drupal 8 error to render template twig with controller - php

Question

I am trying to render a template with my controller but does not work
it show me this error :
LogicException: The controller must return a response (Hello Bob! given). in Symfony\Component\HttpKernel\HttpKernel->handleRaw() (line 163 of core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/HttpKernel.php).
My function :
public function helloAction($name) {
$twigFilePath = drupal_get_path('module', 'acme') . '/templates/hello.html.twig';
$template = $this->twig->loadTemplate($twigFilePath);
return $template->render(array('name' => $name));
}

Answer 1

In Drupal 8 you either return a Response object or a render array from a controller. So you have two options:
1) Place the rendered template into a Response object:
public function helloAction($name) {
$twigFilePath = drupal_get_path('module', 'acme') . '/templates/hello.html.twig';
$template = $this->twig->loadTemplate($twigFilePath);
$markup = $template->render(array('name' => $name));
return new Response($markup);
}
2) Place the rendered template into a render array:
public function helloAction($name) {
$twigFilePath = drupal_get_path('module', 'acme') . '/templates/hello.html.twig';
$template = $this->twig->loadTemplate($twigFilePath);
$markup = $template->render(array('name' => $name));
return array(
'#markup' => $markup,
);
}

Answer 2

Also you can Use the second option without custom template, doing this:
public function helloAction($name) {
$markup = "<p> Without custom Template</p>";
return array(
'#markup' => $markup,
);
}

Answer 3

class ClientController extends ControllerBase implements ContainerInjectionInterface ,ContainerAwareInterface {
protected $twig ;
public function __construct(\Twig_Environment $twig)
{
$this->twig = $twig ;
}
public function index()
{
$twigFilePath = drupal_get_path('module', 'client') . '/templates/index.html.twig';
$template = $this->twig->loadTemplate($twigFilePath);
$user = ['user' => 'name'] ; // as example
$markup = [
'#markup' => $template->render( ['users' => $users ,'kit_form' => $output] ),
'#attached' => ['library' => ['client/index.custom']] ,
];
return $markup;
}
// this is called first then call constructor
public static function create(ContainerInterface $container)
{
return new static(
$container->get('twig') ,
);
}
}
this full example to render twig by dependency injection from controller