Fail creating a controller

[HHFFPP]

Hello,

I'm reading the "Magento 2 Development cookbook" and i don't know why the creation of the controller fails. I have:

 app/code/Packt/HelloWorld/etc/frontend/routes.xml
    <?xml version="1.0"?>
    <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:App/etc/routes.xsd">
        <router id="standard">
            <route id="helloworld" frontName="helloworld">
                <module name="Packt_HelloWorld" />
            </route>
        </router>
    </config>

 app/code/Packt/HelloWorld/Controller/Index/Index.php

    <?php
    
    namespace Packt\HelloWorld\Controller\Index;
    
    class Index extends \Magento\Framework\App\Action\Action
    {
        /**
        * Index action
        *
        * @return $this
        */
    
        public function execute ()
        {
    
        }
    }

I clean the cache, which is the only thing needed according to the book.
and, when i go to the browser /magento2/helloworld

    1 exception(s):
    Exception #0 (Exception): Recoverable Error: Argument 1 passed to Magento\Framework\App\Action\Action::__construct() must be an instance of Magento\Framework\App\Action\Context, instance of Magento\Framework\ObjectManager\ObjectManager given, called in /var/www/html/magento2/vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php on line 93 and defined in /var/www/html/magento2/vendor/magento/framework/App/Action/Action.php on line 67
    
    Exception #0 (Exception): Recoverable Error: Argument 1 passed to Magento\Framework\App\Action\Action::__construct() must be an instance of Magento\Framework\App\Action\Context, instance of Magento\Framework\ObjectManager\ObjectManager given, called in /var/www/html/magento2/vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php on line 93 and defined in /var/www/html/magento2/vendor/magento/framework/App/Action/Action.php on line 67
    #0 /var/www/html/magento2/vendor/magento/framework/App/Action/Action.php(67): Magento\Framework\App\ErrorHandler->handler(4096, 'Argument 1 pass...', '/var/www/html/m...', 67, Array)
    #1 /var/www/html/magento2/vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php(93): Magento\Framework\App\Action\Action->__construct(Object(Magento\Framework\ObjectManager\ObjectManager))
    #2 /var/www/html/magento2/vendor/magento/framework/ObjectManager/Factory/Compiled.php(88): Magento\Framework\ObjectManager\Factory\AbstractFactory->createObject('Packt\\HelloWorl...', Array)
    #3 /var/www/html/magento2/vendor/magento/framework/ObjectManager/ObjectManager.php(57): Magento\Framework\ObjectManager\Factory\Compiled->create('Packt\\HelloWorl...', Array)
    #4 /var/www/html/magento2/vendor/magento/framework/App/ActionFactory.php(40): Magento\Framework\ObjectManager\ObjectManager->create('Packt\\HelloWorl...')
    #5 /var/www/html/magento2/vendor/magento/framework/App/Router/Base.php(300): Magento\Framework\App\ActionFactory->create('Packt\\HelloWorl...')
    #6 /var/www/html/magento2/vendor/magento/framework/App/Router/Base.php(161): Magento\Framework\App\Router\Base->matchAction(Object(Magento\Framework\App\Request\Http), Array)
    #7 /var/www/html/magento2/vendor/magento/framework/App/FrontController.php(50): Magento\Framework\App\Router\Base->match(Object(Magento\Framework\App\Request\Http))
    #8 /var/www/html/magento2/vendor/magento/framework/Interception/Interceptor.php(74): Magento\Framework\App\FrontController->dispatch(Object(Magento\Framework\App\Request\Http))
    #9 /var/www/html/magento2/vendor/magento/framework/Interception/Chain/Chain.php(70): Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', Array)
    #10 /var/www/html/magento2/vendor/magento/framework/Interception/Chain/Chain.php(63): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Framewo...', 'dispatch', Object(Magento\Framework\App\FrontController\Interceptor), Array, 'requestPreproce...')
    #11 /var/www/html/magento2/vendor/magento/module-store/App/FrontController/Plugin/RequestPreprocessor.php(94): Magento\Framework\Interception\Chain\Chain->Magento\Framework\Interception\Chain\{closure}(Object(Magento\Framework\App\Request\Http))
    #12 /var/www/html/magento2/vendor/magento/framework/Interception/Chain/Chain.php(67): Magento\Store\App\FrontController\Plugin\RequestPreprocessor->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
    #13 /var/www/html/magento2/vendor/magento/framework/Interception/Chain/Chain.php(63): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Framewo...', 'dispatch', Object(Magento\Framework\App\FrontController\Interceptor), Array, 'install')
    #14 /var/www/html/magento2/vendor/magento/framework/Module/Plugin/DbStatusValidator.php(69): Magento\Framework\Interception\Chain\Chain->Magento\Framework\Interception\Chain\{closure}(Object(Magento\Framework\App\Request\Http))
    #15 /var/www/html/magento2/vendor/magento/framework/Interception/Chain/Chain.php(67): Magento\Framework\Module\Plugin\DbStatusValidator->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
    #16 /var/www/html/magento2/vendor/magento/framework/Interception/Chain/Chain.php(63): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Framewo...', 'dispatch', Object(Magento\Framework\App\FrontController\Interceptor), Array, 'front-controlle...')
    #17 /var/www/html/magento2/vendor/magento/module-page-cache/Model/App/FrontController/BuiltinPlugin.php(68): Magento\Framework\Interception\Chain\Chain->Magento\Framework\Interception\Chain\{closure}(Object(Magento\Framework\App\Request\Http))
    #18 /var/www/html/magento2/vendor/magento/framework/Interception/Chain/Chain.php(67): Magento\PageCache\Model\App\FrontController\BuiltinPlugin->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
    #19 /var/www/html/magento2/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Framewo...', 'dispatch', Object(Magento\Framework\App\FrontController\Interceptor), Array, 'front-controlle...')
    #20 /var/www/html/magento2/vendor/magento/module-page-cache/Model/App/FrontController/VarnishPlugin.php(55): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))
    #21 /var/www/html/magento2/vendor/magento/framework/Interception/Interceptor.php(142): Magento\PageCache\Model\App\FrontController\VarnishPlugin->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
    #22 /var/www/html/magento2/var/generation/Magento/Framework/App/FrontController/Interceptor.php(26): Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', Array, Array)
    #23 /var/www/html/magento2/vendor/magento/framework/App/Http.php(135): Magento\Framework\App\FrontController\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
    #24 /var/www/html/magento2/vendor/magento/framework/App/Bootstrap.php(258): Magento\Framework\App\Http->launch()
    #25 /var/www/html/magento2/index.php(39): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http))
    #26 {main}

