multipart.php

<?php
namespace Bitrix\Main\Mail;
 
class Multipart extends Part
{
    const MIXED = 'multipart/mixed';
    const ALTERNATIVE = 'multipart/alternative';
    const RELATED = 'multipart/related';
 
    protected $parts = [];
 
    protected $uniqueString;
 
    protected $eol;
 
    public function __construct()
    {
        parent::__construct();
        $this->uniqueString = mb_substr(uniqid(mt_rand(100, 999)), 0, 10);
        $this->setContentType(self::MIXED);
    }
 
    public function setEol($eol)
    {
        parent::setEol($eol);
        foreach ($this->parts as $part)
        {
            $part->setEol($this->getEol());
        }
        return $this;
    }
 
    public function setContentType($type)
    {
        $boundary = $this->getBoundary($type);
        $this->addHeader('Content-Type', "$type; boundary=\"$boundary\"");
        return $this;
    }
 
    public function addPart(Part $part)
    {
        $part->setEol($this->getEol());
        $this->parts[] = $part;
        return $this;
    }
 
    public function toStringHeaders()
    {
        $count = count($this->parts);
        if ($count === 0)
        {
            return '';
        }
        elseif ($count === 1)
        {
            return  current($this->parts)->toStringHeaders();
        }
 
        return parent::toStringHeaders();
    }
 
    public function toStringBody()
    {
        $count = count($this->parts);
        if ($count === 0)
        {
            return '';
        }
        elseif ($count === 1)
        {
            return  current($this->parts)->toStringBody();
        }
 
 
        $result = '';
        $boundary = $this->getBoundary();
        foreach ($this->parts as $part)
        {
            $result .= '--' . $boundary . $this->eol;
            $result .= (string) $part;
        }
        $result .= '--' . $boundary . '--' . $this->eol;
 
        return $result;
    }
 
    protected function getPartCount()
    {
        $count = 0;
        foreach ($this->parts as $part)
        {
            if ($part instanceof Multipart)
            {
                $count += $part->getPartCount();
            }
            else
            {
                $count += 1;
            }
        }
 
        return $count;
    }
 
    protected function getBoundary($contentType = null)
    {
        $type = $contentType ?: $this->getHeader('Content-Type');
        $type = explode(';', $type);
        $type = $type[0];
        switch ($type)
        {
            case self::MIXED:
                $prefix = 'mix';
                break;
 
            case self::ALTERNATIVE:
                $prefix = 'alt';
                break;
 
            default:
                $prefix = '';
        }
 
        return '-------' . $prefix . $this->uniqueString;
    }
}