Php 如何打印每个主题的评论？

我有两个表topics和comments：在comments表中有一个名为topic_id的列，其中id是数字，它对应于用户评论的主题。我在TopicController中使用以下功能列出主题详细信息：

 /**
     * @Route("/topic/{id}", name="topic_details")
     * @param $id
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function topicDetailsAction($id)
    {
        $topic = $this->getDoctrine()->getRepository('AppBundle:Topic')->find($id);

        return $this->render('topics/topic.details.html.twig', array(
            'topic' => $topic
        ));
    }

     /**
     * @Route("/topic/{id}", name="topic_details")
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function listCommentsAction($id)
    {
        $topic = $this->getDoctrine()->getRepository('AppBundle:Topic')->find($id);
        $topicComments = $topic->getComments();

        return $this->render('topics/topic.details.html.twig', array(
            'topicComments' => $topicComments
        ));

    }

return $this->render('topics/topic.details.html.twig', array(
    'topic' => $topic
    'topicComments' => [],
));

    return $this->render('topics/topic.details.html.twig', array(
        'topic' => $topic
    ));

现在，我尝试在CommentController中使用此功能显示当前选定主题的注释：

 /**
     * @Route("/topic/{id}", name="topic_details")
     * @param $id
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function topicDetailsAction($id)
    {
        $topic = $this->getDoctrine()->getRepository('AppBundle:Topic')->find($id);

        return $this->render('topics/topic.details.html.twig', array(
            'topic' => $topic
        ));
    }

     /**
     * @Route("/topic/{id}", name="topic_details")
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function listCommentsAction($id)
    {
        $topic = $this->getDoctrine()->getRepository('AppBundle:Topic')->find($id);
        $topicComments = $topic->getComments();

        return $this->render('topics/topic.details.html.twig', array(
            'topicComments' => $topicComments
        ));

    }

return $this->render('topics/topic.details.html.twig', array(
    'topic' => $topic
    'topicComments' => [],
));

    return $this->render('topics/topic.details.html.twig', array(
        'topic' => $topic
    ));

毕竟，当我尝试打印细枝中特定主题的所有数据时，我得到了以下异常：

变量“topicComments”不存在。 我肯定这个问题不大，可以解决，但不确定我错过了什么。 这是我的小树枝模板：

   {% for comment in topic.comments %}
        {{ comment.description }}
    {% endfor %}

{%extends'base.html.twig%}
{%block body%}


说明：
{{topic.description}}

类别：{{topic.Category}}

创建：{{topic.dateCreated}date（“m/d/Y H:i:s”）}
{topicComments%中的注释为%s}
{{comment.description}}
{%endfor%}
{%endblock%}

您在两个操作中使用相同的模板，但仅在其中一个操作中提供变量

topicComments

一些解决办法是

在控制器中提供空阵列：

 /**
     * @Route("/topic/{id}", name="topic_details")
     * @param $id
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function topicDetailsAction($id)
    {
        $topic = $this->getDoctrine()->getRepository('AppBundle:Topic')->find($id);

        return $this->render('topics/topic.details.html.twig', array(
            'topic' => $topic
        ));
    }

     /**
     * @Route("/topic/{id}", name="topic_details")
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function listCommentsAction($id)
    {
        $topic = $this->getDoctrine()->getRepository('AppBundle:Topic')->find($id);
        $topicComments = $topic->getComments();

        return $this->render('topics/topic.details.html.twig', array(
            'topicComments' => $topicComments
        ));

    }

return $this->render('topics/topic.details.html.twig', array(
    'topic' => $topic
    'topicComments' => [],
));

    return $this->render('topics/topic.details.html.twig', array(
        'topic' => $topic
    ));

测试是否定义了var

{% if topicComments is defined and not topicComments  is empty %}
<div class="container">
    {% for comment in topicComments %}
        {{ comment.description }}
    {% endfor %}
</div>
{% endif %}

---

您在两个操作中使用相同的模板，但仅在其中一个操作中提供变量

topicComments

一些解决办法是

在控制器中提供空阵列：

 /**
     * @Route("/topic/{id}", name="topic_details")
     * @param $id
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function topicDetailsAction($id)
    {
        $topic = $this->getDoctrine()->getRepository('AppBundle:Topic')->find($id);

        return $this->render('topics/topic.details.html.twig', array(
            'topic' => $topic
        ));
    }

     /**
     * @Route("/topic/{id}", name="topic_details")
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function listCommentsAction($id)
    {
        $topic = $this->getDoctrine()->getRepository('AppBundle:Topic')->find($id);
        $topicComments = $topic->getComments();

        return $this->render('topics/topic.details.html.twig', array(
            'topicComments' => $topicComments
        ));

    }

return $this->render('topics/topic.details.html.twig', array(
    'topic' => $topic
    'topicComments' => [],
));

    return $this->render('topics/topic.details.html.twig', array(
        'topic' => $topic
    ));

测试是否定义了var

{% if topicComments is defined and not topicComments  is empty %}
<div class="container">
    {% for comment in topicComments %}
        {{ comment.description }}
    {% endfor %}
</div>
{% endif %}

---

您可以继续传递主题变量实例并在细枝中导航关系，因此呈现控制器：

 /**
     * @Route("/topic/{id}", name="topic_details")
     * @param $id
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function topicDetailsAction($id)
    {
        $topic = $this->getDoctrine()->getRepository('AppBundle:Topic')->find($id);

        return $this->render('topics/topic.details.html.twig', array(
            'topic' => $topic
        ));
    }

     /**
     * @Route("/topic/{id}", name="topic_details")
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function listCommentsAction($id)
    {
        $topic = $this->getDoctrine()->getRepository('AppBundle:Topic')->find($id);
        $topicComments = $topic->getComments();

        return $this->render('topics/topic.details.html.twig', array(
            'topicComments' => $topicComments
        ));

    }

return $this->render('topics/topic.details.html.twig', array(
    'topic' => $topic
    'topicComments' => [],
));

    return $this->render('topics/topic.details.html.twig', array(
        'topic' => $topic
    ));

然后在模板中：

   {% for comment in topic.comments %}
        {{ comment.description }}
    {% endfor %}

---

您可以继续传递主题变量实例并在细枝中导航关系，因此呈现控制器：

 /**
     * @Route("/topic/{id}", name="topic_details")
     * @param $id
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function topicDetailsAction($id)
    {
        $topic = $this->getDoctrine()->getRepository('AppBundle:Topic')->find($id);

        return $this->render('topics/topic.details.html.twig', array(
            'topic' => $topic
        ));
    }

     /**
     * @Route("/topic/{id}", name="topic_details")
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function listCommentsAction($id)
    {
        $topic = $this->getDoctrine()->getRepository('AppBundle:Topic')->find($id);
        $topicComments = $topic->getComments();

        return $this->render('topics/topic.details.html.twig', array(
            'topicComments' => $topicComments
        ));

    }

return $this->render('topics/topic.details.html.twig', array(
    'topic' => $topic
    'topicComments' => [],
));

    return $this->render('topics/topic.details.html.twig', array(
        'topic' => $topic
    ));

然后在模板中：

   {% for comment in topic.comments %}
        {{ comment.description }}
    {% endfor %}

---

很好的描述和非常有用的例子。谢谢很好的描述和非常有用的例子。谢谢非常简单的解决方案。帮了很多忙！感谢鲁门潘切夫，请注意@darkbeee另一个答案的宝贵提示非常简单和容易的解决方案。帮了很多忙！谢谢鲁门潘切夫，注意@DarkBee的另一个答案的宝贵提示