13-examples

Real-World Examples

Overview

This section provides complete, production-ready examples of GraphQL implementations in Magento 2.

Topics Covered

1. Complete Custom Module Example
2. Blog Posts API
3. Product Reviews Extension
4. Custom Wishlist Features
5. Store Locator with GraphQL
6. Custom Customer Attributes
7. Advanced Product Filtering
8. Subscription Management
9. Gift Registry System
10. Custom Checkout Fields

Learning Objectives

By the end of this section, you will:

• Understand complete module structure
• See real-world resolver implementations
• Learn from production-ready code
• Understand common patterns and use cases
• Be able to build your own custom GraphQL features

Example 1: Simple Blog API

Complete implementation of a blog posts GraphQL API.

Module Structure

app/code/Vendor/Blog/
├── etc/
│   ├── module.xml
│   ├── db_schema.xml
│   ├── schema.graphqls
│   └── di.xml
├── Model/
│   ├── Post.php
│   ├── ResourceModel/
│   │   ├── Post.php
│   │   └── Post/
│   │       └── Collection.php
│   ├── Resolver/
│   │   ├── Posts.php
│   │   ├── Post.php
│   │   ├── CreatePost.php
│   │   └── UpdatePost.php
│   └── DataProvider/
│       └── PostDataProvider.php
├── Api/
│   ├── Data/
│   │   └── PostInterface.php
│   └── PostRepositoryInterface.php
└── composer.json

Schema Definition

# etc/schema.graphqls
type Query {
    blogPosts(
        filter: BlogPostFilterInput
        pageSize: Int = 20
        currentPage: Int = 1
    ): BlogPostsOutput @resolver(class: "Vendor\\Blog\\Model\\Resolver\\Posts") @doc(description: "Get blog posts")

    blogPost(id: Int!): BlogPost @resolver(class: "Vendor\\Blog\\Model\\Resolver\\Post") @doc(description: "Get blog post by ID")
}

type Mutation {
    createBlogPost(input: CreateBlogPostInput!): BlogPost @resolver(class: "Vendor\\Blog\\Model\\Resolver\\CreatePost") @doc(description: "Create a new blog post")

    updateBlogPost(id: Int!, input: UpdateBlogPostInput!): BlogPost @resolver(class: "Vendor\\Blog\\Model\\Resolver\\UpdatePost") @doc(description: "Update blog post")
}

input BlogPostFilterInput {
    title: FilterTypeInput
    status: FilterTypeInput
    author_id: FilterTypeInput
}

input CreateBlogPostInput {
    title: String!
    content: String!
    status: String
    author_id: Int
}

input UpdateBlogPostInput {
    title: String
    content: String
    status: String
}

type BlogPostsOutput {
    items: [BlogPost]
    total_count: Int
    page_info: SearchResultPageInfo
}

type BlogPost {
    id: Int
    title: String
    content: String
    status: String
    author_id: Int
    author_name: String @resolver(class: "Vendor\\Blog\\Model\\Resolver\\Post\\AuthorName")
    created_at: String
    updated_at: String
}

Resolver: Get Posts

<?php
namespace Vendor\Blog\Model\Resolver;

use Magento\Framework\GraphQl\Config\Element\Field;
use Magento\Framework\GraphQl\Query\ResolverInterface;
use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
use Magento\Framework\GraphQl\Exception\GraphQlInputException;
use Vendor\Blog\Model\ResourceModel\Post\CollectionFactory;

class Posts implements ResolverInterface
{
    private $collectionFactory;

    public function __construct(CollectionFactory $collectionFactory)
    {
        $this->collectionFactory = $collectionFactory;
    }

    public function resolve(
        Field $field,
        $context,
        ResolveInfo $info,
        array $value = null,
        array $args = null
    ) {
        $pageSize = $args['pageSize'] ?? 20;
        $currentPage = $args['currentPage'] ?? 1;

        $collection = $this->collectionFactory->create();

        // Apply filters
        if (isset($args['filter'])) {
            $this->applyFilters($collection, $args['filter']);
        }

        // Set pagination
        $collection->setPageSize($pageSize);
        $collection->setCurPage($currentPage);

        $items = [];
        foreach ($collection as $post) {
            $items[] = [
                'id' => $post->getId(),
                'title' => $post->getTitle(),
                'content' => $post->getContent(),
                'status' => $post->getStatus(),
                'author_id' => $post->getAuthorId(),
                'created_at' => $post->getCreatedAt(),
                'updated_at' => $post->getUpdatedAt(),
                'model' => $post
            ];
        }

        return [
            'items' => $items,
            'total_count' => $collection->getSize(),
            'page_info' => [
                'page_size' => $pageSize,
                'current_page' => $currentPage,
                'total_pages' => ceil($collection->getSize() / $pageSize)
            ]
        ];
    }

    private function applyFilters($collection, array $filters)
    {
        foreach ($filters as $field => $condition) {
            foreach ($condition as $conditionType => $value) {
                $collection->addFieldToFilter($field, [$conditionType => $value]);
            }
        }
    }
}

