Magento 2: The direct use of ObjectManager is discouraged [duplicate]

Question

This question already has answers here:

How to check if customer is logged in or not? (20 answers)

Closed 3 years ago.

when I am check using object manager it gives me warning that The direct use of ObjectManager is discouraged. Inject necessary dependencies via constructor". How to solve this problem and I also want to know that how to call block file's objectmanager in template file. I am checking customer is login or not using below code.

    $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
    $customerSession = $objectManager->get('Magento\Customer\Model\Session');
       if ($customerSession->isLoggedIn()) {
           //my custom code goes here; 
        }

I am already using below way but it doesn't work for me.

     private $_objectManager;

    public function __construct(
    \Magento\Framework\ObjectManagerInterface $objectmanager) 
    {
     $this->_objectManager = $objectmanager;
    }

   $customerSession = $objectmanager->get('Magento\Customer\Model\Session');
           if ($customerSession->isLoggedIn()) {
               //my custom code goes here; 
            }

Answer 1

Use objectManager by Factory Method to avoid "The direct use of ObjectManager is discouraged." error.

For example To check customer login or not using objectManager

private $_objectManager;

public function __construct(
    \Magento\Framework\ObjectManagerInterface $objectmanager
) {
    $this->_objectManager = $objectmanager;
}

$customer = $this->_objectManager->get('Magento\Customer\Model\Session');

if ($customer->isLoggedIn()) {
    //my custom code goes here; 
}

To check customer login or not using \Magento\Customer\Model\Session class

private $_customerSession;

public function __construct(
    ...
    \Magento\Customer\Model\Session $customerSession, 
    ...
) {
    ...
    $this->_customerSession = $customerSession;
    ...
}

if ($this->_customerSession->isLoggedIn()) {
     //my custom code goes here; 
}

Answer 2

in your code

    private $_objectManager;

    public function __construct(
    \Magento\Framework\ObjectManagerInterface $objectmanager) 
    {
     $this->_objectManager = $objectmanager;
    }

   $customerSession = $this->_objectManager->get('Magento\Customer\Model\Session');
           if ($customerSession->isLoggedIn()) {
               //my custom code goes here; 
            }

Use factory method instead

namespace Test\Module\Block;

class Test extends \Magento\Framework\View\Element\Template
{

    protected $_session;


    public function __construct( 

          \Magento\Customer\Model\Session $session, 

                                ) {
            parent::__construct($context);


            $this->_session = $session;

    }
    public function _isLoggedIn()
    {  

         if($this->_session->isLoggedIn()):
           return true;
         endif;
           return false;
    }