Openlayers 3 feature-driven rotation

Question

I want to set the rotation of an ol.style.Icon to a given feature property. See line 12 of this:

var styleCache_airports={}
var style_airports = function(feature, resolution){
    var value = ""
    var size = 0;
    var style = [ new ol.style.Style({
        image: new ol.style.Icon({
                  imgSize: [32, 32],
                  scale: 0.59375,
                  anchor: [9, 9],
                  anchorXUnits: "pixels",
                  anchorYUnits: "pixels",
                  rotation: function(feature){return feature.get("ELEV") * 0.0174533;},
                  src: "styles/a18_sluis.svg"
            })
    })];
    if ("" !== null && resolution > 28 && resolution < 1400) {
        var labelText = String("");
    } else {
        var labelText = ""
    }
    var key = value + "_" + labelText

    if (!styleCache_airports[key]){
        var text = new ol.style.Text({
              font: '10.725px \'MS Shell Dlg 2\', sans-serif',
              text: labelText,
              textBaseline: "center",
              textAlign: "left",
              offsetX: 5,
              offsetY: 3,
              fill: new ol.style.Fill({
                color: "rgba(0, 0, 0, 255)"
              }),
            });
        styleCache_airports[key] = new ol.style.Style({"text": text})
    }
    var allStyles = [styleCache_airports[key]];
    allStyles.push.apply(allStyles, style);
    return allStyles;
};

This doesn't work, and doesn't throw any errors. If I replace it with a static value, it works. What am I doing wrong?

Answer 1

I was over-complicating. The rotation line should just be:

rotation: feature.get("ELEV") * 0.0174533,