Title: CommonClassesStrategy
Published: May 20, 2026

---

# class CommonClassesStrategy {}

## In this article

 * [Methods](https://developer.wordpress.org/reference/classes/wordpress-aiclientdependencies-http-discovery-strategy-commonclassesstrategy/?output_format=md#methods)
 * [Source](https://developer.wordpress.org/reference/classes/wordpress-aiclientdependencies-http-discovery-strategy-commonclassesstrategy/?output_format=md#source)

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## 󠀁[Methods](https://developer.wordpress.org/reference/classes/wordpress-aiclientdependencies-http-discovery-strategy-commonclassesstrategy/?output_format=md#methods)󠁿

| Name | Description | 
| [CommonClassesStrategy::buzzInstantiate](https://developer.wordpress.org/reference/classes/wordpress-aiclientdependencies-http-discovery-strategy-commonclassesstrategy/buzzinstantiate/) | – | 
| [CommonClassesStrategy::getCandidates](https://developer.wordpress.org/reference/classes/wordpress-aiclientdependencies-http-discovery-strategy-commonclassesstrategy/getcandidates/) | – | 
| [CommonClassesStrategy::getPsr18Candidates](https://developer.wordpress.org/reference/classes/wordpress-aiclientdependencies-http-discovery-strategy-commonclassesstrategy/getpsr18candidates/) | – | 
| [CommonClassesStrategy::isGuzzleImplementingPsr18](https://developer.wordpress.org/reference/classes/wordpress-aiclientdependencies-http-discovery-strategy-commonclassesstrategy/isguzzleimplementingpsr18/) | – | 
| [CommonClassesStrategy::isPsr17FactoryInstalled](https://developer.wordpress.org/reference/classes/wordpress-aiclientdependencies-http-discovery-strategy-commonclassesstrategy/ispsr17factoryinstalled/) | Can be used as a condition. | 
| [CommonClassesStrategy::isSymfonyImplementingHttpClient](https://developer.wordpress.org/reference/classes/wordpress-aiclientdependencies-http-discovery-strategy-commonclassesstrategy/issymfonyimplementinghttpclient/) | – | 
| [CommonClassesStrategy::symfonyPsr18Instantiate](https://developer.wordpress.org/reference/classes/wordpress-aiclientdependencies-http-discovery-strategy-commonclassesstrategy/symfonypsr18instantiate/) | – |

## 󠀁[Source](https://developer.wordpress.org/reference/classes/wordpress-aiclientdependencies-http-discovery-strategy-commonclassesstrategy/?output_format=md#source)󠁿

