<p align="center">
<img src="resources/readme/fullstackreact-google-maps-tutorial.png" alt="Fullstack React Google Maps Tutorial" />
</p>
# Google Map React Component Tutorial [](https://www.fullstackreact.com)
> A declarative Google Map React component using React, lazy-loading dependencies, current-location finder and a test-driven approach by the [Fullstack React](https://fullstackreact.com) team.
See the [demo](https://fullstackreact.github.io/google-maps-react) and [accompanying blog post](https://www.fullstackreact.com/articles/how-to-write-a-google-maps-react-component/).
## Quickstart
First, install the library:
```shell
npm install --save google-maps-react
```
## Automatically Lazy-loading Google API
The library includes a helper to wrap around the Google maps API. The `GoogleApiWrapper` Higher-Order component accepts a configuration object which *must* include an `apiKey`. See [lib/GoogleApi.js](https://github.com/fullstackreact/google-maps-react/blob/master/src/lib/GoogleApi.js#L4) for all options it accepts.
```javascript
import {GoogleApiWrapper} from 'google-maps-react';
// ...
export class MapContainer extends React.Component {}
export default GoogleApiWrapper({
apiKey: (YOUR_GOOGLE_API_KEY_GOES_HERE)
})(MapContainer)
```
Alternatively, the `GoogleApiWrapper` Higher-Order component can be configured by passing a function that will be called with whe wrapped component's `props` and should returned the configuration object.
```javascript
export default GoogleApiWrapper(
(props) => ({
apiKey: props.apiKey,
language: props.language,
}
))(MapContainer)
```
If you want to add a loading container _other than the default_ loading container, simply pass it in the HOC, like so:
```javascript
const LoadingContainer = (props) => (
<div>Fancy loading container!</div>
)
export default GoogleApiWrapper({
apiKey: (YOUR_GOOGLE_API_KEY_GOES_HERE),
LoadingContainer: LoadingContainer
})(MapContainer)
```
## Sample Usage With Lazy-loading Google API:
```javascript
import {Map, InfoWindow, Marker, GoogleApiWrapper} from 'google-maps-react';
export class MapContainer extends Component {
render() {
return (
<Map google={this.props.google} zoom={14}>
<Marker onClick={this.onMarkerClick}
name={'Current location'} />
<InfoWindow onClose={this.onInfoWindowClose}>
<div>
<h1>{this.state.selectedPlace.name}</h1>
</div>
</InfoWindow>
</Map>
);
}
}
export default GoogleApiWrapper({
apiKey: (YOUR_GOOGLE_API_KEY_GOES_HERE)
})(MapContainer)
```
*Note: [Marker](#marker) and [InfoWindow](#infowindow--sample-event-handler-functions) components are disscussed below.*
## Examples
Check out the example site at: [http://fullstackreact.github.io/google-maps-react](http://fullstackreact.github.io/basic)
## Additional Map Props
The Map component takes a number of optional props.
Zoom: (Shown Above) takes a number with the higher value representing a tighter focus on the map's center.
Style: Takes CSS style object - commonly width and height.
```javascript
const style = {
width: '100%',
height: '100%'
}
```
Container Style: Takes CSS style object - optional, commonly when you want to change from the default of position "absolute".
```javascript
const containerStyle = {
position: 'relative',
width: '100%',
height: '100%'
}
```
```javascript
<Map
containerStyle={containerStyle}
```
initialCenter: Takes an object containing latitude and longitude coordinates. Sets the maps center upon loading.
```javascript
<Map
google={this.props.google}
style={style}
initialCenter={{
lat: 40.854885,
lng: -88.081807
}}
zoom={15}
onClick={this.onMapClicked}
>
```
center: Takes an object containing latitude and longitude coordinates. Use this if you want to re-render the map after the initial render.
```javascript
<Map
google={this.props.google}
style={style}
center={{
lat: 40.854885,
lng: -88.081807
}}
zoom={15}
onClick={this.onMapClicked}
>
```
bounds: Takes a [google.maps.LatLngBounds()](https://developers.google.com/maps/documentation/javascript/reference/3/#LatLngBounds) object to adjust the center and zoom of the map.
