关键实施示例
1. 数据库层分离
// bad - mixed concerns
class user {
public function save() {
$db = new pdo('mysql:host=localhost;dbname=app', 'user', 'pass');
$stmt = $db->prepare("insert into users (name, email) values (?, ?)");
$stmt->execute([$this->name, $this->email]);
}
}
// good - separated database logic
class user {
private string $name;
private string $email;
}
class userrepository {
private pdo $db;
public function save(user $user) {
$stmt = $this->db->prepare("insert into users (name, email) values (?, ?)");
$stmt->execute([$user->getname(), $user->getemail()]);
}
}
这个很好的例子将数据结构（user）与存储逻辑（userrepository）分开。这使得代码更易于维护，并且允许在不修改 user 类的情况下更改存储方法。
2. 验证分离
// bad - mixed validation and business logic
class order {
public function process() {
if (empty($this->items)) {
throw new exception('order cannot be empty');
}
if ($this->total < 0) {
throw new exception('invalid total amount');
}
// process order...
}
}
// good - separated validation
class ordervalidator {
public function validate(order $order): array {
$errors = [];
if (empty($order->getitems())) {
$errors[] = 'order cannot be empty';
}
if ($order->gettotal() < 0) {
$errors[] = 'invalid total amount';
}
return $errors;
}
}
class order {
public function process() {
// only handles order processing
}
}
验证逻辑移至专用验证器类，使 order 类能够专注于业务逻辑。
3.视图/模板分离
// bad - mixed html and logic
class productpage {
public function show($id) {
$product = $this->getproduct($id);
echo "{$product->name}
";
echo "price: ${$product->price}
";
}
}
// good - separated presentation
class productcontroller {
public function show($id) {
$product = $this->productrepository->find($id);
return $this->view->render('product/show', ['product' => $product]);
}
}
// product/show.php template
name) ?>
price: $price) ?>
这个很好的例子将显示逻辑分离到模板中，使代码更易于维护，并允许设计人员独立工作。
4. 服务层分离
// bad - mixed business logic
class ordercontroller {
public function checkout() {
$order = new order($_post['items']);
$payment = new payment($_post['card']);
$payment->process();
$order->updatestatus('paid');
$email = new emailservice();
$email->sendconfirmation($order);
}
}
// good - separated services
class orderservice {
private paymentservice $paymentservice;
private emailservice $emailservice;
public function processorder(order $order, paymentdata $paymentdata): void {
$this->paymentservice->process($paymentdata);
$order->updatestatus('paid');
$this->emailservice->sendconfirmation($order);
}
}
class ordercontroller {
public function checkout() {
$this->orderservice->processorder($order, $paymentdata);
}
}
服务层处理复杂的业务逻辑，使控制器专注于请求处理。
5、配置分离
// Bad - Hardcoded configuration
class EmailSender {
private $host = 'smtp.example.com';
private $port = 587;
public function send($message) {
// Sending logic using hardcoded values
}
}
// Good - Separated configuration
// config/mail.php
return [
'host' => 'smtp.example.com',
'port' => 587
];
class EmailSender {
private array $config;
public function __construct(array $config) {
$this->config = $config;
}
public function send($message) {
// Sending logic using config values
}
}
配置与实现分离，使代码更加灵活和可维护。无需修改代码即可更改设置。
