据我了解,使用存储库限制控制器访问数据库层,并且所有查询都通过存储库。但是控制器可以使用模型(laravel 可以在控制器中注入模型而不是 ID)将其传递到存储库或服务 - 例如在用户之间进行交易?或者更好地将 ID 发送到存储库,以查找用户并应用业务逻辑(用户是否有钱,或者他是否被禁止)。
还有一个更通用的问题,你可以使用存储库之外的模型吗?因为如果你将一些表从 postgres 或 mysql 更改为其他表,你的模型也会改变。这意味着你的存储库应该有 get 方法来发回一些 DTO 对象?
注意:这是对此事的一般看法,适用于任何基于 MVC 的应用程序,而不仅仅是 Laravel。
基于MVC模式的应用程序应该由三部分组成:
以下是一些图形表示(我自己制作的):
如上所示(并在下面的资源中详细描述),控制器和视图是交付机制的一部分。它们应该仅通过 服务层对象(服务)与域模型交互。因此,他们不应该了解领域模型组件(实体 - 也称为域对象、数据映射器、存储库等)。更重要的是,控制器应该只有一项职责:将用户请求的值传递给服务层,以便其更新模型。
所以,回答你的第一个问题:不,控制器不应该能够创建域模型元素的任何实例(因此你所谓的“模型”的实例 - 相对于 Laravel 的Active Record) ,或者甚至将这些对象传递给其他组件(如存储库、服务等)。相反,控制器应该只将请求的值(例如,user id)传递给相应的服务。然后,这些服务将创建适当的域模型对象并使用适当的存储库、数据映射器等,以便保存到数据库或从数据库获取。
至于第二个问题(如果我理解正确的话):存储库被视为实体的集合——它们是域模型组件。因此,可以从元素(例如实体实例)中获取、存储、更改或删除元素。因此,根据定义,entities必须与存储库分开定义/使用。对于 Laravel,同样适用:“模型”应与存储库分开定义/使用。
“通用”MVC 实现(为了更清晰):
控制器:
<?php
namespace MyApp\UI\Web\Controller\Users;
use MyApp\Domain\Service\Users;
use Psr\Http\Message\ServerRequestInterface;
/**
* Add a user.
*/
class AddUser {
/**
* User service.
*
* @var Users
*/
private $userService;
/**
*
* @param Users $userService User service.
*/
public function __construct(Users $userService) {
$this->userService = $userService;
}
/**
* Invoke.
*
* @param ServerRequestInterface $request Request.
* @return void
*/
public function __invoke(ServerRequestInterface $request) {
// Read request values.
$username = $request->getParsedBody()['username'];
// Call the corresponding service.
$this->userService->addUser($username);
}
}
服务:
<?php
namespace MyApp\Domain\Service;
use MyApp\Domain\Model\User\User;
use MyApp\Domain\Model\User\UserCollection;
use MyApp\Domain\Service\Exception\UserExists;
/**
* Service for handling the users.
*/
class Users {
/**
* User collection (a repository).
*
* @var UserCollection
*/
private $userCollection;
/**
*
* @param UserCollection $userCollection User collection.
*/
public function __construct(UserCollection $userCollection) {
$this->userCollection = $userCollection;
}
/**
* Find a user by id.
*
* @param int $id User id.
* @return User|null User.
*/
public function findUserById(int $id) {
return $this->userCollection->findUserById($id);
}
/**
* Find all users.
*
* @return User[] User list.
*/
public function findAllUsers() {
return $this->userCollection->findAllUsers();
}
/**
* Add a user.
*
* @param string $username Username.
* @return User User.
*/
public function addUser(string $username) {
$user = $this->createUser($username);
return $this->storeUser($user);
}
/**
* Create a user.
*
* @param string $username Username.
* @return User User.
*/
private function createUser(string $username) {
$user = new User();
$user->setUsername($username);
return $user;
}
/**
* Store a user.
*
* @param User $user User.
* @return User User.