```javascript
var points = [
{ lat: 42.02, lng: -77.01 },
{ lat: 42.03, lng: -77.02 },
{ lat: 41.03, lng: -77.04 },
{ lat: 42.05, lng: -77.02 }
]
var bounds = new this.props.google.maps.LatLngBounds();
for (var i = 0; i < points.length; i++) {
bounds.extend(points[i]);
}
return (
<Map
google={this.props.google}
initialCenter={{
lat: 42.39,
lng: -72.52
}}
bounds={bounds}>
</Map>
);
```
The following props are boolean values for map behavior:
`scrollwheel`, `draggable`, `keyboardShortcuts`, `disableDoubleClickZoom`
The following props are boolean values for presence of controls on the map:
`zoomControl`, `mapTypeControl`, `scaleControl`, `streetViewControl`, `panControl`, `rotateControl`, `fullscreenControl`
The following props are object values for control options such as placement of controls on the map:
`zoomControlOptions`, `mapTypeControlOptions`, `streetViewControlOptions`
See Google Maps [Controls](https://developers.google.com/maps/documentation/javascript/controls) for more information.
It also takes event handlers described below:
### Events
The `<Map />` component handles events out of the box. All event handlers are optional.
#### onReady
When the `<Map />` instance has been loaded and is ready on the page, it will call the `onReady` prop, if given. The `onReady` prop is useful for fetching places or using the autocomplete API for places.
```javascript
fetchPlaces(mapProps, map) {
const {google} = mapProps;
const service = new google.maps.places.PlacesService(map);
// ...
}
render() {
return (
<Map google={this.props.google}
onReady={this.fetchPlaces}
visible={false}>
<Listing places={this.state.places} />
</Map>
)
}
```
#### onClick
To listen for clicks on the `<Map />` component, pass the `onClick` prop:
```javascript
mapClicked(mapProps, map, clickEvent) {
// ...
}
render() {
return (
<Map google={this.props.google}
onClick={this.mapClicked} />
)
}
```
#### onDragend
When our user changes the map center by dragging the Map around, we can get a callback after the event is fired with the `onDragend` prop:
```javascript
centerMoved(mapProps, map) {
// ...
}
render() {
return (
<Map google={this.props.google}
onDragend={this.centerMoved} />
)
}
```
The `<Map />` component also listens to `onRecenter`, `onBounds_changed`, `onCenter_changed`, `onDblclick`, `onDragstart`, `onHeading_change`, `onIdle`, `onMaptypeid_changed`, `onMousemove`, `onMouseout`, `onMouseover`, `onProjection_changed`, `onResize`, `onRightclick`, `onTilesloaded`, `onTilt_changed`, and `onZoom_changed` events. See Google Maps [Events](https://developers.google.com/maps/documentation/javascript/events) for more information.
### Visibility
You can control the visibility of the map by using the `visible` prop. This is useful for situations when you want to use the Google Maps API without a map. The `<Map />` component will load like normal. See the [Google places demo](https://fullstackreact.github.io/google-maps-react/#/places)
For example:
```javascript
<Map google={this.props.google}
visible={false}>
<Listing places={this.state.places} />
</Map>
```
## Subcomponents
The `<Map />` api includes subcomponents intended on being used as children of the `Map` component. Any child can be used within the `Map` component and will receive the three `props` (as children):
* `map` - the Google instance of the `map`
* `google` - a reference to the `window.google` object
* `mapCenter` - the `google.maps.LatLng()` object referring to the center of the map instance
### Marker
To place a marker on the Map, include it as a child of the `<Map />` component.
```javascript
<Map google={this.props.google}
style={{width: '100%', height: '100%', position: 'relative'}}
className={'map'}
zoom={14}>
<Marker
title={'The marker`s title will appear as a tooltip.'}
name={'SOMA'}
position={{lat: 37.778519, lng: -122.405640}} />
<Marker
name={'Dolores park'}
position={{lat: 37.759703, lng: -122.428093}} />
<Marker />
<Marker
name={'Your position'}
position={{lat: 37.762391, lng: -122.439192}}
icon={{
url: "/path/to/custom_icon.png",
anchor: new google.maps.Point(32,32),
scaledSize: new google.maps.Size(64,64)
}} />
</Map>
```
The `<Marker />` component accepts a `position` prop that defines the location for the `position` on the map. It can be either a raw object or a `google.maps.LatLng()` instance.
