How to create a front controller that uses an empty layout

Question

I want my front controller to serve an xml type and for that reason i need that controller to use a layout that doesn't include any html tags.

On my controller class i have the following code:

<?php

namespace Vendor\Module\Controller\Feed;
use Magento\Framework\View\Result\PageFactory;
use Magento\Framework\App\Action\Context;

class Index extends \Magento\Framework\App\Action\Action
{
    protected $pageFactory;
    public function __construct(Context $context, PageFactory $pageFactory)
    {
        $this->pageFactory = $pageFactory;
        return parent::__construct($context);
    }

    public function execute()
    {        
        // $this->getResponse()->setHeader('Content-Type','text/xml');
        $page_object = $this->pageFactory->create();
        return $page_object;
    }  
}

The pageFactory object seems to be including the theme's base layout. Overriding the <container name="root"> node on this controller-action layout, doesn't stop it from rendering head and body tags.

Is there a different object i should be using in the execute() function? What would be the correct way of getting the front controller to use an empty layout?

Answer 1

I assume you do not actualy need an empty result, but JSON or XML result.

For the JSON result you can inject \Magento\Framework\Controller\Result\JsonFactory $resultJsonFactory into your constructor. Then you are free to pass the response like this:

public function execute()
{
    $result = $this->resultJsonFactory->create();
    return $result->setData(['success' => true]);
}

RAW result: inject Magento\Framework\Controller\Result\RawFactory $rawResultFactory

public function execute()
{
    $result = $this->rawResultFactory->create();
    $result->setHeader('Content-Type', 'text/xml');
    $result->setContents('<root><science></science></root>');
    return $result;
}

Please refer to Alan Storm's quickie for details http://magento-quickies.alanstorm.com/post/141260832260/magento-2-controller-result-objects