Adding Custom Layout Handles in Magento 2

Thanks to Magento 2’s MVVM approach the traditional responsibilities of a controller object have been pushed into the “view model” layer (i.e. a block’s _prepareLayout method).

The main job a controller performs in Magento 2 is to

1. Determine what sort of response is needed (HTML page, JSON, Redirect)
2. Create an object to handle that response
3. Return that object to the system for processing

For a standard HTML page, this means injecting a page factory object in your controller’s constructor

public function __construct(
    Context $context,
    PageFactory $resultPageFactory
) {
    $this->resultPageFactory = $resultPageFactory;
}

and using that factory to return an object in the controller’s execute method.

$resultPage = $this->resultPageFactory->create();
return $resultPage;

One benefit of this is, it’s pretty easy to add custom layout handles to your response. Every page object has an addHandle method

$resultPage = $this->resultPageFactory->create();
$resultPage->addHandle('my_custom_handle');
return $resultPage;

and your response will include the additional handle. This was possible in Magento 1, but required redefining a specific controller action method in your controller, and making sure you included a call to the parent method. It’s not an earth shattering improvement, but its something that makes life a little easier for module developers.