51Degrees Geo-Location Node.js  4.4

const FiftyOneDegreesLocation = require((process.env.directory || __dirname) + '/../');

const myResourceKey = process.env.RESOURCE_KEY || '!!YOUR_RESOURCE_KEY!!';

let server;

if (myResourceKey.substring(0, 2) === '!!') {

console.log('You need to create a resource key at ' +

'https://configure.51degrees.com and paste it into the code, ' +

'replacing !!YOUR_RESOURCE_KEY!!');

} else {

// Create a new pipeline and set the config.

// You need to create a resource key at https://configure.51degrees.com

// and paste it into the code.

// The JavaScriptBuilderSettings allow you to provide an endpoint

// which will be requested by the client side JavaScript.

// This should return the contents of the JSONBundler element which

// is automatically added to the Pipeline.

const pipeline = new FiftyOneDegreesLocation.GeoLocationPipelineBuilder({

resourceKey: myResourceKey,

javascriptBuilderSettings: {

endPoint: '/json'

}

}).build();

// Logging of errors and other messages.

// Valid logs types are info, debug, warn, error

pipeline.on('error', console.error);

const http = require('http');

server = http.createServer((req, res) => {

const flowData = pipeline.createFlowData();

// Add any information from the request

// (headers, cookies and additional client side provided information)

flowData.evidence.addFromRequest(req);

flowData.process().then(function () {

res.statusCode = 200;

if (req.url.startsWith('/json')) {

// Return the json to the client.

res.setHeader('Content-Type', 'application/json');

res.end(JSON.stringify(flowData.jsonbundler.json));

} else {

res.setHeader('Content-Type', 'text/html');

let output = '';

const data = flowData.location;

console.log(data);

// Print results of client side processing to the page.

output += `<h2>Example</h2>

<div id="content">

<p>

The following values are determined sever-side on the first request.

As the server has no location information to work from, these

values will all be unknown:

</p>

<dl>

<dt><strong>Country</strong></dt>

<dv>` + (data && data.country && data.country.hasValue

? data.country.value

: ('Unknown (' + (data && data.country ? data.country.noValueMessage : 'no data') + ')')) + `</dv>

<dt><strong>State</strong></dt>

<dv>` + (data && data.state && data.state.hasValue

? data.state.value

: ('Unknown (' + (data && data.state ? data.state.noValueMessage : 'no data') + ')')) + `</dv>

<dt><strong>County</strong></dt>

<dv>` + (data && data.county && data.county.hasValue

? data.county.value

: ('Unknown (' + (data && data.county ? data.county.noValueMessage : 'no data') + ')')) + `</dv>

<dt><strong>Town/City</strong></dt>

<dv>` + (data && data.town && data.town.hasValue

? data.town.value

: ('Unknown (' + (data && data.town ? data.town.noValueMessage : 'no data') + ')')) + `</dv>

</dl>

<p>

When the button below is clicked, JavaScript running on the client-side

will be used to obtain additional evidence (i.e. the location information

from the device). If no additional information appears then it may

indicate an external problem such as JavaScript being disabled in

your browser.

</p>

<p>

Note that the accuracy of the information is dependent on the accuracy

of the location data returned by your device. Any device that lacks GPS

is likely to return a highly inaccurate result. Among devices with GPS,

some have a significantly lower margin of error than others.

</p>

<button type="button" onclick="buttonClicked()">Use my location</button>

</div>

<script>

buttonClicked = function () {

// This function will fire when the JSON data object is updated

// with information from the server.

// The sequence is:

// 1. Response contains JavaScript property 'JavaScript'. This is not executed immediately on the client as it will prompt the user to allow access to location.

// 2. When the button is clicked, the fod.complete function is called, passing 'location' as the second parameter. This lets the code know that we want to execute

// any JavaScript needed to obtain the location data that is needed to determine the user's postal address details.

// 3. The execution of the location JavaScript triggers a background callback to the webserver that includes the new evidence (i.e. lat/lon).

// 4. The web server responds with new JSON data that contains the updated property values based on the new evidence.

// 5. The JavaScript integrates the new JSON data and fires the 'complete' callback function below, which then displays the results.

fod.complete(function (data) {

let fieldValues = [];

if (data.location) {

fieldValues.push(["Country", data.location.country]);

fieldValues.push(["State", data.location.state]);

fieldValues.push(["County", data.location.county]);

fieldValues.push(["Town/City", data.location.town]);

}

else {

fieldValue.push(["Location data is empty. This probably means that something has gone wrong with the JavaScript evaluation.", ""])

}

displayValues(fieldValues);

}, 'location');

}

function displayValues(fieldValues) {

var list = document.createElement("dl");

fieldValues.forEach(function (entry) {

var name = document.createElement("dt");

var value = document.createElement('dv');

var bold = document.createElement('strong');

var fieldname = document.createTextNode(entry[0]);

var fieldvalue = document.createTextNode(entry[1]);

bold.appendChild(fieldname);

name.appendChild(bold);

value.appendChild(fieldvalue);

list.appendChild(name);

list.appendChild(value);

});

var element = document.getElementById("content");

element.appendChild(list);

}

</script>`;

// Get JavaScript to put inside the page to gather extra evidence

const js = `<script>${flowData.javascriptbuilder.javascript}</script>`;

res.end(js + output);

}

});

});

const port = 3000;

server.listen(port);

console.log('Server listening on port: ' + port);

}