B2B-2469: Improve category children loading

Author: rganin

app/code/Magento/CatalogGraphQl/Model/Resolver/Products/DataProvider/CategoryTree/Wrapper/Forgery.php

@@ -19,7 +19,7 @@ class Forgery
     /**
      * Most top node id in the tree structure.
      */
-    private const DUMMY_ROOT_ID = 0;
+    private const TOP_NODE_ID = 0;
 
     /**
      * Flat index of the tree.
@@ -49,30 +49,28 @@ public function __construct(Hydrator $hydrator)
      */
     public function forge(Category $category): void
     {
-        $pathElements = array_map(
-            function ($element) {
-                return (int)$element;
-            },
-            explode('/', $category->getPath())
-        );
-        if (!$this->hasNodeById(self::DUMMY_ROOT_ID)) {
-            $this->indexById[self::DUMMY_ROOT_ID] = new Node(self::DUMMY_ROOT_ID, $this);
+        if (!$this->hasNodeById(self::TOP_NODE_ID)) {
+            $this->indexById[self::TOP_NODE_ID] = new Node(self::TOP_NODE_ID);
         }
-        $parentId = self::DUMMY_ROOT_ID;
-        foreach ($pathElements as $id) {
-            if ($this->hasNodeById($parentId)) {
+        $parentId = self::TOP_NODE_ID;
+        array_map(
+            function ($id) use (&$parentId, $category) {
+                $id = (int)$id;
                 if (!$this->hasNodeById($id)) {
-                    $this->indexById[$id] = new Node($id, $this);
+                    $this->indexById[$id] = new Node($id);
+                }
+                if ($this->hasNodeById($parentId)) {
                     $this->getNodeById($parentId)->addChild($this->indexById[$id]);
                     if ($category->getId() == $id) {
-                        $this->indexById[$id]->setModel($category);
+                        $this->indexById[$id]->setModelData(
+                            $this->hydrator->hydrateCategory($category)
+                        );
                     }
                 }
-            } elseif (!$this->hasNodeById($id)) {
-                $this->indexById[$id] = new Node($id, $this);
-            }
-            $parentId = $id;
-        }
+                $parentId = $id;
+            },
+            explode('/', $category->getPath())
+        );
     }
 
     /**
@@ -96,14 +94,4 @@ public function hasNodeById(int $id) : bool
     {
         return isset($this->indexById[$id]);
     }
-
-    /**
-     * Get category hydrator.
-     *
-     * @return Hydrator
-     */
-    public function getHydrator()
-    {
-        return $this->hydrator;
-    }
 }

app/code/Magento/CatalogGraphQl/Model/Resolver/Products/DataProvider/CategoryTree/Wrapper/Node.php

@@ -25,34 +25,26 @@ class Node
     private $children = [];
 
     /**
-     * @var Category
+     * @var array
      */
-    private $model;
-
-    /**
-     * @var Forgery
-     */
-    private $forgery;
+    private $modelData;
 
     /**
      * @param int $id
-     * @param Forgery $forgery
      */
-    public function __construct(int $id, Forgery $forgery)
+    public function __construct(int $id)
     {
         $this->id = $id;
-        $this->forgery = $forgery;
     }
 
     /**
-     * Set category model for node.
+     * Set category model data for node.
      *
-     * @param Category $category
      * @return $this
      */
-    public function setModel(Category $category): self
+    public function setModelData(?array $modelData): self
     {
-        $this->model = $category;
+        $this->modelData = $modelData;
         return $this;
     }
 
@@ -78,16 +70,6 @@ public function getChildren(): array
         return $this->children;
     }
 
-    /**
-     * Get category model for node.
-     *
-     * @return Category
-     */
-    public function getModel(): Category
-    {
-        return $this->model;
-    }
-
     /**
      * Get node id.
      *
@@ -105,11 +87,11 @@ public function getId(): int
      */
     public function renderArray(): ?array
     {
-        if (!$this->model) {
+        if (!$this->modelData) {
             return null;
         }
         return array_merge(
-            $this->forgery->getHydrator()->hydrateCategory($this->model),
+            $this->modelData,
             [
                 'children' => array_filter(
                     array_map(