mapbox layer fill-color based on TEXT property - properties

Question

Is is possible to set the fill-color stops, based on a text property rather than a numeric value
e.g fill based on province name
My input dataset has a property/Column called PROV_ID and contains a 2 letter ID for each state/Province
So I am aiming toward something in the lines of: 'stops': [['GP', 'YELLOW']]
The code however does not render any fill-colors when when implemented as shown below, I have replaced my PROV_ID in the code below with the Primary key property [numeric] to test, and that works fine
I guess the question is really then if fill-color stops is limited to numeric properties only?
map.addLayer({
'id': 'countiesLayer',
'type': 'fill', /*define the type of layer fill, line, point, fill-extrusion, background, raster, circle*/
'source': 'mySrcName',
'source-layer': '3_Fields-83vr21',
'layout': {
'visibility': 'visible'
},
/*there are many options for styling - this is a simple style*/
'paint': {
'fill-color': {
'property': 'PROV_ID',
'stops': [['GP', 'YELLOW']]
},
'fill-outline-color': 'white'
}
});

Answer 1

I think you need an expression with the function match.
The code would be (not tested):
map.addLayer({
'id': 'countiesLayer',
'type': 'fill', /*define the type of layer fill, line, point, fill-extrusion, background, raster, circle*/
'source': 'mySrcName',
'source-layer': '3_Fields-83vr21',
'layout': {
'visibility': 'visible'
},
/*there are many options for styling - this is a simple style*/
'paint': {
'fill-color': ['match', ['get', 'PROV_ID'], // get the property
'GP', 'yellow', // if 'GP' then yellow
'XX', 'black', // if 'XX' then black
'white'] // white otherwise
},
'fill-outline-color': 'white'
}
});
From the docs:
match
Selects the output whose label value matches the input value, or
the fallback value if no match is found. The input can be any string
or number expression (e.g. ["get", "building_type"]). Each label can
either be a single literal value or an array of values.
["match",
input: InputType (number or string),
label_1: InputType | [InputType, InputType, ...], output_1: OutputType,
label_n: InputType | [InputType, InputType, ...], output_n: OutputType, ...,
default: OutputType ]: OutputType