如何在 Symfony 5 中创建用于序列化 json 的自定义 Normilizer？

Question

我正在使用 symfony 创建 REST api，最终想要 return 自定义 json。例如隐藏一些字段，从关系对象中获取特定字段（来自外键）等等（底部的例子）。

我有两个具有 ManyToOne/OneToMany 关系的实体，产品和类别。

Product.php:

<?php

namespace App\Entity;

use App\Repository\ProductRepository;
use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity(repositoryClass=ProductRepository::class)
 */
class Product
{
    /**
     * @ORM\Id
     * @ORM\GeneratedValue
     * @ORM\Column(type="integer")
     */
    private $id;

    /**
     * @ORM\Column(type="string", length=255)
     */
    private $name;

    /**
     * @ORM\Column(type="text")
     */
    private $description;

    /**
     * @ORM\Column(type="float")
     */
    private $price;

    /**
     * @ORM\Column(type="boolean")
     */
    private $available;

    /**
     * @ORM\ManyToOne(targetEntity=Category::class, inversedBy="products")
     * @ORM\JoinColumn(nullable=false)
     */
    private $category;

    // ...
    // Rest of getters & setters
    // ...

    public function getCategory(): ?Category
    {
        return $this->category;
    }

    public function setCategory(?Category $category): self
    {
        $this->category = $category;

        return $this;
    }

Category.php:

<?php

namespace App\Entity;

use App\Repository\CategoryRepository;
use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Collections\Collection;
use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity(repositoryClass=CategoryRepository::class)
 */
class Category
{
    /**
     * @ORM\Id
     * @ORM\GeneratedValue
     * @ORM\Column(type="integer")
     */
    private $id;

    /**
     * @ORM\Column(type="string", length=255)
     */
    private $name;

    /**
     * @ORM\OneToMany(targetEntity=Product::class, mappedBy="category")
     */
    private $products;

    public function __construct()
    {
        $this->products = new ArrayCollection();
    }

    // ...
    // Rest of getters & setters
    // ...

    /**
     * @return Collection|Product[]
     */
    public function getProducts(): Collection
    {
        return $this->products;
    }

    public function addProduct(Product $product): self
    {
        if (!$this->products->contains($product)) {
            $this->products[] = $product;
            $product->setCategory($this);
        }

        return $this;
    }

    public function removeProduct(Product $product): self
    {
        if ($this->products->removeElement($product)) {
            // set the owning side to null (unless already changed)
            if ($product->getCategory() === $this) {
                $product->setCategory(null);
            }
        }

        return $this;
    }

    public function __toString()
    {
        return $this->getName();
    }
}

这是我的控制器：

class ProductApiController extends AbstractController
{
    /**
     * @Route("/products", name = "api_product_list")
     */
    public function getAll(SerializerInterface $serializer, ProductRepository $repo): Response
    {
        $products = $repo->findAll();
        $jsonObject = $serializer->serialize($products, 'json', [
            'circular_reference_handler' => function () {
                return null;
            }]
        );
        return new Response($jsonObject, 200, ['Content-Type' => 'application/json']);
    }
}

这是我当前的输出：

{
  "id": 1,
  "name": "Gaming pc",
  "description": "A nice computer",
  "price": 9800,
  "available": true,
  "category": {
    "id": 1,
    "name": "Computers",
    "products": [
      null
    ],
    "__initializer__": null,
    "__cloner__": null,
    "__isInitialized__": true
    }
}

这是我想要得到的输出：

{
  "id": 1,
  "name": "Gaming pc",
  "description": "A nice computer",
  "price": 9800,
  "available": true,
  "category": "Computers" // Basically this is why I need a custom serializer
}

这是 documentation，但我不知道在我的情况下该怎么做。

Answer 1

在 src/Serializer/ProductNormalizer.php 下：（路径必须准确，否则你必须 register it manually）

<?php

namespace App\Serializer;

use App\Entity\Product;
use Symfony\Component\Serializer\Normalizer\ContextAwareNormalizerInterface;
use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;

class ProductNormalizer implements ContextAwareNormalizerInterface
{
    private $normalizer;

    public function __construct(ObjectNormalizer $normalizer)
    {
        $this->normalizer = $normalizer;
    }

    public function normalize($product, string $format = null, array $context = [])
    {
        $data = $this->normalizer->normalize($product, $format, $context);
        $data = [
            'id' => $product->getId(),
            'name' => $product->getName(),
            'description' => $product->getDescription(),
            'price' => $product->getPrice(),
            'available' => $product->getAvailable(),
            'category' => $product->getCategory()->getName(), //Customize to your needs
        ];
        return $data;
    }

    public function supportsNormalization($data, string $format = null, array $context = [])
    {
        return $data instanceof product;
    }
}

如何在 Symfony 5 中创建用于序列化 json 的自定义 Normilizer？

How to create a custom Normilizer for serializing json in Symfony 5?

php

serialization

normalization

symfony