Symfony 2 : How to render a template outside a controller or in a service?

Question

如何在 Controller 外部或服务中呈现模板？

我一直在关注 Symfony2 的文档。 Doc

namespace Acme\HelloBundle\Newsletter;

use Symfony\Component\Templating\EngineInterface;

class NewsletterManager
{
    protected $mailer;

    protected $templating;

    public function __construct(
        \Swift_Mailer $mailer,
        EngineInterface $templating
    ) {
        $this->mailer = $mailer;
        $this->templating = $templating;
    }

    // ...
}

这就是我调用我的助手的地方:

$transport = \Swift_MailTransport::newInstance();
$mailer = \Swift_Mailer::newInstance($transport);
$helper = new MailHelper($mailer);
$helper->sendEmail($from, $to, $subject, $path_to_twig, $arr_to_twig);

所以这里缺少的第一件事是构造方法的第二个参数:

$helper = new MailHelper($mailer);

但是我将如何实例化EngineInterface？

当然不可能:

new EngineInterface();

我完全迷失在这里。

我需要做的就是为正在发送的电子邮件呈现一个模板。

Answer 1

仅注入(inject) @twig 并将渲染的模板传递给邮件正文:

<?php

namespace Acme\Bundle\ContractBundle\Event;

use Acme\Bundle\ContractBundle\Event\ContractEvent;

class ContractListener
{
    protected $twig;
    protected $mailer;

    public function __construct(\Twig_Environment $twig, \Swift_Mailer $mailer)
    {
        $this->twig = $twig;
        $this->mailer = $mailer;
    }

    public function onContractCreated(ContractEvent $event)
    {
        $contract = $event->getContract();

        $body = $this->renderTemplate($contract);

        $projectManager = $contract->getProjectManager();

        $message = \Swift_Message::newInstance()
            ->setSubject('Contract ' . $contract->getId() . ' created')
            ->setFrom('noreply@example.com')
            ->setTo('dev@example.com')
            ->setBody($body)
        ;
        $this->mailer->send($message);
    }

    public function renderTemplate($contract)
    {
        return $this->twig->render(
            'AcmeContractBundle:Contract:mailer.html.twig',
            array(
                'contract' => $contract
            )
        );
    }
}