/**
* Tokenize the HTTP field for subsequent processing.
*
* Note: we don't need to worry about multi-byte characters; HTTP fields must be ISO-8859-1 encoded.
*
* @param string $httpField
* @param string $fromField
*
* @return array<string>
*/
public function tokenize($httpField, $fromField)
{
$quoteSeparators = array('"', "'");
$tokenList = array();
$stringAccumulator = '';
$lastQuote = '';
// Iterate through field, character-by-character
for ($i = 0; $i < strlen($httpField); $i++) {
$chr = substr($httpField, $i, 1);
switch (true) {
// We are at the end of a quoted string
case $chr === $lastQuote:
$tokenList[] = $stringAccumulator;
$stringAccumulator = '';
$lastQuote = '';
break;
// We have found the beginning of a quoted string
// We have found the beginning of a quoted string
case in_array($chr, $quoteSeparators):
$lastQuote = $chr;
break;
// We are already within a quoted string, but not yet at the end
// We are already within a quoted string, but not yet at the end
case strlen($lastQuote):
$stringAccumulator .= $chr;
break;
// Separators found, add previously accumulated string & separator to token list
// Separators found, add previously accumulated string & separator to token list
case Tokens::isSeparator($chr, Preference::MIME === $fromField):
if (strlen($stringAccumulator)) {
$tokenList[] = $stringAccumulator;
$stringAccumulator = '';
}
$tokenList[] = $chr;
break;
// Simply accumulate characters
// Simply accumulate characters
default:
$stringAccumulator .= $chr;
break;
}
}
// Handle final component
if (strlen($stringAccumulator)) {
$tokenList[] = $stringAccumulator;
}
// Remove any padding whitespace from token list
$tokenList = array_map('trim', $tokenList);
return $tokenList;
}
/**
* Checks to see if the bundle is valid for a mime type, if an anomaly is detected then an exception is thrown.
*
* @throws InvalidVariantException
*
* @param array<string> $bundle
*/
private function validateBundleMimeVariant(array $bundle)
{
if (count($bundle) < 3 || Tokens::MIME_SEPARATOR !== $bundle[1] || Tokens::isSeparator($bundle[0], true) || Tokens::isSeparator($bundle[2], true)) {
throw new InvalidVariantException('"' . implode('', $bundle) . '" is not a valid mime type');
}
}
