Serializing Entity Relation only to Id with JMS Serializer

Question

I'm trying to serialize a entity relation with JMS Serializer.

Here is the Entity:

class Ad
{ 

    /**
     * @Type("string")
     * @Groups({"manage"})
     * 
     * @var string
     */
    private $description;

    /**
     * @Type("Acme\SearchBundle\Entity\Country")
     * @Groups({"manage"})
     * 
     * @var \Acme\SearchBundle\Entity\Country
     */
    private $country;

    /**
     * @Type("string")
     * @Groups({"manage"})
     * 
     * @var string
     */
    private $title;

    /**
     * Set description
     *
     * @param string $description
     * @return Ad
     */
    public function setDescription($description)
    {
        $this->description = $description;

        return $this;
    }

    /**
     * Get description
     *
     * @return string 
     */
    public function getDescription()
    {
        return $this->description;
    }

    /**
     * Set country
     *
     * @param \Acme\SearchBundle\Entity\Country $country
     * @return Ad
     */
    public function setCountry($country)
    {
        $this->country= $country;

        return $this;
    }

    /**
     * Get country
     *
     * @return string 
     */
    public function getCountry()
    {
        return $this->country;
    }

    /**
     * Set title
     *
     * @param string $title
     * @return Ad
     */
    public function setTituloanuncio($title)
    {
        $this->title = $title;

        return $this;
    }

    /**
     * Get title
     *
     * @return string 
     */
    public function getTitle()
    {
        return $this->title;
    }

}

And the Entity of the relationship:

class Country
{

    /**
     * @Type("string")
     * @Groups("manage")
     * 
     * @var string
     */
    private $id;

    /**
     * @Type("string")
     * @Groups("admin")
     * 
     * @var string
     */
    private $description;

    /**
     * Set description
     * @Groups("")
     *
     * @param string $description
     * @return Country
     */
    public function setDescripcionpais($description)
    {
        $this->description = $description;

        return $this;
    }

    /**
     * Get description
     *
     * @return string 
     */
    public function getDescription()
    {
        return $this->description;
    }

    }

    /**
     * Get id
     *
     * @return string 
     */
    public function getId()
    {
        return $this->id;
    }
}

I serialize the entity but I don't know how to convert the country attribute into a simple field.

I get this result in json:

{"description":"foo", "title":"bar", "country":{"id":"en"} }

But I want to get the id field of the country like this:

{"description":"foo", "title":"bar", "country": "en" }

It is possible with JMS Serializer?

Thank you.

[EDIT]

@VirtualProperty doesn't work.

Answer 1

Yes, you could use @VirtualProperty annotation:

/**
 * @VirtualProperty
 * @SerializedName("foo")
 */
public function bar()
{
    return $this->country->getCode();
}

But be aware when it comes to deserialization:

@VirtualProperty This annotation can be defined on a method to indicate that the data returned by the method should appear like a property of the object.

> Note: This only works for serialization and is completely ignored during deserialization.

Hope this helps...