Pubnub block for running an ArcGIS demographic analysis request via an ArcGIS Online hosted geoenrichment service.

esri_geoenrichment_input_proxy

/*
    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 url = "PROXY_SERVICE_URL";

    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']"
        };   
  
       return xhr.fetch(url, http_options).then((x) => {
            const body = JSON.parse(x.body);
            
            //console.log("Response payload: " + x.body);
            
            // 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);
  }
};