php - how to unset/remove a protected property

Question

I have a Product object/class as follows:

class Product
{

    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @Exclude()
     * @ORM\Column(name="deletedAt", type="datetime", nullable=true)
     */
    private $deletedAt;

    /**
     * @Assert\NotBlank()
     * @Assert\MinLength( limit=3, message=" Product Name should have at least {{ limit }} characters.")
     * @ORM\Column(name="name", type="string", length=100 , nullable=false)
     */
    protected $name;

    /**
     * @var datetime $created
     * @Gedmo\Timestampable(on="create")
     * @ORM\Column(type="datetime")
     */
    private $created;

    /**
     * @var datetime $updated
     * @Gedmo\Timestampable(on="update")
     * @ORM\Column(type="datetime")
     */
    private $updated;

    /**
     * @ORM\Column(name="description", type="string", length=350)
     */
    protected $description;


    /**
     * @Assert\NotBlank()
     * @ORM\Column(name="code", type="string", length=100)
     */
    protected $code;


    /**
     * @Assert\NotBlank()
     * @ORM\ManyToOne(targetEntity="Shopious\MainBundle\Entity\Category", inversedBy="products")
     * @ORM\JoinColumn(name="category_id", referencedColumnName="id", onDelete="CASCADE", nullable=true)
     */
    protected $category;

    /**
     * @Assert\NotBlank()
     * @Assert\Min(limit = "0", message = "negative number is invalid")
     * @Assert\Type(type="float", message="The value {{ value }} is not a valid number.")
     * @ORM\Column(name="price", type="float")
     */
    protected $price;

    /**
     * @Assert\NotBlank()
     * @Assert\Min(limit = "0", message = "negative number is invalid")
     * @Assert\Type(type="float", message="The value {{ value }} is not a valid number.")
     * @ORM\Column(name="height", type="float")
     */
    protected $height;

    /**
     * @Assert\NotBlank()
     * @Assert\Min(limit = "0", message = "negative number is invalid")
     * @Assert\Type(type="float", message="The value {{ value }} is not a valid number.")
     * @ORM\Column(name="width", type="float")
     */
    protected $width;

    /**
     * @Assert\NotBlank()
     * @Assert\Min(limit = "0", message = "negative number is invalid")
     * @Assert\Type(type="float", message="The value {{ value }} is not a valid number.")
     * @ORM\Column(name="length", type="float")
     */
    protected $length;

    /**
     * @Assert\NotBlank()
     * @Assert\Min(limit = "0", message = "negative number is invalid")
     * @Assert\Type(type="float", message="The value {{ value }} is not a valid number.")
     * @ORM\Column(name="weight", type="float" )
     */
    protected $weight;

    /**
     * @Accessor(getter="getShopRef")
     * @ORM\ManyToOne(targetEntity="Shopious\MainBundle\Entity\Shop", inversedBy="products")
     * @ORM\JoinColumn(name="shop_id", referencedColumnName="id", onDelete="CASCADE" , nullable=false)
     */
    protected $shop;


    /**
     * @ORM\OneToMany(targetEntity="ProductAttribute", mappedBy="product", cascade={"persist","remove"})
     */
    protected $attributes;

}

and so I have a Product object and I wanted to remove all the attributes of that product, so I did:

unset(product->attributes)

however it complained that the attributes can't be accessed. How is it possible to set the attributes of the Product to be nil?

Answer 1

根据定义，受保护的属性只能从定义它的类的实例或后代中访问。

这就是为什么人们会选择将属性设置为受保护而不是公开的，以使其无法在类实例之外进行更改。

要取消设置，必须在类内完成，即

  public function removeAttributes(){
      unset($this->attributes);
  }

Answer 2

我认为你必须为它创建一个公共函数：

class product{
    // Include everything from above

    public function unset_attributes(){
        unset($this->attributes);
    }
}

可以在此处找到有关对象内受保护变量的更多信息。

Answer 3

您可以使用反射将私有/受保护的属性设置为null.

http://php.net/manual/en/reflectionproperty.setvalue.php

class Foo {
    public static $staticProperty;

    public $property;
    protected $privateProperty;
}

$reflectionClass = new ReflectionClass('Foo');

$reflectionProperty = $reflectionClass->getProperty('privateProperty');
$reflectionProperty->setAccessible(true);
$reflectionProperty->setValue($foo, null);