Call block function from helper

Question

I tried to call the block function from my custom module helper like this:

$resultLayout = $this->_resultLayoutFactory->create(); 
$block = $resultLayout->getLayout()->getBlock('category.products.list');
if ($block) {
  $collection = $block->getLoadedProductCollection();
}

but i got an error like this:

Exception #0 (RuntimeException): Illegal state

Answer 1

If the block that you're trying to instantiate is defined in the layout then first you need to inject an instance of \Magento\Framework\View\Result\PageFactory.

Helper Class

...
protected $_resultPageFactory;
...
public function __construct(
   ...
   \Magento\Framework\View\Result\PageFactory $resultPageFactory,
   ...
) {
   ...
   $this->_resultPageFactory = $resultPageFactory;
   ...
}

Then you can instantiate your block using its name from the layout.

$resultPage = $this->_resultPageFactory->create();
$blockInstance = $resultPage->getLayout()->getBlock('category.products.list');

If the block that you're trying to instantiate is not defined in the layout then first you need to inject an instance of \Magento\Framework\View\LayoutFactory.

Helper Class

...
protected $_layoutFactory;
...
public function __construct(
   ...
   \Magento\Framework\View\LayoutFactory $layoutFactory,
   ...
) {
   ...
   $this->_layoutFactory = $layoutFactory;
   ...
}

Then you can instantiate your block using this layout factory.

$this->_layoutFactory->create()->createBlock('Magento\Catalog\Block\Product\ListProduct');