Nested element manager provider

src/base/NestedElementManagerProviderInterface.php

@@ -0,0 +1,31 @@
+<?php
+/**
+ * @link https://craftcms.com/
+ * @copyright Copyright (c) Pixel & Tonic, Inc.
+ * @license https://craftcms.github.io/license/
+ */
+
+namespace craft\base;
+
+use craft\elements\NestedElementManager;
+
+/**
+ * NestedElementManagerProviderInterface defines the common interface to be implemented by elements that provide
+ * one or more nested element providers for the elements that can be owned by them.
+ *
+ *
+ * @mixin ElementTrait
+ * @mixin Component
+ * @author Pixel & Tonic, Inc. <[email protected]>
+ * @since 5.x
+ */
+interface NestedElementManagerProviderInterface extends ElementInterface
+{
+    /**
+     * Returns the nested element manager by the attribute name.
+     *
+     * @param string $attribute The attribute name
+     * @return ?NestedElementManager
+     */
+    public function getNestedElementManager(string $attribute): ?NestedElementManager;
+}

src/controllers/NestedElementsController.php

@@ -10,11 +10,13 @@
 use Craft;
 use craft\base\ElementInterface;
 use craft\base\NestedElementInterface;
+use craft\base\NestedElementManagerProviderInterface;
 use craft\db\Table;
 use craft\elements\db\ElementQueryInterface;
 use craft\elements\ElementCollection;
 use craft\helpers\Db;
 use craft\web\Controller;
+use http\Exception\InvalidArgumentException;
 use yii\web\BadRequestHttpException;
 use yii\web\ForbiddenHttpException;
 use yii\web\Response;
@@ -65,8 +67,16 @@ public function beforeAction($action): bool
             throw new ForbiddenHttpException('User is not authorized to perform this action');
         }
 
-        // Set the nested elements for the action
-        $this->nestedElements = $this->owner->$attribute;
+        if ($this->owner instanceof NestedElementManagerProviderInterface) {
+            $manager = $this->owner->getNestedElementManager($attribute);
+            if (!$manager) {
+                throw new InvalidArgumentException('Owner does not provide a nested element manager for the given attribute');
+            }
+
+            $this->nestedElements = $manager->getValue($owner, true);
+        } else {
+            $this->nestedElements = $this->owner->$attribute;
+        }
 
         return true;
     }

src/elements/NestedElementManager.php

@@ -172,7 +172,13 @@ private function nestedElementQuery(ElementInterface $owner): ElementQueryInterf
         return call_user_func($this->queryFactory, $owner);
     }
 
-    private function getValue(ElementInterface $owner, bool $fetchAll = false): ElementQueryInterface|ElementCollection
+    /**
+     * @param ElementInterface $owner
+     * @param bool $fetchAll
+     * @return ElementQueryInterface|ElementCollection
+     * @throws \craft\errors\InvalidFieldException
+     */
+    public function getValue(ElementInterface $owner, bool $fetchAll = false): ElementQueryInterface|ElementCollection
     {
         if (isset($this->valueGetter)) {
             return call_user_func($this->valueGetter, $owner, $fetchAll);
@@ -199,7 +205,12 @@ private function getValue(ElementInterface $owner, bool $fetchAll = false): Elem
         return $query;
     }
 
-    private function setValue(ElementInterface $owner, ElementQueryInterface|ElementCollection $value): void
+    /**
+     * @param ElementInterface $owner
+     * @param ElementQueryInterface|ElementCollection $value
+     * @return void
+     */
+    public function setValue(ElementInterface $owner, ElementQueryInterface|ElementCollection $value): void
     {
         if ($this->valueSetter === false) {
             return;

src/elements/User.php

@@ -11,6 +11,7 @@
 use craft\base\Element;
 use craft\base\ElementInterface;
 use craft\base\NameTrait;
+use craft\base\NestedElementManagerProviderInterface;
 use craft\db\Query;
 use craft\db\Table;
 use craft\elements\actions\DeleteUsers;
@@ -85,7 +86,7 @@
  * @author Pixel & Tonic, Inc. <[email protected]>
  * @since 3.0.0
  */
-class User extends Element implements IdentityInterface
+class User extends Element implements IdentityInterface, NestedElementManagerProviderInterface
 {
     use NameTrait;
 
@@ -2549,6 +2550,17 @@ public function beforeDelete(): bool
         return true;
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function getNestedElementManager(string $attribute): ?NestedElementManager
+    {
+        return match ($attribute) {
+            'addresses' => $this->getAddressManager(),
+            default => null,
+        };
+    }
+
     /**
      * Validates a cookie's stored user agent against the current request's user agent string,
      * if the 'requireMatchingUserAgentForSession' config setting is enabled.