topic Re: Arcade Data Expression - Intersects for Dashboard List in ArcGIS Online Questions

Arcade Data Expression - Intersects for Dashboard List

RyanElvrum5 — Wed, 08 Mar 2023 14:24:42 GMT

I am attempting to create a Data Expression to be used in a Dashboard List widget. My arcade expression is attempting to perform an intersect for each point feature in my FeatureSet to check if it intersects with a line in a different FeatureSet.

My understanding is that the Intersect needs to be performed on 1 input feature at a time, so I feel like some type of loop needs to occur. I then want to return all the point features that intersect a line as a FeatureSet to be used in the List widget. I believe this should be possible, but I think I am stuck at creating a For-in loop to perform an intersect for each point feature and store the results to be returned as a FeatureSet. Below is what my code looks like so far. Everything down to line 24 works, so I do not believe I have any issues up until that point. Everything after line 24 is where I am getting lost.

//Portal var port = "Https://www.arcgis.com" //ArcGIS Online item ID var itemID = "4c82c3b6b8d64c6ca0ecd20d813531f2" //Rest layer ID - Storm Gravity Mains var GMlayerID = 60 //Rest layer ID - Storm Manholes var MHlayerID = 57 //Fields returned - All (Default) var fields = ['*'] //Geometry returned var geo = True //Set up Gravity Main feature set var fsGM = FeatureSetByPortalItem(Portal(port), itemId, GMlayerID, fields,geo) //Set up Manhole feature set var fsMH = FeatureSetByPortalItem(Portal(port), itemId, MHlayerID, fields,geo) //Filter statement used to filter feature set down to Gravity Mains with an upsteam invert value that is less than downstream invert value var FilterStatementGM = "UpstreamInvert < DownstreamInvert AND TrunkMain = 'Y'" //Returns filtered Gravity Mains var filteredfsGM = Filter(fsGM, FilterStatementGM) //Filter statement used to filter feature set down to Gravity Mains with an upsteam invert value that is less than downstream invert value var FilterStatementMH = "TrunkMain = 'Y' AND NeedsGPS = 1 AND MajorDBDistrict = 'J'" //Returns filtered Manholes var filteredfsMH = Filter(fsMH, FilterStatementMH) var MHlist = '' for (var f in filteredfsMH){ Intersects(f, filteredfsGM) MHlist += f.FacilityID } return MHlist

Re: Arcade Data Expression - Intersects for Dashboard List

jcarlson — Wed, 08 Mar 2023 14:33:04 GMT

There is an example expression that performs a "spatial join" between two layers, which you can access right here: https://github.com/Esri/arcade-expressions/blob/master/dashboard_data/SpatialAggregation.md

Re: Arcade Data Expression - Intersects for Dashboard List

RyanElvrum5 — Wed, 08 Mar 2023 14:55:41 GMT

Thanks Josh, I am slowly trying to digest the information in your link! Do you know if the Contains function is applicable to points intersecting lines? I am struggling to find any alternatives for a "spatial join" type function.

Re: Arcade Data Expression - Intersects for Dashboard List

RyanElvrum5 — Wed, 08 Mar 2023 15:52:58 GMT

Josh, thanks again for providing the link. I pretty much have it working now. I am able to return a list of features, and I was able to use the Intersects() function to do so.

The only thing I want to look into more deeply is, if instead of "creating" a new feature (list?/array?/object?) for the output, I'd rather return a FeatureSet of the actual features so that I may use the List widget Action: Zoom to Feature. I want the users to be able to select an item in the list and zoom directly to it. I will come back and update this thread if I can figure that out.

//Portal var port = "Https://www.arcgis.com" //ArcGIS Online item ID var itemID = "4c82c3b6b8d64c6ca0ecd20d813531f2" //Rest layer ID - Storm Gravity Mains var GMlayerID = 60 //Rest layer ID - Storm Manholes var MHlayerID = 57 //Fields returned - All (Default) var fields = ['*'] //Geometry returned var geo = True //Set up Gravity Main feature set var fsGM = FeatureSetByPortalItem(Portal(port), itemId, GMlayerID, fields,geo) //Set up Manhole feature set var fsMH = FeatureSetByPortalItem(Portal(port), itemId, MHlayerID, fields,geo) //Filter statement used to filter feature set down to Gravity Mains with an upsteam invert value that is less than downstream invert value var FilterStatementGM = "UpstreamInvert < DownstreamInvert AND TrunkMain = 'Y'" //Returns filtered Gravity Mains var filteredfsGM = Filter(fsGM, FilterStatementGM) //Filter statement used to filter feature set down to Gravity Mains with an upsteam invert value that is less than downstream invert value var FilterStatementMH = "TrunkMain = 'Y' AND NeedsGPS = 1 AND MajorDBDistrict = 'J'" //Returns filtered Manholes var filteredfsMH = Filter(fsMH, FilterStatementMH) var MHlist = []; var MH; for (var f in filteredfsMH){ var m = Intersects(f, filteredfsGM); MH = { 'attributes':{ 'facilityID': f['FacilityID'], 'cnt': Count(m) } } Push(MHlist, MH); }; var out_dict = { 'fields':[ {'name': 'facilityID', 'alias': 'FacilityID', 'type': 'esriFieldTypeString'}, {'name': 'cnt', 'alias': 'Count', 'type': 'esriFieldTypeInteger'} ], 'geometryType': '', 'features': MHlist }; return FeatureSet(Text(out_dict))