Magento 2 Renderer generates "Fatal error"

Question

I don't understand what is wrong with this Renderer code:

<?php
namespace Darsh\Banner\Block\Adminhtml\Grid\Renderer;
use Magento\Framework\DataObject as DObject;
use Magento\Framework\Data\Form\Element\Renderer\RendererInterface as RI;
use Magento\Framework\Data\Form\Element\AbstractElement as AE;
use Magento\Backend\Block\Widget\Grid\Column\Renderer\AbstractRenderer as AR;

class ImageView extends AE implements RI
{
        ## public function render(\Magento\Framework\Object $row)
        public function render(DObject $row)
        {
                echo "<pre/>";print_r($row);die;
        }
}

Whenever I compile my code with this in "Darsh_Banner" module, it generates fatal error in "Repositories Code Generation:" step as below:

PHP Fatal error:  Declaration of Darsh\Banner\Block\Adminhtml\Grid\Renderer\ImageView::render() must be compatible with Magento\Framework\Data\Form\Element\Renderer\RendererInterface::render(Magento\Framework\Data\Form\Element\AbstractElement $element) in /var/www/html/magento-2/app/code/Darsh/Banner/Block/Adminhtml/Banner/Grid/Renderer/ImageView.php on line 9

Grid.php of Darsh-Banner module:

<?php
namespace Darsh\Banner\Block\Adminhtml\Banner;

class Grid extends \Magento\Backend\Block\Widget\Grid\Extended
{
    /**
     * @var \Magento\Framework\Module\Manager
     */
    protected $moduleManager;

    /**
     * @var \Darsh\Banner\Model\bannerFactory
     */
    protected $_bannerFactory;

    /**
     * @var \Darsh\Banner\Model\Status
     */
    protected $_status;

    /**
     * @param \Magento\Backend\Block\Template\Context $context
     * @param \Magento\Backend\Helper\Data $backendHelper
     * @param \Darsh\Banner\Model\bannerFactory $bannerFactory
     * @param \Darsh\Banner\Model\Status $status
     * @param \Magento\Framework\Module\Manager $moduleManager
     * @param array $data
     *
     * @SuppressWarnings(PHPMD.ExcessiveParameterList)
     */
    public function __construct(
        \Magento\Backend\Block\Template\Context $context,
        \Magento\Backend\Helper\Data $backendHelper,
        \Darsh\Banner\Model\BannerFactory $bannerFactory,
        \Darsh\Banner\Model\Status $status,
        \Magento\Framework\Module\Manager $moduleManager,
        array $data = []
    ) {
        $this->_bannerFactory = $bannerFactory;
        $this->_status = $status;
        $this->moduleManager = $moduleManager;
        parent::__construct($context, $backendHelper, $data);
    }

    /**
     * @return void
     */
    protected function _construct()
    {
        parent::_construct();
        $this->setId('postGrid');
        $this->setDefaultSort('banner_id');
        $this->setDefaultDir('DESC');
        $this->setSaveParametersInSession(true);
        $this->setUseAjax(true);
        $this->setVarNameFilter('post_filter');
    }

    /**
     * @return $this
     */
    protected function _prepareCollection()
    {
        $collection = $this->_bannerFactory->create()->getCollection();
        $this->setCollection($collection);

        parent::_prepareCollection();
        return $this;
    }

    /**
     * @return $this
     * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
     */
    protected function _prepareColumns()
    {
        $this->addColumn(
            'banner_id',
            [
                'header' => __('ID'),
                'type' => 'number',
                'index' => 'banner_id',
                'header_css_class' => 'col-id',
                'column_css_class' => 'col-id'
            ]
        );
        $this->addColumn(
            'title',
            [
                'header' => __('Title'),
                'index' => 'title',
                'class' => 'xxx'
            ]
        );

        $this->addColumn(
            'image',
            [
                'header' => __('Image'),
                'index' => 'image',
                'class' => 'xxx',
                ## 'renderer' => 'Darsh\Banner\Block\Adminhtml\Banner\Grid\Renderer\ImageView'
            ]
        );


