Leaflet geoJSON - function within setStyle()

Question

I have 2 styling methods for countries on my map:
style_init() for the initial style of a country,
style_new() for when a country changes and I want to re-style it on the map:

style_init(feature: any)           style_new(feature: any)
{                                  {
    return {                           return {
        fillColor: '#ffffff',              fillColor: '#000000', // new style here...
        color: '#ffffff',                  color: '#ffffff',
        ...                                ...
    };                                 };
}                                  }

I'm successfully using style_init() when initialising the map:

this.map_layer = L.geoJSON(this.countries, {
    style: this.style_init
}).addTo(this.map);

To update the style of a country, I'm currently embedding the style code into setStyle():

this.map_layer.eachLayer(function (layer: any)
{
    if( layer.feature.name == target_country )
    {
        layer.setStyle({
            fillColor: '#000000', // currently using raw style code here...
            color: '#000000',
        });
    }
});

I'm using setStyle() instead of .addTo(map) because the countries have already been added and I don't want to remove and re-add them or add a new country over the top of the existing initial country.
However, I want to use my style_new() method within the setStyle() call, like this:

this.map_layer.eachLayer(function (layer: any)
{
    if( layer.feature.name == target_country )
    {
        layer.setStyle({
            this.style_new() // using my function here instead
        });
    }
});

But trying this produces errors such as:
':' expected
'this' implicitly has type 'any' because it does not have a type annotation

How can I make setStyle() use my predefined function, instead of having the write the explicit style code?

Answer 1

Since style_new function returns style object, it must not be embedded in the object specifiers {} when you call it, so code should look like this:

this.map_layer.eachLayer(function (layer: any) {
  if( layer.feature.name == target_country) {
    layer.setStyle(this.style_new());
  }
});