如何使用表单构建器显示抽象列表作为复选框并从实体初始化列表？ （Symfony2的）

Question

我有包含用户字段的表单。我想显示复选框语言列表。必须将选中的语言保存到数据库中。

所以我有2个实体类：User和UserSiteLanguage。请参阅下面的ORM和实体类。 ＆＃39; fos_user_user＆＃39;表格不包含语言的任何真实字段。并且＆＃39; user_site_language＆＃39;是一个表，其中包含为用户选择的绑定语言。

User.orm.xml

<entity name="UserBundle\Entity\User" table="fos_user_user">

        <id name="id" type="integer" column="id">
            <generator strategy="AUTO"/>
        </id>
        <!-- Profile fields -->
        ...skipped ...

        <one-to-many field="siteEnabledLanguages" target-entity="UserBundle\Entity\UserSiteLanguage" mapped-by="user">
            <cascade>
                <cascade-all/>
            </cascade>
        </one-to-many>
    </entity>

UserSiteLanguage.orm.xml

<entity name="UserBundle\Entity\UserSiteLanguage" 
        table="user_site_language">

    <unique-constraints>
        <unique-constraint name="user_site_lang_locale_idx" columns="user_id,locale" />
    </unique-constraints>

    <lifecycle-callbacks>
        <lifecycle-callback type="prePersist" method="prePersist" />
        <lifecycle-callback type="preUpdate" method="preUpdate" />
    </lifecycle-callbacks>

    <id name="id" type="integer" column="id">
        <generator strategy="AUTO"/>
    </id>

    <field name="locale" column="locale" type="string" length="5" />       

    <many-to-one field="user" target-entity="UserBundle\Entity\User" inversed-by="siteEnabledLanguages">
        <join-column name="user_id" referenced-column-name="id" />
    </many-to-one>

</entity>

user.php的

class User extends BaseUser{
        private $siteEnabledLanguages;

        /**
         * Add siteEnabledLanguage
         *
         * @param \UserBundle\Entity\UserSiteLanguage $siteEnabledLanguage
         *
         * @return User
         */
        public function addSiteEnabledLanguage(\UserBundle\Entity\UserSiteLanguage $siteEnabledLanguage)
        {
            $this->siteEnabledLanguages[] = $siteEnabledLanguage;

            return $this;
        }

        /**
         * Remove siteEnabledLanguage
         *
         * @param \UserBundle\Entity\UserSiteLanguage $siteEnabledLanguage
         */
        public function removeSiteEnabledLanguage(\UserBundle\Entity\UserSiteLanguage $siteEnabledLanguage)
        {
            $this->siteEnabledLanguages->removeElement($siteEnabledLanguage);
        }

        /**
         * Get siteEnabledLanguages
         */
        public function getSiteEnabledLanguages()
        {
            return $this->siteEnabledLanguages; 
        }
}

UserSiteLanguage.php

class UserSiteLanguage
{
    private $locale;
    private $id;
    private $user;

    // getters, setters
}

类AbstractUserFormType扩展AbstractType

{
...
      ->add('siteEnabledLanguages', 'entity', array(
           'choices' => $this->getLocaleList(),
           'class' => 'UserBundle:UserSiteLanguage',
           'property' => 'locale',
           'multiple' => true,
           'expanded' => true,
     ))

  protected function getLocaleList()
  {
      $localesList = array();
      $locales     = $this->container->getParameter('lexik_translation.managed_locales');

      foreach ($locales as $locale) {
          $localeName = Intl::getLocaleBundle()->getLocaleName($locale);
          $localesList[$locale] = $localeName;
      }

      return $localesList;
  }
}

在我的FormType上，我尝试使用＆＃39; entity＆＃39;来显示区域设置列表。字段类型。我从配置文件中获取语言环境列表。 当我使用这个FormType时，我得到错误：＆＃39;类型＆＃34;对象或数组＆＃34;，＆＃34;字符串＆＃34;的预期参数;给定＆＃39;

哪个可能是问题？