Laravel框架源码解析之反射的使用详解

?php
 namespace A\B;
 
 class Foo { }
 
 $function = new \ReflectionClass('stdClass');
 
 var_dump($function->inNamespace());
 var_dump($function->getName());
 var_dump($function->getNamespaceName());
 var_dump($function->getShortName());
 
 $function = new \ReflectionClass('A\\B\\Foo');
 
 var_dump($function->inNamespace());
 var_dump($function->getName());
 var_dump($function->getNamespaceName());
 var_dump($function->getShortName());
?>

bool(false)
string(8) "stdClass"
string(0) ""
string(8) "stdClass"

bool(true)
string(7) "A\B\Foo"
string(3) "A\B"
string(3) "Foo"

$app = require_once __DIR__.'/../bootstrap/app.php';

/*
|--------------------------------------------------------------------------
| Run The Application
|--------------------------------------------------------------------------
|
| Once we have the application, we can handle the incoming request
| through the kernel, and send the associated response back to
| the client's browser allowing them to enjoy the creative
| and wonderful application we have prepared for them.
|
*/

$kernel = $app->make(Illuminate\Contracts\Http\Kernel::class);

$response = $kernel->handle(
 $request = Illuminate\Http\Request::capture()
);

$response->send();

$kernel->terminate($request, $response);

$app = new Illuminate\Foundation\Application(
 realpath(__DIR__.'/../')
);

public function make($abstract, array $parameters = [])
{
  $abstract = $this->getAlias($abstract);

  if (isset($this->deferredServices[$abstract])  ! isset($this->instances[$abstract])) {
   $this->loadDeferredProvider($abstract);
  }

  return parent::make($abstract, $parameters);
}

// 真正的make方法，它直接调用了resolve继续去实现make的功能
// $abstract = 'HelpSpot\API'
public function make($abstract, array $parameters = [])
{
 // $abstract = 'HelpSpot\API'
 return $this->resolve($abstract, $parameters);
}

...

protected function resolve($abstract, $parameters = [])
{
 ...
 // 判断是否可以合理反射
 // $abstract = 'HelpSpot\API'
 if ($this->isBuildable($concrete, $abstract)) {
  // 实例化具体实例 (实际并不是实例化,而是通过反射“解刨”了)
  $object = $this->build($concrete);
 } else {
  $object = $this->make($concrete);
 }
 ...
}

public function build($concrete)
{
  // $concrete = 'HelpSpot\API'
  if ($concrete instanceof Closure) {
   return $concrete($this, $this->getLastParameterOverride());
  }
  // 实例化反射类
  $reflector = new ReflectionClass($concrete);

  // 检查类是否可实例化
  if (! $reflector->isInstantiable()) {
   return $this->notInstantiable($concrete);
  }

  $this->buildStack[] = $concrete;

  // 获取类的构造函数
  $constructor = $reflector->getConstructor();
  
  if (is_null($constructor)) {
   array_pop($this->buildStack);

   return new $concrete;
  }

  $dependencies = $constructor->getParameters();

  $instances = $this->resolveDependencies(
   $dependencies
  );

  array_pop($this->buildStack);
   
  // 从给出的参数创建一个新的类实例。
  return $reflector->newInstanceArgs($instances);
}