Magento 2: Get rendered block from external script

Question

I would like to get the html of a particular block from an external script and include it somewhere else.

In magento 1.x I would do something like this:

<?php
include_once "app/Mage.php";
umask(0);
Mage::app()->loadArea('frontend');

$layout = Mage::getSingleton('core/layout');

//load default xml layout handle and generate blocks
$layout->getUpdate()->load('default');
$layout->generateXml()->generateBlocks();

//get the loaded head and header blocks and output
$headBlock = $layout->getBlock('head');
$headerBlock = $layout->getBlock('header');
echo $headBlock->toHtml() . $headerBlock->toHtml();

https://magento.stackexchange.com/a/5080/23559

I would like to ask you, which is the correct way to achieve this with Magento 2?

Thank you!

Answer 1

This is how I managed to get the content I needed. My question is: is this an acceptable way or should I do it another way? This uses object manager directly, thing that in module's development is discouraged. May I use it in this context?

<?php

use \Magento\Framework\App\Bootstrap;
use \Magento\Store\Model\Store;
use \Magento\Store\Model\StoreManager;


require __DIR__ . '/app/bootstrap.php';
$_SERVER[StoreManager::PARAM_RUN_CODE] = 'default';
$bootstrap = Bootstrap::create(BP, $_SERVER);
$obj = $bootstrap->getObjectManager();

/* @var \Magento\Framework\App\RequestInterface $req */
$req = $obj->create("\\Magento\\Framework\\App\\RequestInterface");
$req->setParams(array('message' => 'Hello Mage 2'));

/* @var Magento\Framework\App\State $state */
$state = $obj->get('Magento\Framework\App\State');
$state->setAreaCode('frontend');

/* @var Magento\Store\Model\StoreManagerInterface $storeManager */
$storeManager = $obj->create("\\Magento\\Store\\Model\\StoreManagerInterface");
$storeManager->setCurrentStore(1);

/* @var \Magento\Framework\View\LayoutInterface $layout */
$layout = $obj->create("\\Magento\\Framework\\View\\LayoutInterface");

/* @var \Magento\Framework\View\Element\Messages $block */
$block = $layout->createBlock('Magento\Framework\View\Element\Messages', 'messages');

/* @var  \Magento\Framework\Message\MessageInterface $message */
$message = $obj->create('Magento\Framework\Message\Error');
$message->setText($req->getParam("message")." from ". $storeManager->getStore()->getName() );

$block->addMessage($message);
echo $block->toHtml();

and the result is

<div class="messages"><div class="message message-error error"><div data-ui-id="messages-message-error" >Hello Mage 2 from Default Store View</div></div></div>