<?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\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"));
|
}
|
}
|
