Ttdfjt

It's working copy. You can compare with your block class. Here I use Form as block class

namespace VendorModuleBlock;


class Form extends MagentoFrameworkViewElementTemplate

 protected $customerSession;

 /**
 * Construct
 *
 * @param MagentoFrameworkViewElementTemplateContext $context
 * @param MagentoCustomerModelSession $customerSession
 * @param array $data
 */
 public function __construct(
 MagentoFrameworkViewElementTemplateContext $context,
 MagentoCustomerModelSession $customerSession,
 array $data = []
 ) 
 parent::__construct($context, $data);

 $this->customerSession = $customerSession;
 

 public function _prepareLayout()
 

 var_dump($this->customerSession->getCustomer()->getId());
 exit();
 return parent::_prepareLayout();
 

When You define block which use session You have to disable cache for it.

 <block class="VendorModuleBlockIndex" name="Name"
 template="Vendor_Module::template/path.phtml" cacheable="false">
 </block>

You need to inject MagentoCustomerModelSession $customerSession, class to get customer ID from customer session.

protected $_customerSession;

public function __construct(
 ...
 MagentoCustomerModelSession $customerSession,
 ...
) 
 ...
 $this->_customerSession = $customerSession;
 ...


public function getCustomer()

 echo $this->_customerSession->getCustomer()->getId(); //Print current customer ID

 $customerData = $this->_customerSession->getCustomer(); 
 print_r($customerData->getData()); //Print current Customer Data

NOTE: You only get customer id if customer logged in and customer session initialized

It seems to work when you pass the Context object to the parent class before instantiating the customer session :

class History extends MagentoFrameworkViewElementTemplate


 /**
 * @var Session
 */
 protected $_session;

 public function __construct(
 TemplateContext $context,
 MagentoCustomerModelSession $session,
 array $data
 )
 
 parent::__construct($context, $data);
 $this->_session = $session;
 

 public function _prepareLayout()
 

 var_dump($this->_session->getCustomerId());
 exit();
 return parent::_prepareLayout();
 

While we are injecting customer session in block to retrive logged in customer data and we are not getting customer data from block because Magento 2 reset all the customer sessions when FPC is enabled.

Please use cacheable="false" for bloick in your layout :

<referenceContainer name="content"> 
 <block class="ArmanTestBlockList" name="list" template="Arman_Test::list.phtml" cacheable="false"> 
 </block>
 </referenceContainer> 

In this case, Magento 2 ignore this page from caching.

If you need only the customer_id then without loading whole object (see method getCustomer method) you can get it by simply using getCustomerId method.

As getId method also calls getCustomerId method.

file : vendor/magento/module-customer/Model/Session.php

/**
 * Retrieve customer model object
 *
 * @return Customer
 * use getCustomerId() instead
 */
public function getCustomer()

 if ($this->_customerModel === null) 
 $this->_customerModel = $this->_customerFactory->create()->load($this->getCustomerId());
 

 return $this->_customerModel;



/**
 * Retrieve customer id from current session
 *
 * @api
 * @return int|null
 */
public function getCustomerId()

 if ($this->storage->getData('customer_id')) 
 return $this->storage->getData('customer_id');
 
 return null;


/**
 * Retrieve customer id from current session
 *
 * @return int|null
 */
public function getId()

 return $this->getCustomerId();