Symfony REST API 数据验证实践：精简控制器之道

<?php

namespace App\Entity;

use Symfony\Component\Validator\Constraints as Assert;
// 如果是Doctrine实体，还需要引入ORM相关注解
// use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity(repositoryClass="App\Repository\AuthorRepository")
 */
class Author
{
    /**
     * @ORM\Id()
     * @ORM\GeneratedValue()
     * @ORM\Column(type="integer")
     */
    private $id;

    /**
     * @ORM\Column(type="string", length=255)
     * @Assert\NotBlank(message="作者名称不能为空。")
     * @Assert\Length(
     *     min=2,
     *     max=255,
     *     minMessage="作者名称至少需要 {{ limit }} 个字符。",
     *     maxMessage="作者名称不能超过 {{ limit }} 个字符。"
     * )
     */
    private $name;

    // ... 其他属性和Getter/Setter方法 ...

    public function getId(): ?int
    {
        return $this->id;
    }

    public function getName(): ?string
    {
        return $this->name;
    }

    public function setName(string $name): self
    {
        $this->name = $name;

        return $this;
    }
}

<?php

namespace App\Controller;

use App\Entity\Author;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\Routing\Annotation\Route;
use Symfony\Component\Validator\Validator\ValidatorInterface;

class AuthorController extends AbstractController
{
    /**
     * @Route("/api/authors", name="api_authors_store", methods={"POST"})
     */
    public function store(Request $request, ValidatorInterface $validator): JsonResponse
    {
        // 1. 获取请求数据并填充到实体对象
        $author = new Author();
        // 假设请求体是JSON格式，可以使用$request->toArray()获取
        $data = $request->toArray(); 

        // 确保name键存在，并进行类型转换
        if (!isset($data['name']) || !is_string($data['name'])) {
             return $this->json(
                ['status' => 'error', 'message' => 'Invalid or missing "name" field.'],
                JsonResponse::HTTP_BAD_REQUEST
            );
        }
        $author->setName($data['name']);

        // ... 填充其他属性，例如：
        // $author->setEmail($data['email'] ?? null);

        // 2. 执行验证
        $errors = $validator->validate($author);

        // 3. 处理验证结果
        if (count($errors) > 0) {
            $errorMessages = [];
            foreach ($errors as $error) {
                $errorMessages[] = [
                    'property' => $error->getPropertyPath(), // 哪个属性出错
                    'value' => $error->getInvalidValue(),   // 错误的值
                    'message' => $error->getMessage(),      // 错误信息
                ];
            }
            // 返回400 Bad Request状态码，并附带详细错误信息
            return $this->json(
                ['status' => 'error', 'message' => 'Validation Failed', 'errors' => $errorMessages],
                JsonResponse::HTTP_BAD_REQUEST
            );
        }

        // 4. 数据有效，进行业务处理（例如：持久化到数据库）
        $entityManager = $this->getDoctrine()->getManager();
        $entityManager->persist($author);
        $entityManager->flush();

        // 5. 返回成功响应
        return $this->json(
            ['status' => 'success', 'message' => 'Author created successfully', 'author' => [
                'id' => $author->getId(), 
                'name' => $author->getName()
            ]],
            JsonResponse::HTTP_CREATED // 返回201 Created状态码
        );
    }
}

<?php

namespace App\Dto;

use Symfony\Component\Validator\Constraints as Assert;

class AuthorCreateRequest
{
    /**
     * @Assert\NotBlank(message="作者名称不能为空。")
     * @Assert\Length(
     *     min=2,
     *     max=255,
     *     minMessage="作者名称至少需要 {{ limit }} 个字符。",
     *     maxMessage="作者名称不能超过 {{ limit }} 个字符。"
     * )
     */
    public $name;

    // ... 其他请求字段
    // public $email;
}

<?php

namespace App\Controller;

use App\Entity\Author;
use App\Dto\AuthorCreateRequest;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\Routing\Annotation\Route;
use Symfony\Component\Validator\Validator\ValidatorInterface;
use Symfony\Component\Serializer\SerializerInterface; // 引入SerializerInterface

class AuthorController extends AbstractController
{
    /**
     * @Route("/api/authors", name="api_authors_store_dto", methods={"POST"})
     */
    public function storeWithDto(
        Request $request, 
        ValidatorInterface $validator, 
        SerializerInterface $serializer // 注入SerializerInterface
    ): JsonResponse {
        // 1. 反序列化请求数据到DTO对象
        try {
            /** @var AuthorCreateRequest $authorRequest */
            $authorRequest = $serializer->deserialize(
                $request->getContent(), 
                AuthorCreateRequest::class, 
                'json'
            );
        } catch (\Exception $e) {
            return $this->json(
                ['status' => 'error', 'message' => 'Invalid JSON format or data type.'],
                JsonResponse::HTTP_BAD_REQUEST
            );
        }

        // 2. 执行DTO验证
        $errors = $validator->validate($authorRequest);

        if (count($errors) > 0) {
            $errorMessages = [];
            foreach ($errors as $error) {
                $errorMessages[] = [
                    'property' => $error->getPropertyPath(),
                    'value' => $error->getInvalidValue(),
                    'message' => $error->getMessage(),
                ];
            }
            return $this->json(
                ['status' => 'error', 'message' => 'Validation Failed', 'errors' => $errorMessages],
                JsonResponse::HTTP_BAD_REQUEST
            );
        }

        // 3. DTO验证通过，将数据从DTO传输到实体对象
        $author = new Author();
        $author->setName($authorRequest->name);
        // ... 其他属性的映射

        // 4. 持久化实体
        $entityManager = $this->getDoctrine()->getManager();
        $entityManager->persist($author);
        $entityManager->flush();

        return $this->json(
            ['status' => 'success', 'message' => 'Author created successfully', 'author' => [
                'id' => $author->getId(), 
                'name' => $author->getName()
            ]],
            JsonResponse::HTTP_CREATED
        );
    }
}