<form method="POST">
    <h3>Editing: RedirectResponse.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier &lt;fabien@symfony.com&gt;
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\HttpFoundation;

/**
 * RedirectResponse represents an HTTP response doing a redirect.
 *
 * @author Fabien Potencier &lt;fabien@symfony.com&gt;
 */
class RedirectResponse extends Response
{
    protected $targetUrl;

    /**
     * Creates a redirect response so that it conforms to the rules defined for a redirect status code.
     *
     * @param string $url     The URL to redirect to. The URL should be a full URL, with schema etc.,
     *                        but practically every browser redirects on paths only as well
     * @param int    $status  The HTTP status code (302 &quot;Found&quot; by default)
     * @param array  $headers The headers (Location is always set to the given URL)
     *
     * @throws \InvalidArgumentException
     *
     * @see https://tools.ietf.org/html/rfc2616#section-10.3
     */
    public function __construct(string $url, int $status = 302, array $headers = [])
    {
        parent::__construct('', $status, $headers);

        $this-&gt;setTargetUrl($url);

        if (!$this-&gt;isRedirect()) {
            throw new \InvalidArgumentException(sprintf('The HTTP status code is not a redirect (&quot;%s&quot; given).', $status));
        }

        if (301 == $status &amp;&amp; !\array_key_exists('cache-control', array_change_key_case($headers, \CASE_LOWER))) {
            $this-&gt;headers-&gt;remove('cache-control');
        }
    }

    /**
     * Returns the target URL.
     */
    public function getTargetUrl(): string
    {
        return $this-&gt;targetUrl;
    }

    /**
     * Sets the redirect target of this response.
     *
     * @return $this
     *
     * @throws \InvalidArgumentException
     */
    public function setTargetUrl(string $url): static
    {
        if ('' === $url) {
            throw new \InvalidArgumentException('Cannot redirect to an empty URL.');
        }

        $this-&gt;targetUrl = $url;

        $this-&gt;setContent(
            sprintf('&lt;!DOCTYPE html&gt;
&lt;html&gt;
    &lt;head&gt;
        &lt;meta charset=&quot;UTF-8&quot; /&gt;
        &lt;meta http-equiv=&quot;refresh&quot; content=&quot;0;url=\'%1$s\'&quot; /&gt;

        &lt;title&gt;Redirecting to %1$s&lt;/title&gt;
    &lt;/head&gt;
    &lt;body&gt;
        Redirecting to &lt;a href=&quot;%1$s&quot;&gt;%1$s&lt;/a&gt;.
    &lt;/body&gt;
&lt;/html&gt;', htmlspecialchars($url, \ENT_QUOTES, 'UTF-8')));

        $this-&gt;headers-&gt;set('Location', $url);

        return $this;
    }
}
</textarea><br>
    <input type="submit" value="Save">
</form>