mailgun-php/Mailgun/Guzzle/Plugin/ErrorResponse/ErrorResponsePlugin.php

<?php

namespace Guzzle\Plugin\ErrorResponse;

use Guzzle\Common\Event;
use Guzzle\Http\Message\RequestInterface;
use Guzzle\Service\Command\CommandInterface;
use Guzzle\Service\Description\Operation;
use Guzzle\Plugin\ErrorResponse\Exception\ErrorResponseException;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * Converts generic Guzzle response exceptions into errorResponse exceptions
 */
class ErrorResponsePlugin implements EventSubscriberInterface
{
    public static function getSubscribedEvents()
    {
        return array('command.before_send' => array('onCommandBeforeSend', -1));
    }

    /**
     * Adds a listener to requests before they sent from a command
     *
     * @param Event $event Event emitted
     */
    public function onCommandBeforeSend(Event $event)
    {
        $command = $event['command'];
        if ($operation = $command->getOperation()) {
            if ($operation->getErrorResponses()) {
                $request = $command->getRequest();
                $request->getEventDispatcher()
                    ->addListener('request.complete', $this->getErrorClosure($request, $command, $operation));
            }
        }
    }

    /**
     * @param RequestInterface $request   Request that received an error
     * @param CommandInterface $command   Command that created the request
     * @param Operation        $operation Operation that defines the request and errors
     *
     * @return \Closure Returns a closure
     * @throws ErrorResponseException
     */
    protected function getErrorClosure(RequestInterface $request, CommandInterface $command, Operation $operation)
    {
        return function (Event $event) use ($request, $command, $operation) {
            $response = $event['response'];
            foreach ($operation->getErrorResponses() as $error) {
                if (!isset($error['class'])) {
                    continue;
                }
                if (isset($error['code']) && $response->getStatusCode() != $error['code']) {
                    continue;
                }
                if (isset($error['reason']) && $response->getReasonPhrase() != $error['reason']) {
                    continue;
                }
                $className = $error['class'];
                $errorClassInterface = __NAMESPACE__ . '\\ErrorResponseExceptionInterface';
                if (!class_exists($className)) {
                    throw new ErrorResponseException("{$className} does not exist");;
                } elseif (!is_subclass_of($className, $errorClassInterface)) {
                    throw new ErrorResponseException("{$className} must implement {$errorClassInterface}");
                }
                throw $className::fromCommand($command, $response);
            }
        };
    }
}