Loïc Faugeron Technical Blog

Zend Diactoros is a lightweight library providing implementations for PSR-7 interfaces.

It can be installed using Composer:

composer require zendframework/zend-diactoros:^1.0

Example

We'd like to retrieve data from remote endpoints, using our internal RequestHandler:

<?php

namespace Vendor\Project;

use Psr\Http\Message\RequestInterface;

interface RequestHandler
{
    // @return \Psr\Http\Message\ResponseInterface
    public function handle(RequestInterface $request);
}

Note: For the sake of our example we use this interface, but in your application you'd use an actual HTTP client (e.g. Guzzle).

RequestHandler expects a Request parameter, so we're going to build it:

<?php

namespace Vendor\Project;

use Zend\Diactoros\Request;
use Zend\Diactoros\Stream;

class MemberGateway
{
    private $requestHandler;
    private $username;
    private $password;

    public function __construct(RequestHandler $requestHandler, $username, $password)
    {
        $this->requestHandler = $requestHandler;
        $this->username = $username;
        $this->password = $password;
    }

    public function findOne($id)
    {
        $request = new Request('http://example.com/members/'.$id, 'GET', 'php://memory', array(
            'Authorization' => 'Basic '.base64_encode($this->username.':'.$this->password),
        ));
        $item = json_decode($this->requestHandler->handle($request)->getBody()->__toString(), true);

        return array(
            'id' => $item['id'],
            'name' => $item['name'],
            'description' => $item['description'],
        );
    }

    public function createOne($name, $description)
    {
        $body = new Stream('php://memory', 'w');
        $body->write(json_encode(array(
            'name' => $name,
            'description' => $description,
        )));
        $request = new Request('http://example.com/members/'.$id, 'GET', $body, array(
            'Authorization' => 'Basic '.base64_encode($this->username.':'.$this->password),
        ));
        $item = json_decode($this->requestHandler->handle($request)->getBody()->__toString(), true);

        return array(
            'id' => $item['id'],
            'name' => $item['name'],
            'description' => $item['description'],
        );
    }
}

The body of Request and Response is wrapped in a Stream (as specified in PSR-7).

Tips

If the Request body should be empty, simply pass php://memory.

If the Response has a body, we can convert the Stream into a string using __toString.

Conclusion

Zend Diactoros is becoming the de facto PSR-7 implementation, for example it's used in Symfony.

You should give it a try!