topic Re: How to return null in Arcade with Calculate Field (python works fine)? in ArcGIS Pro Questions

How to return null in Arcade with Calculate Field (python works fine)?

JimmyKnowles — Fri, 21 Dec 2018 22:26:11 GMT

Trying to use the Calculate Field GP tool in ArcGIS Pro 2.2.3. I need to use logic (if else statements) to modify some field values.

I've searched and searched and can't find how to do this in Arcade.

In python, the following works fine. It actually sets the field to Null (verified by an isNull definition query).

return None‍‍

In Arcade, the following just returns 0

return null‍‍

I've tried a bunch of other things with Arcade, but no success.

Anyone have any ideas how to return null with Arcade?

Re: How to return null in Arcade with Calculate Field (python works fine)?

StephenM — Sat, 22 Dec 2018 01:04:32 GMT

Empty strings might be an option, since they return true from Arcade's IsEmpty() function.

Re: How to return null in Arcade with Calculate Field (python works fine)?

JimmyKnowles — Wed, 26 Dec 2018 18:44:19 GMT

Thanks Stephen. That might be an option. I've already got records that have attributes w/ Null and due to my OC tendencies, I'd like all these records to to use the same 'null' value.

I got it to work with python code, so not a huge deal, was just curious if anyone had a solution in Arcade.

Re: How to return null in Arcade with Calculate Field (python works fine)?

StephenM — Thu, 27 Dec 2018 18:23:03 GMT

Yeah, Python seems like the way to go here. It's strange that in Arcade <Null> table values return true from the IsEmpty() function, but null itself returns 0 back to the table.

Re: How to return null in Arcade with Calculate Field (python works fine)?

XanderBakker — Fri, 28 Dec 2018 12:36:04 GMT

I also noticed this in ArcGIS Pro. Very weird, even for a Text field assigning the Null value end up writing a 0 to the table. Kory Kramer have you seen this before?

I did a test in ArcGIS Online and created two fields (a text and a double field) and assinged Null to both fields using an Arcade expression:

In the pop-up it is not very what the actual assiged values is, so I exported the hosted feature layer to FGDB and loaded it into ArcGIS Pro to discover that there is an actual Null value in the Double Field, but the text field contains an empty string:

Re: How to return null in Arcade with Calculate Field (python works fine)?

KoryKramer — Fri, 28 Dec 2018 15:24:34 GMT

Thanks for pinging me, Xander Bakker‌! No, I haven't seen this before and after checking, I don't see any other reports of this.

Jimmy Knowles‌ How are you!?

I'm going to run this by a product engineer on the Pro team, but unfortunately it looks like a bug to me. Basically, whenever I use Arcade to calculate null into a field (regardless of data type) it says that it succeeds and writes 0 to the field.

I tested with Text, Short and Double. So that is a bit different from what Xander saw when running the calculation in ArcGIS Online. I think we'll need to get a bug logged for this and Jimmy, I can get you attached to that when we have it. Glad that you have an easy Python workaround. I'll follow up on this soon.

Cheers

Re: How to return null in Arcade with Calculate Field (python works fine)?

JimmyKnowles — Fri, 28 Dec 2018 16:53:14 GMT

Thanks Xander Bakker for the confirmation and for testing the behavior in AGOL. Kory Kramer, thanks for the additional info as well and for working to get the bug logged. Life is good, I'll send you an email.

Re: How to return null in Arcade with Calculate Field (python works fine)?

KoryKramer — Fri, 28 Dec 2018 18:42:36 GMT

Jimmy: for Pro [BUG-000119064: Calculating a value to null using Arcade returns 0.]

Xander: the behavior in Online isn't as pervasive and seems to only affect Text fields [BUG-000119062: Calculating a Text field value to null using Arcade returns 0, not null.]

Re: How to return null in Arcade with Calculate Field (python works fine)?

XanderBakker — Fri, 28 Dec 2018 19:37:56 GMT

Hi Kory Kramer , thanks for attending this issue. You are right, it seems that the problem in ArcGIS Pro is more pervasive.

Re: How to return null in Arcade with Calculate Field (python works fine)?

