How to symbolize Space Planner app by occupant load?

[MollyE]

I've seen a couple examples of Space Planners that have the units symbolized based on how many occupants are currently assigned to it, as in these examples from CloudPoint and CERN below. The images link to the videos I pulled these pictures from if you want to check them out.

 

However I cannot seem to figure out how they achieved this. I see an option in the web map to adjust transparency based on a field, which I can then set to the Capacity field, but that's not quite what I'm looking for; the capacity will always stay the same regardless of occupants assigned. I cannot seem to find a field in the units layer that updates when assigning occupants.

Does anyone know how this was achieved? Or have any ideas of things to try?

Thanks!

[AaronKoelker]

Off the top of my head I would guess they might be using an arcade expression to check against the Occupants feature class and return a count of how many times the room's Unit ID appears in that table. This tutorial might help point you in the right direction: Access attributes from another layer with ArcGIS Arcade | Documentation

[MollyE]

Ah, that's a great idea. I actually remember going through this tutorial while in school, but I completely forgot it was possible. 

Thanks, @AaronKoelker!

[Andrew-Bowne]

The display layer could be a View created in the database where the count of occupants are joined to the units similar to what @AaronKoelker mentions above.  The operational Units layer could then be sitting on top of that layer but symbolized as transparent.  

Although, now after I typed all that - we have to account for Branch Versioning in DB Views, which is a whole other animal.  

[GauravJobanputra]

@AaronKoelker and @Andrew-Bowne thanks for your input.

@MollyE from the responses and examples above and assuming you have the Capacity field populated, you can create a new field (say, called Occupancy) and calculate the value based on relation with Capacity and current assignments. You can use Arcade or if you are in Enterprise then even an Attribute Rule so it is tied to the feature layer. You can then symbolize based on chosen values (like Vacant, Full, Under, Over).