Promises

Asynchronous methods throughout Google Maps JavaScript API return Promises.

Support

API Methods return Promises
Directions Yes
Distance Matrix Yes
Elevation Yes
Geocoder Yes
Maximum Zoom Imagery Yes
Places No
Places AutocompleteService Partial1
Streetview Yes

Usage

See this guide on using Promises or the examples below for making asynchronous method calls with Google Maps JavaScript API.

Async and await

The await operator is used to wait for a Promise. It can only be used inside an async function.

const app = async () => {
  const elevationService = google.maps.ElevationService();
  const locations = [{lat: 27.986065, lng:86.922623}];

  const response = await elevationService.getElevationForLocation({locations});
  console.log(response.results);
};

app();

Then, catch, and finally

The Promise object has then, catch, and finally methods that take callback functions.

const elevationService = google.maps.ElevationService();
const locations = [{lat: 27.986065, lng:86.922623}];

const promise = elevationService.getElevationForLocation({locations});

promise
    .then((response) => {
      console.log(response.results);
    })
    .catch((error) => {
      console.log(error);
    });
    .finally(() => {
      console.log('done');
    });

Async callback pattern

The callback pattern is still valid and supported.

const elevationService = google.maps.ElevationService();
const locations = [{lat: 27.986065, lng:86.922623}];

const callback = (results, status) => {
  if (status === 'OK') {
    console.log(results);
  } else {
    // handle this case
  }
};

elevationService.getElevationForLocation({locations}, callback);

  1. Currently Promises are only supported in getPlacePredictions()