Use a data expression to create a new field based on values in another field for use in a pie chart

Bec

Hi!  I'm trying to build a data expression in an ArcGIS Online dashboard that will take a field called, HOUR_OF_CRASH, which is an integer field and not a time field, and populate a new field called, TOD, which will be a text field for the time of day the hour falls within so that the new field can be used to build a pie chart within the dashboard.  The current data expression is shown below.

var portal = Portal("https://www.arcgis.com");

var fs = FeatureSetByPortalItem('d651aa4112e5408ea9a1cfabecd6485c', 23)
// Create schema for the returned FeatureSet
var fields = [
    { name: "HOUR_OF_CRASH", type: "esriFieldTypeInteger" },
    { name: "TOD", type: "esriFieldTypeString" }
];

var features = [];

for (var f in fs) {
    var hour = f.HOUR_OF_CRASH;
    var tod;

    if (hour >= 0 && hour <= 5){
        tod = "Night";
    } else if (hour >= 6 && hour <= 8){
        tod = "Morning";
    } else if (hour >= 9 && hour <= 15){
        tod = "Day";
    } else if (hour >= 16 && hour <= 23){
        tod = "Evening";
    } else {
        tod = null;
    }

    Push(features, {
        attributes: {
            HOUR_OF_CRASH: hour,
            TOD: tod
        }
    });
}

Unfortunately, this data expression won't function within the dashboard and doesn't give me quite the output I am looking for in the end.  See the below image of the output.

 My experience with data expression is relatively limited.  Any advice would be greatly appreciated!

 

Bec

RPGIS

Hi @Bec,

So the issue is that you are not returning a feature. When creating a custom data expression you should return a value similar to the one below.

var portal = Portal("https://www.arcgis.com");

var fs = FeatureSetByPortalItem('d651aa4112e5408ea9a1cfabecd6485c', 23)
// Create schema for the returned FeatureSet
var fields = [
    { name: "HOUR_OF_CRASH", type: "esriFieldTypeInteger" },
    { name: "TOD", type: "esriFieldTypeString" }
];

var features = []; 
for (var f in fs) {
    var hour = f.HOUR_OF_CRASH;
    var tod = When( hour >= 0 && hour <= 5, "Night", hour >= 6 && hour <= 8, "Morning", hour >= 9 && hour <= 15, "Day", 16 && hour <= 23, "Evening", Null )
	Push( features, { attributes: { HOUR_OF_CRASH: hour, TOD: tod } })
	}
return FeatureSet( fields, Values, geometry:'' )