在React组件中使用Google Map API

Question

I am struggling over the way to use Google Map API inside a React component. I did not want to use popular react-google-maps nor google-map-react packages, but rather create my own.

I managed to load the script tag with the Google Map API from the React component. However, how do I manipulate the Google API from here? For example, initializing the map with even basic configuration like below?

  map = new google.maps.Map(document.getElementById('map'), {
    center: {lat: -34.397, lng: 150.644},
    zoom: 8
  });

Here is my component. Any advice is appreciated! thanks!

 import React, { Component } from 'react'; // Load Google API in script tag and append function loadScript(src) { return new Promise((resolve, reject) => { let script = document.createElement('script'); script.src = src; script.addEventListener('load', function() { resolve(); }); script.addEventListener('error', function(e) { reject(e); }); document.body.appendChild(script); }); } const script = 'https://maps.googleapis.com/maps/api/js?key=MY_API_KEY'; class MyGoogleMap extends Component { constructor(props) { super(props); this.state = {}; } componentDidMount() { // first load the script into html loadScript(script).then(function() { console.log('SUCCESS'); // Where do I go from here? }); } render() { return <div />; } } export default MyGoogleMap; 

Answer 1

Create GoogleMap component with ref, to display google map inside that div.

import React, { Component } from 'react';

class GoogleMap extends Component {
     componentDidMount() {
         new google.maps.Map(this.refs.map, {
            zoom: 12,
            center: {
                lat: this.props.lat,
                lng: this.props.lon
             }
          });
      }

  render() {
      return <div className="google-map" ref="map" />
  }
}

export default GoogleMap;

Use it in Component you like like this:

<GoogleMap lat={lat} lon={lon}/>

by passing latitude and longitude of a city. To be able to see it you need to set width and height of css class google-map (or whatever you name it). for example:

div.google-map {
    height: 150px;
    width: 250px;
}

Fiddle.js preview

EDIT

inside head load script:

<script src="https://maps.googleapis.com/maps/api/js"></script>

I tought you have done that, because in your code you also use new google.maps... . If you cant call it like just google, try new window.google.maps...

Answer 2

I actually found my own solution, so I am sharing for anyone who would meet the same problem.

The basic logic is to use window object to access google . So, after I load the script as I did from the question, I initialize my map as:

  initMap = () => { // 'google' could be accessed from 'window' object const map = new window.google.maps.Map( document.getElementById('googleMap'), { zoom: 14, center: { lat: LATITUDE, lng: LONGTITUDE } } ); // putting a marker on it const marker = new window.google.maps.Marker({ position: { lat: LATITUDE, lng: LONGTITUDE }, map: map }); }; render() { return ( <div id="googleMap" style={width: WIDTH, height: HEIGHT}/> ); } 

Any comment is welcomed :)