Php Symfony 3.4表单EntityType所选值为空

我对Symfony 3.4 EntityType有问题

CategoryType.php

class CategoryType extends AbstractType
{

    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('title')
            ->add('spec', CollectionType::class, [
                'entry_type' => SpecificationType::class,
                'allow_add' => true,
                'allow_delete' => true,
                'label' => false,
            ]);
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => Category::class,
        ));
    }
}

class SpecificationType extends AbstractType
{

    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('title', EntityType::class, [
            'class' => Specification::class,
            'label' => false,
        ]);
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => Specification::class,
        ));
    }

    public function getBlockPrefix()
    {
        return 'specification';
    }
}

{{ form_widget(form.title) }}
{{ form_widget(form.spec) }}

/**
 * @ORM\ManyToMany(targetEntity="Specification", inversedBy="categoryList")
 * @ORM\JoinTable(name="category_specification")
 */
private $spec;

SpecificationType.php

class CategoryType extends AbstractType
{

    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('title')
            ->add('spec', CollectionType::class, [
                'entry_type' => SpecificationType::class,
                'allow_add' => true,
                'allow_delete' => true,
                'label' => false,
            ]);
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => Category::class,
        ));
    }
}

class SpecificationType extends AbstractType
{

    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('title', EntityType::class, [
            'class' => Specification::class,
            'label' => false,
        ]);
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => Specification::class,
        ));
    }

    public function getBlockPrefix()
    {
        return 'specification';
    }
}

{{ form_widget(form.title) }}
{{ form_widget(form.spec) }}

/**
 * @ORM\ManyToMany(targetEntity="Specification", inversedBy="categoryList")
 * @ORM\JoinTable(name="category_specification")
 */
private $spec;

表单按预期呈现：标题为文本字段，2个选择元素。但问题是渲染选择元素并没有选择选定值

form.html.twig

class CategoryType extends AbstractType
{

    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('title')
            ->add('spec', CollectionType::class, [
                'entry_type' => SpecificationType::class,
                'allow_add' => true,
                'allow_delete' => true,
                'label' => false,
            ]);
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => Category::class,
        ));
    }
}

class SpecificationType extends AbstractType
{

    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('title', EntityType::class, [
            'class' => Specification::class,
            'label' => false,
        ]);
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => Specification::class,
        ));
    }

    public function getBlockPrefix()
    {
        return 'specification';
    }
}

{{ form_widget(form.title) }}
{{ form_widget(form.spec) }}

/**
 * @ORM\ManyToMany(targetEntity="Specification", inversedBy="categoryList")
 * @ORM\JoinTable(name="category_specification")
 */
private $spec;

结果

预期结果

当在

SpecificationType.php

EntityType:：class

中被替换为

TextField:class

时，现在表单呈现的不是2个选择元素，而是2个文本输入（预期行为），分配的值正确：

我开始挖掘这些select元素最初是如何呈现的，发现这个block

{%-block choice\u widget\u options-%}

负责呈现select元素

在这个区块内是代码的和平：

<option value="{{ choice.value }}"{% if choice.attr %}{% with { attr: choice.attr } %}{{ block('attributes') }}{% endwith %}{% endif %}{% if choice is selectedchoice(value) %} selected="selected"{% endif %}>{{ choice_translation_domain is same as(false) ? choice.label : choice.label|trans({}, choice_translation_domain) }}</option>

找到了解决办法

正如@Nickolaus所写的：

[…]您遇到了这个问题，因为在您的实现中它是一个复合表单，没有简单的表单，而且symfony无法解析在子表单中创建的哪个字段需要用作实体字段的源

因此，解决方案是：

重构

SpecificationType.php

如下：

class SpecificationType extends AbstractType
{
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'class' => Specification::class,
            'label' => false,
        ));
    }

    public function getParent()
    {
        return EntityType::class;
    }

    public function getBlockPrefix()
    {
        return 'specification';
    }
}

使用

getParent（）

方法，将所有字段配置移动到

configureOptions

并删除

buildForm（）

方法

---

最后。。浪费了这么多时间。

您能展示一下

spec

属性是如何在

Category

实体中定义的吗？@Djengobarm请查看更新部分。