How to restart session once destroyed in Magento 2?

Question

In one of my controller file I have destroyed customer session (Instance of Magento\Customer\Model\Session)and started it again due to some specific requirement.

public function execute()
{
    $customerId = $this->session->getCustomer()->getId(); // 4
    $this->session->destroy();
    $this->session->start();
    $this->session->setCid($customerId);
    return $this->pageFactory->create();
}

And in another controller file I am trying to get session value as given below:

public function execute()
{
    $customerId =  $this->session->getCid();
    var_dump($customerId);exit;
}

which gives NULL. If I am not destroying customer session in first controller then I am able to get session value in second controller properly. What I am missing?

$this->session->destroy(); is also deleting session variables set through PHP's $_SESSION. For example if I add $_SESSION['cid'] = 4; after $this->session->destroy();, I am not able to get it through echo $_SESSION['cid'];

Answer 1

=> Create session in your first controller :

<?php

namespace Company\Module\Controller\Index;

use Magento\Framework\App\Action\Action;
use Magento\Framework\App\Action\Context;
use Magento\Framework\View\Result\PageFactory;

class Index extends Action {
    public $customerSession;
    /**
     * @param Context $context
     */
    public function __construct(
        ..................................
        Context $context,
        \Magento\Customer\Model\Session $customerSession,
        PageFactory $resultPageFactory
        ..................................
    ) {
        parent::__construct($context);
        $this->resultPageFactory = $resultPageFactory;
        $this->customerSession = $customerSession;
    }

    public function execute() {
        $resultPage = $this->resultPageFactory->create();
        $resultPage->getConfig()->getTitle()->prepend(__('Company Module Controller 1'));
        $this->customerSession->setMyValue('test value');
        $this->customerSession->destroy();
        $this->customerSession->start();
        $this->customerSession->setMyValue('regenerate test value');
        return $resultPage;
    }
}
?>

=> For Getting session value in your second controller :

<?php

namespace Company\Module\Controller\Save;

use Magento\Framework\App\Action\Action;
use Magento\Framework\App\Action\Context;
use Magento\Framework\View\Result\PageFactory;

class Save extends Action {

    public $customerSession;

    /**
     * @param Context $context
     */
    public function __construct(
        ..................................
        Context $context,
        \Magento\Customer\Model\Session $customerSession,
        PageFactory $resultPageFactory
        ..................................
    ) {
        parent::__construct($context);
        $this->resultPageFactory = $resultPageFactory;
        $this->customerSession = $customerSession;
    }

    public function execute() {
        $resultPage = $this->resultPageFactory->create();
        $resultPage->getConfig()->getTitle()->prepend(__('Company Module Controller 2'));
        $this->customerSession->start(); // Refresh session before getting value
        var_dump($this->customerSession->getMyValue());
        return $resultPage;
    }
}

Hope this answer will helpful for you.