Demographics analysis with self-renewing ArcGIS token

pubnub_esri_geoenrichment.js

/*
    This ArcGIS-based pubnub block shows a pattern for running powerful demographic data searches.

    Declare the Event Handler with the export syntax. The incoming message is called request.
    The request object can either be a single point or a polygon. Here is an example, 'y' is Latitude
    and 'x' is Longitude:

    {
        "x": -122.435, 
        "y": 37.785    
    }
*/
export default (request) => {

    // Require XHR to make external calls
    const xhr = require("xhr");
    
    // Require console to print debug information
    const console = require('console');
    
    // Need a token? Create a free developer account at developers.arcgis.com
    // Information on auto-majically generating a token: http://resources.arcgis.com/en/help/arcgis-rest-api/index.html#//02r3000000m5000000
    const accessToken = "jmWtooJqFI8vLL8bxkwxJtM7BHnJT-r8pYHDXljhckAPyghQwayml9IOOpXnRXQ4C2mHGNUb98MdpraxjvgPHj1hnNuNRUjrF_6ndBxcw8aIx4h9YAd5rmgiYIhjbAKLu18xvoVT1V8cRG18butZRQ..";


    const url = "https://www.arcgis.com/sharing/rest/oauth2/token/";
    
    const CLIENT_ID = '<GET THIS FROM DEVELOPERS.ARCGIS.COM>';
    const CLIENT_SECRET = '<GET THIS FROM DEVELOPERS.ARCGIS.COM>';
    
    const http_options = {
        "method": "POST",
        "headers": {
            "Content-Type": "application/x-www-form-urlencoded"
        }, 
    
       // For more info on variable names: http://doc.arcgis.com/en/esri-demographics/
        "body":"&client_id=" + CLIENT_ID +
            "&grant_type=client_credentials"+
            "&client_secret=" + CLIENT_SECRET
    };
    
    return getToken().then(() => {
        const arcgisToken = request.message.arcgisToken;
        return getDemographics(arcgisToken);
    })
    
    function getToken(){
        const store = require('kvstore');
        
        return store.getItem('arcgisToken').then((value) => {
            console.log(value);
            if (value !== "null") {
                request.message.arcgisToken = value;
                // console.log(`Token Exists: ${value}`);
                return request;
            } 
            else {  
                return xhr.fetch(url, http_options).then((x) => {
                    const body = JSON.parse(x.body);
                    console.log(body);
                    
                    store.setItem('arcgisToken', body.access_token, (body.expires_in / 60) - 5);
                    request.message.arcgisToken = body.access_token;
                    
                    return request;
                }).catch((exc) => { 
                    console.log("Exception in xhr request: " + exc);
                    return request.abort()
                });                
            }
        })  
    }

    function getDemographics(accessToken){
        try {
        
        // NOTE: The manually created developer access token expires in 24 hours ;-)        
        
        const http_options = {
            "method": "POST",
            "headers": {
                "Content-Type": "application/x-www-form-urlencoded"
            }, 

           // For more info on variable names: http://doc.arcgis.com/en/esri-demographics/
            "body":"f=json" +
            "&studyAreas=[{'geometry':{'x':" +  request.message.lon + ",'y':" + request.message.lat + "}}]" +
            "&analysisvariables=['populationtotals.TOTPOP_CY','Wealth.MEDHINC_CY','5yearincrements.MEDAGE_CY']" +
            "&token=" + accessToken
        };   
    
  
        // ArcGIS REST API call
        // Documentation for the ArcGIS Geoenrichment service: https://developers.arcgis.com/rest/geoenrichment/api-reference/geoenrichment-service-overview.htm
        console.log("test", http_options);
        const url = "https://geoenrich.arcgis.com/arcgis/rest/services/World/geoenrichmentserver/GeoEnrichment/enrich";
        return xhr.fetch(url, http_options).then((x) => {
            const body = JSON.parse(x.body);
   
            if(body.hasOwnProperty("error")){
                if(body.error.hasOwnProperty("code") === 498){
                    console.log("TOKEN EXPIRED!");
                    return getToken().then(() => {
                        const arcgisToken = request.message.arcgisToken;
                        return getDemographics(arcgisToken);
                    });                   
                }
            }
            else {
                
                // Remove everything but attributes information to cleanup the console output
                // You can get a description of the attributes here: https://developers.arcgis.com/rest/geoenrichment/api-reference/get-variables.htm
                const totalPopulation = body.results[0].value.FeatureSet[0].features[0].attributes.TOTPOP_CY;
                const medianHouseholdIncome = body.results[0].value.FeatureSet[0].features[0].attributes.MEDHINC_CY;
                const medianAge = body.results[0].value.FeatureSet[0].features[0].attributes.MEDAGE_CY;
                
                console.log(
                    "Total Population: " + totalPopulation +
                    ", Median Household Income: " + medianHouseholdIncome +
                    ", Median Age: " + medianAge
                );   
                
                request.message.data = {
                    "totalPopulation":totalPopulation,
                    "medianHouseholdIncome": medianHouseholdIncome,
                    "medianAge": medianAge
                };   
            }
            
            return request.ok();
        }).catch((x) => { 
            console.log("Exception in xhr request: " + x); 
        });

      } catch (e) {
        console.error('Uncaught exception:', e);
        return request.abort();
      }
    }
};