point-inpolygon-geo.js

/**

Algorithm implementation to check whether a given location (specified by an address) is within boundaries of a geographical region
(region name is also provided as input).
This uses Point In Polygon (PIP) algorithm[https://www.npmjs.com/package/@turf/boolean-point-in-polygon] 
to check coordinate is inside our outside the polygon represented by the GeoJSON data.

Author: Shreyak Chakraborty
*/

const axios = require('axios');
const pointInPolygon = require('@turf/boolean-point-in-polygon').default;

var inputs = {
	region: "Downers Grove IL",
	address: "1903 Elmore Ave Downers Grove, IL 60515",  //inside boundary
//   address: "1903 Elmore Ave Downers Grove, IL 60515", //outside boundary
}

var region = inputs.region;
var address =inputs.address;


if (region != "") {

	// get polygon shape data of the region
	var geojson_url = `https://nominatim.openstreetmap.org/search.php?q=${encodeURI(region)}&polygon_geojson=1&format=json`;

	axios(geojson_url,{ 
		headers: { 
		    'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240' 
		}
	   } 
	)
	.then(result2 => {
		// console.log(result2);
		var geodata = result2.data[0];
		var polygon = geodata.geojson;
		// console.log(polygon);

		//geocode the address to get point
		var geojson_url2 = `https://maps.googleapis.com/maps/api/geocode/json?address=${encodeURI(address)}&key=<APIKEY>`;
		axios(geojson_url2,{ 
				headers: { 
					'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240' 
				}
			} 
		)
		.then(result3 => {
			// console.log(result3);
			var geodata2 = result3.data.results[0];
			const point = {
				type:"Point",
				coordinates: [geodata2.geometry.location.lng,geodata2.geometry.location.lat]
			};
			
			// console.log(point);
			if (pointInPolygon(point, polygon)) {
				console.log(`${address} is within boundaries of ${region}`);
			}
			else{
				console.log(`${address} is outside boundaries of ${region}`);
			}
		})
			
	})
}
else{
	console.log(`No data for ${address}`);
}