Work in progress - BNG and Feature Links (BC link) seem to have

mutually exclusive solutions - zoomTo after changing projection on
map is necessary to inform Leaflet of the changed CRS (scale difference)
but the history gets messed up and the BC link doesn't quite render
(you have to generate a moveend on the map, then it'll draw).

Removed a section  of code from _handleLink that sets the map viewer
projection when there is a single map layer and it has a different projection
from that of the map BECAUSE this is handled by the MapMLLayer in
selectAlternateProjection and we don't want to trigger the promise
involved in disconnecting / reconnecting all map layers (happens when
mapml-viewer projection attribute changed callback happens).

src/layer.js

@@ -158,6 +158,8 @@ export class MapLayer extends HTMLElement {
                 opacity: this.opacity
               }
             );
+            this._attachedToMap();
+            this._validateDisabled();
             resolve();
           })
           .catch((error) => {
@@ -171,23 +173,20 @@ export class MapLayer extends HTMLElement {
           mapprojection: this.parentElement.projection,
           opacity: this.opacity
         });
-        resolve();
-      }
-    })
-      .then(() => {
         this._attachedToMap();
         this._validateDisabled();
-      })
-      .catch((e) => {
-        if (e.type === 'changeprojection') {
-          this.src = e.detail.href;
-        } else {
-          console.log(e);
-          this.dispatchEvent(
-            new CustomEvent('error', { detail: { target: this } })
-          );
-        }
-      });
+        resolve();
+      }
+    }).catch((e) => {
+      if (e.type === 'changeprojection') {
+        this.src = e.detail.href;
+      } else {
+        console.log(e);
+        this.dispatchEvent(
+          new CustomEvent('error', { detail: { target: this } })
+        );
+      }
+    });
   }
   _attachedToMap() {
     // set i to the position of this layer element in the set of layers

src/mapml-viewer.js

@@ -360,8 +360,12 @@ export class MapViewer extends HTMLElement {
               layersReady.push(reAttach.whenReady());
             }
             Promise.allSettled(layersReady).then(() => {
-              this.zoomTo(lat, lon, zoom);
+              // if don't do a zoomTo, the BNG experiment ends up at zoom=5 (incorrectly)
+              // BUT the feature link from Canada/BC to BCTILE layer works
+              // can have one but not both tbd
+              //
               this._resetHistory();
+              this.zoomTo(lat, lon, zoom);
               this._map.announceMovement.enable();
             });
           }

src/mapml/utils/Util.js

@@ -527,12 +527,6 @@ export var Util = {
       }
       if (!link.inPlace && newLayer)
         layer.whenReady().then(() => {
-          if (
-            newLayer &&
-            ['_parent', '_self'].includes(link.target) &&
-            layer.parentElement.querySelectorAll('layer-').length === 1
-          )
-            layer.parentElement.projection = layer._layer.getProjection();
           if (!layer.extent) {
             layer._layer._setLayerElExtent();
           }