Magento 2 : Call Helper Without Using __construct in Own Module

Question

I have created a new module and override the

\Magento\Catalog\Block\Product\View\Description

function using preference. In this module we create new helper located in

Custom_Hello/Helper/Data.php

Then how to call this helper in

Custom_Hello/Block/Product/View/Description.php

If we use __construct got some error.

public function __construct(\Custom\Hello\Helper\Data $helper)
    {
        $this->helper = $helper;
    }

Anyone helpme

Answer 1

You can add your custom helper in constructor, but as this method is present in the class you're extending then you'd pass the right parameters in it, not just your helper

class Description extends \Magento\Catalog\Block\Product\View\Description

You are extending \Magento\Catalog\Block\Product\View\Description so let's see constructor in this class (in 2.3 version, you can check this in your project for other version, if that's the case)

public function __construct(
    \Magento\Framework\View\Element\Template\Context $context,
    \Magento\Framework\Registry $registry,
    array $data = []
) {
    $this->_coreRegistry = $registry;
    parent::__construct($context, $data);
}

So, in your class you'd pass that $context & $registry parameters. You can do that this way

public function __construct(
    \Custom\Hello\Helper\Data $helper,
    \Magento\Framework\View\Element\Template\Context $context,
    \Magento\Framework\Registry $registry,
    array $data = []
) {
    $this->helper = $helper;
    parent::__construct($context, $registry, $data);
}

Answer 2

I got the solution. If we use following way

public function __construct(
        \Magento\Framework\View\Element\Template\Context $context,
        \Magento\Framework\Registry $registry,
        \Custom\Hello\Helper\Data $dataHelper,
        array $data = []
    ) {
        parent::__construct($context, $registry, $data);
        $this->_dataHelper = $dataHelper;
    }

Answer 3

In Custom_Hello/Block/Product/View/Description.php File

protected $helper;

public function __construct(
        \Magento\Catalog\Block\Product\Context $context, 
        \Custom\Hello\Helper\Data $helper
        array $data = []
    )
    {
        $this->helper= $heper;
        parent::__construct($context, $data);
    }

And You Can Call Your Helper Function Like this

$this->helper->yourFunctionName() 

Answer 4

You can use directly without contructor

$this->helper('CompanyName\ModuleName\Helper\Data')->yourfunctionname();