feat: Add Htmlable contract interface for HTTP responses (#6794)

Author: huangdijia

src/CoreMiddleware.php

@@ -19,6 +19,7 @@
 use Hyperf\Context\RequestContext;
 use Hyperf\Context\ResponseContext;
 use Hyperf\Contract\Arrayable;
+use Hyperf\Contract\Htmlable;
 use Hyperf\Contract\Jsonable;
 use Hyperf\Contract\NormalizerInterface;
 use Hyperf\Di\ClosureDefinitionCollectorInterface;
@@ -186,7 +187,7 @@ protected function prepareHandler(array|string $handler): array
     /**
      * Transfer the non-standard response content to a standard response object.
      *
-     * @param null|array|Arrayable|Jsonable|ResponseInterface|string $response
+     * @param null|array|Arrayable|Htmlable|Jsonable|ResponseInterface|string $response
      */
     protected function transferToResponse($response, ServerRequestInterface $request): ResponsePlusInterface
     {
@@ -210,6 +211,12 @@ protected function transferToResponse($response, ServerRequestInterface $request
                 ->setBody(new SwooleStream((string) $response));
         }
 
+        if ($response instanceof Htmlable) {
+            return $this->response()
+                ->addHeader('content-type', 'text/html')
+                ->setBody(new SwooleStream((string) $response));
+        }
+
         if ($this->response()->hasHeader('content-type')) {
             return $this->response()->setBody(new SwooleStream((string) $response));
         }