demo_map.js

import React from 'react';
import { compose, withProps, withHandlers } from "recompose";
import { withScriptjs, withGoogleMap, GoogleMap, Marker } from "react-google-maps";
import { MarkerClusterer } from "react-google-maps/lib/components/addons/MarkerClusterer";
import axios from 'axios';

const MapWithAMarkerClusterer = compose(
  withProps({
    googleMapURL: "https://maps.googleapis.com/maps/api/js?key=AIzaSyC4R6AN7SmujjPUIGKdyao2Kqitzr1kiRg&v=3.exp&libraries=geometry,drawing,places",
    loadingElement: <div style={{ height: `100%` }} />,
    containerElement: <div style={{ height: `400px` }} />,
    mapElement: <div style={{ height: `100%` }} />,
  }),
  withHandlers({
    onMarkerClustererClick: () => (markerClusterer) => {
      const clickedMarkers = markerClusterer.getMarkers()
      console.log(`Current clicked markers length: ${clickedMarkers.length}`)
      console.log(clickedMarkers)
    },
  }),
  withScriptjs,
  withGoogleMap
)(props =>
  <GoogleMap
    defaultZoom={3}
    defaultCenter={{ lat: 25.0391667, lng: 121.525 }}
  >
    <MarkerClusterer
      onClick={props.onMarkerClustererClick}
      averageCenter
      enableRetinaIcons
      gridSize={60}
    >
      {props.markers.map(marker => (
        <Marker
          key={marker.photo_id}
          position={{ lat: marker.latitude, lng: marker.longitude }}
        />
      ))}
    </MarkerClusterer>
  </GoogleMap>
);

class DemoMap extends React.PureComponent {
  componentWillMount() {
    this.setState({ markers: [] })
  }

  componentDidMount() {
    const url = [
      // Length issue
      `https://gist.githubusercontent.com`,
      `/farrrr/dfda7dd7fccfec5474d3`,
      `/raw/758852bbc1979f6c4522ab4e92d1c92cba8fb0dc/data.json`
    ].join("")

			axios.get(url)
      .then(response => {
      	this.setState({ markers: response.data.photos });
      })
      .catch(error => {
          console.log(error);
      });
  }

  render() {
    return (
      <MapWithAMarkerClusterer markers={this.state.markers} />
    )
  }
}

export default DemoMap;