The block instance is passed to the «*.phtml» templates as $block variable, not $this

dmitry_fedyuk · November 22, 2015, 10:39am

This is a change from Magento 1.x where a template can access the block by the $this variable.

Let’s compare, for example, the standard catalog/product/list templates.

Magento 1.x:

OpenMage/magento-mirror/blob/1.9.2.2/app/design/frontend/base/default/template/catalog/product/list.phtml#L35-L35


$_productCollection=$this->getLoadedProductCollection();

Magento 2:

github.com

magento/magento2/blob/2.0.0/app/code/Magento/Catalog/view/frontend/templates/product/list.phtml#L12-L16


/**
* Product list template
*
* @var $block \Magento\Catalog\Block\Product\ListProduct
*/

github.com

magento/magento2/blob/2.0.0/app/code/Magento/Catalog/view/frontend/templates/product/list.phtml#L19-L19


$_productCollection = $block->getLoadedProductCollection();

The $this variable is also available, but now it is a reference to a \Magento\Framework\View\TemplateEngine\Php instance

github.com

magento/magento2/blob/2.0.0/lib/internal/Magento/Framework/View/TemplateEngine/Php.php#L52-L68


public function render(BlockInterface $block, $fileName, array $dictionary = [])
{
    ob_start();
    try {
        $tmpBlock = $this->_currentBlock;
        $this->_currentBlock = $block;
        extract($dictionary, EXTR_SKIP);
        include $fileName;
        $this->_currentBlock = $tmpBlock;
    } catch (\Exception $exception) {
        ob_end_clean();
        throw $exception;
    }
    /** Get output buffer. */
    $output = ob_get_clean();
    return $output;
}

As you can see, a template also has the following local variables:

$fileName — its own file name
$tmpBlock — the parent block

A template has also has the local variables extracted from a $dictionary, it is set from the block’s _viewVars property

github.com

magento/magento2/blob/2.0.0/lib/internal/Magento/Framework/View/Element/Template.php#L255


{
    $relativeFilePath = $this->getRootDirectory()->getRelativePath($fileName);
    \Magento\Framework\Profiler::start(
        'TEMPLATE:' . $fileName,
        ['group' => 'TEMPLATE', 'file_name' => $relativeFilePath]
    );


    if ($this->validator->isValid($fileName)) {
        $extension = pathinfo($fileName, PATHINFO_EXTENSION);
        $templateEngine = $this->templateEnginePool->get($extension);
        $html = $templateEngine->render($this->templateContext, $fileName, $this->_viewVars);
    } else {
        $html = '';
        $templatePath = $fileName ?: $this->getTemplate();
        $this->_logger->critical(
            "Invalid template file: '{$templatePath}' in module: '{$this->getModuleName()}'"
            . " block's name: '{$this->getNameInLayout()}'"
        );
    }


    \Magento\Framework\Profiler::stop('TEMPLATE:' . $fileName);

github.com

magento/magento2/blob/2.0.0/lib/internal/Magento/Framework/View/Element/Template.php#L23-L28


/**
 * Assigned variables for view
 *
 * @var array
 */
protected $_viewVars = [];

You can make a local variable available in a template by calling the \Magento\Framework\View\Element\Template::assign method:

github.com

magento/magento2/blob/2.0.0/lib/internal/Magento/Framework/View/Element/Template.php#L219-L236


/**
 * Assign variable
 *
 * @param   string|array $key
 * @param   mixed $value
 * @return  $this
 */
public function assign($key, $value = null)
{
    if (is_array($key)) {
        foreach ($key as $subKey => $subValue) {
            $this->assign($subKey, $subValue);
        }
    } else {
        $this->_viewVars[$key] = $value;
    }
    return $this;
}

dmitry_fedyuk · December 14, 2015, 6:12am