Anonymous User — Mon, 19 Aug 2019 02:43:09 GMT

Kory Kramer‌, has this bug been fixed with Pro 2.4? I can't find reference to the ArcGIS Pro bug on the Esri support site under BUG-000119064 but can find the ArcGIS Online BUG-000119062 .

Re: How to return null in Arcade with Calculate Field (python works fine)?

KoryKramer — Tue, 20 Aug 2019 13:15:21 GMT

Hi Mark - unfortunately, no, it has not yet been addressed. You should now be able to find it here: https://support.esri.com/en/bugs/nimbus/QlVHLTAwMDExOTA2NA== where you can click the Subscribe button.

The implicit casting behavior of null is to go to 0 in Arcade. There are cases where we override this so the dev team will look at getting the correct overrides in place...

Re: How to return null in Arcade with Calculate Field (python works fine)?

TanyaBagley-Online — Mon, 04 Nov 2019 16:39:14 GMT

I recently needed to populate some fields with a true <Null> value instead of a 0.

In ArcGIS Pro, using Arcade to try and calculate this field value to a true null, resulted only in populating the field with a zero or 0. I did some research and found that if I set the Expression Type to Python 3 (instead of Arcade) and then Calculate Field field_name = None (no quotes around None, gave me actual true null values in the cells of the selected records).

Re: How to return null in Arcade with Calculate Field (python works fine)?

KoryKramer — Thu, 07 Nov 2019 14:38:43 GMT

Looky here: BUG-000119064: Calculating a value to null using Arcade returns 0..

Pro 2.5 should be out in January. I guess until then (as I'm assuming others have been doing now anyway) stick with Python, and the 2020 resolution will be to use Arcade to calculate Null!

Re: How to return null in Arcade with Calculate Field (python works fine)?

TristanTaylor — Thu, 05 Dec 2019 18:15:00 GMT

Jimmy Knowles Kory Kramer I know this is very late in the game, with the bug fix coming in January, but I was just able to successfully return true Null in Arcade by just using "return" (without "null")

Re: How to return null in Arcade with Calculate Field (python works fine)?

KoryKramer — Thu, 05 Dec 2019 18:31:55 GMT

What version of Pro? Calculating on what data type?

I just tried in 2.4.1 on a Long and Text field and using just 'return' returns 0.

Re: How to return null in Arcade with Calculate Field (python works fine)?

JimmyKnowles — Fri, 06 Dec 2019 22:39:48 GMT

Kory & Tristan, I tested this in 2.4.2 and using Arcade in the 'Calculate Field' GP tool, it yields the same results as we've seen previously. It appears Tristan is using Attribute Rules. I can confirm that when using Attribute Rules, an Arcade expression of just 'return' does indeed return Null for both Text and Double.

I haven't needed this since almost exactly a year ago, so didn't even think if attribute rules would have helped or not.

Re: How to return null in Arcade with Calculate Field (python works fine)?

Anonymous User — Thu, 12 Dec 2019 20:14:35 GMT

I see some using "return "... is there a way to do this in an attribute rule that is an "edit return"?

return {

'result': $feature.attribute,

'edit': [

{

'className': 'anotherFeatureClass',

'updates': [

{

'globalID': objectsGlobalID,

'attributes': {

'anotherFeaturesAttribute': null // i'd like to update the other feature with "<Null>"

}

]

}

]

}

Re: How to return null in Arcade with Calculate Field (python works fine)?

TL2 — Thu, 16 Jan 2020 19:23:01 GMT

Xander Bakker‌ I have the above question too.

Re: How to return null in Arcade with Calculate Field (python works fine)?

XanderBakker — Sat, 11 Dec 2021 10:15:08 GMT

Hi T L and Caleb Melies ,

I'm just wondering, if you follow the advise of ttaylo13 and just leave it blank, does that work?

return {
    'result': $feature.attribute,
    'edit': [
        {
            'className': 'anotherFeatureClass', 
            'updates': [
                {
                    'globalID': objectsGlobalID,
                    'attributes': {
                        'anotherFeaturesAttribute': 
                    }
                }
            ]
        }
    ]
} ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: How to return null in Arcade with Calculate Field (python works fine)?

TL2 — Thu, 16 Jan 2020 21:05:37 GMT

Looks like its fixed in 2.5