Pass and use the Default Centre setting as documented

Author: haydngreatnews

wagtailgmaps/static/wagtailgmaps/js/map-field-panel.js

@@ -5,6 +5,7 @@ class MapInputController extends window.StimulusModule.Controller {
         this.geocoder = new google.maps.Geocoder();
         this.latlngMode = Boolean(this.element.dataset.latlngmode);
         this.zoom = Number(this.element.dataset.zoom);
+        this.defaultCentre = this.element.dataset.defaultcentre;
 
         // Trigger the event so the maps can start doing their things
         var event; // The custom event that will be created
@@ -129,7 +130,7 @@ class MapInputController extends window.StimulusModule.Controller {
 
         // Set the map to the initial location
         controller.geocodeAddress(
-            initValue,
+            initValue || controller.defaultCentre,
             controller.textboxTarget,
             controller.marker,
             controller.map

wagtailgmaps/templates/wagtailgmaps/forms/widgets/map_input.html

@@ -5,6 +5,7 @@
     data-lat="{{ lat }}"
     data-lng="{{ lng }}"
     data-latlngMode="{{ latlngMode }}"
+    data-defaultCentre="{{ default_centre }}"
 >
     {% include "django/forms/widgets/text.html" %}
     <br/>

wagtailgmaps/widgets.py

@@ -35,6 +35,7 @@ def get_context(self, name, value, attrs):
                 "latlngMode": self.latlngMode,
                 "map_id": self.get_map_id(attrs["id"]),
                 "zoom": self.zoom,
+                "default_centre": self.default_centre,
             }
         )