ENGCOM-2421: Added breadcrumbs support #112

 - Merge Pull Request magento/graphql-ce#112 from magento/graphql-ce:19-add-breadcrumbs-support
 - Merged commits:
   1. 34ed6d1
   2. 78a67c3
   3. 3d973af
   4. cfd7502

app/code/Magento/CatalogGraphQl/Model/Resolver/Category/Breadcrumbs.php

@@ -0,0 +1,62 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\CatalogGraphQl\Model\Resolver\Category;
+
+use \Magento\CatalogGraphQl\Model\Resolver\Category\DataProvider\Breadcrumbs as BreadcrumbsDataProvider;
+use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
+use Magento\Framework\GraphQl\Config\Element\Field;
+use Magento\Framework\GraphQl\Query\ResolverInterface;
+use Magento\Framework\GraphQl\Query\Resolver\Value;
+use Magento\Framework\GraphQl\Query\Resolver\ValueFactory;
+
+/**
+ * Retrieves breadcrumbs
+ */
+class Breadcrumbs implements ResolverInterface
+{
+    /**
+     * @var BreadcrumbsDataProvider
+     */
+    private $breadcrumbsDataProvider;
+
+    /**
+     * @var ValueFactory
+     */
+    private $valueFactory;
+
+    /**
+     * @param BreadcrumbsDataProvider $breadcrumbsDataProvider
+     * @param ValueFactory $valueFactory
+     */
+    public function __construct(
+        BreadcrumbsDataProvider $breadcrumbsDataProvider,
+        ValueFactory $valueFactory
+    ) {
+        $this->breadcrumbsDataProvider = $breadcrumbsDataProvider;
+        $this->valueFactory = $valueFactory;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function resolve(Field $field, $context, ResolveInfo $info, array $value = null, array $args = null): Value
+    {
+        if (!isset($value['path'])) {
+            $result = function () {
+                return null;
+            };
+            return $this->valueFactory->create($result);
+        }
+
+        $result = function () use ($value) {
+            $breadcrumbsData = $this->breadcrumbsDataProvider->getData($value['path']);
+            return count($breadcrumbsData) ? $breadcrumbsData : null;
+        };
+        return $this->valueFactory->create($result);
+    }
+}

app/code/Magento/CatalogGraphQl/Model/Resolver/Category/DataProvider/Breadcrumbs.php

@@ -0,0 +1,58 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\CatalogGraphQl\Model\Resolver\Category\DataProvider;
+
+use Magento\Catalog\Model\ResourceModel\Category\CollectionFactory;
+
+/**
+ * Breadcrumbs data provider
+ */
+class Breadcrumbs
+{
+    /**
+     * @var CollectionFactory
+     */
+    private $collectionFactory;
+
+    /**
+     * @param CollectionFactory $collectionFactory
+     */
+    public function __construct(
+        CollectionFactory $collectionFactory
+    ) {
+        $this->collectionFactory = $collectionFactory;
+    }
+
+    /**
+     * @param string $categoryPath
+     * @return array
+     */
+    public function getData(string $categoryPath): array
+    {
+        $breadcrumbsData = [];
+
+        $pathCategoryIds = explode('/', $categoryPath);
+        $parentCategoryIds = array_slice($pathCategoryIds, 2, -1);
+
+        if (count($parentCategoryIds)) {
+            $collection = $this->collectionFactory->create();
+            $collection->addAttributeToSelect(['name', 'url_key']);
+            $collection->addAttributeToFilter('entity_id', $parentCategoryIds);
+
+            foreach ($collection as $category) {
+                $breadcrumbsData[] = [
+                    'category_id' => $category->getId(),
+                    'category_name' => $category->getName(),
+                    'category_level' => $category->getLevel(),
+                    'category_url_key' => $category->getUrlKey(),
+                ];
+            }
+        }
+        return $breadcrumbsData;
+    }
+}

app/code/Magento/CatalogGraphQl/etc/schema.graphqls

@@ -381,6 +381,14 @@ interface CategoryInterface @typeResolver(class: "Magento\\CatalogGraphQl\\Model
         currentPage: Int = 1 @doc(description: "Specifies which page of results to return. The default value is 1."),
         sort: ProductSortInput @doc(description: "Specifies which attribute to sort on, and whether to return the results in ascending or descending order.")
     ): CategoryProducts @doc(description: "The list of products assigned to the category") @resolver(class: "Magento\\CatalogGraphQl\\Model\\Resolver\\Category\\Products")
+    breadcrumbs: [Breadcrumb] @doc(description: "Breadcrumbs, parent categories info") @resolver(class: "Magento\\CatalogGraphQl\\Model\\Resolver\\Category\\Breadcrumbs")
+}
+
+type Breadcrumb @doc(description: "Breadcrumb item"){
+    category_id: Int @doc(description: "Category ID")
+    category_name: String @doc(description: "Category name")
+    category_level: Int @doc(description: "Category level")
+    category_url_key: String @doc(description: "Category URL key")
 }
 
 type CustomizableRadioOption implements CustomizableOptionInterface @doc(description: "CustomizableRadioOption contains information about a set of radio buttons that are defined as part of a customizable option") {