Solarium客户端中参数2的TypeError

Question

我正在尝试使用Search_api_solr v4.1、SolariaV6.0和symfony/event-dispatcher v3.4.47启动一个客户端，但我一直收到一个TypeError。

TypeError: Argument 2 passed to Solarium\Core\Client\Client::__construct() 
must be an instance of Psr\EventDispatcher\EventDispatcherInterface, 
instance of Symfony\Component\EventDispatcher\EventDispatcher given

我不太明白为什么它需要一个Psr\EventDispatcher\EventDispatcherInterface的实例，而所有关于solarium的文档都说要使用Symfony\Component\EventDispatcher\EventDispatcher.

我的适配器和事件分派器如下所示

use Solarium\Client;
use Solarium\Core\Client\Adapter\Curl;
use Symfony\Component\EventDispatcher\EventDispatcher; 

function get_search_query() {
$adapter = new Curl();
$eventDispatcher = new EventDispatcher();

$config = ['endpoint' => ['localhost' => [
                'host' => $id,
                'port' => $port,
                'path' => '/',
                'collection' => '$core',],],];

$search = new Client($adapter, $eventDispatcher, $config);
$query = $search->createSelect();
}

有没有其他人遇到过这个问题，或者知道解决这个问题的方法？

Answer 1

当您在new Client()上创建日光客户端时，第二个参数要求您提供一个实现Psr\EventDispatcher\EventDispatcherInterface的类。但是，在use语句中，您要创建的EventDispatcher是Symfony\Component\EventDispatcher\EventDispatcher。

将use语句更改为PSR事件分派器，就可以了。

Answer 2

当您深入研究Symfony源代码时，可以查看以下内容：

if (interface_exists(PsrEventDispatcherInterface::class)) {
    /**
     * Allows providing hooks on domain-specific lifecycles by dispatching events.
     */
    interface EventDispatcherInterface extends PsrEventDispatcherInterface
    {
        /**
         * Dispatches an event to all registered listeners.
         *
         * For BC with Symfony 4, the $eventName argument is not declared explicitly on the
         * signature of the method. Implementations that are not bound by this BC constraint
         * MUST declare it explicitly, as allowed by PHP.
         *
         * @param object      $event     The event to pass to the event handlers/listeners
         * @param string|null $eventName The name of the event to dispatch. If not supplied,
         *                               the class of $event should be used instead.
         *
         * @return object The passed $event MUST be returned
         */
        public function dispatch($event/*, string $eventName = null*/);
    }
} else {
    /**
     * Allows providing hooks on domain-specific lifecycles by dispatching events.
     */
    interface EventDispatcherInterface
    {
        /**
         * Dispatches an event to all registered listeners.
         *
         * For BC with Symfony 4, the $eventName argument is not declared explicitly on the
         * signature of the method. Implementations that are not bound by this BC constraint
         * MUST declare it explicitly, as allowed by PHP.
         *
         * @param object      $event     The event to pass to the event handlers/listeners
         * @param string|null $eventName The name of the event to dispatch. If not supplied,
         *                               the class of $event should be used instead.
         *
         * @return object The passed $event MUST be returned
         */
        public function dispatch($event/*, string $eventName = null*/);
    }
}

所以你的问题是interface_exists(PsrEventDispatcherInterface::class)返回false。THis接口来自这个包https://packagist.org/packages/psr/event-dispatcher，所以我会尝试使用composer require psr/event-dispatcher来修复它。

编辑:您的symfony事件调度程序版本已过时。请更新到5.3以解决此问题。