nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }

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

JimmyKnowles

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).

<SPAN class="keyword token">return</SPAN> None‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN></SPAN>

In Arcade, the following just returns 0

<SPAN class="keyword token">return</SPAN> null‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN></SPAN>

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

Anyone have any ideas how to return null with Arcade?

Encontre mais publicações marcadas com

Accepted answers

All comments

AJR

There isn't an arcade function to count the number of vertices in a shape - https://developers.arcgis.com/arcade/function-reference/geometry_functions/

using Count(Text(Geometry($feature))) returns a result when used in the field calculator (null shapes are returned as empty strings), but trying to use Count(Text(Geometry($feature))) > 0 as a null shape filter fails when used as part of an attribute rule (i.e. null shapes pass the check)

Bud

For what it's worth, I was able to set a value to null using Arcade in the field calculator in ArcGIS Pro 3.2.2 (mobile and file geodatabases):

return null

It worked for setting the shape field to null as well (mobile and file geodatabases).

Bud

Arcade:

Instead of checking for a null shape, can you count the vertices? If there are no vertices, then could you assume the shape is null? (or the geometry is nill or null)

Or if it is a line or polygon FC, could you check if the length is greater than 0? If I remember correctly, it's possible to check the length using an Arcade function or by referring to the Shape.Length "field". Related comment here: hasCurve Arcade geometry property.

SQL:

Is there a way to check if the shape is null using SQL (within the Arcade expression)?

Or if not, could you use a related database view that has a calculated field for flagging isNull (0 or 1)? And then use Arcade to reference the flag field in the related view?

Attribute Rules Idea: Use a database function in an attribute rule
Python Questions: Use a SQL expression inside a Python or Arcade field calculation?

Bud

Attribute Rules Idea: isBlankShape function (shape is null, or geometry is nil or null)
ArcGIS Pro Idea: Conditionally skip field calculation for certain rows

AJR

This bug also manifests itself if you try to use an arcade expression to operate on the shape and some of the shapes are null. There doesn't seem to be any way in arcade to detect if the shape is null before attempting to use it (i.e. intersect it with another feature class). I'm curious when/if this bug is on the timeline for getting fixed.

LyonMNGIS

Hi,

I am still having issues with null in Arcade for text fields. Has anyone had any luck with null values for text fields?

iif (OutString == '', null, OutString);

Thanks

BertKraan

I came along this issue after a 'feature class to feature class' conversion altered the <null> values in one of my attributes to '0' (arcgis pro 2.6.0)

I used this calculate field expression to fix it:

iif ($feature.wijziging == 0,null,$feature.wijziging)

Not very happy about the unwanted conversion though but happy enough to find your tips here!

Have a great day Guys!

Bert

TristanTaylor

My apologies, Kory, I didn't notice that the problem specifically pertained to Field Calculator until after I posted!

TL2

Looks like its fixed in 2.5

XanderBakker

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?

<SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">{</SPAN>
    <SPAN class="string token">'result'</SPAN><SPAN class="punctuation token">:</SPAN> $feature<SPAN class="punctuation token">.</SPAN>attribute<SPAN class="punctuation token">,</SPAN>
    <SPAN class="string token">'edit'</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">[</SPAN>
        <SPAN class="punctuation token">{</SPAN>
            <SPAN class="string token">'className'</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'anotherFeatureClass'</SPAN><SPAN class="punctuation token">,</SPAN> 
            <SPAN class="string token">'updates'</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">[</SPAN>
                <SPAN class="punctuation token">{</SPAN>
                    <SPAN class="string token">'globalID'</SPAN><SPAN class="punctuation token">:</SPAN> objectsGlobalID<SPAN class="punctuation token">,</SPAN>
                    <SPAN class="string token">'attributes'</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">{</SPAN>
                        <SPAN class="string token">'anotherFeaturesAttribute'</SPAN><SPAN class="punctuation token">:</SPAN> 
                    <SPAN class="punctuation token">}</SPAN>
                <SPAN class="punctuation token">}</SPAN>
            <SPAN class="punctuation token">]</SPAN>
        <SPAN class="punctuation token">}</SPAN>
    <SPAN class="punctuation token">]</SPAN>
<SPAN class="punctuation token">}</SPAN> <SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

TL2

Xander Bakker‌ I have the above question too.

Anonymous User

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>"

}

]

}

]

}

JimmyKnowles

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.

KoryKramer

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.

TristanTaylor

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")

KoryKramer

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!

TanyaBagley-Online

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).

Calculating a true null value in a field using Expression Type Python 3

XanderBakker

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:

StephenM

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.

JimmyKnowles

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.

StephenM

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

Participe da Conversa

Membros conectados podem postar, seguir atualizações e mais. Novo aqui? Registre uma conta gratuita.

Links Rápidos

Community Help
Find useful guides, FAQs, and documents to help you navigate and make the most of Esri Community.