Question

以下是路线的一些Laravel代码：

Route::get('a', function() {
    return 'hello';
});

调用此路线时，Content-Type标头值为text/HTML。

此默认行为来自哪里？它设置为：

Nginx的？
PHP？
Laravel？

Answer 1

Laravel扩展了Symphony的请求/响应，但仍然严重依赖于他们的默认行为。此特定功能基于Symphony的Response::prepare功能。

public function prepare(Request $request)
{
    //does a lot of things, would not go into detail
        // Content-type based on the Request
        if (!$headers->has('Content-Type')) {
            $format = $request->getRequestFormat();
            if (null !== $format && $mimeType = $request->getMimeType($format)) {
                $headers->set('Content-Type', $mimeType);
            }
        }
 //Does a lot more things
}

这是基于$request->getMimeType($format)函数，而$format来自$request->getRequestFormat()

public function getRequestFormat($default = 'html')
{
    if (null === $this->format) {
        $this->format = $this->attributes->get('_format');
    }
    return null === $this->format ? $default : $this->format;
}

注意默认值是＆＃34; html＆＃34;当没有明确设置请求格式时。它也只会在您尚未明确设置的情况下进行设置。

mime类型基于在https://github.com/symfony/http-foundation/blob/master/Request.php#L1844

初始化的查找

框架的确超出了这个水平，并提供了替代方案，例如： JsonResponse（laravel在执行response()->json()时使用的内容）并且此响应使用不同的默认值。

Answer 2

laravel会自动将字符串转换为完整的HTTP响应。

我在symfony / http-foundation / response.php中找到了这个方法。可能是这个方法用于创建响应头。

 public function prepare(Request $request)
 {
    $headers = $this->headers;

    if ($this->isInformational() || $this->isEmpty()) {
        $this->setContent(null);
        $headers->remove('Content-Type');
        $headers->remove('Content-Length');
    } else {
        // Content-type based on the Request
       if (!$headers->has('Content-Type')) {
            $format = $request->getRequestFormat();
            if (null !== $format && $mimeType = $request->getMimeType($format)) {
                $headers->set('Content-Type', $mimeType);
            }
        }

        // Fix Content-Type
        $charset = $this->charset ?: 'UTF-8';
        if (!$headers->has('Content-Type')) {
            $headers->set('Content-Type', 'text/html; charset='.$charset);
        } elseif (0 === stripos($headers->get('Content-Type'), 'text/') && false === stripos($headers->get('Content-Type'), 'charset')) {
            // add the charset
            $headers->set('Content-Type', $headers->get('Content-Type').'; charset='.$charset);
        }

        // Fix Content-Length
        if ($headers->has('Transfer-Encoding')) {
            $headers->remove('Content-Length');
        }

        if ($request->isMethod('HEAD')) {
            // cf. RFC2616 14.13
            $length = $headers->get('Content-Length');
            $this->setContent(null);
            if ($length) {
                $headers->set('Content-Length', $length);
            }
        }
    }

    // Fix protocol
    if ('HTTP/1.0' != $request->server->get('SERVER_PROTOCOL')) {
        $this->setProtocolVersion('1.1');
    }

    // Check if we need to send extra expire info headers
    if ('1.0' == $this->getProtocolVersion() && false !== strpos($this->headers->get('Cache-Control'), 'no-cache')) {
        $this->headers->set('pragma', 'no-cache');
        $this->headers->set('expires', -1);
    }

    $this->ensureIEOverSSLCompatibility($request);

    return $this;
}

Answer 3

使用路径时，标题值由laravel设置。这是symfony/http-foundation/Response.php

的摘录

public function __construct($content = '', $status = 200, $headers = array())
{
    $this->headers = new ResponseHeaderBag($headers);
    $this->setContent($content);
    $this->setStatusCode($status);
    $this->setProtocolVersion('1.0');

    /* RFC2616 - 14.18 says all Responses need to have a Date */
    if (!$this->headers->has('Date')) {
        $this->setDate(\DateTime::createFromFormat('U', time()));
    }
}

希望这有帮助！

哪个部分将`Content-Type`设置为`text / HTML`作为响应

3 个答案: