React-Leaflet example

https://github.com/PaulLeCam/react-leaflet

by CĂ©sar Guadarrama

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/6.1.19/browser.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.0.1/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.0.1/react-dom.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.0.1/leaflet.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.0.1/leaflet.js"></script>
<script src="https://unpkg.com/react-leaflet@1.0.0/dist/react-leaflet.js"></script>
<div id="container"></div>

CSS

.leaflet-container {
    height: 400px;
    width: 100%;
}

Babel + JSX

const React = window.React;
const { Map, TileLayer, Marker, Popup, Polygon } = window.ReactLeaflet;

class SimpleExample extends React.Component {
  constructor() {
    super();
    this.state = {
      positions: [[51.505, -0.09]]
    };
  }
  
  addPosition = (e) => {
    const {positions} = this.state
    console.log('Adding positions', positions)
    positions.push([e.latlng.lat, e.latlng.lng])
    this.setState({positions})
  }

  render() {
    return (
      <Map 
        center={[51.505, -0.09]} 
        onClick={this.addPosition}
        zoom={13} 
        >
        <TileLayer
          attribution='&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
          url='http://{s}.tile.osm.org/{z}/{x}/{y}.png'
        />
        <Polygon positions={this.state.positions} color="blue" />
      </Map>
    );
  }
}

window.ReactDOM.render(<SimpleExample />, document.getElementById('container'));