        $this->addColumn(
            'is_active',
            [
                'header' => __('Status'),
                'index' => 'is_active',
                'type' => 'options',
                'options' => $this->_status->getOptionArray()
            ]
        );


        $this->addColumn(
            'edit',
            [
                'header' => __('Edit'),
                'type' => 'action',
                'getter' => 'getId',
                'actions' => [
                    [
                        'caption' => __('Edit'),
                        'url' => [
                            'base' => '*/*/edit'
                        ],
                        'field' => 'banner_id'
                    ]
                ],
                'filter' => false,
                'sortable' => false,
                'index' => 'stores',
                'header_css_class' => 'col-action',
                'column_css_class' => 'col-action'
            ]
        );

        $block = $this->getLayout()->getBlock('grid.bottom.links');
        if ($block) {
            $this->setChild('grid.bottom.links', $block);
        }

        return parent::_prepareColumns();
    }

    /**
     * @return $this
     */
    protected function _prepareMassaction()
    {
        $this->setMassactionIdField('banner_id');
        $this->getMassactionBlock()->setTemplate('Darsh_Banner::banner/grid/massaction_extended.phtml');
        $this->getMassactionBlock()->setFormFieldName('banner');

        $this->getMassactionBlock()->addItem(
            'delete',
            [
                'label' => __('Delete'),
                'url' => $this->getUrl('banner/*/massDelete'),
                'confirm' => __('Are you sure?')
            ]
        );

        $statuses = $this->_status->getOptionArray();

        $this->getMassactionBlock()->addItem(
            'status',
            [
                'label' => __('Change status'),
                'url' => $this->getUrl('banner/*/massStatus', ['_current' => true]),
                'additional' => [
                    'visibility' => [
                        'name' => 'status',
                        'type' => 'select',
                        'class' => 'required-entry',
                        'label' => __('Status'),
                        'values' => $statuses
                    ]
                ]
            ]
        );


        return $this;
    }

    /**
     * @return string
     */
    public function getGridUrl()
    {
        return $this->getUrl('banner/*/grid', ['_current' => true]);
    }

    /**
     * @param \Darsh\Banner\Model\banner|\Magento\Framework\Object $row
     * @return string
     */
    public function getRowUrl($row)
    {
        return $this->getUrl(
            'banner/*/edit',
            ['banner_id' => $row->getId()]
        );
    }
}

I tried changing "implementing from" classes but same error.

Anyone please provide suggestion.

Answer 1

Re: the specific error you're seeing -- you have a class named

Darsh\Banner\Block\Adminhtml\Grid\Renderer\ImageView

Which defined a render method that looks like this (short class names expanded)

public function render(\Magento\Framework\DataObject $row)
{
    echo "<pre/>";print_r($row);die;
}

Your class implements the Magento\Framework\Data\Form\Element\Renderer\RendererInterface interface, which has an abstract render method

public function render(\Magento\Framework\Data\Form\Element\AbstractElement $element);

Your render method accepts a single Magento\Framework\DataObject parameter.

The interface accepts a Magento\Framework\Data\Form\Element\AbstractElement parameter.

This makes your class incompatible with the interface. To fix this specific error, you need to change the type hint on your class to

public function render(\Magento\Framework\Data\Form\Element\AbstractElement $row)
{
    echo "<pre/>";print_r($row);die;
}

Answer 2

Try this: In Grid.php

$this->addColumn(
            'column_id',
            [
                'header'   => __('Column Name'),
                'index'    => 'column_id',
                'type'     => 'column type', //file, number,etc.
                'renderer' => 'PackageName\Modulename\Block\Adminhtml\Modulename\Grid\Renderer\RendererFileName',
            ]
        );

In RendererFileName.php

class ImageView extends \Magento\Backend\Block\Widget\Grid\Column\Renderer\AbstractRenderer {
    public function render(DataObject $row) {
         echo "Hello world"; exit;  //Your code here
    }
}

Answer 3

You should use the following render function in your renderer file to fix this error.

public function render(\Magento\Framework\DataObject $row) {

}