README

为PSR-7 HTTP消息提供附加接口。使PSR-7 HTTP中间件（或应用程序）更简单、更可组合。

HttpContext

HttpContext包含PSR-7 HTTP请求、HTTP响应和状态。

interface HttpContextInterface
{
    public function getRequest() : ServerRequestInterface;

    public function getResponse() : ResponseInterface;

    public function isTerminated(): bool;

    public function withRequest(ServerRequestInterface $request): HttpContextInterface;

    public function withResponse(ResponseInterface $response): HttpContextInterface;

    public function withIsTerminated(bool $isTerminated): HttpContextInterface;

    public function handledBy(HttpHandlerInterface $handler): HttpContextInterface;

}

HttpHandler

处理HttpContext。这是典型MVC Web框架中HTTP中间件、HTTP应用程序或控制器操作的抽象。

interface HttpHandlerInterface
{
    public function __invoke(HttpContextInterface $context) : HttpContextInterface;
}

与流行PSR-7中间件的比较

• 无可调用链
• 自然组合管道

示例

use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Message\ResponseInterface;
use N1215\Http\Context\HttpContextInterface;
use N1215\Http\Context\HttpHandlerInterface;

class HttpHandler implements HttpHandlerInterface {

    public function __invoke(HttpContextInterface $context): HttpContextInterface
    {
        //do stuff
        $context->getResponse()->getBody()->write('Hello, world!');
        return $context;
    }

}

/**
 * @var ServerRequestInterface $request
 */
$request = ServerRequestFactory::fromGlobals();

/**
 * @var ResponseInterface $response
 */
$response = new Response();

$context = new HttpContext($request, $response); // implements HttpContextInterface

$handler = new HttpHandler();

$newContext = $handler->__invoke($context); // or $handler($context);

$newResponse = $newContext->getResponse();

顺序上下文处理

$context = new HttpContext($request, $response);

$first = new FirstHttpHandler(); // implements HttpHandlerInterface
$second = new SecondHttpHandler(); // implements HttpHandlerInterface

$newContext = $second($first($context));

顺序上下文处理（方法链）

$context = new HttpContext($request, $response);

$newContext = $context
    ->handledBy(new FirstHttpHandler());
    ->handledBy(new SecondHttpHandler());

将处理器管道作为HttpHandler组合

class HandlerPipeline implements HttpHandlerInterface {

    /**
     * @var HttpHandlerInterface[]
     */
    private $handlers = [];


    public function __construct(array $handlers = []) {
        $this->handlers = $handlers;
    }

    public function __invoke(HttpContextInterface $context) : HttpContextInterface
    {
        foreach($this->handlers as $handler) {
            if($context->isTerminated()) {
                return $context;
            }
            $context = $handler->__invoke($context);
        }

        return $context;
    }
}

$context = new HttpContext($request, $response);

$pipeline = new HandlerPipeline([
    new FirstHttpHandler(),
    new SecondHttpHandler(),
]);

$newContext = $pipeline($context);

许可

MIT许可。