Using data expression to find intersection with separate polygon layer

ChristineLazina11

Hello all!

I'm hoping to find some help troubleshooting this Arcade code used in a data expression for a dashboard. I'm far from an expert on Arcade so there may be something silly I'm misunderstanding. 

The situation: 
I have one large feature layer of all sewer lines in our network, that I am looking to break into 3 separate service areas in the dashboard, so I can track stats for each service area separately. (Unfortunately I do not have the ability to edit this UN sewer line layer, and there is not an appropriate attribute in existence to filter for these service areas without using a spatial query). 

My code: 

//Define the Enterprise portal connection
var myportal = Portal("https://samplesite.net/portal"
)

// Get the line layer: UN - Sewer Lines
var SewerLines = FeatureSetByPortalItem(
    myportal,
    '2c08361d8abe4308afba3d25c857a11c',
    3,
    ['*'], 
    true
)

// Get the polygon layer: Separated Service Areas, 
//filtered for Core Service Area feature only
var CoreSvcArea = Filter(
    FeatureSetByPortalItem( 
    myportal,
    '41c17045b4cf4359a8237db163fe82a6',
    0,
    ['*'], 
    true), 
    "ServiceAreaName = 'RVSS Core Service Area'"
)

// Create an empty array to store intersecting features
var CoreLines = []

// Loop through each sewer line
for (var line in SewerLines) {
    //Check if the given line intersects any core service area polygon, 
    //Filter() returns those intersection polygon features (if any) in 
    //a new array called intersxtion
    var intersxtion = Filter(CoreSvcArea, Intersects(line, CoreSvcArea))

//If count of features in intersxtion is not 0, means an intersxtion
//with given line exists, and it is added to the end feature set
    if (Count(intersxtion) > 0) {
        // Add the intersecting line to the result array
        Push(CoreLines, line)
    }
}

// Return the intersecting sewer lines as a FeatureSet
return FeatureSet(CoreLines)

 

Issues:
When I test this code it returns the error "g.charAt is not a function". I believe I have isolated the issue as coming from the filter/intersection expression on line 34, but it could potentially be from the next few lines of code in the loop expression as that was a bit hard to isolate and test directly. Can anyone tell me what functionality inside this expression would be trying to call a string and not finding one? (this is my understanding of the error). Or if there is a better way to achieve the identification of overlapping features in this scenario I'm all ears! 

Many thanks for any insight,

Christine

kenbuja

I had edited my first response to explain why you were getting that error.

In addition, there was another issue with your code. A data expression has to return a FeatureSet, but you were returning an array. You would have to convert the array of lines into a FeatureSet to use it in the dashboard.

This code should work when a service area is comprised of multiple polygons

//Define the Enterprise portal connection
var myportal = Portal("https://samplesite.net/portal");

// Get the line layer: UN - Sewer Lines
var SewerLines = FeatureSetByPortalItem(
  myportal,
  "2c08361d8abe4308afba3d25c857a11c",
  3,
  ["*"],
  true
);

// Get the polygon layer: Separated Service Areas,
//filtered for Core Service Area feature only
var CoreSvcAreas = Filter(
  FeatureSetByPortalItem(
    myportal,
    "41c17045b4cf4359a8237db163fe82a6",
    0,
    ["*"],
    true
  ),
  "ServiceAreaName = 'RVSS Core Service Area'"
);

var dict = {
  fields: Schema(SewerLines)["fields"],
  geometryType: Schema(SewerLines)["geometryType"],
  features: []
};

for (var CoreSvcArea in CoreSvcAreas) {
  for (var line in Intersects(SewerLines, CoreSvcArea)) {
    var attributes = {};
    for (var attr in line) {
      attributes[attr] = line[attr];
    }
    Push(dict["features"], { attributes: attributes });
  }
}

return FeatureSet(dict);