":0,"_55"_null,"72":null}

I know I'm obviously not doing something right with the whole asynchronous nature of it all so if anyone has any guidance I would greatly appreciate it. I'm still not up to par with how to work with async functions in react native.

Answer 1

This is beacause when you call the function pouchDB_helper.pouchDB_config() it returns a promise.

There are different ways to use this to your advantage.

In your util/pouchdb change the function as following:

export async function pouchDB_config() {
  return await AsyncStorage.getItem('company_id');
}

Now you can call this function as follows:

pouchDB_config().then((company_id) => {
  console.log(company_id);
});

Or you can call it anywhere else within an async function:

const otherAsyncFunction = async () => {
  const company_id = await pouchDB_config();
  console.log(company_id);
}