In Magento 2, the $this
variable no longer refereces to a template's block object. It refers to a template class
Magento\Framework\View\TemplateEngine\Php
However, this template class has a passthrough __call
method
#File: vendor/magento/framework/View/TemplateEngine/Php.php
public function __call($method, $args)
{
return call_user_func_array([$this->_currentBlock, $method], $args);
}
Which ensure any method calls make it through to the actual block. This also explains why you can't call protected methods from phtml
templates.
In addition to this though, every (I think?) template has a variable named $block
populated, which also refers to the parent block object. You can see this in use in Magento's list template
#File: vendor/magento/module-catalog/view/frontend/templates/product/list.phtml
//...
$_productCollection = $block->getLoadedProductCollection();
where the $block
variable is used, but never explicitly defined.
Other than the differences mentioned above, is there any difference between using one technique over the other? i.e. Do both $block
and $this->currentBlock
refer to the same object?
Best Answer
In a template file,
$block
and$this->_currentBlock
are the same thing.Take a look at the
render
method in thePhp.php
template engine.Before including the template file, this happens:
$this->_currentBlock = $block;
then the template file is included using a simpleinclude $fileName;
.This means that inside a template you are still inside the
Php
template engine. That's why$this
works, and that's why$block
is defined.[EDIT]
I just found out that using
$this
inside templates is discouraged.The php sniffer with the EcgM2 standards shows a warning when using
$this
inside templates.Replacing
$this
with$block
makes the warning go away.