Removing polygon holes in OpenLayers

Question

I wrote some code for removal of polygon holes whose area value is under the hardcoded threshold.

source_g.getFeatures()[0].getGeometry().getPolygons().forEach(function(poly){

    if(!(poly.getLinearRings().length<=1)) 
    {
        poly.getLinearRings().forEach(function(ring){ 
            if(Math.abs(ring.getArea()) < 0.1){ 

               ring.setCoordinates([])
            }
        })
    };
})

The idea is to set coordinates of inner LinearRings to [], I tried to do that on the whole feature and it disappeared. But for LinearRings it's not doing the same.

Answer 1

The geometry is defined as an array of coordinates, not collections of Polygons and LinearRings, so what is returned by getPolygons() and getLinearRings() should be treated as clones and you will need to rebuild the geometry from coordinates

var geom = source_g.getFeatures()[0].getGeometry();
var geomCoords = [];
geom.getPolygons().forEach(function(poly){
    var polyCoords = [];
    poly.getLinearRings().forEach(function(ring, index){ 
        if(index == 0 || Math.abs(ring.getArea()) >= 0.1){ 
           polyCoords.push(ring.getCoordinates());
        }
    };
    geomCoords.push(polyCoords);
});
geom.setCoordinates(geomCoords);