If no `position` is passed in the `props`, the marker will default to the current position of the map, i.e. the `mapCenter` prop.
You can also pass any other `props` you want with the `<Marker />`. It will be passed back through marker events.
The marker component can also accept a child InfoMarker component for situations where there is only 1 marker and 1 infowindow.
```javascript
<Marker
title="Location"
id={1}
position={markerCenter}
draggable={true}
onDragend={this.moveMarker.bind(this)}
>
<InfoWindow
visible={showInfoWindow}
style={styles.infoWindow}
>
<div className={classes.infoWindow}>
<p>Click on the map or drag the marker to select location where the incident occurred</p>
</div>
</InfoWindow>
</Marker>
```
### Events
The `<Marker />` component listens for events, similar to the `<Map />` component.
#### onClick
You can listen for an `onClick` event with the (appropriately named) `onClick` prop.
```javascript
onMarkerClick(props, marker, e) {
// ..
}
render() {
return (
<Map google={this.props.google}>
<Marker onClick={this.onMarkerClick}
name={'Current location'} />
</Map>
)
}
```
#### mouseover
You can also pass a callback when the user mouses over a `<Marker />` instance by passing the `onMouseover` callback:
```javascript
onMouseoverMarker(props, marker, e) {
// ..
}
render() {
return (
<Map google={this.props.google}>
<Marker onMouseover={this.onMouseoverMarker}
name={'Current location'} />
</Map>
)
}
```
### Polygon
To place a polygon on the Map, set `<Polygon />` as child of Map component.
```javascript
render() {
const triangleCoords = [
{lat: 25.774, lng: -80.190},
{lat: 18.466, lng: -66.118},
{lat: 32.321, lng: -64.757},
{lat: 25.774, lng: -80.190}
];
return(
<Map google={this.props.google}
style={{width: '100%', height: '100%', position: 'relative'}}
className={'map'}
zoom={14}>
<Polygon
paths={triangleCoords}
strokeColor="#0000FF"
strokeOpacity={0.8}
strokeWeight={2}
fillColor="#0000FF"
fillOpacity={0.35} />
</Map>
)
}
```
#### Events
The `<Polygon />` component listens to `onClick`, `onMouseover` and `onMouseout` events.
### Polyline
To place a polyline on the Map, set `<Polyline />` as child of Map component.
```javascript
render() {
const triangleCoords = [
{lat: 25.774, lng: -80.190},
{lat: 18.466, lng: -66.118},
{lat: 32.321, lng: -64.757},
{lat: 25.774, lng: -80.190}
];
return(
<Map google={this.props.google}
style={{width: '100%', height: '100%', position: 'relative'}}
className={'map'}
zoom={14}>
<Polyline
path={triangleCoords}
strokeColor="#0000FF"
strokeOpacity={0.8}
strokeWeight={2} />
</Map>
)
}
```
#### Events
The `<Polyline />` component listens to `onClick`, `onMouseover` and `onMouseout` events.
### InfoWindow
The `<InfoWindow />` component included in this library is gives us the ability to pop up a "more info" window on our Google map.
The visibility of the `<InfoWindow />` component is controlled by a `visible` prop. The `visible` prop is a boolean (`PropTypes.bool`) that shows the `<InfoWindow />` when true and hides it when false.
There are two ways how to control a position of the `<InfoWindow />` component.
You can use a `position` prop or connect the `<InfoWindow />` component directly to an existing `<Marker />` component by using a `marker` prop.
