Data Expression for Pie Chart in Dashboard Fails

[Anonymous User]

I'm creating  a dashboard for road signs.  Each sign has the installation year (4 digit integer).  (The field name is "Installation"). I want to show a pie chart that shows if signs are <10 years old, 11-20 years old, or >20 years old.  

This is my first time trying to do this in a data expression, and I can't get the correct results.  It says all the signs are 11-20 years old.  I also realized the "ageyrs" variable says it's Nan.  So something somewhere isn't calculating right.  Can anyone spot what I need to fix in my code?

var p = 'https://www.arcgis.com';
var itemId = 'xxx';
var layerId = 0;

var fs = Filter(FeatureSetByPortalItem(Portal(p),itemID,layerID,['Installation']),'Installation > 0');
var ageyrs = Year(Now())-fs
var agechoice = iif(ageyrs>20,'>20 Years Old',(iif(ageyrs<10,'<10 Years Old','11-20 Years Old')))

var Dict = {
    'fields':[
        {'name': 'sign_age', 'type':'esriFieldTypeDouble'},
        {'name': 'agecat', 'type':'esriFieldTypeString'}],
        'geometryType':'',
        'features':
        [{'attributes':
            {'sign_age':ageyrs,
             'agecat':agechoice
        }}]};

return FeatureSet(Text(Dict))

@XanderBakker 

[XanderBakker]

Hi @Anonymous User ,

One of the issues in your code is that you using "fs" as if it contains the installation date. In this case "fs" is a featureset and you will loop through the features, read out the installation date and and fill the output "Dict" with the values calculated. Have a look at the code below:

var p = 'https://www.arcgis.com'; 
var itemId = 'xxx'; 
var layerId = 0; 
var fs = Filter(FeatureSetByPortalItem(Portal(p), itemID, layerID,['Installation']),'Installation > 0'); 
var ageyrs = Year(Now())-fs;
var agechoice = iif(ageyrs>20,'>20 Years Old',(iif(ageyrs<10,'<10 Years Old','11-20 Years Old')));
var Dict = {
    'fields':[ 
        {'name': 'sign_age', 'type':'esriFieldTypeDouble'}, 
        {'name': 'agecat', 'type':'esriFieldTypeString'}], 
    'geometryType':'', 
    'features': []};

var index = 0;
for (var f in fs) {
    var instalationdate = f['Installation'];
    var ageyrs = DateDiff(Now(), instalationdate, 'years');
    var agechoice = iif(ageyrs>20,'>20 Years Old',
                       (iif(ageyrs<10,'<10 Years Old',
                       '11-20 Years Old')));

    Dict.features[index] = {   
            'attributes': {   
                'sign_age': ageyrs,
                'agecat': agechoice
            }}   
    index++; 
};  

return FeatureSet(Text(Dict));

If you just want to return a count per age class you could also create an intermediate dictionary for each class value and update the count. 

[Anonymous User]

That definitely helps and makes more sense.  However it still isn't calculating the Sign Age correctly.  Therefore all the signs show up as 11-20yrs old which isn't correct.  Does it matter that the the Installation field is an integer field?

[XanderBakker]

Hi @Anonymous User ,

I'm glad it works and as you noticed there is a big difference between an integer and a date. I changed the calculation using DateDiff, but this requires two dates to compare. In your case using an integer your calculation does the job. 

[Anonymous User]

Thank you so much for your help!! 

[Anonymous User · Accepted solution]

I made  a few minor tweaks and got it to work! Thank you so much for you help! I was searching for a quite some time yesterday trying to figure this out.  Below is the updated code.

var p = 'https://www.arcgis.com'; 
var itemId = 'xxx'; 
var layerId = 0; 
var fs = Filter(FeatureSetByPortalItem(Portal(p), itemID, layerID,['Installation']),'Installation > 0'); 

var Dict = {
    'fields':[ 
        {'name': 'sign_age', 'type':'esriFieldTypeDouble'}, 
        {'name': 'agecat', 'type':'esriFieldTypeString'}], 
    'geometryType':'', 
    'features': []};

var index = 0;
for (var f in fs) {
    var insdate = f['Installation'];
    var ageyrs = Year(Now())-insdate;
    var agechoice = iif(ageyrs>20,'>20 Years Old',
                       (iif(ageyrs<10,'<10 Years Old',
                       '11-20 Years Old')));

    Dict.features[index] = {   
            'attributes': {   
                'sign_age': ageyrs,
                'agecat': agechoice
            }}   
    index++; 
};  

return FeatureSet(Text(Dict));