<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <[email protected]>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\Mime\Encoder;
/**
* @author Chris Corbyn
*/
class Base64Encoder implements EncoderInterface
{
/**
* Takes an unencoded string and produces a Base64 encoded string from it.
*
* Base64 encoded strings have a maximum line length of 76 characters.
* If the first line needs to be shorter, indicate the difference with
* $firstLineOffset.
*/
public function encodeString(string $string, ?string $charset = 'utf-8', int $firstLineOffset = 0, int $maxLineLength = 0): string
{
if (0 >= $maxLineLength || 76 < $maxLineLength) {
$maxLineLength = 76;
}
$encodedString = base64_encode($string);
$firstLine = '';
if (0 !== $firstLineOffset) {
$firstLine = substr($encodedString, 0, $maxLineLength - $firstLineOffset)."\r\n";
$encodedString = substr($encodedString, $maxLineLength - $firstLineOffset);
}
return $firstLine.trim(chunk_split($encodedString, $maxLineLength, "\r\n"));
}
}