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    <h3>Editing: NativeMailerHandler.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php declare(strict_types=1);

/*
 * This file is part of the Monolog package.
 *
 * (c) Jordi Boggiano &lt;j.boggiano@seld.be&gt;
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Monolog\Handler;

use Monolog\Logger;
use Monolog\Formatter\LineFormatter;

/**
 * NativeMailerHandler uses the mail() function to send the emails
 *
 * @author Christophe Coevoet &lt;stof@notk.org&gt;
 * @author Mark Garrett &lt;mark@moderndeveloperllc.com&gt;
 */
class NativeMailerHandler extends MailHandler
{
    /**
     * The email addresses to which the message will be sent
     * @var string[]
     */
    protected $to;

    /**
     * The subject of the email
     * @var string
     */
    protected $subject;

    /**
     * Optional headers for the message
     * @var string[]
     */
    protected $headers = [];

    /**
     * Optional parameters for the message
     * @var string[]
     */
    protected $parameters = [];

    /**
     * The wordwrap length for the message
     * @var int
     */
    protected $maxColumnWidth;

    /**
     * The Content-type for the message
     * @var string|null
     */
    protected $contentType;

    /**
     * The encoding for the message
     * @var string
     */
    protected $encoding = 'utf-8';

    /**
     * @param string|string[] $to             The receiver of the mail
     * @param string          $subject        The subject of the mail
     * @param string          $from           The sender of the mail
     * @param int             $maxColumnWidth The maximum column width that the message lines will have
     */
    public function __construct($to, string $subject, string $from, $level = Logger::ERROR, bool $bubble = true, int $maxColumnWidth = 70)
    {
        parent::__construct($level, $bubble);
        $this-&gt;to = (array) $to;
        $this-&gt;subject = $subject;
        $this-&gt;addHeader(sprintf('From: %s', $from));
        $this-&gt;maxColumnWidth = $maxColumnWidth;
    }

    /**
     * Add headers to the message
     *
     * @param string|string[] $headers Custom added headers
     */
    public function addHeader($headers): self
    {
        foreach ((array) $headers as $header) {
            if (strpos($header, &quot;\n&quot;) !== false || strpos($header, &quot;\r&quot;) !== false) {
                throw new \InvalidArgumentException('Headers can not contain newline characters for security reasons');
            }
            $this-&gt;headers[] = $header;
        }

        return $this;
    }

    /**
     * Add parameters to the message
     *
     * @param string|string[] $parameters Custom added parameters
     */
    public function addParameter($parameters): self
    {
        $this-&gt;parameters = array_merge($this-&gt;parameters, (array) $parameters);

        return $this;
    }

    /**
     * {@inheritDoc}
     */
    protected function send(string $content, array $records): void
    {
        $contentType = $this-&gt;getContentType() ?: ($this-&gt;isHtmlBody($content) ? 'text/html' : 'text/plain');

        if ($contentType !== 'text/html') {
            $content = wordwrap($content, $this-&gt;maxColumnWidth);
        }

        $headers = ltrim(implode(&quot;\r\n&quot;, $this-&gt;headers) . &quot;\r\n&quot;, &quot;\r\n&quot;);
        $headers .= 'Content-type: ' . $contentType . '; charset=' . $this-&gt;getEncoding() . &quot;\r\n&quot;;
        if ($contentType === 'text/html' &amp;&amp; false === strpos($headers, 'MIME-Version:')) {
            $headers .= 'MIME-Version: 1.0' . &quot;\r\n&quot;;
        }

        $subject = $this-&gt;subject;
        if ($records) {
            $subjectFormatter = new LineFormatter($this-&gt;subject);
            $subject = $subjectFormatter-&gt;format($this-&gt;getHighestRecord($records));
        }

        $parameters = implode(' ', $this-&gt;parameters);
        foreach ($this-&gt;to as $to) {
            mail($to, $subject, $content, $headers, $parameters);
        }
    }

    public function getContentType(): ?string
    {
        return $this-&gt;contentType;
    }

    public function getEncoding(): string
    {
        return $this-&gt;encoding;
    }

    /**
     * @param string $contentType The content type of the email - Defaults to text/plain. Use text/html for HTML messages.
     */
    public function setContentType(string $contentType): self
    {
        if (strpos($contentType, &quot;\n&quot;) !== false || strpos($contentType, &quot;\r&quot;) !== false) {
            throw new \InvalidArgumentException('The content type can not contain newline characters to prevent email header injection');
        }

        $this-&gt;contentType = $contentType;

        return $this;
    }

    public function setEncoding(string $encoding): self
    {
        if (strpos($encoding, &quot;\n&quot;) !== false || strpos($encoding, &quot;\r&quot;) !== false) {
            throw new \InvalidArgumentException('The encoding can not contain newline characters to prevent email header injection');
        }

        $this-&gt;encoding = $encoding;

        return $this;
    }
}
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