```javascript
//note: code formatted for ES6 here
export class MapContainer extends Component {
state = {
showingInfoWindow: false,
activeMarker: {},
selectedPlace: {},
};
onMarkerClick = (props, marker, e) =>
this.setState({
selectedPlace: props,
activeMarker: marker,
showingInfoWindow: true
});
onMapClicked = (props) => {
if (this.state.showingInfoWindow) {
this.setState({
showingInfoWindow: false,
activeMarker: null
})
}
};
render() {
return (
<Map google={this.props.google}
onClick={this.onMapClicked}>
<Marker onClick={this.onMarkerClick}
name={'Current location'} />
<InfoWindow
marker={this.state.activeMarker}
visible={this.state.showingInfoWindow}>
<div>
<h1>{this.state.selectedPlace.name}</h1>
</div>
</InfoWindow>
</Map>
)
}
}
```
### Events
The `<InfoWindow />` throws events when it's showing/hiding. Every event is optional and can accept a handler to be called when the event is fired.
```javascript
<InfoWindow
onOpen={this.windowHasOpened}
onClose={this.windowHasClosed}
visible={this.state.showingInfoWindow}>
<div>
<h1>{this.state.selectedPlace.name}</h1>
</div>
</InfoWindow>
```
#### onClose
The `onClose` event is fired when the `<InfoWindow />` has been closed. It's useful for changing state in the parent component to keep track of the state of the `<InfoWindow />`.
#### onOpen
The `onOpen` event is fired when the window has been mounted in the Google map instance. It's useful for keeping track of the state of the `<InfoWindow />` from within the parent component.
### Circle
To place a circle on the Map, set `<Circle />` as child of Map component.
```javascript
render() {
const coords = { lat: -21.805149, lng: -49.0921657 };
return (
<Map
initialCenter={coords}
google={this.props.google}
style={{width: 500, height: 500, position: 'relative'}}
zoom={14}
>
<Circle
radius={1200}
center={coords}
onMouseover={() => console.log('mouseover')}
onClick={() => console.log('click')}
onMouseout={() => console.log('mouseout')}
strokeColor='transparent'
strokeOpacity={0}
strokeWeight={5}
fillColor='#FF0000'
fillOpacity={0.2}
/>
</Map>
);
}
```
#### Events
The `<Circle />` component listens to `onClick`, `onMouseover` and `onMouseout` events.
The `GoogleApiWrapper` automatically passes the `google` instance loaded when the component mounts (and will only load it once).
#### Custom Map Style
To set your own custom map style, import your custom map style in JSON format.
```javascript
const mapStyle = [
{
featureType: 'landscape.man_made',
elementType: 'geometry.fill',
stylers: [
{
color: '#dceafa'
}
]
},
]
_mapLoaded(mapProps, map) {
map.setOptions({
styles: mapStyle
})
}
render() {
return (
<Map
style={style}
google={this.props.google}
zoom={this.state.zoom}
initialCenter={this.state.center}
onReady={(mapProps, map) => this._mapLoaded(mapProps, map)}
>
...
</Map>
);
}
```
## Manually loading the Google API
If you prefer not to use the automatic loading option, you can also pass the `window.google` instance as a `prop` to your `<Map />` component.
```javascript
<Map google={window.google} />
```
## Issues?
If you have some issues, please make an issue on the issues tab and try to include an example. We've had success with https://codesandbox.io
An example template might look like: [https://codesandbox.io/s/rzwrk2854](https://codesandbox.io/s/rzwrk2854)
## Contributing
```shell
git clone https://github.com/fullstackreact/google-maps-react.git
cd google-maps-react
npm install
make dev
```
The Google Map React component library uses React and the Google API to give easy access to the Google Maps library.
___
# Fullstack React Book
<a href="https://fullstackreact.com">
<img align="right" src="resources/readme/fullstack-react-hero-book.png" alt="Fullstack React Book" width="155" height="250" />
</a>
This Google Map React component library was built alongside the blog post [How to Write a Google Maps React Component](https://www.fullstackreact.com/articles/how-to-write-a-google-maps-react-component/).
This repo was written and is maintained by the [Fullstack React](https://fullstackreact.com) team. In the book we cover many more projects like this. We walk through each line of code, explain why it's there and how it works.
This app is only one of several apps we have in the book. If you're looking to learn React, there's no faster way than by spending a few hours with the Fullstack React book.
<div style="clear:both"></div>
## License
[MIT](/LICENSE)