如何在React Native和Reflux中进行多个API调用

Question

I am following Indrik Lasn's React/Reflux/Thunk tutorial in React Native Training and having a hard time editing the code to allow for chained API calls.

Tutorial Link: https://medium.com/react-native-training/learn-how-to-build-a-rn-redux-cryptocurrency-app-chapter-iii-a454dda156b

How do I chain multiple API calls from coinmarketcap.com's API?

This is the code I thought would work. Developer tools shows the data is coming in for the 2 API calls but once the 2nd API loads into the browser, it replaces the data from the 1st API data within the view?

import axios from 'axios';  
import { apiBaseURL } from './../Utils/Constants';  
import {    
  FETCHING_COIN_DATA,  
  FETCHING_COIN_DATA_SUCCESS,           
  FETCHING_COIN_DATA_FAIL  
} from './../Utils/ActionTypes';


export default function FetchCoinData() {
return dispatch => {

    dispatch({ type: FETCHING_COIN_DATA })

     axios.get(`${apiBaseURL}/v1/ticker/bitcoin`)
        .then(res => dispatch({ type: FETCHING_COIN_DATA_SUCCESS, payload: res.data })) 
        .then(() => axios.get(`${apiBaseURL}/v1/ticker/litecoin`))
        .then(res => dispatch({ type: FETCHING_COIN_DATA_SUCCESS, payload: res.data })) 
        .catch(err => {
            dispatch({ type: FETCHING_COIN_DATA_FAIL, payload: err.data })
        });
}
}

Answer 1

async componentDidMount() {
  const firstRequest = await axios.get('https://maps.googleapis.com/maps/api/geocode/json?&address=' + this.props.p1);
  const secondRequest = await axios.get('https://maps.googleapis.com/maps/api/geocode/json?&address=' + this.props.p2);
  const thirdRequest = await axios.get('https://maps.googleapis.com/maps/api/directions/json?origin=place_id:' + firstRequest.data.results.place_id + '&destination=place_id:' + secondRequest.data.results.place_id + '&key=' + 'API-KEY-HIDDEN');

  this.setState({
    p1Location: firstRequest.data,
    p2Location: SecondRequest.data,
    route: thirdRequest.data,
  });
}

Answer 2

You can use async library to make the API calls all at the same time. You can also include a callback function which is invoked after the result from all the executed functions is received.

import async from "async";
async.parallel([
  function(callback) {
    axios.get(`${apiBaseURL}/v1/ticker/bitcoin`).then(res => callback(res));
  },
  function(callback) {
    axios.get(`${apiBaseURL}/v1/ticker/ethereum`).then(res => callback(res));
  }
], function(err, results) {
    // after all the api calls are finished
    const bitcoinRes = results[0];
    const ethereumRes = results[1];
});