improve how we get parents for subdivision fields

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Fixed a bug where it wasn’t possible to override named transforms in GraphQL queries. ([#15572](https://github.com/craftcms/cms/issues/15572))
+- Fixed a bug where address subdivision fields could be incorrectly labelled and/or populated with the wrong options. ([#15551](https://github.com/craftcms/cms/issues/15551), [#15584](https://github.com/craftcms/cms/pull/15584))
 
 ## 4.11.4 - 2024-08-21
 

src/helpers/Cp.php

@@ -7,6 +7,7 @@
 
 namespace craft\helpers;
 
+use CommerceGuys\Addressing\Subdivision\SubdivisionRepository as BaseSubdivisionRepository;
 use Craft;
 use craft\base\Element;
 use craft\base\ElementInterface;
@@ -1301,6 +1302,8 @@ public static function addressFieldsHtml(Address $address): string
                 $addressesService->getUsedSubdivisionFields($address->countryCode),
             )) + $requiredFields;
 
+        $parents = self::_getSubdivisionParents($address, $visibleFields);
+
         return
             static::textFieldHtml([
                 'status' => $address->getAttributeStatus('addressLine1'),
@@ -1337,7 +1340,7 @@ public static function addressFieldsHtml(Address $address): string
                 $belongsToCurrentUser ? 'address-level2' : 'off',
                 isset($visibleFields['locality']),
                 isset($requiredFields['locality']),
-                [$address->countryCode, $address->administrativeArea],
+                $parents['locality'],
                 true,
             ) .
             self::_subdivisionField(
@@ -1346,7 +1349,7 @@ public static function addressFieldsHtml(Address $address): string
                 $belongsToCurrentUser ? 'address-level3' : 'off',
                 isset($visibleFields['dependentLocality']),
                 isset($requiredFields['dependentLocality']),
-                [$address->countryCode, $address->administrativeArea, $address->locality],
+                $parents['dependentLocality'],
                 false,
             ) .
             static::textFieldHtml([
@@ -1378,6 +1381,49 @@ public static function addressFieldsHtml(Address $address): string
             ]);
     }
 
+    /**
+     * Get parents array that needs to be passed to the subdivision repository getList() method to get the list of subdivisions back.
+     *
+     * For the administrativeArea, the parent is always just the country code.
+     *
+     * For the locality:
+     *      - it could be just the country code
+     *          - for countries that don't use administrativeArea field; that's the case with Andorra
+     *      - it could be the country code and the administrative area code
+     *          - for countries that use both administrative areas and localities; e.g. Chile (Chile => Araucania > Carahue)
+     *          - the administrative area can be passed as null too;
+     *              this will be triggered for the United Kingdom (GB), where you can conditionally turn on administrativeArea;
+     *              in the case of GB, not passing null as the second value would result
+     *              in the administrativeAreas list being returned for the locality field (https://github.com/craftcms/cms/issues/15551);
+     *
+     * For the dependentLocality:
+     *      - as above but taking locality into consideration too; e.g. China has all 3 levels of subdivisions and has lists for all 3 of them
+     *          (China => Heilongjiang Sheng > Hegang Shi > Dongshan Qu)
+     *
+     * @param Address $address
+     * @param array $visibleFields
+     * @return array
+     */
+    private static function _getSubdivisionParents(Address $address, array $visibleFields): array
+    {
+        $baseSubdivisionRepository = new BaseSubdivisionRepository();
+
+        $localityParents = [$address->countryCode];
+        $administrativeAreas = $baseSubdivisionRepository->getList([$address->countryCode]);
+
+        if (array_key_exists('administrativeArea', $visibleFields) || empty($administrativeAreas)) {
+            $localityParents[] = $address->administrativeArea;
+        }
+
+        $dependentLocalityParents = $localityParents;
+        $localities = $baseSubdivisionRepository->getList($localityParents);
+        if (array_key_exists('locality', $visibleFields) || empty($localities)) {
+            $dependentLocalityParents[] = $address->locality;
+        }
+
+        return ['locality' => $localityParents, 'dependentLocality' => $dependentLocalityParents];
+    }
+
     private static function _subdivisionField(
         Address $address,
         string $name,