Using Arcade to color code a polygon layer based on attribute values

HugoBouckaert1

Hi 

In a map I use a "Custom Expression" to change the rendering style of a polygon layer, and use Arcade to make a custom expression. In Arcade, I combine all possible combinations of two fields. One field is named PIP and the other BIOSECURITY. Both use the same domain, namely a simple YES/NO choice where the code for "NO" = 0 and the code for YES = 1. However both fields can also be empty.

The logic is that I use decode to change the values of PIP differently from those of BIOSECURITY so they can never be the same. Once that is done, I add them up. Because the values are always different, each addition should be unique. I use a WHEN statement in which I add up the unique combinations of the values in the two fields. 

WHEN

(Decode($feature.PIP, 0, 2, 1, 4, 5) + Decode($feature.BIOSECURITY, 0, 22, 1, 32, 55) == 60,'Unique Color Code',

Decode($feature.PIP, 0, 2, 1, 4, 5) + Decode($feature.BIOSECURITY, 0, 22, 1, 32, 55) == 59, 'Another Unique Color Code',  'Default Value ')

But where I write 'Unique Color Code',  and ''Another Unique Color Code' I would actually like to instruct Arcade to render those layers with a particular color, e.g. green or red.  

I found some examples, but I think is for when you embed Arcade in JavaScript  

Decode($feature.PIP, 0, 2, 1, 4, 5) + Decode($feature.BIOSECURITY, 0, 22, 1, 32, 55) == 60, 'background-color:ff984f'‌

I also tried:  

Decode($feature.PIP, 0, 2, 1, 4, 5) + Decode($feature.BIOSECURITY, 0, 22, 1, 32, 55) == 60, '#ff984f'

Is there any way in Arcade to directly assign colors to a polygon layer, based on a WHEN statement, as in the code snippet above?

Thanks

Hugo 

 

HugoBouckaert1

Thanks for your help, your code is much better (and elegant) than mine.

I am now formatting the colour schemes manually, seeing I have clear confirmation this cannot be done in Arcade. 

I have looked into using JSON for defining drawinginfo for webmaps before. So this is what I am doing now also for the new results from the categories resulting from the arcade code.   First I use  the arcgis.gis API to search for the webmap in question, and get the mapitem. Then I do this:  

mapitem.get_data().

The resultant JSON output is then put in a JSON formatter, after which I use everything that belongs to drawingInfo into a python progam as a variable. After that I search for layers in the other webmap, and copy the new JSON variable over by doing this:     

layer ['layerDefinition'] = mysavedJSON

Thanks again for your help. 

Cheers

Hugo