*/
private function storeUser(User $user) {
if ($this->userCollection->userExists($user)) {
throw new UserExists('Username "' . $user->getUsername() . '" already used');
}
return $this->userCollection->storeUser($user);
}
}
存储库:
<?php
namespace MyApp\Domain\Infrastructure\Repository\User;
use MyApp\Domain\Model\User\User;
use MyApp\Domain\Infrastructure\Mapper\User\UserMapper;
use MyApp\Domain\Model\User\UserCollection as UserCollectionInterface;
/**
* User collection.
*/
class UserCollection implements UserCollectionInterface {
/**
* User mapper (a data mapper).
*
* @var UserMapper
*/
private $userMapper;
/**
*
* @param UserMapper $userMapper User mapper.
*/
public function __construct(UserMapper $userMapper) {
$this->userMapper = $userMapper;
}
/**
* @inheritDoc
*/
public function findUserById(int $id) {
return $this->userMapper->fetchUserById($id);
}
/**
* @inheritDoc
*/
public function findAllUsers() {
return $this->userMapper->fetchAllUsers();
}
/**
* @inheritDoc
*/
public function storeUser(User $user) {
return $this->userMapper->saveUser($user);
}
/**
* @inheritDoc
*/
public function userExists(User $user) {
return $this->userMapper->userExists($user);
}
}
存储库接口:
<?php
namespace MyApp\Domain\Model\User;
use MyApp\Domain\Model\User\User;
/**
* An interface to a collection of users.
*/
interface UserCollection {
/**
* Find a user by id.
*
* @param int $id User id.
* @return User|null User.
*/
public function findUserById(int $id);
/**
* Find all users.
*
* @return User[] User list.
*/
public function findAllUsers();
/**
* Store a user.
*
* @param User $user User.
* @return User User.
*/
public function storeUser(User $user) {
return $this->userMapper->saveUser($user);
}
/**
* Check if the given user exists.
*
* @param User $user User.
* @return bool True if user exists, false otherwise.
*/
public function userExists(User $user);
}
实体:
<?php
namespace MyApp\Domain\Model\User;
/**
* User.
*/
class User {
/**
* Id.
*
* @var int
*/
private $id;
/**
* Username.
*
* @var string
*/
private $username;
/**
* Get id.
*
* @return int
*/
public function getId() {
return $this->id;
}
/**
* Set id.
*
* @param int $id Id.
* @return $this
*/
public function setId(int $id) {
$this->id = $id;
return $this;
}
/**
* Get username.
*
* @return string
*/
public function getUsername() {
return $this->username;
}
/**
* Set username.
*
* @param string $username Username.
* @return $this
*/
public function setUsername(string $username) {
$this->username = $username;
return $this;
}
}
数据映射器:
<?php
namespace MyApp\Domain\Infrastructure\Mapper\User;
use PDO;
use MyApp\Domain\Model\User\User;
use MyApp\Domain\Infrastructure\Mapper\User\UserMapper;
/**
* PDO user mapper.
*/
class PdoUserMapper implements UserMapper {
/**
* Database connection.
*
* @var PDO
*/
private $connection;
/**
*
* @param PDO $connection Database connection.
*/
public function __construct(PDO $connection) {
$this->connection = $connection;
}
/**
* Fetch a user by id.
*
* Note: PDOStatement::fetch returns FALSE if no record is found.
*
* @param int $id User id.
* @return User|null User.
*/
public function fetchUserById(int $id) {
$sql = 'SELECT * FROM users WHERE id = :id LIMIT 1';
$statement = $this->connection->prepare($sql);
$statement->execute([
'id' => $id,
]);
$data = $statement->fetch(PDO::FETCH_ASSOC);
return ($data === false) ? null : $this->convertDataToUser($data);
}
/**
* Fetch all users.
*
* @return User[] User list.
*/
public function fetchAllUsers() {
$sql = 'SELECT * FROM users';
$statement = $this->connection->prepare($sql);
$statement->execute();
$data = $statement->fetchAll(PDO::FETCH_ASSOC);
return $this->convertDataToUserList($data);
}
/**
* Check if a user exists.
*
* Note: PDOStatement::fetch returns FALSE if no record is found.
*
* @param User $user User.
* @return bool True if the user exists, false otherwise.
