表单视图中带有复选框列表的一对多符号

我有两个实体

员工和免费日

一名员工可以有一天或多天的空闲时间。空闲日定义为一周中的某一天，因此周一=>1，周二=>2等。

在员工表单视图中，我想将FreeDay实体显示为复选框列表，如下所示：

天数表单视图

但我得到了这个错误：

警告：spl_object_hash（）要求参数1为对象，给定为整数

我真的很困惑，我不知道如何摆脱这个问题。

实体代码如下：

员工实体：

namespace AppBundle'Entity;
use Doctrine'ORM'Mapping as ORM;
use Gedmo'Mapping'Annotation as Gedmo;
use Symfony'Component'Validator'Constraints as Assert;

/**
 * Employee
 *
 * @Gedmo'SoftDeleteable(fieldName="deletedAt")
 */
class Employee
{
/**
 * @ORM'OneToMany(targetEntity="FreeDay", mappedBy="employee", cascade={"persist","remove"},orphanRemoval=true)
 */
private $freedays;

/**
 * Constructor
 */
public function __construct()
{
    $this->freedays = new 'Doctrine'Common'Collections'ArrayCollection();
}
/**
 * Add freedays
 *
 * @param 'AppBundle'Entity'Free $freeday
 *
 * @return Employee
 */
public function addFreeDay('AppBundle'Entity'FreeDay $freeday)
{
    $this->freedays[] = $freeday;
    return $this;
}
/**
 * Remove freeday
 *
 * @param 'AppBundle'Entity'FreeDay $freeday
 */
public function removeFreeDay('AppBundle'Entity'FreeDay $freeday)
{
    $this->freedays->removeElement($freeday);
}
/**
 * Get freeday
 *
 * @return 'Doctrine'Common'Collections'Collection
 */
public function getFreeDays()
{
    return $this->freedays;
}
}

自由日实体：

namespace AppBundle'Entity;
use Doctrine'ORM'Mapping as ORM;
use Gedmo'Mapping'Annotation as Gedmo;
use Symfony'Component'Validator'Constraints as Assert;
class FreeDay
{
/**
 * @var int
 *
 * @ORM'Column(name="id", type="integer")
 * @ORM'Id
 * @ORM'GeneratedValue(strategy="AUTO")
 */
private $id;
/**
 * @var int
 * @ORM'ManyToOne(targetEntity="Employee", inversedBy="freedays")
 * @ORM'JoinColumn(name="employee_id", referencedColumnName="id", onDelete="CASCADE")
 */
private $employee;
/**
 * @var int
 *
 * @ORM'Column(name="day", type="integer")
 */
private $day;

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

/**
 * Set day
 *
 * @param integer $day
 *
 * @return FreeDay
 */
public function setDay($day)
{
    $this->day = $day;
    return $this;
}
/**
 * Get day
 *
 * @return int
 */
public function getDay()
{
    return $this->day;
}
/**
 * Set employee
 *
 * @param 'AppBundle'Entity'Employee $employee
 *
 * @return FreeDay
 */
public function setEmployee('AppBundle'Entity'Employee $employee = null)
{
    $this->employee = $employee;
    return $this;
}
/**
 * Get employee
 *
 * @return 'AppBundle'Entity'Employee
 */
public function getEmployee()
{
    return $this->employee;
}

EmployeeType.php

class EmployeeType extends AbstractType
{

public function buildForm(FormBuilderInterface $builder, array $options)
{

    $builder
        ->add('freedays', EntityType::class, array(
            'class'=>'AppBundle:FreeDay',
            'choices'=>$this->getDays(),
            'expanded'=>true,
            'multiple'=>true
        ))
        ->add('save', SubmitType::class, array('label' => 'Salva'))
    ;
}

private function getDays() {
    return array(
        'Monday'=>1,
        'Tuesday'=>2,
        'Wednesday'=>3,
        'Thursday'=>4,
        'Friday'=>5,
        'Saturday'=>6,
    );
}
public function configureOptions(OptionsResolver $resolver)
{
    $resolver->setDefaults(array(
        'data_class' => 'AppBundle'Entity'Employee',
    ));
}
}