google-map-react/API.md

GoogleMap API

parameters

apiKey (string) (Deprecated use bootstrapURLKeys)

Google maps api key. (Optional, but your map will be rate-limited with no key)

bootstrapURLKeys (object)

Example:

<GoogleMap
  bootstrapURLKeys={{
    key: API_KEY,
    language: 'ru',
    region: 'ru',
    ...otherUrlParams,
  }}
>

defaultCenter (array or object)

[lat, lng] or { lat: lat, lng: lng} Default lat/lng at which to center the map - changing this prop throws a warning

center (array or object)

[lat, lng] or { lat: lat, lng: lng} Lat/lng at which to center the map

defaultZoom: (number)

Default map zoom level - changing this prop throws a warning

zoom (number)

Map zoom level

hoverDistance (number)

Default: 30

margin (array)

In onChange callback, gives you a marginBounds argument property, where lat lng will be shifted using margin you have set. For example, you could use a simple check pointInRect to not show Markers near map bounds.

debounced (bool)

Default: true

layerTypes (string[])

You can add some "layers" for map like a traffic or transit

layerTypes={['TrafficLayer', 'TransitLayer']}

callbacks

options (func|object)

Set map options such as controls positions / styles, etc.

Example:

createMapOptions: function (maps) {
    return {
      panControl: false,
      mapTypeControl: false,
      scrollwheel: false,
      styles: [{ stylers: [{ 'saturation': -100 }, { 'gamma': 0.8 }, { 'lightness': 4 }, { 'visibility': 'on' }] }]
    }
  }

 <GoogleMap  options={createMapOptions} ... />

See "Custom map options example" in Examples below for a further example.

onClick (func)

({ x, y, lat, lng, event })

The event prop in args is the outer div onClick event, not the gmap-api 'click' event.

Example:

_onClick = ({x, y, lat, lng, event}) => console.log(x, y, lat, lng, event)
// ES5 users
function _onClick(obj){ console.log(obj.x, obj.y, obj.lat, obj.lng, obj.event);}

<GoogleMap  onClick={_onClick} ... />

onBoundsChange (func) (Deprecated use onChange)

({ center, zoom, bounds, marginBounds })

[lat, lng] = center;
[topLat, leftLng, bottomLat, rightLng] = bounds;

resetBoundsOnResize (bool)

When true this will reset the map bounds if the parent resizes.

Default: false

onChildClick (func)

onChildMouseEnter (func)

onChildMouseLeave (func)

onZoomAnimationStart (func)

onZoomAnimationEnd (func)

onMapTypeIdChange (func)

When the user changes the map type (HYBRID, ROADMAP, SATELLITE, TERRAIN) this fires

distanceToMouse (func)

googleMapLoader (func)

onGoogleApiLoaded (func)

Directly access the maps API - use at your own risk!

<GoogleMap  onGoogleApiLoaded={({map, maps}) => console.log(map, maps)} />

To prevent warning message add yesIWantToUseGoogleMapApiInternals property to GoogleMap

<GoogleMap  onGoogleApiLoaded={({map, maps}) => console.log(map, maps)}
                       yesIWantToUseGoogleMapApiInternals
 />

Child Component API

parameters

lat (number)

Latitude to place the marker component

lng (number)

Longitude to place the marker component

$hover (bool) [automatic]

GoogleMap passes a $hover prop to hovered components. To detect hover it an uses internal mechanism, explained in x_distance_hover example

Example:

render() {
    const style = this.props.$hover ? greatPlaceStyleHover : greatPlaceStyle;

    return (
       <div style={style}>
          {this.props.text}
       </div>
    );
  }

Utility functions

fitBounds (func)

Use fitBounds to get zoom and center.

Example:

import { fitBounds } from 'google-map-react/utils';

const bounds = {
  nw: {
    lat: 50.01038826014866,
    lng: -118.6525866875
  },
  se: {
    lat: 32.698335045970396,
    lng: -92.0217273125
  }
};

// Or

const bounds = {
  ne: {
    lat: 50.01038826014866,
    lng: -118.6525866875
  },
  sw: {
    lat: 32.698335045970396,
    lng: -92.0217273125
  }
};

const size = {
  width: 640, // Map width in pixels
  height: 380, // Map height in pixels
};

const {center, zoom} = fitBounds(bounds, size);

tile2LatLng (func)

latLng2Tile (func)

getTilesIds (func)

Tips

My map doesn't appear

Make sure the container element has width and height. The map will try to fill the parent container, but if the container has no size, the map will collapse to 0 width / height.

