Magento 2 : How can I call helper function on override product list block

Question

I want to show some extra data on product list page so I override the vendor\magento\module-catalog\Block\Product\ListProduct.php . For this I refer Add custom block on listing page : Magento2. It work.

But I need to call my helper function in my override block file. Created new file name ListProduct.php in app\code\Vendor\Module_Name\Block\Product

namespace Vendor\Module_Name\Block\Product;
 class ListProduct extends \Magento\Catalog\Block\Product\ListProduct
 {

  // I need to call my module helper function here:

   public function test(){

   }
 }

How can I call my helper function inside this block file. Thanks

Answer 1

you can call your helper function as per below,

 namespace Vendor\Module_Name\Block\Product;
     class ListProduct extends \Magento\Catalog\Block\Product\ListProduct
     {
           public function __construct(
            \Magento\Catalog\Block\Product\Context $context,        
            \Magento\Framework\Data\Helper\PostHelper $postDataHelper,
            \Magento\Catalog\Model\Layer\Resolver $layerResolver,
            \Magento\Catalog\Api\CategoryRepositoryInterface $categoryRepository,
            \Magento\Framework\Url\Helper\Data $urlHelper,
            \Vendor\Mymodule\Helper\Data $dataHelper,
            array $data = []
        ) {
            $this->dataHelper = $dataHelper;       
            parent::__construct(
                $context,
                $postDataHelper,
                $layerResolver,
                $categoryRepository,
                $urlHelper,
                $data
            );
        }

       public function test(){
            $this->dataHelper->getHelperFunction();
       }
    }

Remove var folder and refresh again.

Answer 2

You will have to overwrite the constructor of the parent class and add your extra class instance on to it something like:

<?php

namespace Vendor\Module_Name\Block\Product;

use Magento\Catalog\Block\Product\Context;
use Magento\Framework\Data\Helper\PostHelper;
use Magento\Catalog\Model\Layer\Resolver;
use Magento\Framework\Url\Helper\Data as UrlHelper;
use Vendor\Mymodule\Helper\Data as Helper;

use Magento\Catalog\Block\Product\ListProduct as MagentoListProduct

class ListProduct extends MagentoListProduct
{
    /**
     * @param Context $context
     * @param \Magento\Framework\Data\Helper\PostHelper $postDataHelper
     * @param \Magento\Catalog\Model\Layer\Resolver $layerResolver
     * @param CategoryRepositoryInterface $categoryRepository
     * @param \Magento\Framework\Url\Helper\Data $urlHelper
     * @param array $data
     */
    public function __construct(
        Helper $customHelper
        Context $context,
        PostHelper $postDataHelper,
        Resolver $layerResolver,
        CategoryRepositoryInterface $categoryRepository,
        UrlHelper $urlHelper,
        array $data = []
    ) {
        $this->customHelper = $customHelper;
        parent::__construct(
            $context,
            $postDataHelper,
            $layerResolver,
            $categoryRepository,
            $urlHelper,
            $data
        );
    }


    public function test()
    {
        $this->customHelper->yourCustomMethod();
    }
}

But if its only the helper you would like to use in the PHTML file you need not overwrite the ListProduct block you can use the following method as well.

First you can overwrite the template file using an custom theme.

In the new file you can get a instance of you helper using:

$customHelper = $this->helper('Vendor\Mymodule\Helper\Data');

And ofcourse you would need to clear the var folder either by

rm -rf ./var/*

or you can do it by

php bin/magento cache:clean
php bin/magento cache:flush

Hope this helps

Answer 3

Ugly way will be:

     namespace Vendor\Module_Name\Block\Product;
     class ListProduct extends \Magento\Catalog\Block\Product\ListProduct
     {
       public function test(){
           $dataHelper = \Magento\Framework\App\ObjectManager::getInstance()->get("\Vendor\Mymodule\Helper\Data");
           // Do some stuff with $dataHelper
       }
     }

It will be better in case you need test some things quickly.