mapserver/public/js/map/overlays/XPProtectorOverlay.js

import AbstractGeoJsonOverlay from './AbstractGeoJsonOverlay.js';

export default AbstractGeoJsonOverlay.extend({
  initialize: function() {
    AbstractGeoJsonOverlay.prototype.initialize.call(this, "xpprotector");
  },

  createFeature: function(protector){
    return {
      "type":"Feature",
      "geometry": {
        "type":"Polygon",
        "coordinates":[[
            [protector.x-5 + 0.5,protector.z-5 + 0.5],
            [protector.x-5 + 0.5,protector.z+6 + 0.5],
            [protector.x+6 + 0.5,protector.z+6 + 0.5],
            [protector.x+6 + 0.5,protector.z-5 + 0.5],
            [protector.x-5 + 0.5,protector.z-5 + 0.5]
        ]]
      },
      "properties":{
          "name": protector.attributes.xpthreshold,
          "popupContent": protector.attributes.xpthreshold
      }
    };
  }
});