方法@返回属性的子类

Question

我有一个抽象类foo和一个摘要建造者foobuilder

abstract class Foo {

}

abstract class FooBuilder {
  protected Foo $model;

  /**
  * Return the class instance
  *
  * @return Model  //What is the correct return type?? 
  */
  public function get()
  {
    return $this->model;
  }
}

我想在我的孩子建造者中使用方法get（）返回类型是子类，而不是抽象foo。

class Bar extends Foo {
}

abstract class BarBuilder {
  public function __construct()
  {
    $this->model = new Bar();
  }
}

$barBuilder = BarBuilder();
$bar = $barBuilder->get(); //The type is "Bar", but IDE thinks is "Foo"

有什么方法可以返回phpdoc中的静态属性的静态类型？类似@return static（$ this-＆gt; model）之类的东西？

一个示例是Laravel雄辩在somemodel :: find（）中所做的。 IDE知道类型可以是somemodel。但是@return只有模型。

Answer 1

在DocBlock中使用仿制药确实有助于phpstorm（我的是2021.2.2）：

class Foo
{
}

/**
 * @template T of Foo
 */
class FooBuilder
{
    /**
     * @var T
     */
    protected Foo $model;

    /**
     * @return T
     */
    public function get(): Foo
    {
        return $this->model;
    }
}

class Child extends Foo
{
    public function testCompletion(){}
}

/**
 * @extends FooBuilder<Child>
 */
class ChildBuilder extends FooBuilder
{
}

class AnotherChild extends Foo
{
    public function otherMethod(){}
}

/**
 * @extends FooBuilder<AnotherChild>
 */
class AnotherChildBuilder extends FooBuilder
{
}

$childBuilder = new ChildBuilder();
$childBuilder->get()->testCompletion(); // testCompletion is suggested

$anotherChildBuilder = new AnotherChildBuilder();
$anotherChildBuilder->get()->otherMethod(); // otherMethod is suggested

Answer 2

您可能应该将FOO用作示例中的返回类型；但是为了娱乐，您可以使用静态返回类型来确定下面的子实例

class Foo
{
    /**
     * @return string
     */
    public function Iam(): string
    {
        return "hello";
    }
}

class Helper
{
    /**
     * Return the class instance
     *
     * @return static
     */
    public static function get(): static
    {
        return new self();
    }
}

class FooBuilder extends helper
{
    protected Foo $model;

    public function mememe()
    {
        echo "I am a method";
    }
}

class FooBuilder2 extends helper
{
    protected Foo $model;

    public function xray()
    {
        echo "I am a method";
    }
}

$test = FooBuilder::get();
$test->mememe();

$test2 = FooBuilder2::get();
$test2->xray();