Add.php

<?php
/**
 *
 * SM CartQuickPro - Version 1.1.0
 * Copyright (c) 2017 YouTech Company. All Rights Reserved.
 * @license - Copyrighted Commercial Software
 * Author: YouTech Company
 * Websites: http://www.magentech.com
 */
 
namespace Sm\CartQuickPro\Controller\Wishlist\Index;

use Magento\Catalog\Api\ProductRepositoryInterface;
use Magento\Framework\App\Action;
use Magento\Framework\Data\Form\FormKey\Validator;
use Magento\Framework\Exception\NotFoundException;
use Magento\Framework\Exception\NoSuchEntityException;
use Magento\Framework\Controller\ResultFactory;

/**
 * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
 */
class Add extends \Magento\Wishlist\Controller\AbstractIndex
{
    /**
     * @var \Magento\Wishlist\Controller\WishlistProviderInterface
     */
    protected $wishlistProvider;

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

    /**
     * @var ProductRepositoryInterface
     */
    protected $productRepository;

    /**
     * @var Validator
     */
    protected $formKeyValidator;

    /**
     * @param Action\Context $context
     * @param \Magento\Customer\Model\Session $customerSession
     * @param \Magento\Wishlist\Controller\WishlistProviderInterface $wishlistProvider
     * @param ProductRepositoryInterface $productRepository
     * @param Validator $formKeyValidator
     */
    public function __construct(
        Action\Context $context,
        \Magento\Customer\Model\Session $customerSession,
        \Magento\Wishlist\Controller\WishlistProviderInterface $wishlistProvider,
        ProductRepositoryInterface $productRepository,
        Validator $formKeyValidator
    ) {
        $this->_customerSession = $customerSession;
        $this->wishlistProvider = $wishlistProvider;
        $this->productRepository = $productRepository;
        $this->formKeyValidator = $formKeyValidator;
        parent::__construct($context);
    }

    /**
     * Adding new item
     *
     * @return \Magento\Framework\Controller\Result\Redirect
     * @throws NotFoundException
     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
     * @SuppressWarnings(PHPMD.NPathComplexity)
     * @SuppressWarnings(PHPMD.UnusedLocalVariable)
     */
    public function execute()
    {
        $result = [];
		$params = $this->getRequest()->getParams();
        $resultRedirect = $this->resultFactory->create(ResultFactory::TYPE_REDIRECT);
        if (!$this->formKeyValidator->validate($this->getRequest())) {
            return $resultRedirect->setPath('*/');
        }

        $wishlist = $this->wishlistProvider->getWishlist();
        if (!$wishlist) {
            throw new NotFoundException(__('Page not found.'));
        }

        $session = $this->_customerSession;

        $requestParams = $this->getRequest()->getParams();

        if ($session->getBeforeWishlistRequest()) {
            $requestParams = $session->getBeforeWishlistRequest();
            $session->unsBeforeWishlistRequest();
        }

        $productId = isset($requestParams['product']) ? (int)$requestParams['product'] : null;
        if (!$productId) {
            $resultRedirect->setPath('*/');
            return $resultRedirect;
        }

        try {
            $product = $this->productRepository->getById($productId);
        } catch (NoSuchEntityException $e) {
            $product = null;
        }

        if (!$product || !$product->isVisibleInCatalog()) {
            $this->messageManager->addErrorMessage(__('We can\'t specify a product.'));
            $resultRedirect->setPath('*/');
            return $resultRedirect;
        }

        try {
            $buyRequest = new \Magento\Framework\DataObject($requestParams);

            $result = $wishlist->addNewItem($product, $buyRequest);
            if (is_string($result)) {
                throw new \Magento\Framework\Exception\LocalizedException(__($result));
            }
            $wishlist->save();

            $this->_eventManager->dispatch(
                'wishlist_add_product',
                ['wishlist' => $wishlist, 'product' => $product, 'item' => $result]
            );

            $referer = $session->getBeforeWishlistUrl();
            if ($referer) {
                $session->setBeforeWishlistUrl(null);
            } else {
                $referer = $this->_redirect->getRefererUrl();
            }

            $this->_objectManager->get('Magento\Wishlist\Helper\Data')->calculate();

            $this->messageManager->addComplexSuccessMessage(
                'addProductSuccessMessage',
                [
                    'product_name' => $product->getName(),
                    'referer' => $referer
                ]
            );
			$message = __(
				'%1 has been added to your Wish List.',
				 $product->getName()
			);
			$result['success'] = true;
			$result['messages'] =  $message;
			if (isset($params['isWishlistPage'])){
				$_layout  = $this->_objectManager->get('Magento\Framework\View\LayoutInterface');
				$_layout->getUpdate()->load(['cartquickpro_wishlist_index_index']);
				$_layout->generateXml();
				$_output = $_layout->getOutput();
				$result['content'] = $_output;
				$result['isWishlistPageContent'] =  true;
			}
        } catch (\Magento\Framework\Exception\LocalizedException $e) {
            $this->messageManager->addErrorMessage(
                __('We can\'t add the item to Wish List right now: %1.', $e->getMessage())
            );
			$result['success'] = false;
			$result['messages'] = __('We can\'t add the item to Wish List right now: %1.', $e->getMessage());
        } catch (\Exception $e) {
            $this->messageManager->addExceptionMessage(
                $e,
                __('We can\'t add the item to Wish List right now.')
            );
			$result['success'] = false;
			$result['messages'] =  __('We can\'t add the item to Wish List right now.');
        }

        $result['isWishlistBtn'] =   (!isset($params['isWishlistPage']) && $wishlist->getItemsCount()) ? true : false ;
		return $this->_jsonResponse($result);
    }
	
	protected function _jsonResponse($result)
    {
        return $this->getResponse()->representJson(
            $this->_objectManager->get('Magento\Framework\Json\Helper\Data')->jsonEncode($result)
        );
    }
}