Adding an XML array in the user session

Question

I'm getting some data from an API. I want to save those data in my user session so that the API isn't called each time the page is reached.

1. First time: load API, save in session
2. After, load session

So this is my simple class :

class CadencierDataSession extends CustomerUserData
{

    public function getCadencier() {
        return $this->_customerSession->getCadencier();
    }

    public function setCadencier($cadencier) {
        $this->_customerSession->setCadencier($cadencier);
    }

    public function unsetCadencier() {
        $this->_customerSession->unsCadencier();
    }

}

This is how it's called :

$cadencierDataSession = new CadencierDataSession();
$cadencier = $cadencierDataSession->getCadencier();
$follow = "from session";
if($cadencier == null) {
  $follow = "from api";
  $cadencier = (new Cadencier())->get_cadencier($codeClient);
  $cadencierDataSession->setCadencier($cadencier);
  die('ok');
}

When I reach the setCadencier line, Magento throught this error :

Fatal error: Uncaught Exception: Serialization of 'SimpleXMLElement' is not allowed in /vendor/magento/framework/Session/SessionManager.php:139 Stack trace: #0 /vendor/magento/framework/Session/SessionManager.php(139): session_write_close() #1 [internal function]: Magento\Framework\Session\SessionManager->writeClose() #2 {main} thrown in /vendor/magento/framework/Session/SessionManager.php on line 139

Who to avoid it? I'd like to keep the XML structure so that I don't have to recode this page.

Answer 1

The SimpleXMLElement returned from the API is an object, and you most likely want to get a string representation. Try the following:

$cadencierDataSession = new CadencierDataSession();
$cadencier = $cadencierDataSession->getCadencier();
$follow = "from session";
if($cadencier == null) {
  $follow = "from api";
  $cadencier = (new Cadencier())->get_cadencier($codeClient);
  $cadencierDataSession->setCadencier($cadencier->asXML());
  die('ok');
}