topic Re: Arcade Expression Error in ArcGIS Pro Questions

Arcade Expression Error

PaulMAlexander — Wed, 11 Dec 2024 17:21:44 GMT

Afternoon everyone. I have created an attribute rule that when i update a field in one polygon, it updates the same field in an intersecting polygon. When I check the expression to validate it, it says it is valid. When I run it, I recieve and error message stating, " The index passed was not within the valid range." Any ideas on why this may occur?

Re: Arcade Expression Error

CodyPatterson — Wed, 11 Dec 2024 17:25:09 GMT

Hey @PaulMAlexander

Any chance you could post a screenshot of the rule an error?

Cody

Re: Arcade Expression Error

jcarlson — Wed, 11 Dec 2024 18:08:36 GMT

Pro validates your expression based on a subset of records, so it may not know about potential values elsewhere in your data. Or for a spatial operation, it sees that the expression is valid, but once it tries to perform the steps you wrote, it hits an error.

For intersections, that usually means you've got a feature that does not intersect with anything from your other layer. If you don't have it already, throw in a quick check to make sure that the intersection has features in it.

// your other code here // let's call the intersection "xs" var xs = Intersects($feature, someOtherLayer) // add a check, if there are > 0 features, do what you need if( Count(xs) > 0 ){ return First(someOtherLayer)['someAttribute'] } else { return 'No Intersecting Feature Found' }

Re: Arcade Expression Error

MikeMillerGIS — Wed, 11 Dec 2024 22:32:59 GMT

Just a comment on Josh's code. Calling Count and then First results in an extra query. For optimal performance, just call First and check if the result is valid.

var xs = Intersects($feature, someOtherLayer) var intersected_feature = First(someOtherLayer) if (IsEmpty(intersected_feature)){ return 'No Intersecting Feature Found' } return intersected_feature['other_attribute']

Re: Arcade Expression Error

jcarlson — Thu, 12 Dec 2024 14:24:08 GMT

Thanks!