r-geo.js

var React = require('react'),
    ReactDOM = require('react-dom');

class UserLocation extends React.Component {
    constructor(props, geoWatchId, lat, lng) {
        super(props);

        // Internal vars
        this.geoWatchId = geoWatchId ? geoWatchId : null;
        this.lat = lat ? lat : null;
        this.lng = lng ? lng : null;

        this.state = {
            countryName: 'global',
            countrySlug: 'global'
        };
    }

    componentDidMount() {
        var _this = this;

        navigator.geolocation.getCurrentPosition(
            (position) => {
                this.lat = position.coords.latitude;
                this.lng = position.coords.longitude;
            },
            (error) => console.log( error.message ),
            {enableHighAccuracy: true, maximumAge: 5000, timeout: 20000}
        );

        this.geoWatchId = navigator.geolocation.watchPosition(
            (position) => {
                this.lat = position.coords.latitude;
                this.lng = position.coords.longitude;
            }
        );

        this.serverRequest = $.getJSON('/geo.json', function( countries ) {
            if (countries) {
                for (var c in countries) {
                    if (countries[c].lat == _this.lat && countries[c].lng == _this.lng) {
                        _this.setState({
                            countryName: countries[c].name,
                            countrySlug: countries[c].slug
                        });

                        return;
                    }
                }
            }
        });
    }

    componentWillUnmount() {
        this.serverRequest.abort();
        navigator.geolocation.clearWatch( this.geoWatchId );
    }

    render () {
        return (
            <div className="row">
                <div className="large-12 columns">
                    Detectamos que voce esta no {this.state.countryName}, ...
                </div>
            </div>
        );
    }
}

ReactDOM.render(
    <UserLocation />,
    document.getElementById('regionSelection')
);