Source: map-google-maps/src/main/resources/META-INF/resources/js/GoogleMapsGeocoder.es.js

/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

import State from 'metal-state';

/**
 * GoogleMapsGeocoder
 * @review
 */
class GoogleMapsGeocoder extends State {

	/**
	 * Creates a new geocoder using Google Map's API
	 * @param  {Array} args List of arguments to be passed to State
	 * @review
	 */
	constructor(...args) {
		super(...args);

		this._geocoder = new google.maps.Geocoder();
	}

	/**
	 * Handles the server response of a successfull address/location resolution
	 * @param {function} callback Callback that will be executed on success
	 * @param {Object} location Raw location information
	 * @param {Object} response Server response
	 * @param {Object} status Server response status
	 * @protected
	 * @review
	 */
	_handleGeocoderResponse(callback, location, response, status) {
		const result = {
			data: {},
			error: status === google.maps.GeocoderStatus.OK ? null : status,
		};

		if (!result.error) {
			const geocoderResult = response[0];
			const geolocation = geocoderResult.geometry.location;

			result.data = {
				address: geocoderResult.formatted_address,
				location: {
					lat: geolocation.lat(),
					lng: geolocation.lng(),
				},
			};
		}
		else {
			result.data = {
				address: '',
				location,
			};
		}

		callback(result);
	}

	/**
	 * Transforms a given address into valid latitude and longitude
	 * @param {string} query Address to be transformed into latitude and longitude
	 * @param {function} callback Callback that will be executed on success
	 * @review
	 */
	forward(query, callback) {
		const payload = {
			address: query,
		};

		this._geocoder.geocode(
			payload,
			this._handleGeocoderResponse.bind(this, callback)
		);
	}

	/**
	 * Transforms a given location object (lat, lng) into a valid address
	 * @param {string} location Location information to be sent to the server
	 * @param {function} callback Callback that will be executed on success
	 * @review
	 */
	reverse(location, callback) {
		const payload = {
			location,
		};

		this._geocoder.geocode(
			payload,
			this._handleGeocoderResponse.bind(this, callback, location)
		);
	}
}

export default GoogleMapsGeocoder;
export {GoogleMapsGeocoder};