The best way to replace die and echo magento 2.1.8

Question

I'm running phpcs which is code sniffer for magento 2. and I got this error from it :

 ERROR | Use of echo language construct is discouraged.
 ERROR | Use of die language construct is discouraged. 

When I looked into the code I found that the class controller has echo and die like this :

public function execute()
    {
        $json_encode = array();
        $itemId = (int)$this->getRequest()->getParam('item_id');
        $error = 0; $msg_error = "";
        try {
            $this->sidebar->checkQuoteItem($itemId);
            $this->sidebar->removeQuoteItem($itemId);
            $json_encode["sub_total_html"] = $this->_blockCart->renderTotals();
            $json_encode["items_count"] = $this->_blockCart->getQuote()->getItemsCount();

            /* render Order Total block on checkout/cart  */
            $grand_total = $this->_blockCart->displayBaseGrandtotal();
            $json_encode["grand_total_html"] = $this->_layoutFactory->create()
                        ->createBlock('Magento\Checkout\Block\Cart\Totals')
                        ->setData('grand_total', $grand_total)
                        ->setTemplate('Cmsmart_Ajaxcart::module-checkout/cart/totals/grand-total.phtml')
                        ->toHtml();

            /* return $this->jsonResponse(); */
        } catch (\Magento\Framework\Exception\LocalizedException $e) {
            $error = 1;
            $msg_error = $e->getMessage();
           /*  return $this->jsonResponse($e->getMessage()); */
        } catch (\Exception $e) {
            $error = 1;
            $msg_error = $e->getMessage();
            /* $this->logger->critical($e);
            return $this->jsonResponse($e->getMessage()); */
        }
        $json_encode["error"] = $error;
        $json_encode["error_msg"] = $msg_error;
        echo json_encode($json_encode);
        die;
    }

I found somewhere that to replace echo and die use setBody() so I changed it the code above replacing echo and die like this :

$this->getResponse()
    ->clearHeaders()
    ->setHeader('Content-Type', 'application/json')
    ->setBody($json_encode);

This is solution from this link

But it breaks the behavior in the front-end because I'm using Ajax. Any idea ? I also added exit at the of the setBody() but still it freezing.

Note that this code is snippet from cmsmart

Answer 1

Use JsonFactory class like below:

public function __construct(
    ---     
    \Magento\Framework\Controller\Result\JsonFactory $resultJsonFactory
    ---
) {
    ---
    $this->resultJsonFactory        = $resultJsonFactory;
    ---
}


public function execute(){
----
    $jsonResult = $this->resultJsonFactory->create();
    $jsonResult->setData($json_encode);
    return $jsonResult;
}