Magento2 - Missing required argument

Question

I'm trying to create a block I can call in my override of 'root.phtml'.

In the root file, I added some extra classes to the body depending on the url, so I've created a module which I call on this page.

I've overridden root.phtml in my theme folder, and I've created a seperate module to call in this phtml file. This is just to get the current URL (so if you have a better suggestion, please come forward) however when I try to load the application it comes up with

    Missing required argument $data of Karl\OverrideView\Block\OverrideView

The file being refered to is;

namespace Karl\OverrideView\Block;

class OverrideView
{

public $assetRepository;
protected $_storeManager;

public function __construct(

    \Magento\Framework\View\Element\Template\Context $context,
    array $data = [],
    \Magento\Store\Model\StoreManagerInterface $storeManager
){
    $this->_storeManager = $storeManager;
    return parent::construct($context, $data);
}

public function getFullUrl(){
    return $this->_storeManager->getStore()->getCurrentUrl(false);
}
}

Answer 1

In your constructor you are calling parent::construct(), but you are not extending any class. You must extend the class to which you are override or to the class \Magento\Framework\View\Element\Template and there is a typo in constructor name (two underscores are missing), the proper name is __construct

Also, write your constructor this way:

public function __construct(

    \Magento\Framework\View\Element\Template\Context $context,
    \Magento\Store\Model\StoreManagerInterface $storeManager,
    array $data = []
){
    $this->_storeManager = $storeManager;
    return parent::__construct($context, $data);
}

Answer 2

I was having the same error, all my __constructs and Extending's are correct, if you are scratching your head wondering... why when I do:

php bin/magento setup:upgrade

it breaks everything and get this error, but then when I do:

php bin/magento setup:di:compile

the same code works fine afterwards, but then would break again if you do another:

php bin/magento setup:upgrade

??

Then most likely is that you have got your array $DATA in the middle of your Construct definition, this would cause this issue and the solution is to move this right to the end of your __constrct definition, see example below:

Example, this will NOT work:

public function __construct (
      \Magento\Framework\Model\Context $ModelContext, 
      array $Data = [],
      \Magento\Framework\Registry $Registry

But this will work:

public function __construct (
      \Magento\Framework\Model\Context $ModelContext,
      \Magento\Framework\Registry $Registry,
      array $Data = []

I hope this helps.