Symfony2 - 数组到字符串转换错误

Question

我已经阅读了其他主题,但它并没有解决我的问题所以:

我有这个

->add('role', 'choice', array(
                'label' => 'I am:',
                'mapped' => true,
                'expanded' => true,
                'multiple' => false,
                'choices' => array(
                    'ROLE_NORMAL' => 'Standard',
                    'ROLE_VIP' => 'VIP',
                ) 
            ))

无论我做什么,我都会收到这个错误:

Notice: Array to string conversion in C:\xampp\htdocs\xxx\vendor\symfony\symfony  \src\Symfony\Component\Form\Extension\Core\ChoiceList\ChoiceList.php line 458 

在我的表单类型中,甚至没有调用setRole方法(当我将它重命名为某些垃圾时,仍然会发生错误).为什么会这样？

//编辑

完整堆栈跟踪:

in C:\xampp\htdocs\xxx\vendor\symfony\symfony\src\Symfony\Component\Form\Extension\Core\ChoiceList\ChoiceList.php at line 458  -

     */
    protected function fixIndex($index)
    {
        if (is_bool($index) || (string) (int) $index === (string) $index) {
            return (int) $index;
        }

    at ErrorHandler ->handle ('8', 'Array to string conversion', 'C:\xampp\htdocs     \xxx\vendor\symfony\symfony\src\Symfony\Component\Form\Extension\Core\ChoiceList\ChoiceList.php', '458', array('index' => array()))
in C:\xampp\htdocs\xxx\vendor\symfony\symfony\src\Symfony\Component\Form\Extension\Core\ChoiceList\ChoiceList.php at line 458  +
at ChoiceList ->fixIndex (array())
in C:\xampp\htdocs\xxx\vendor\symfony\symfony\src\Symfony\Component\Form\Extension\Core\ChoiceList\ChoiceList.php at line 476  +
at ChoiceList ->fixIndices (array(array()))
in C:\xampp\htdocs\xxx\vendor\symfony\symfony\src\Symfony\Component\Form\Extension\Core\ChoiceList\SimpleChoiceList.php at line 152  +
at SimpleChoiceList ->fixChoices (array(array()))
in C:\xampp\htdocs\xxx\vendor\symfony\symfony\src\Symfony\Component\Form\Extension\Core\ChoiceList\ChoiceList.php at line 204  +
at ChoiceList ->getIndicesForChoices (array(array()))
in C:\xampp\htdocs\xxx\vendor\symfony\symfony\src\Symfony\Component\Form\Extension\Core\DataTransformer\ChoiceToBooleanArrayTransformer.php at line 63  +
at ChoiceToBooleanArrayTransformer ->transform (array())
in C:\xampp\htdocs\xxx\vendor\symfony\symfony\src\Symfony\Component\Form\Form.php at line 1019  +
at Form ->normToView (array())
in C:\xampp\htdocs\xxx\vendor\symfony\symfony\src\Symfony\Component\Form\Form.php at line 332  +
at Form ->setData (array())
in C:\xampp\htdocs\xxx\vendor\symfony\symfony\src\Symfony\Component\Form\Extension\Core\DataMapper\PropertyPathMapper.php at line 59  +
at PropertyPathMapper ->mapDataToForms (object(User), object(RecursiveIteratorIterator))
in C:\xampp\htdocs\xxx\vendor\symfony\symfony\src\Symfony\Component\Form\Form.php at line 375  +
at Form ->setData (object(User))
in C:\xampp\htdocs\xxx\vendor\friendsofsymfony\user-bundle\FOS\UserBundle\Controller\RegistrationController.php at line 49  +
at RegistrationController ->registerAction (object(Request))
at call_user_func_array (array(object(RegistrationController), 'registerAction'), array(object(Request)))
in C:\xampp\htdocs\xxx\app\bootstrap.php.cache at line 2770  +
at HttpKernel ->handleRaw (object(Request), '1')
in C:\xampp\htdocs\xxx\app\bootstrap.php.cache at line 2744  +
at HttpKernel ->handle (object(Request), '1', true)
in C:\xampp\htdocs\xxx\app\bootstrap.php.cache at line 2874  +
at ContainerAwareHttpKernel ->handle (object(Request), '1', true)
in C:\xampp\htdocs\xxx\app\bootstrap.php.cache at line 2175  +
at Kernel ->handle (object(Request))
in C:\xampp\htdocs\xxx\web\app_dev.php at line 29  +

Answer 1

Symfony试图将你的$ role(数组属性)转换为非多选字段(字符串).

有几种方法可以解决这个问题:

1. 在您的选择表单小部件中将multiple设置为true.
2. 从改变映射数组到字符串为$角色在你的实体属性.
3. 如果您坚持不改变上述选项,则可以创建DataTransformer. 这不是最佳解决方案,因为如果您的数组包含多个元素,您将丢失数据.

例:

<?php
namespace Acme\DemoBundle\Form\DataTransformer;

use Symfony\Component\Form\DataTransformerInterface;
use Symfony\Component\Form\Exception\TransformationFailedException;

class StringToArrayTransformer implements DataTransformerInterface
{
    /**
     * Transforms an array to a string. 
     * POSSIBLE LOSS OF DATA
     *
     * @return string
     */
    public function transform($array)
    {
        return $array[0];
    }

    /**
     * Transforms a string to an array.
     *
     * @param  string $string
     *
     * @return array
     */
    public function reverseTransform($string)
    {
        return array($string);
    }
}

然后在你的表单类中:

use Acme\DemoBundle\Form\DataTransformer\StringToArrayTransformer;
/* ... */
$transformer = new StringToArrayTransformer();
$builder->add($builder->create('role', 'choice', array(
                'label' => 'I am:',
                'mapped' => true,
                'expanded' => true,
                'multiple' => false,
                'choices' => array(
                    'ROLE_NORMAL' => 'Standard',
                    'ROLE_VIP' => 'VIP',
                )
              ))->addModelTransformer($transformer));

您可以在此处阅读有关DataTransformers的更多信息:http://symfony.com/doc/current/cookbook/form/data_transformers.html