topic Re: Trying to automatically calculate geodesic length as an attribute Rule that triggers on creation? in ArcGIS Pro Questions

Trying to automatically calculate geodesic length as an attribute Rule that triggers on creation?

BryceBarth — Thu, 14 May 2020 21:26:55 GMT

I am trying to set up an attribute Rule that will calculate the geodesic length of the polyline upon creation. However I keep getting a message saying the projection is invalid. The feature, dataframe and the Dataset in the GDb that it is reading from are all set to the exact same projection. How can I do this? Is it an issue with Arcade language?

Re: Trying to automatically calculate geodesic length as an attribute Rule that triggers on creation?

XanderBakker — Fri, 15 May 2020 13:25:46 GMT

Hi Bryce Barth

If you look at the help of the function (Geometry Functions | ArcGIS for Developers ) you will see this:

Returns the geodetic length of the input geometry or FeatureSet in the given units. This is more reliable measurement of length than Length() because it takes into account the Earth's curvature. Support is limited to geometries with a Web Mercator (wkid 3857) or a WGS 84 (wkid 4326) spatial reference.

If you have a different coordinate system it will not work.

Re: Trying to automatically calculate geodesic length as an attribute Rule that triggers on creation?

DerekDay — Tue, 02 Jan 2024 15:55:15 GMT

Hello, I am having trouble using the Attribute Rule to calculate “LengthGeodetic” Feet in WGS84 (wkid 4326). It is saying Projection is Invalid. Any recommendations?

Thank you!

Re: Trying to automatically calculate geodesic length as an attribute Rule that triggers on creation?

FelixOConnor — Thu, 20 Mar 2025 18:16:56 GMT

Have there been any updates or changes to this? I am no longer seeing the bolded portion of your quoted section on the developer page.