| protected assertValidKey ( string $key ) | ||
| $key | string | |
protected function assertValidKey($key)
{
if (!is_string($key)) {
throw new InvalidArgumentException('Invalid key: ' . var_export($key, true) . '. Key should be a string.');
}
// valid key according to PSR-6 rules
$invalid = preg_quote(static::KEY_INVALID_CHARACTERS, '/');
if (preg_match('/[' . $invalid . ']/', $key)) {
throw new InvalidArgumentException('Invalid key: ' . $key . '. Contains (a) character(s) reserved ' . 'for future extension: ' . static::KEY_INVALID_CHARACTERS);
}
}