When we switch map style, re-add any data layers

resources/assets/es6/mapbox-utils.js

@@ -20,7 +20,23 @@ const addMapTypeOption = (map, menu, option, checked = false) => {
         input.setAttribute('checked', 'checked');
     }
     input.addEventListener('click', function () {
+        let source = map.getSource('points');
         map.setStyle('mapbox://styles/mapbox/' + option + '-v9');
+        map.on('style.load', function () {
+            map.addLayer({
+                'id': 'points',
+                'type': 'symbol',
+                'source': {
+                    'type': 'geojson',
+                    'data': source._data
+                },
+                'layout': {
+                    'icon-image': '{icon}-15',
+                    'text-field': '{title}',
+                    'text-offset': [0, 1]
+                }
+            });
+        });
     });
     let label = document.createElement('label');
     label.setAttribute('for', option);