Introduction to Zend Expressive

A simple Hello World

Using composer, execute the following command in the directory in which the application will be installed: composer create-project zendframework/zend-expressive-skeleton expressive-skeleton.

During installation process, you will be asked to make various decisions.

For the default installation question, say no (n);
For the router, let’s use Aura Router (#1);
For the container, let’s use Zend ServiceManager (#3);
For the template, let’s use Zend View (#3);
Finally, for the error handler, let’s use Whoops (#1).

Once installed, get yourself in the root directory, expressive-skeleton, launch the built-in PHP CLI server: php -S 0.0.0.0:8080 -t public public/index.php. Go to https://localhost:8080/ with your browser, your application should now be up and running.

Let’s configure a new path to a new middleware. First, open the router config file in config/autoload/routes.global.php and add the lines as follow:

<?php

return [
    'dependencies' => [
        ...
    ],

    'routes' => [
        [
            'dependencies' => [
                'invokables' => [
                    ...
                ],
                'factories' => [
                    ...
                    // Add the following line
                    App\Action\HelloWorldAction::class => App\Action\HelloWorldFactory::class,
                ],
            ],
        ],
        // Following lines should be added
        [
            'name' => 'hello-world',
            'path' => '/hello-world',
            'middleware' => App\Action\HelloWorldAction::class,
            'allowed_methods' => ['GET'],
        ],
    ],
];

Put the following content in src/App/Action/HelloWorldFactory.php:

<?php

namespace App\Action;

use Interop\Container\ContainerInterface;
use Zend\Expressive\Template\TemplateRendererInterface;

class HelloWorldFactory
{
    public function __invoke(ContainerInterface $container)
    {
        $template = ($container->has(TemplateRendererInterface::class))
            ? $container->get(TemplateRendererInterface::class)
            : null;

        return new HelloWorldAction($template);
    }
}

Then, this content in src/App/Action/HelloWorldAction.php:

<?php

namespace App\Action;

use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Zend\Diactoros\Response\HtmlResponse;
use Zend\Diactoros\Response\JsonResponse;
use Zend\Expressive\Template;
use Zend\Expressive\Plates\PlatesRenderer;
use Zend\Expressive\Twig\TwigRenderer;
use Zend\Expressive\ZendView\ZendViewRenderer;

class HelloWorldAction
{
    private $template;

    public function __construct(Template\TemplateRendererInterface $template = null)
    {
        $this->template = $template;
    }

    public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next = null)
    {
        $data = [];

        return new HtmlResponse($this->template->render('app::hello-world'));
    }
}

Then, finally, simply put the following in templates/app/hello-world.phtml:

<?php echo 'Hello World'; ?>

We are done ! Navigate to https://localhost:8080/hello-world, and say “hi” to Zend Expressive !