persistent overlays per client

static/js/map/CustomOverlay.js

@@ -0,0 +1,40 @@
+
+var customOverlays = {};
+
+try {
+  customOverlays = JSON.parse(localStorage["mapserver-customOverlays"])
+} catch (e){}
+
+function save(){
+  localStorage["mapserver-customOverlays"] = JSON.stringify(customOverlays);
+}
+
+export default function(map, overlays){
+
+  Object.keys(customOverlays)
+  .filter(name => overlays[name])
+  .forEach(name => {
+    const layer = overlays[name];
+
+    if (customOverlays[name] && !map.hasLayer(layer)){
+      //Add
+      map.addLayer(layer);
+    }
+
+    if (!customOverlays[name] && map.hasLayer(layer)){
+      //Remove
+      map.removeLayer(layer);
+    }
+  });
+
+  map.on('overlayadd', e => {
+    customOverlays[e.name] = true;
+    save();
+  });
+
+  map.on('overlayremove', e => {
+    customOverlays[e.name] = false;
+    save();
+  });
+
+}

static/js/map/MapComponent.js

@@ -4,6 +4,7 @@ import CoordinatesDisplay from './CoordinatesDisplay.js';
 import WorldInfoDisplay from './WorldInfoDisplay.js';
 import SearchControl from './SearchControl.js';
 import Overlaysetup from './Overlaysetup.js';
+import CustomOverlay from './CustomOverlay.js';
 import layerManager from './LayerManager.js';
 import config from '../config.js';
 
@@ -33,6 +34,7 @@ export default {
 
     //All overlays
     Overlaysetup(cfg, map, overlays, wsChannel, layerManager);
+    CustomOverlay(map, overlays);
 
     new CoordinatesDisplay({ position: 'bottomleft' }).addTo(map);
     new WorldInfoDisplay(wsChannel, { position: 'bottomright' }).addTo(map);
@@ -54,8 +56,6 @@ export default {
     map.on('zoomend', updateHash);
     map.on('moveend', updateHash);
     map.on('baselayerchange', updateHash);
-
-    //TODO: overlay persistence (state, localstorage)
   },
 
   onbeforeupdate(newVnode, oldVnode) {