Positioning a marker

Initially any map object has its top left corner at lat lng coordinates. It's up to you to set the object origin to 0,0 coordinates.

Example (centering the marker):

const MARKER_SIZE = 40;
const greatPlaceStyle = {
  position: 'absolute',
  width: MARKER_SIZE,
  height: MARKER_SIZE,
  left: -MARKER_SIZE / 2,
  top: -MARKER_SIZE / 2
}

render() {
  return (
    <div style={greatPlaceStyle}>
      {this.props.text}
    </div>
  );
}

Rendering in a modal

If at the moment of GoogleMap control created, a modal has no size (width,height=0) or/and not displayed, the simple solution is to add something like this in render:

render() {
  return this.props.modalIsOpen
    ? <GoogleMap />
    : null;
}

Adding a SearchBox

import React from 'react';
import ReactDOM from 'react-dom';

export default class SearchBox extends React.Component {
  static propTypes = {
    placeholder: React.PropTypes.string,
    onPlacesChanged: React.PropTypes.func
  }
  render() {
    return <input ref="input" {...this.props} type="text"/>;
  }
  onPlacesChanged = () => {
    if (this.props.onPlacesChanged) {
      this.props.onPlacesChanged(this.searchBox.getPlaces());
    }
  }
  componentDidMount() {
    var input = ReactDOM.findDOMNode(this.refs.input);
    this.searchBox = new google.maps.places.SearchBox(input);
    this.searchBox.addListener('places_changed', this.onPlacesChanged);
  }
  componentWillUnmount() {
    // https://developers.google.com/maps/documentation/javascript/events#removing
    google.maps.event.clearInstanceListeners(this.searchBox);
  }
}

You will need to preload the google maps API, but google-map-react checks if the base api is already loaded, and if so, uses it, so it won't load a second copy of the library.

<script type="text/javascript" src="https://maps.google.com/maps/api/js?libraries=places"></script>

Override the default minimum zoom

WARNING: Setting this option can break markers calculation, causing no homeomorphism between screen coordinates and map.

You can use the minZoom custom option to prevent our minimum-zoom calculation:

function createMapOptions() {
  return {
    minZoom: 2,
  };
}

Define touch device behavior of scrolling & panning for the map

Google Maps provides control over the behavior of touch based interaction with the map. For example, on mobile devices swiping up on the map might mean two things: Scrolling the container or panning the map. To resolve this ambigiuity, you can use the custom map option gestureHandling to get the required behavior.

function createMapOptions() {
  return {
    gestureHandling: 'greedy' // Will capture all touch events on the map towards map panning
  }
}

The default setting is gestureHandling:auto which tries to detect based on the page/content sizes if a greedy setting is best (no scrolling is required) or cooperative (scrolling is possible)

For more details see the google documentation for this setting.

Heatmap Layer

For enabling heatmap layer, just add heatmapLibrary={true} and provide data for heatmap in heatmap as props.

Example

<GoogleMapReact
    bootstrapURLKeys={{ key: [YOUR_KEY] }}
    zoom={zoom}
    center={center}
    heatmapLibrary={true}
    heatmap={{
      positions: [
        {
          lat: 60.714305,
          lng: 47.051773,
        },
        ...
      ],
      options: {
        radius: 20,
        opacity: 0.7,
        gradient: [
          'rgba(0, 255, 255, 0)',
          'rgba(0, 255, 255, 1)',
          ...
        ]
      },
    }}
  >
    {markers}
  </GoogleMapReact>

Important Note

If you have multiple GoogleMapReact components in project and you want to use heatmap layer so provide heatmapLibrary={true} for all GoogleMapReact components so component will load heatmap library at the beginning with google map api.

Localizing the Map

This is done by setting bootstrapURLKeys.language and bootstrapURLKeys.region. Also notice that setting region to 'cn' is required when using the map from within China, see google documentation for more info. Setting 'cn' will result in use of the specific API URL for China.