我正在研究Symfony2中的Web应用程序.我找到了一些需要Symfony更高级的建议/解释的地方.

我的数据库的一部分设置如下：

我有属于卡属性集的卡,由卡值组成.

我有卡属性集有很多属性,卡属性可以属于许多卡属性集(显然是多对多的关系).

然后,根据card属性,该属性具有属性值,例如,text具有varchar类型的value_text,boolean具有boolean类型的value_boolean.

您可以想象在制作表单以创建新卡时,表单需要根据其所属的卡属性集生成输入字段,并且取决于属于该属性集的属性吗？

所以这是我的问题;有没有办法根据用户选择的实体动态生成表单中的输入字段.我读过有关活动但我不确定它们是否满足我的需求.

这是我的实体的代码(我删除了Getters和Setters以获得更简单的视图)：

卡：

/**
 * card
 *
 * @ORM\Table()
 * @ORM\Entity(repositoryClass="clientsBundle\Entity\cardRepository")
 * @UniqueEntity(
 *      fields={"cardLabel"},*      message="A card with this label already exists"
 * )
 */
class card
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id",type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @var string
     *
     * @ORM\Column(name="card_label",type="string",length=999)
     */
    private $cardLabel;

    /**
     * @ORM\ManyToOne(targetEntity="project",inversedBy="project_cards")
     * @ORM\JoinColumn(name="project_id",referencedColumnName="id",onDelete = "SET NULL")
     */
    protected $card_project;

     /**
     * @ORM\ManyToOne(targetEntity="cardAttributeSet",inversedBy="cas_cards")
     * @ORM\JoinColumn(name="cas_id",referencedColumnName="id")
     **/
    protected $cardAttrSet;

    /**
     * @ORM\OneToMany(targetEntity="cardAttrValue",mappedBy="card",cascade={"persist"},orphanRemoval=true)
     **/
    protected $card_values;

    /**
    * @ORM\ManyToMany(targetEntity="user",mappedBy="cards")
    */
    private $users;

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

卡属性：

/**
 * cardAttribute
 *
 * @ORM\Table()
 * @ORM\Entity(repositoryClass="clientsBundle\Entity\cardAttributeRepository")
 * @UniqueEntity(
 *      fields={"name"},*      message="An attribute with this name already exists"
 * )
 */
class cardAttribute
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id",type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @var string
     *
     * @ORM\Column(name="name",length=255)
     */
    private $name;

    /**
     * @var string
     *
     * @ORM\Column(name="type",length=255)
     */
    private $type;
}

卡属性集

/**
 * cardAttributeSet
 *
 * @ORM\Table()
 * @ORM\Entity(repositoryClass="clientsBundle\Entity\cardAttributeSetRepository")
 * @UniqueEntity(
 *      fields={"casLabel"},*      message="An attribute set with this label already exists"
 * )
 */
class cardAttributeSet
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id",type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    public $id;

    /**
     * @var string
     *
     * @ORM\Column(name="cas_label",length=255)
     */
    private $casLabel;

    /**
     * @ORM\OneToMany(targetEntity="card",mappedBy="cardAttrSet")
     */
    private $cas_cards;

    /**
     * @ORM\ManyToMany(targetEntity="cardAttribute")
     * @ORM\JoinTable(name="cas_attribute",*          joinColumns={@ORM\JoinColumn(name="cas_id",referencedColumnName="id")},*          inverseJoinColumns={@ORM\JoinColumn(name="attribute_id",referencedColumnName="id")}  
     *          )
     */
    private $attributes;

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

卡属性值

/**
 * cardAttrValue
 *
 * @ORM\Table()
 * @ORM\Entity(repositoryClass="clientsBundle\Entity\cardAttrValueRepository")
 * @UniqueEntity(
 *      fields={"valueText"}
 * )
 */
class cardAttrValue
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id",type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @var string
     *
     * @ORM\Column(name="value_text",length=255,nullable=true)
     */
    private $valueText;

    /**
     * @var string
     *
     * @ORM\Column(name="value_varchar",nullable=true)
     */
    private $valueVarchar;

    /**
     * @var integer
     *
     * @ORM\Column(name="value_int",type="integer",nullable=true,nullable=true)
     */
    private $valueInt;

    /**
     * @var boolean
     *
     * @ORM\Column(name="value_boolean",type="boolean",nullable=true)
     */
    private $valueBoolean;

    /**
     * @ORM\ManyToOne(targetEntity="card",inversedBy="card_values")
     * @ORM\JoinColumn(name="card_id",referencedColumnName="id")
     **/
    private $card;

    /**
     * @ORM\ManyToOne(targetEntity="cardAttribute")
     * @ORM\JoinColumn(name="cardAttributes_id",referencedColumnName="id")
     **/
    private $cardAttribute;
}

class CardAttributeValueType extends AbstractType

public function buildForm(FormBuilderInterface $builder,array $options)
{
    $builder->addEventListener(FormEvents::PRE_SET_DATA,function(FormEvent $event) {
        $value = $event->getData();
        $form = $event->getForm();

        if (!$value) {
            return;
        }

        switch ($value->getCardAttribute()->getType()) {
            case 'text':
                $form->add('valueVarchar','text');
                break;

            // Same for other attribute types
        }
     }
}

public function getCardValues()
{
    $collection = new ArrayCollection();

    if (!$this->cardAttrSet) {
        return $collection;
    }

    // Add existing values
    foreach ($this->card_values as $value) {
        $collection[$value->getCardAttribute()->getId()] = $value;
    }

    // Get all attributes from the set and create values for missing attributes
    foreach ($this->cardAttrSet->getAttributes() as $attr) {
        if (!isset($collection[$attr->getId()])) {
            $value = new cardAttrValue();
            $value->setCardAttribute($attr);

            $collection[$attr->getId()] = $value;
        }
    }

    return $collection;
}