[php] Exception: Serialization of 'Closure' is not allowed

So I am not sure exactly what I would have to show you guys, how ever if you need more code please do not hesitate to ask:

So this method will set up the initMailer for Zend with in our application:

protected function _initMailer()
{
    if ('testing' !==  APPLICATION_ENV) {
        $this->bootstrap('Config');
        $options = $this->getOptions();
        $mail = new Zend_Application_Resource_Mail($options['mail']);
    }elseif ('testing'  ===  APPLICATION_ENV) {
        //change the mail transport only if dev or test
        if (APPLICATION_ENV <> 'production') {

            $callback = function()
            {
                return 'ZendMail_' . microtime(true) .'.tmp';
            };

            $mail = new Zend_Mail_Transport_File(
                array('path' => '/tmp/mail/',
                        'callback'=>$callback
                )
            );

            Zend_Mail::setDefaultTransport($mail);
        }
    }


    return $mail;
}

You can see the closure that lies with in. When I run any tests that use this code I get:

Exception: Serialization of 'Closure' is not allowed 

and thus all the tests in relation to this "closure" fails. So I am here asking you guys what I should do.

For clarification on the above, all were doing is saying that any email we send out we want to store information about that email in a folder in the /tmp/mail/ directory in a file.

Direct Closure serialisation is not allowed by PHP. But you can use powefull class like PHP Super Closure : https://github.com/jeremeamia/super_closure

This class is really simple to use and is bundled into the laravel framework for the queue manager.

From the github documentation :

$helloWorld = new SerializableClosure(function ($name = 'World') use ($greeting) {
    echo "{$greeting}, {$name}!\n";
});

$serialized = serialize($helloWorld);

You have to disable Globals

 /**
 * @backupGlobals disabled
 */

As already stated: closures, out of the box, cannot be serialized.

However, using the __sleep(), __wakeup() magic methods and reflection u CAN manually make closures serializable. For more details see extending-php-5-3-closures-with-serialization-and-reflection

This makes use of reflection and the php function eval. Do note this opens up the possibility of CODE injection, so please take notice of WHAT you are serializing.