use Enqueue\AmqpExt\AmqpContext;

use Enqueue\Stomp\StompContext;

use Enqueue\Fs\FsContext;

use Enqueue\Sqs\SqsContext;

use Enqueue\Redis\RedisContext;

use Enqueue\Dbal\DbalContext;

class Enqueue_Enqueue_Model_Config_Field_Transportdefault extends Mage_Core_Model_Config_Data

{

/**

protected function _beforeSave()

{

$return = parent::_beforeSave();

$transport = $this->getValue();

$data = [

'rabbitmq_amqp' => [

'name' => 'RabbitMQ AMQP',

'package' => 'enqueue/amqp-ext',

'class' => AmqpContext::class,

],

'amqp' => [

'name' => 'AMQP',

'package' => 'enqueue/amqp-ext',

'class' => AmqpContext::class,

],

'rabbitmq_stomp' => [

'name' => 'RabbitMQ STOMP',

'package' => 'enqueue/stomp',

'class' => StompContext::class,

],

'stomp' => [

'name' => 'STOMP',

'package' => 'enqueue/stomp',

'class' => StompContext::class,

],

'fs' => [

'name' => 'Filesystem',

'package' => 'enqueue/fs',

'class' => FsContext::class,

],

'sqs' => [

'name' => 'Amazon AWS SQS',

'package' => 'enqueue/sqs',

'class' => SqsContext::class,

],

'redis' => [

'name' => 'Redis',

'package' => 'enqueue/redis',

'class' => RedisContext::class,

],

'dbal' => [

'name' => 'Doctrine DBAL',

'package' => 'enqueue/dbal',

'class' => DbalContext::class,

],

];

if (false == isset($data[$transport])) {

throw new \LogicException(sprintf('Unknown transport: "%s"', $transport));

}

if (false == $this->isClassExists($data[$transport]['class'])) {

Mage::throwException(sprintf('%s transport requires package "%s". Please install it via composer. #> php composer.php require %s',

$data[$transport]['name'], $data[$transport]['package'], $data[$transport]['package']

));

}

return $return;

}

/**

private function isClassExists($class)

{

try {

return class_exists($class);

} catch (\Exception $e) { // in dev mode error handler throws exception

return false;

}

}

}

<backend_model>enqueue/config_field_transportdefault</backend_model>