    ```php
    final class CommonClassesStrategy implements DiscoveryStrategy
    {
        /**
         * @var array
         */
        private static $classes = [MessageFactory::class => [['class' => NyholmHttplugFactory::class, 'condition' => [NyholmHttplugFactory::class]], ['class' => GuzzleMessageFactory::class, 'condition' => [GuzzleRequest::class, GuzzleMessageFactory::class]], ['class' => DiactorosMessageFactory::class, 'condition' => [DiactorosRequest::class, DiactorosMessageFactory::class]], ['class' => SlimMessageFactory::class, 'condition' => [SlimRequest::class, SlimMessageFactory::class]]], StreamFactory::class => [['class' => NyholmHttplugFactory::class, 'condition' => [NyholmHttplugFactory::class]], ['class' => GuzzleStreamFactory::class, 'condition' => [GuzzleRequest::class, GuzzleStreamFactory::class]], ['class' => DiactorosStreamFactory::class, 'condition' => [DiactorosRequest::class, DiactorosStreamFactory::class]], ['class' => SlimStreamFactory::class, 'condition' => [SlimRequest::class, SlimStreamFactory::class]]], UriFactory::class => [['class' => NyholmHttplugFactory::class, 'condition' => [NyholmHttplugFactory::class]], ['class' => GuzzleUriFactory::class, 'condition' => [GuzzleRequest::class, GuzzleUriFactory::class]], ['class' => DiactorosUriFactory::class, 'condition' => [DiactorosRequest::class, DiactorosUriFactory::class]], ['class' => SlimUriFactory::class, 'condition' => [SlimRequest::class, SlimUriFactory::class]]], HttpAsyncClient::class => [['class' => SymfonyHttplug::class, 'condition' => [SymfonyHttplug::class, Promise::class, [self::class, 'isPsr17FactoryInstalled']]], ['class' => Guzzle7::class, 'condition' => Guzzle7::class], ['class' => Guzzle6::class, 'condition' => Guzzle6::class], ['class' => Curl::class, 'condition' => Curl::class], ['class' => React::class, 'condition' => React::class]], HttpClient::class => [['class' => SymfonyHttplug::class, 'condition' => [SymfonyHttplug::class, [self::class, 'isPsr17FactoryInstalled'], [self::class, 'isSymfonyImplementingHttpClient']]], ['class' => Guzzle7::class, 'condition' => Guzzle7::class], ['class' => Guzzle6::class, 'condition' => Guzzle6::class], ['class' => Guzzle5::class, 'condition' => Guzzle5::class], ['class' => Curl::class, 'condition' => Curl::class], ['class' => Socket::class, 'condition' => Socket::class], ['class' => Buzz::class, 'condition' => Buzz::class], ['class' => React::class, 'condition' => React::class], ['class' => Cake::class, 'condition' => Cake::class], ['class' => Artax::class, 'condition' => Artax::class], ['class' => [self::class, 'buzzInstantiate'], 'condition' => [\WordPress\AiClientDependencies\Buzz\Client\FileGetContents::class, \WordPress\AiClientDependencies\Buzz\Message\ResponseBuilder::class]]], Psr18Client::class => [['class' => [self::class, 'symfonyPsr18Instantiate'], 'condition' => [SymfonyPsr18::class, Psr17RequestFactory::class]], ['class' => GuzzleHttp::class, 'condition' => [self::class, 'isGuzzleImplementingPsr18']], ['class' => [self::class, 'buzzInstantiate'], 'condition' => [\WordPress\AiClientDependencies\Buzz\Client\FileGetContents::class, \WordPress\AiClientDependencies\Buzz\Message\ResponseBuilder::class]]]];
        public static function getCandidates($type)
        {
            if (Psr18Client::class === $type) {
                return self::getPsr18Candidates();
            }
            return self::$classes[$type] ?? [];
        }
        /**
         * @return array The return value is always an array with zero or more elements. Each
         *               element is an array with two keys ['class' => string, 'condition' => mixed].
         */
        private static function getPsr18Candidates()
        {
            $candidates = self::$classes[Psr18Client::class];
            // HTTPlug 2.0 clients implements PSR18Client too.
            foreach (self::$classes[HttpClient::class] as $c) {
                if (!is_string($c['class'])) {
                    continue;
                }
                try {
                    if (ClassDiscovery::safeClassExists($c['class']) && is_subclass_of($c['class'], Psr18Client::class)) {
                        $candidates[] = $c;
                    }
                } catch (\Throwable $e) {
                    trigger_error(sprintf('Got exception "%s (%s)" while checking if a PSR-18 Client is available', get_class($e), $e->getMessage()), \E_USER_WARNING);
                }
            }
            return $candidates;
        }
        public static function buzzInstantiate()
        {
            return new \WordPress\AiClientDependencies\Buzz\Client\FileGetContents(Psr17FactoryDiscovery::findResponseFactory());
        }
        public static function symfonyPsr18Instantiate()
        {
            return new SymfonyPsr18(null, Psr17FactoryDiscovery::findResponseFactory(), Psr17FactoryDiscovery::findStreamFactory());
        }
        public static function isGuzzleImplementingPsr18()
        {
            return defined('GuzzleHttp\ClientInterface::MAJOR_VERSION');
        }
        public static function isSymfonyImplementingHttpClient()
        {
            return is_subclass_of(SymfonyHttplug::class, HttpClient::class);
        }
        /**
         * Can be used as a condition.
         *
         * @return bool
         */
        public static function isPsr17FactoryInstalled()
        {
            try {
                Psr17FactoryDiscovery::findResponseFactory();
            } catch (NotFoundException $e) {
                return \false;
            } catch (\Throwable $e) {
                trigger_error(sprintf('Got exception "%s (%s)" while checking if a PSR-17 ResponseFactory is available', get_class($e), $e->getMessage()), \E_USER_WARNING);
                return \false;
            }
            return \true;
        }
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/php-ai-client/third-party/http/discovery/strategy/commonclassesstrategy.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.0/src/wp-includes/php-ai-client/third-party/Http/Discovery/Strategy/CommonClassesStrategy.php#L48)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.0/src/wp-includes/php-ai-client/third-party/Http/Discovery/Strategy/CommonClassesStrategy.php#L48-L116)

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