ZF3:创建一个在ServiceManager中注册了抽象工厂的类时的ServiceNotFoundException

Question

我对抽象工厂示例有问题。

我在创建一个在ServiceManager中注册了抽象工厂的类时获得了ServiceManager。

首先，我下载和作曲家。

composer require zendframework/zend-servicemanager

然后，我在单个文件中运行ServiceManager示例(为了简单起见)。

<?php
require_once 'vendor/autoload.php';

use Interop\Container\ContainerInterface;
use Zend\ServiceManager\ServiceManager;
use Zend\ServiceManager\Factory\InvokableFactory;
use Zend\ServiceManager\Factory\FactoryInterface;
use Zend\ServiceManager\Factory\AbstractFactoryInterface;

类，这些类应该使用ServiceManager获取。

class A
{
    public $text;

    public function __construct() 
    {
        $this->text = "Default text";
    }
}

我使用文档中的MyAbstractFactory。

class MyAbstractFactory implements AbstractFactoryInterface
{
  public function canCreate(ContainerInterface $container, $requestedName)
  {
    return in_array('Traversable', class_implements($requestedName), true);
  }

  public function __invoke(ContainerInterface $container, 
                           $requestedName,
                           array $options = null)
  {
    return $requestedName();
  }
}

我用注册抽象工厂创建ServiceManager。

$serviceManager = new ServiceManager([
    // Neither works    
  //'abstract_factories' => array('MyAbstractFactory')
  'abstract_factories' => array( new MyAbstractFactory() )
  //'abstract_factories' => array( MyAbstractFactory::class )
  /*  
    'abstract_factories' => [
        MyAbstractFactory::class => new MyAbstractFactory()
    ]
  */  
]);

最后，我试图获得A类的实例。

$a = $serviceManager->get(A::class);
var_dump($a);

我得到带有堆栈跟踪的Fatal error: Uncaught Zend\ServiceManager\Exception\ServiceNotFoundException: Unable to resolve service "A" to a factory; are you certain you provided it during configuration?

.\vendor\zendframework\zend-servicemanager\src\ServiceManager.php(763): Zend\ServiceManager\ServiceManager->getFactory('A') #1
.\vendor\zendframework\zend-servicemanager\src\ServiceManager.php(200): Zend\ServiceManager\ServiceManager->doCreate('A') #2
.\script.php(53): Zend\ServiceManager\ServiceManager->get('A') #3

Answer 1

我对这个问题的表述是错误的。@rkeet的评论表明了这一点。

由于我的目标是ServiceManager中抽象工厂注册的工作示例，所以我发布了一个单文件脚本，其中简化了canCreate()，以检查类是否存在。

<?php
// composer require zendframework/zend-servicemanager

require_once 'vendor/autoload.php';

use Interop\Container\ContainerInterface;
use Zend\ServiceManager\ServiceManager;
use Zend\ServiceManager\Factory\AbstractFactoryInterface;


class A
{
    public $text;

    public function __construct() 
    {
        $this->text = "Default text";
    }
}


class MyAbstractFactory implements AbstractFactoryInterface
{
    public function canCreate(ContainerInterface $container, $requestedName)
    {
        return class_exists($requestedName);
    }

    public function __invoke(ContainerInterface $container, 
                             $requestedName,
                             array $options = null)
    {
        return new $requestedName();
    }
}


$serviceManager = new ServiceManager([
  //'abstract_factories' => array('MyAbstractFactory') // works
  //'abstract_factories' => array( new MyAbstractFactory() ) // works
  'abstract_factories' => array( MyAbstractFactory::class ) // also works
]);


try {
    $a = $serviceManager->get(A::class);
    var_dump($a);
    echo "<br/>\n";
    $b = $serviceManager->get(B::class);
    var_dump($b);
} catch (Exception $e) {
    echo $e->getMessage() . "<br/>\n";
    echo "{$e->getFile()}  ({$e->getLine()})";
}
?>

正如@rkeet所指出的，如果有人需要使用最初的示例，类A应该实现可穿。