Swiftmailer Css Inliner plugin

CssInlinerPlugin.php

<?php

namespace AppBundle\Swiftmailer\Plugins;

use TijsVerkoyen\CssToInlineStyles\CssToInlineStyles;

class CssInlinerPlugin implements \Swift_Events_SendListener
{
    /**
     * @var CssToInlineStyles
     */
    private $converter;

    /**
     * @param CssToInlineStyles $converter
     */
    public function __construct(CssToInlineStyles $converter)
    {
        $this->converter = $converter;
    }

    /**
     * @param \Swift_Events_SendEvent $event
     */
    public function beforeSendPerformed(\Swift_Events_SendEvent $event)
    {
        $message = $event->getMessage();

        if ($message->getContentType() === 'text/html') {
            $this->parse($message);
        }

        foreach ($message->getChildren() as $part) {
            if (0 !== strpos($part->getContentType(), 'text/html')) {
                continue;
            }

            $this->parse($part);
        }
    }

    /**
     * Do nothing
     *
     * @param \Swift_Events_SendEvent $event
     */
    public function sendPerformed(\Swift_Events_SendEvent $event)
    {
        // Do Nothing
    }

    /**
     * @param \Swift_Mime_MimeEntity $mimeEntity
     *
     * @throws \TijsVerkoyen\CssToInlineStyles\Exception
     */
    protected function parse(\Swift_Mime_MimeEntity $mimeEntity)
    {
        $this->converter->setCSS('');
        $this->converter->setHTML($mimeEntity->getBody());

        $mimeEntity->setBody($this->converter->convert());
    }
}

services.yml

services:
    css_inliner:
        class: 'TijsVerkoyen\CssToInlineStyles\CssToInlineStyles'
        public: false
        calls:
            - ['setUseInlineStylesBlock', [true]]
            
    swift_css_inliner_plugin:
        class: 'AppBundle\Swiftmailer\Plugins\CssInlinerPlugin'
        public: false
        arguments: 
            - '@css_inliner'
        tags:
            - {name: 'swiftmailer.default.plugin'}