Arcade script to colour polygons

Question

Hello, I am trying to add styling to my polygon layer using values in two different fields.  I am new to Arcade and a coding amateur at best.  I can get it to work by adding another duplicate layer to my web map and colouring it green if there's something in the Date field, but I want to avoid having to add extra un-necessary layers/complication to my web map.

So, to summise:

Field 1 - To Be Assessed  - This is a Y or N text field - pre-populated.

Field 2 - Date Assessed - This is a Date Field - empty to start with, to be filled in by the surveyor.
-----------------------------------------

If field 1 = Y - colour polygon RED

If field 1 = N - colour polygon BLUE

If field 2 is not null, or has a date in it, colour polygon GREEN

So far I have got as far as the below but I am not getting it to work:

----------------------------------------

var survey = $feature['Survey_2024'];
var result = "";

If (IsEmpty(survey)) {Console("SURVEY=?");}

else if (survey == 'N') {result += "NO SURVEY";}

else {result += "YES - SURVEY REQUIRED";}

if (isEmpty($feature.Date_Assessed)) { } else
{result += "COMPLETE";}

result = Trim(result);
if (result=="") {
result = "No Data";
}

return result;

Grateful for any help!  Many thanks, Harry

jcarlson · Answer

Does the editor show you a message if you over over the red sections? Usually that would mean there's something wrong with the field name.

If the field really is "Survey_2021", try using bracket notation, like $feature['Survey_2021'] instead. Capitalization counts!

HarryBell · Answer

Hi Josh

Wow - that makes it look easy!  I've tried putting it in as is, but it has the red blocks and doesn't let me save it - have I missed something?  Thanks for your help!

jcarlson · Answer

Your pseudo-code makes it pretty easy to understand.

If field 1 = Y - colour polygon RED
If field 1 = N - colour polygon BLUE
If field 2 is not null, or has a date in it, colour polygon GREEN

When you have a series of conditions, the function When is your friend. The conditions will evaluate in order, so put the most important ones first. And you need to include a fallback option at the end.

return When(
  !IsEmpty($feature.field_2), 'Green',
  $feature.field_1 == 'Y', 'Red',
  $feature.field_1 == 'N', 'Blue',
  'Other'
)

Note that this will give you categories, but won't directly define the color. You'll need to open up each category and configure the symbol settings accordingly.