[YC-1171] set validation for geom field

geocity/apps/forms/admin.py

@@ -556,6 +556,22 @@ def clean_maximum_date(self):
 
         return maximum_date
 
+    def clean_map_widget_configuration(self):
+        selected_input_type = self.cleaned_data.get("input_type")
+        map_widget_configuration = self.cleaned_data.get("map_widget_configuration")
+
+        if (
+            selected_input_type == models.Field.INPUT_TYPE_GEOM
+            and not map_widget_configuration
+        ):
+            raise forms.ValidationError(
+                _(
+                    "Vous devez obligatoirement sélectionner une configuration de carte avancée."
+                )
+            )
+
+        return map_widget_configuration
+
     class Media:
         js = ("js/admin/form_field.js",)