HeaderUtils.php

<?php
 
/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
 
namespace Symfony\Component\HttpFoundation;
 
class HeaderUtils
{
    public const DISPOSITION_ATTACHMENT = 'attachment';
    public const DISPOSITION_INLINE = 'inline';
 
    private function __construct()
    {
    }
 
    public static function split(string $header, string $separators): array
    {
        $quotedSeparators = preg_quote($separators, '/');
 
        preg_match_all('
            /
                (?!\s)
                    (?:
                        # quoted-string
                        "(?:[^"\\\\]|\\\\.)*(?:"|\\\\|$)
                    |
                        # token
                        [^"'.$quotedSeparators.']+
                    )+
                (?<!\s)
            |
                # separator
                \s*
                (?<separator>['.$quotedSeparators.'])
                \s*
            /x', trim($header), $matches, PREG_SET_ORDER);
 
        return self::groupParts($matches, $separators);
    }
 
    public static function combine(array $parts): array
    {
        $assoc = [];
        foreach ($parts as $part) {
            $name = strtolower($part[0]);
            $value = $part[1] ?? true;
            $assoc[$name] = $value;
        }
 
        return $assoc;
    }
 
    public static function toString(array $assoc, string $separator): string
    {
        $parts = [];
        foreach ($assoc as $name => $value) {
            if (true === $value) {
                $parts[] = $name;
            } else {
                $parts[] = $name.'='.self::quote($value);
            }
        }
 
        return implode($separator.' ', $parts);
    }
 
    public static function quote(string $s): string
    {
        if (preg_match('/^[a-z0-9!#$%&\'*.^_`|~-]+$/i', $s)) {
            return $s;
        }
 
        return '"'.addcslashes($s, '"\\"').'"';
    }
 
    public static function unquote(string $s): string
    {
        return preg_replace('/\\\\(.)|"/', '$1', $s);
    }
 
    public static function makeDisposition(string $disposition, string $filename, string $filenameFallback = ''): string
    {
        if (!\in_array($disposition, [self::DISPOSITION_ATTACHMENT, self::DISPOSITION_INLINE])) {
            throw new \InvalidArgumentException(sprintf('The disposition must be either "%s" or "%s".', self::DISPOSITION_ATTACHMENT, self::DISPOSITION_INLINE));
        }
 
        if ('' === $filenameFallback) {
            $filenameFallback = $filename;
        }
 
        // filenameFallback is not ASCII.
        if (!preg_match('/^[\x20-\x7e]*$/', $filenameFallback)) {
            throw new \InvalidArgumentException('The filename fallback must only contain ASCII characters.');
        }
 
        // percent characters aren't safe in fallback.
        if (false !== strpos($filenameFallback, '%')) {
            throw new \InvalidArgumentException('The filename fallback cannot contain the "%" character.');
        }
 
        // path separators aren't allowed in either.
        if (false !== strpos($filename, '/') || false !== strpos($filename, '\\') || false !== strpos($filenameFallback, '/') || false !== strpos($filenameFallback, '\\')) {
            throw new \InvalidArgumentException('The filename and the fallback cannot contain the "/" and "\\" characters.');
        }
 
        $params = ['filename' => $filenameFallback];
        if ($filename !== $filenameFallback) {
            $params['filename*'] = "utf-8''".rawurlencode($filename);
        }
 
        return $disposition.'; '.self::toString($params, ';');
    }
 
    private static function groupParts(array $matches, string $separators): array
    {
        $separator = $separators[0];
        $partSeparators = substr($separators, 1);
 
        $i = 0;
        $partMatches = [];
        foreach ($matches as $match) {
            if (isset($match['separator']) && $match['separator'] === $separator) {
                ++$i;
            } else {
                $partMatches[$i][] = $match;
            }
        }
 
        $parts = [];
        if ($partSeparators) {
            foreach ($partMatches as $matches) {
                $parts[] = self::groupParts($matches, $partSeparators);
            }
        } else {
            foreach ($partMatches as $matches) {
                $parts[] = self::unquote($matches[0][0]);
            }
        }
 
        return $parts;
    }
}