Magento2 :Change the object maganer to constructor

Question

Can anyone help me how to change the object manager to a constructor in magento2:

$om = \Magento\Framework\App\ObjectManager::getInstance();
            $customerSession = $om->get('Magento\Customer\Model\Session');
            $customerData = $customerSession->getCustomer()->getData();
            $customerId = $customerSession->getCustomerId();
            $customerObj = $om->create('Magento\Customer\Model\Customer')
                ->load($customerId);
            $customerData = $customerObj->getDataModel();
    try {
                    $customerData->setCustomAttribute('r_what_percent_of_the_pharmacy', $r_what_percent_of_the_pharmacy);
                    $customerData->setCustomAttribute('r_what_percent_of_prescrip', $r_what_percent_of_prescrip);
                    $customerData->setCustomAttribute('r_how_many_total_prescriptions', $r_how_many_total_prescriptions);
                    $customerData->setCustomAttribute('r_has_the_owner_or_pharmacy', $r_has_the_owner_or_pharmacy);
                    $customerData->setCustomAttribute('r_does_the_pharmacy_solicit', $r_does_the_pharmacy_solicit);
                    $customerData->setCustomAttribute('r_is_your_clinic_or_pharmacy', $r_is_your_clinic_or_pharmacy);
                    $customerData->setCustomAttribute('r_are_one_or_more_practiti', $r_are_one_or_more_practiti);
                    $customerData->setCustomAttribute('r_does_the_pharmacy_offer', $r_does_the_pharmacy_offer);
                    $customerData->setCustomAttribute('r_any_exceptions', $r_any_exceptions);
                    $customerData->setCustomAttribute('r_any_exceptions_circumstances', $r_any_exceptions_circumstances);
                    $customerData->setCustomAttribute('r_does_the_pharmacy_clinic', $r_does_the_pharmacy_clinic);
                    $customerData->setCustomAttribute('r_currentstep', $r_currentstep);
                    $customerObj->updateData($customerData);
                    $customerObj->save();
                } catch (Exception $e) {
                    return $e->getMessage();
                }

Answer 1

If you want to inject ObjectManager in constractor in your class, you can do following way:

use Magento\Framework\ObjectManagerInterface;
class YourClassName 
{

protected $objectManager;


/**
 * @param ObjectManagerInterface $objectManager
 */
public function __construct(
    ObjectManagerInterface $objectManager
) {
    $this->objectManager = $objectManager;
  }

public function yourFunctionName(){
    $customerSession = $this->objectManager->get('Magento\Customer\Model\Session');
    $customerData = $customerSession->getCustomer()->getData();
    $customerId = $customerSession->getCustomerId();
    $customerObj = $this->objectManager->create('Magento\Customer\Model\Customer')
        ->load($customerId);
    $customerData = $customerObj->getDataModel();
    try {
            $customerData->setCustomAttribute('r_what_percent_of_the_pharmacy', $r_what_percent_of_the_pharmacy);
            $customerData->setCustomAttribute('r_what_percent_of_prescrip', $r_what_percent_of_prescrip);
            $customerData->setCustomAttribute('r_how_many_total_prescriptions', $r_how_many_total_prescriptions);
            $customerData->setCustomAttribute('r_has_the_owner_or_pharmacy', $r_has_the_owner_or_pharmacy);
            $customerData->setCustomAttribute('r_does_the_pharmacy_solicit', $r_does_the_pharmacy_solicit);
            $customerData->setCustomAttribute('r_is_your_clinic_or_pharmacy', $r_is_your_clinic_or_pharmacy);
            $customerData->setCustomAttribute('r_are_one_or_more_practiti', $r_are_one_or_more_practiti);
            $customerData->setCustomAttribute('r_does_the_pharmacy_offer', $r_does_the_pharmacy_offer);
            $customerData->setCustomAttribute('r_any_exceptions', $r_any_exceptions);
            $customerData->setCustomAttribute('r_any_exceptions_circumstances', $r_any_exceptions_circumstances);
            $customerData->setCustomAttribute('r_does_the_pharmacy_clinic', $r_does_the_pharmacy_clinic);
            $customerData->setCustomAttribute('r_currentstep', $r_currentstep);
            $customerObj->updateData($customerData);
            $customerObj->save();
        } catch (Exception $e) {
            return $e->getMessage();
        }
 }  
}

Answer 2

I think what you ask is simply to convert "object manager code" to proper "constructor injection code".

Injecting ObjectManager in constructor is rare and mostly used for factories. Don't do that.

For most cases, just create a constructor like this

public function __construct(  
) {

}

and add all classes you need to it like this:

/** @var \Magento\Customer\Model\Session */
protected $session;

/** @var \Magento\Customer\Model\Customer */
protected $customer;

public function __construct(
    \Magento\Customer\Model\Session $session,
    \Magento\Customer\Model\Customer $customer
) {
    $this->session = $session;
    $this->customer = $customer;
}

Magento 2 automatically creates instances of the specified classes for you.

In yourFunction name, you can then use these objects like this (just an example):

public function yourFunctionName(){
    $customerId = $this->session->getCustomerId();
    $customerObj = $this->customer->load($customerId);
    $customerData = $customerObj->getDataModel();
}