Symfony2 serialize() Error at offset

Question

I'm trying to serialize an php array to xml, but something is waaay off here. Problem might be rabbitmq -related too.. Had similar errors before after implementing the rabbitmq into the system.

The code:

$encoders = array(new XmlEncoder(), new JsonEncoder());
$normalizers = array(new GetSetMethodNormalizer());
$serializer = new Serializer($normalizers, $encoders);

if($return_type == "xml")
{
      // Create xml-response out of the information found, and return it:
      return $serializer->serialize($options, 'xml');
}
else if($return_type == "json")
{
      // Create json-response out of the information found, and return it:
      return $serializer->serialize($options, 'json');
}

The error:

Notice: unserialize(): Error at offset 0 of 30 bytes

500 Internal Server Error - ContextErrorException

The json-part works just fine, but serializing to xml gives the error. What am I missing here?

Edit: Part of stacktrace of the error.

[2015-10-05 12:37:13] request.CRITICAL: Uncaught PHP Exception Symfony\Component\Debug\Exception\ContextErrorException: "Notice: unserialize(): Error at offset 0 of 30 bytes" at C:\wamp\www\Projects\myproject\v.0.1\vendor\oldsound\rabbitmq-bundle\OldSound\RabbitMqBundle\RabbitMq\RpcClient.php line 63 {"exception":"[object] (Symfony\Component\Debug\Exception\ContextErrorException(code: 0): Notice: unserialize(): Error at offset 0 of 30 bytes at C:\wamp\www\Projects\myproject\v.0.1\vendor\oldsound\rabbitmq-bundle\OldSound\RabbitMqBundle\RabbitMq\RpcClient.php:63)"} []

Edit2: There seems to be something else going on in here. It shows this in the full stacktrace:

vendor\oldsound\rabbitmq-bundle\OldSound\RabbitMqBundle\RabbitMq\RpcClient.php'‌​, '63', array('msg' => object(AMQPMessage), 'messageBody' => 'error: Invalid Character Error'))

Why is that there?

Edit3: I put some echoes into the code, just before the serializing, and righ after it, and it print the first but not the second.

echo "TESTING, ROW: ".__LINE__;
$xml = $serializer->serialize($options, 'xml');
echo "TESTING, ROW: ".__LINE__;

I also put that code inside try-catch, but it's not giving any errors from that..? There is something shady going on in here..

Edit4: I tried the serializer with something simple like this:

$xml = $serializer->serialize(array("test"=>1), 'xml');

And that seems to work just fine. This makes me wanna ask: what characters doesn't the serializer like in the original array? Unfortunately I cannot show the insides of the array, but if anyone has some ideas about non-acceptable chars when using serializer, I'd be happy to hear.

Answer 1

It seems that the serializer didn't like my array keys. I had keys that had spaces in them like this:

array("spaced key" => $data);

When I changed the keys to this:

array("spaced_key" => $data);

it started to work.