我对Abstract Factories示例有疑问。
在ServiceManager中注册了Abstract Factory的类创建类时,我得到ServiceNotFoundException
。
首先,我用作曲家下载zend-servicemanager
composer require zendframework/zend-servicemanager
然后,我在单个文件中运行ServiceManager示例(为简单起见)。
<?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;
应通过ServiceManager获得的类。
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();
}
}
我用注册的Abstract Factory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,我尝试获取A类的实例。
$a = $serviceManager->get(A::class);
var_dump($a);
我明白了
Fatal error: Uncaught Zend\ServiceManager\Exception\ServiceNotFoundException: Unable to resolve service "A" to a factory; are you certain you provided it during configuration?
与堆栈跟踪
.\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
答案 0 :(得分:0)
我对问题的表述是错误的。 @rkeet的评论很清楚。
由于我的目标是在ServiceManager中进行抽象工厂注册的工作示例,因此我发布了单文件脚本,其中canCreate()
被简化,只是为了检查该类是否存在。
<?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,如果有人需要原始示例工作,则类A
应该实现Traversable。