Node.js modules for City of Philadelphia geolocation and polling location APIs

phlfindpolls-sample.js

require('./phlgeolocate');
require('./phlfindpolls');

var address = process.argv[2] || '1234 Market Street';

var geo = new PHLgeolocate();
geo.getCoordinates(address, function(coords) {
	
	var options = {};
	options.outFields = ['WARD_1,DIVISION_1,POLLING_PL,ADDRESS,PARKING_AC,BUILDING_A'];
	var poll = new PHLfindpolls(options);
	poll.findLocation(coords[0].latitude, coords[0].longitude, function(result) {
		for(item in result[0].attributes) {
			console.log(item + ': ' + result[0].attributes[item]);
		}
	});

});

phlfindpolls.js

var http = require('http');

PHLfindpolls = function(options) {
	var geometryType = options.geometryType || 'esriGeometryPoint';
	var inSR = options.inSR || 4326;
	var spatialRel = options.spatialRel || 'esriSpatialRelWithin';
	var returnCountOnly = options.returnCountOnly || 'false';
	var returnIdsOnly = options.returnIdsOnly || 'false'
	var returnGeometry = options.returnGeometry || 'false';
	var f = options.f || 'pjson';

	this.responseBody;
	this.apiHost = 'http://gis.phila.gov/ArcGIS/rest/services/PhilaGov';
	this.locationPath = '/PollingPlaces/MapServer/1/query';
	this.settings = {
		geometryType: geometryType,
		inSR: inSR,
		spatialRel: spatialRel,
		returnCountOnly: returnCountOnly,
		returnIdsOnly: returnIdsOnly,
		returnGeometry: returnGeometry,
		outFields: encodeURI(options.outFields.join(',')),
		f: f
	};
};

PHLfindpolls.prototype.findLocation = function(latitude, longitude, callback) {
	var url = this.apiHost + this.locationPath;
	url += '?';
	for(item in this.settings) {
		url +=  item + '=' + encodeURI(this.settings[item]) + '&';
	}
	url += 'geometry={"x":"' + longitude + '","y":"' + latitude + '"}';
	this.makeApiCall(url, callback);
};

PHLfindpolls.prototype.makeApiCall = function (url, callback) {
	var self = this;
	self.responseBody = '';
	http.get(url, function(res) {
		res.setEncoding('utf8');
		res.on('data', function(chunk) {
			self.responseBody += chunk;
		});
		res.on('end', function(){
			var result = JSON.parse(self.responseBody);
			callback(result.features);
		});
	});
};

exports.PHLfindpolls = PHLfindpolls;

phlgeolocate-sample.js

require('./phlgeolocate');

var address = process.argv[2] || '1234 Market Street';

var geo = new PHLgeolocate();
geo.getCoordinates(address, function(result) {
	console.log(result);
});

phlgeolocate.js

var http = require('http');

PHLgeolocate = function() {
	this.geoHost = 'http://services.phila.gov';
	this.locationPath = '/ULRS311/Data/Location/';
	this.liAddressKeyPath = '/ULRS311/Data/LIAddressKey/';
	this.minConfidence = 85;
	this.responseBody;
};

PHLgeolocate.prototype.getCoordinates = function (address, callback) {
	var url = this.geoHost + this.locationPath + encodeURI(address);
	this.makeApiCall(url, callback);
};

PHLgeolocate.prototype.getAddressKey = function (address, callback) {
	var url = this.geoHost + this.liAddressKeyPath + encodeURI(address);
	this.makeApiCall(url, callback);
};

PHLgeolocate.prototype.makeApiCall = function (url, callback) {
	var self = this;
	self.responseBody = '';
	http.get(url, function(res) {
		res.setEncoding('utf8');
		res.on('data', function(chunk) {
			self.responseBody += chunk;
		});
		res.on('end', function(){
			var result = self.parseResponse(JSON.parse(self.responseBody));
			callback(result);
		});
	});
};

PHLgeolocate.prototype.parseResponse = function (result) {
	var self = this;
	locations = [];
	for(var i=0; i<result.Locations.length; i++) {
		var location = result.Locations[i]
		if(location.Address.Similarity >= self.minConfidence) {
			var geometry = { address: location.Address.StandardizedAddress, similarity: location.Address.Similarity, latitude: location.YCoord, longitude: location.XCoord };
			locations.push(geometry);
		}
	}
	return locations;
};

exports.PHLgeolocate = PHLgeolocate;

~$ node sample.js "20 N. Third Street"
WARD_1: 5
DIVISION_1: 16
POLLING_PL: OLD FIRST REFORMED CHURCH
ADDRESS: 330 RACE ST
PARKING_AC: N
BUILDING_A: R