Changing colour of point based on null value using Arcade Expression in ArcGIS Online?

Question

I have a map in ArcGIS Online with a point layer showing lighting assets. These are symbolised based on unique type (post = circle, column = square).

The user will update a separate field to have a unique alphanumeric ID for each Asset.

I would like to use an Arcade expression to change the colour of the points when the field value changes from null to its new ID.

E.g. If the Unique ID is null the point colour is red, if the Unique ID is not null then colour green.

I haven't used the Arcade language before and cannot find guidance online for this particular query.

Answer 1

You can try this http://www.arcgis.com/home/webmap/viewer.html?webmap=93bca1dfa0d14676adbefe160c7a8c3b

//check the id for null values
IF (isEmpty($feature.id)) { 
    //id is null check the type
    When($feature.type == 'Male', "Male with no ID", 
    $feature.type == 'Female', 'Female with no ID', 
    "Other")

} else {
        //id is good check the type
    When($feature.type == 'Male', "Male with ID", 
    $feature.type == 'Female', 'Female with ID', 
    "Other")

}

Answer 2

I recently had the same issue. I used

IIF(IsEmpty($feature.ID), "NOT FILLED", "FILLED")