In this part i would should see something... but no.

I continue and put

<?php
namespace Packt\HelloWorld\Controller\Index;

class Index extends \Magento\Framework\App\Action\Action
{
	/** @var \Magento\Framework\View\Result\PageFactory */
	protected $resultPageFactory;

	public function __construct (
		\Magento\Framework\App\Action\Context $context,
		\Magento\Framework\View\Result\PageFactory $resultPageFactory
	)
	{
		$this->resultPageFactory = $resultPageFactory;
		parent::__construct($context);
	}
	/**
	* Index action
	*
	* @return $this
	*/

	public function execute ()
	{
		$resultPage = $this->resultPageFactory->create();
		return $resultPage;
	}
}

and after delete var/generation, execute setup:di:compile, clear and flush the cache... i only see a grey window (background-color)

[HHFFPP]

I think it's working, maybe in a strange way.

If i put in the execute function:

$this->getResponse()->appendBody('Hello world');

it shows the text, but not load the layout of the shop.

So the book is wrong and you need to do a "setup:di:compile" after create a new controller.

[Damian Culotta]

Hi @HHFFPP,

Can you try this example?

namespace Packt\HelloWorld\Controller\Index;
 
use Magento\Framework\App\RequestInterface;
 
/**
 * HelloWorld index controller
 */
class Index extends \Magento\Framework\App\Action\Action
{
 
    /**
     * @var \Magento\Framework\Translate\Inline\StateInterface
     */
    protected $inlineTranslation;
 
    /**
     * @var \Magento\Framework\App\Config\ScopeConfigInterface
     */
    protected $scopeConfig;
 
    /**
     * @param \Magento\Framework\App\Action\Context $context
     * @param \Magento\Framework\Translate\Inline\StateInterface $inlineTranslation
     * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
     */
    public function __construct(
        \Magento\Framework\App\Action\Context $context,
        \Magento\Framework\Translate\Inline\StateInterface $inlineTranslation,
        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
    ) {
        parent::__construct($context);
        $this->inlineTranslation = $inlineTranslation;
        $this->scopeConfig = $scopeConfig;
    }
 
    /**
     * Dispatch request
     *
     * @param RequestInterface $request
     * @return \Magento\Framework\App\ResponseInterface
     * @throws \Magento\Framework\Exception\NotFoundException
     */
    public function dispatch(RequestInterface $request)
    {
        return parent::dispatch($request);
    }
}

[HugoFerrer]

Aparently it's really working. But in this point of the example you only see the background color, but when i advance in the code i show the layout