*/
public function userExists(User $user) {
$sql = 'SELECT COUNT(*) as cnt FROM users WHERE username = :username';
$statement = $this->connection->prepare($sql);
$statement->execute([
':username' => $user->getUsername(),
]);
$data = $statement->fetch(PDO::FETCH_ASSOC);
return ($data['cnt'] > 0) ? true : false;
}
/**
* Save a user.
*
* @param User $user User.
* @return User User.
*/
public function saveUser(User $user) {
return $this->insertUser($user);
}
/**
* Insert a user.
*
* @param User $user User.
* @return User User.
*/
private function insertUser(User $user) {
$sql = 'INSERT INTO users (username) VALUES (:username)';
$statement = $this->connection->prepare($sql);
$statement->execute([
':username' => $user->getUsername(),
]);
$user->setId($this->connection->lastInsertId());
return $user;
}
/**
* Update a user.
*
* @param User $user User.
* @return User User.
*/
private function updateUser(User $user) {
$sql = 'UPDATE users SET username = :username WHERE id = :id';
$statement = $this->connection->prepare($sql);
$statement->execute([
':username' => $user->getUsername(),
':id' => $user->getId(),
]);
return $user;
}
/**
* Convert the given data to a user.
*
* @param array $data Data.
* @return User User.
*/
private function convertDataToUser(array $data) {
$user = new User();
$user
->setId($data['id'])
->setUsername($data['username'])
;
return $user;
}
/**
* Convert the given data to a list of users.
*
* @param array $data Data.
* @return User[] User list.
*/
private function convertDataToUserList(array $data) {
$userList = [];
foreach ($data as $item) {
$userList[] = $this->convertDataToUser($item);
}
return $userList;
}
}
查看:
<?php
namespace MyApp\UI\Web\View\Users;
use MyApp\UI\Web\View\View;
use MyApp\Domain\Service\Users;
use MyLib\Template\TemplateInterface;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ResponseFactoryInterface;
/**
* Add a user.
*/
class AddUser extends View {
/**
* User service.
*
* @var Users
*/
private $userService;
/**
*
* @param ResponseFactoryInterface $responseFactory Response factory.
* @param TemplateInterface $template Template.
* @param Users $userService User service.
*/
public function __construct(ResponseFactoryInterface $responseFactory, TemplateInterface $template, Users $userService) {
parent::__construct($responseFactory, $template);
$this->userService = $userService;
}
/**
* Display a form for adding a user.
*
* @return ResponseInterface Response.
*/
public function index() {
$body = $this->template->render('@Template/Users/add-user.html.twig', [
'activeMainMenuItem' => 'addUser',
'action' => '',
]);
$response = $this->responseFactory->createResponse();
$response->getBody()->write($body);
return $response;
}
/**
* Add a user.
*
* @return ResponseInterface Response.
*/
public function addUser() {
$body = $this->template->render('@Template/Users/add-user.html.twig', [
'activeMainMenuItem' => 'addUser',
'message' => 'User successfully added.',
]);
$response = $this->responseFactory->createResponse();
$response->getBody()->write($body);
return $response;
}
}
资源:
这是一个固执己见的答案,但这是我的看法。我的建议是不要为了在 Laravel 中拥有存储库而添加存储库层。无论您需要什么方法,都将它们添加到模型类中,当它们变得臃肿/期望它变得臃肿时,只需考虑存储库(很可能您需要一个服务类或其他一些抽象)。
由于所有这些雄辩的模型类都可以从容器中解析,因此很容易使用它们。它可以在任何地方访问,甚至在您提到的控制器中也可以注入,这提供了极大的便利。
存储库有助于更改例如底层数据库,但是 eloquent 已经为我们提供了这种灵活性。当您计划更改数据库时,我认为这不会是一个简单的更改,所以为什么要将逻辑包装在另一层抽象中(不必要)。
至少从我的经验来看,存储库模式不太适合活动记录模式。 Laravel 遵循以下内容。存储库非常适合数据映射器模式(例如 Symfony 使用它)。这就是为什么在 Laravel 文档中你看不到他们拥抱存储库模式。相反,您可以在 symfony 文档中看到它。
所以我建议拥抱这个框架而不是对抗它