topic Re: Arcgis Arcade in dasboards in ArcGIS Dashboards Questions

Arcgis Arcade in dasboards

JiříKomínek — Wed, 02 Feb 2022 06:51:29 GMT

Hi, I am trying to create a dashboard where I would spatially query two layers (point and polygon). I need to return the number of points lying in each polygon to a sheet. In Mapviewer this is not a problem using the arcade language, but I have spent many hours in the dashboard with no result. I am attaching the code that works in Mapviewer and I need to get it into Dashboard.

var osoby=FeatureSetByName($map,"Dopravní nehody / Traffic accidents") var pocetOsob=Count(Intersects(osoby, $feature)) var intersectArea=Intersects(FeatureSetByName($map,"Traffic accidents"),$feature ) var list_pricin= groupBy(intersectArea, "id", {name:"count", expression: "id", statistic: "COUNT"}) var pocet= Count(list_pricin) return pocet

Re: Arcgis Arcade in dasboards

jcarlson — Wed, 02 Feb 2022 13:24:35 GMT

In Dashboard Data Expressions, you need to return a FeatureSet object for the Dashboard to work with the output.

The scenario you describe, counting points in a polygon, is exactly what is demonstrated in this example expression here: https://github.com/Esri/arcade-expressions/blob/master/dashboard_data/SpatialAggregation.md

Simply replace the layer / field names with your own, and it should work.

Re: Arcgis Arcade in dasboards

JiříKomínek — Wed, 02 Feb 2022 15:15:52 GMT

Thanks! yes I know this github repository. But it gives me an error . I don't know why I understand what the code is doing, I have gone through the functions, tested if it returns featuresets, but in the for part it gives me an error. I don't know how to debug arcade code

Re: Arcgis Arcade in dasboards

jcarlson — Wed, 02 Feb 2022 15:22:19 GMT

Debugging Arcade is easier in a web environment where you can use the Console function to return intermediate outputs. If your expression is going to work, it's going to have to look a lot like the linked expression from my initial reply. If we amend that expression and add some console functions, we may get a clearer idea of what's working and what isn't. For instance, you could alter the first part of your expression to return the count of features.

// Portal var portal = Portal('https://www.arcgis.com/'); // Create FeatureSet for polygons var poly_fs = FeatureSetByPortalItem( portal, '312cebfea2624e108e234220b04460b8', 0, [ 'ZONE' ], true ); // See if polygons were returned Console(`${Count(poly_fs)} features in poly_fs.`) // Create Featureset for points var pt_fs = FeatureSetByPortalItem( portal, '848d61af726f40d890219042253bedd7', 0, [ 'capacity_mw' ], true ); // See if points were returned Console(`${Count(pt_fs)} features in pt_fs.`)