react-hook-geolocation :earth_africa:

A React hook to access data from the Geolocation API.

Installation

Using npm:

npm install --save react-hook-geolocation

Using yarn:

yarn add react-hook-geolocation

Usage

import useGeolocation from "react-hook-geolocation";

const ComponentWithGeolocation = () => {
  const geolocation = useGeolocation();

  return !geolocation.error ? (
    <ul>
      <li>Latitude: {geolocation.latitude}</li>
      <li>Longitude: {geolocation.longitude}</li>
      <li>Location accuracy: {geolocation.accuracy}</li>
      <li>Altitude: {geolocation.altitude}</li>
      <li>Altitude accuracy: {geolocation.altitudeAccuracy}</li>
      <li>Heading: {geolocation.heading}</li>
      <li>Speed: {geolocation.speed}</li>
      <li>Timestamp: {geolocation.timestamp}</li>
    </ul>
  ) : (
    <p>No geolocation, sorry.</p>
  );
};

Using PositionOptions

There is a way to use PositionOptions to fine tune response coming from watchPosition of the Geolocation API.

If you want to use this feature, simply provide useGeolocation with a PositionOptions object:

const geolocation = useGeolocation({
  enableHighAccuracy: true,
  maximumAge: 15000,
  timeout: 12000,
});

Using a callback function

You can supply a second parameter to useGeolocation which will be called every time the data from the Geolocation API is updated. This callback function is then called with the geolocation object with all its properties.

If you don't use PositionOptions, I recommend that you supply {} as your first argument.

const onGeolocationUpdate = (geolocation) => {
  console.log("Here’s some new data from the Geolocation API: ", geolocation);
};

const geolocation = useGeolocation({}, onGeolocationUpdate);

Waiting for the user to opt in

The best practice is to only try to geolocate the user on the user’s request, or at least when it is indicated to the user why the browser is asking for their location.

If you would like to bail out of this hook immediately asking for geolocation access from the user when the component mounts, you can pass a third isEnabled parameter to the hook with the value false, and set it to true later once the reason for asking for geolocation is indicated to the user.

const geolocation = useGeolocation({}, () => {}, false);

Setting this parameter from true to false will not cut access to already retrieved geolocation data, it will however stop watching for changes in geolocation data until the parameter is set back to true again.

Notes

Access to data from the Geolocation API needs user permission.

If permission to access geolocation was previously granted by the user, geolocation data will be available. If permission to access was not granted previously, the user will be prompted to give permission when the component mounts.

If permission was previously denied by the user, if the user agent does not support the Geolocation API, or if some other error occurs, the object returned from the hook will still contain all members, and values will be null. If you are lucky, geolocation.error.message and geolocation.error.code might contain something useful to help you determine what went wrong.

Caveats

Geolocation API is available only in secure contexts (a.k.a. only using HTTPS).

Getting geolocation data can take time, especially with high accuracy enabled – getting a GPS fix can take up to a minute.

Contributions

Contributions are welcome. File bug reports, create pull requests, feel free to reach out at [email protected].

License

MIT