Map Viewer - Styles Data Expression - Return field A,B or C based on Max(X,Y,Z)

[BlakeMorrison]

I have 3 editable fields, each of which is related to a 4th, 5th and 6th field. The idea is that field 4,5,6 are the held quantities of fields 1,2,3. I want to base the layer style on the highest held quantity of whatever item.

Eg.

Feature 1: Style based on Grapes=60

Field 1: Oranges ------------ Field 4: 45

Field 2: Apples ------------- Field 5: 10

Field 3: Grapes ------------- Field 6: 60

Feature 2: Style based on Bananas = 80

Field 1: Apples ------------- Field 4: 15

Field 2: Bananas ------------- Field 5: 80

I've got the following code together which logically functions (finds and returns the appropriate pair of values), but I think I have an incorrect format being returned.

var fields = [
          { name: $feature.item1 , value: $feature.quantity1 },
          { name: $feature.item2 , value: $feature.quantity2 },
          { name: $feature.item3 , value: $feature.quantity3 },
];

function comparevalue(a,b){
  if (a['value']>b['value'])
    return -1;
  if (a['value']<b['value'])
    return 1;
  return 0;
};

return First(Sort(fields,comparevalue))

The above code returns:

dictionary
name: Grapes
value: 60

but this is not usable to set a style apparrently.

[AnneFitz]

The Arcade visualization profile, used for styling your data based on an Arcade expression, only accepts a return type of Number or Text. Dictionaries are not a supported return type in this profile.

You could create two separate expressions -- the first which finds the field name, and the second which gets the quantity/value of that field. Basically, you could use the same expression twice but specify either the name or value in the return.

First(Sort(fields,comparevalue)).name // or value depending on expression

Then use that with the "Types and Size" style.

[BlakeMorrison]

Thanks for your response! Sorry for my slow reply. I'm going to check out your solution as well.

[BlakeMorrison · Accepted solution]

I got what I wanted working like this:

var fields = [
          { alias: $feature.variety1 , value: $feature.var1_perc },
          { alias: $feature.variety2 , value: $feature.var2_perc },
          { alias: $feature.variety3 , value: $feature.var3_perc },
];

function getPredominantCategory(fields){
  var maxValue = null;
  var maxCategory = "";
  for(var k in fields){
    if(fields[k].value > maxValue){
      maxValue = fields[k].value;
      maxCategory = fields[k].alias;
    } else if (fields[k].value == maxValue){
      maxCategory = maxCategory + "/" + fields[k].alias;
    }
  }
  return IIF(maxValue <= 0, null, maxCategory);
}

getPredominantCategory(fields);