Symfony呈现作者姓名

Question

我是symfony的新手，我想知道如何从我的评论表中呈现作者的用户名。我只是不知道如何使用该键来呈现另一个表中的值。此外，如果你看到我应该改变的东西，我很感激。如果有人可以给我一个例子，那就太好了！

错误/树枝：

An exception has been thrown during the rendering of a template ("Catchable Fatal Error: Object of class Proxies\__CG__\AppBundle\Entity\User could not be converted to string").

<div class="panel panel-default">
                        <div class="panel-heading">
                            <strong>{{ item.author }}</strong> <span class="text-muted">{{ item.publishedAt|date('Y-m-d H:i:s') }}</span>
                            {% if is_granted('ROLE_USER') %}
                                <a class="btn btn-primary" href="{{ path('comment_comment_new', {'productId': data.id, 'commentId': item.id}) }}">Add Comment</a>
                            {% endif %}
                        </div>
                        <div class="panel-body">
                            {{ item.content }}
                        </div>
                    </div>

用户实体：

 /**
 * @ORM\Entity
 * @ORM\Table(name="user")
 * @UniqueEntity(fields={"email"}, message="It looks like your already have an account!")
 */
class User implements UserInterface
{
    /**
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     * @ORM\Column(type="integer")
     */
    private $id;

    /**
     * @Assert\NotBlank()
     * @Assert\Email()
     * @ORM\Column(type="string", unique=true)
     */
    private $email;

    /**
     * @ORM\Column(type="string")
     */
    private $password;

    /**
     * @Assert\NotBlank(groups={"Registration"})
     * @var string
     */
    private $plainPassword;

    /**
     * @ORM\Column(type="json_array")
     */
    private $roles = array();

    /**
     * @ORM\OneToMany(targetEntity="Comment", mappedBy="author")
     */
    private $user;

    public function __construct()
    {
        $this->user = new ArrayCollection();
    }

    public function getUsername()
    {
        return $this->email;
    }

    public function getRoles()
    {
        $roles = $this->roles;

        if (!in_array('ROLE_USER', $roles))
        {
            $roles[] = 'ROLE_USER';
        }

        return $roles;
    }

    /**
     * @return mixed
     */
    public function getId()
    {
        return $this->id;
    }

    public function getPassword()
    {
        return $this->password;
    }

    public function getSalt()
    {
    }

    public function getEmail()
    {
        return $this->email;
    }

    public function eraseCredentials()
    {
        $this->plainPassword = null;
    }

    /**
     * @param mixed $email
     */
    public function setEmail($email)
    {
        $this->email = $email;
    }

    /**
     * @param mixed $password
     */
    public function setPassword($password)
    {
        $this->password = $password;
    }

    /**
     * @return mixed
     */
    public function getPlainPassword()
    {
        return $this->plainPassword;
    }

    /**
     * @param mixed $plainPassword
     */
    public function setPlainPassword($plainPassword)
    {
        $this->plainPassword = $plainPassword;
        $this->password = null;
    }

    /**
     * @param mixed $roles
     */
    public function setRoles($roles)
    {
        $this->roles = $roles;
    }

    /**
     * @return mixed
     */
    public function getUser()
    {
        return $this->user;
    }

}

评论实体：

/**
 * @ORM\Entity(repositoryClass="AppBundle\Repository\CommentRepository")
 * @ORM\Table(name="comments")
 */
class Comment
{
    public function __construct()
    {
        $this->publishedAt = new \DateTime();
    }

    /**
     * @ORM\Column(type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @var Product
     *
     * @ORM\ManyToOne(targetEntity="AppBundle\Entity\Product")
     * @ORM\JoinColumn(nullable=false)
     */
    private $product;

    /**
     * @var string
     *
     * @ORM\Column(type="text")
     * @Assert\Length(
     *     min=5,
     *     minMessage="Comment is too short!",
     *     max=10000,
     *     maxMessage="Comment is too long!"
     * )
     */
    private $content;

    /**
     * @var User
     *
     * @ORM\ManyToOne(targetEntity="AppBundle\Entity\User", inversedBy="user")
     * @ORM\JoinColumn(name="author_id", referencedColumnName="id")
     */
    private $author;

    /**
     * @var \DateTime
     *
     * @ORM\Column(type="datetime")
     * @Assert\DateTime
     */
    private $publishedAt;

    /**
     * @ORM\ManyToOne(targetEntity="AppBundle\Entity\Comment")
     * @ORM\JoinColumn(nullable=false)
     */
    private $comment;

    /**
     * @return mixed
     */
    public function getId()
    {
        return $this->id;
    }

    /**
     * @param mixed $id
     */
    public function setId($id)
    {
        $this->id = $id;
    }

    /**
     * @return Product
     */
    public function getProduct()
    {
        return $this->product;
    }

    /**
     * @param Product $product
     */
    public function setProduct($product)
    {
        $this->product = $product;
    }

    /**
     * @return string
     */
    public function getContent()
    {
        return $this->content;
    }

    /**
     * @param string $content
     */
    public function setContent($content)
    {
        $this->content = $content;
    }

    /**
     * @return User
     */
    public function getAuthor()
    {
        return $this->author;
    }

    /**
     * @param User $author
     */
    public function setAuthor($author)
    {
        $this->author = $author;
    }

    /**
     * @return \DateTime
     */
    public function getPublishedAt()
    {
        return $this->publishedAt;
    }

    /**
     * @param \DateTime $publishedAt
     */
    public function setPublishedAt($publishedAt)
    {
        $this->publishedAt = $publishedAt;
    }

    /**
     * @return mixed
     */
    public function getCommentlist()
    {
        return $this->comment;
    }

    /**
     * @param mixed $commentlist
     */
    public function setCommentlist($comment)
    {
        $this->comment = $comment;
    }

}

Answer 1

{{ item.author }}是用户对象

指定要显示的用户属性：

例：

{{ item.author.username }}