Resolver: Create Post

<?php
namespace Vendor\Blog\Model\Resolver;

use Magento\Framework\GraphQl\Config\Element\Field;
use Magento\Framework\GraphQl\Query\ResolverInterface;
use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
use Magento\Framework\GraphQl\Exception\GraphQlInputException;
use Magento\Framework\GraphQl\Exception\GraphQlAuthorizationException;
use Vendor\Blog\Api\PostRepositoryInterface;
use Vendor\Blog\Model\PostFactory;

class CreatePost implements ResolverInterface
{
    private $postRepository;
    private $postFactory;

    public function __construct(
        PostRepositoryInterface $postRepository,
        PostFactory $postFactory
    ) {
        $this->postRepository = $postRepository;
        $this->postFactory = $postFactory;
    }

    public function resolve(
        Field $field,
        $context,
        ResolveInfo $info,
        array $value = null,
        array $args = null
    ) {
        // Check authentication
        if (!$context->getUserId()) {
            throw new GraphQlAuthorizationException(
                __('You must be logged in to create a post')
            );
        }

        // Validate input
        if (!isset($args['input']['title']) || empty($args['input']['title'])) {
            throw new GraphQlInputException(__('Title is required'));
        }

        if (!isset($args['input']['content']) || empty($args['input']['content'])) {
            throw new GraphQlInputException(__('Content is required'));
        }

        try {
            // Create post
            $post = $this->postFactory->create();
            $post->setTitle($args['input']['title']);
            $post->setContent($args['input']['content']);
            $post->setStatus($args['input']['status'] ?? 'draft');
            $post->setAuthorId($args['input']['author_id'] ?? $context->getUserId());

            // Save post
            $savedPost = $this->postRepository->save($post);

            return [
                'id' => $savedPost->getId(),
                'title' => $savedPost->getTitle(),
                'content' => $savedPost->getContent(),
                'status' => $savedPost->getStatus(),
                'author_id' => $savedPost->getAuthorId(),
                'created_at' => $savedPost->getCreatedAt(),
                'updated_at' => $savedPost->getUpdatedAt()
            ];

        } catch (\Exception $e) {
            throw new GraphQlInputException(
                __('Unable to create post: %1', $e->getMessage())
            );
        }
    }
}

Example Queries

Get All Posts

{
  blogPosts(pageSize: 10, currentPage: 1) {
    items {
      id
      title
      content
      status
      author_name
      created_at
    }
    total_count
    page_info {
      page_size
      current_page
      total_pages
    }
  }
}

Get Single Post

{
  blogPost(id: 1) {
    id
    title
    content
    status
    author_id
    author_name
    created_at
    updated_at
  }
}

Create Post

mutation {
  createBlogPost(
    input: {
      title: "My First Blog Post"
      content: "This is the content of my first blog post."
      status: "published"
    }
  ) {
    id
    title
    content
    status
    created_at
  }
}

Filter Posts

{
  blogPosts(
    filter: {
      status: { eq: "published" }
      title: { like: "%GraphQL%" }
    }
    pageSize: 5
  ) {
    items {
      id
      title
      status
    }
    total_count
  }
}

Example 2: Product Review System

See Product Reviews Extension for complete implementation.

Example 3: Custom Customer Attributes

See Custom Customer Attributes for complete implementation.

Code Organization Best Practices

1. Separate Concerns

• Models: Data structures and business logic
• Resolvers: GraphQL field resolution
• Data Providers: Data fetching and transformation
• Services: Reusable business operations

2. Use Dependency Injection

public function __construct(
    PostRepositoryInterface $postRepository,
    SearchCriteriaBuilder $searchCriteriaBuilder,
    LoggerInterface $logger
) {
    $this->postRepository = $postRepository;
    $this->searchCriteriaBuilder = $searchCriteriaBuilder;
    $this->logger = $logger;
}

3. Implement Proper Error Handling

try {
    $result = $this->processData($args);
    return $result;
} catch (NoSuchEntityException $e) {
    throw new GraphQlNoSuchEntityException(__($e->getMessage()));
} catch (\Exception $e) {
    $this->logger->critical($e);
    throw new GraphQlInputException(__('An error occurred'));
}

4. Use Type Hints and Return Types

public function resolve(
    Field $field,
    $context,
    ResolveInfo $info,
    array $value = null,
    array $args = null
): array {
    // Implementation
}

Testing Examples

See each example directory for corresponding test files.

Next Steps

Explore each example in detail:

1. Complete Module Example
2. Blog API
3. Product Reviews

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