annotations.rst

Attributes and annotations
==========================

PHP 8 support
~~~~~~~~~~~~~~~
JMS serializer now supports PHP 8 attributes, with a few caveats:
- Due to the missing support for nested attributes, the syntax for a few attributes has changed
(see the ``VirtualProperty`` ``options`` syntax here below)
- There is an edge case when setting this exact serialization group ``#[Groups(['value' => 'any value here'])]``.
(when there is only one item in th serialization groups array and has as key ``value`` the attribute will not work as expected,
please use the alternative syntax ``#[Groups(groups: ['value' => 'any value here'])]`` that works with no issues),
- Some support for unions exists.  For unions of primitive types, the system will try to resolve them automatically.  For
classes that contain union attributes, the ``#[UnionDiscriminator]`` attribute must be used to specify the type of the union.

Converting your annotations to attributes
-----------------------------------------

Example:

.. code-block :: php

    /**
     * @VirtualProperty(
     *     "classlow",
     *     exp="object.getVirtualValue(1)",
     *     options={@Until("8")}
     * )
     * @VirtualProperty(
     *     "classhigh",
     *     exp="object.getVirtualValue(8)",
     *     options={@Since("6")}
     * )
     */
    #[VirtualProperty('classlow', exp: 'object.getVirtualValue(1)', options: [[Until::class, ['8']]])]
    #[VirtualProperty('classhigh', exp: 'object.getVirtualValue(8)', options: [[Since::class, ['6']]])]
    class ObjectWithVersionedVirtualProperties
    {
        /**
         * @Groups({"versions"})
         * @VirtualProperty
         * @SerializedName("low")
         * @Until("8")
         */
        #[Groups(['versions'])]
        #[VirtualProperty]
        #[SerializedName('low')]
        #[Until('8')]
        public function getVirtualLowValue()
        {
            return 1;
        }
    ...

To automate migration of Annotations to Attributes you can use `rector/rector` with following config:

.. code-block :: php

    <?php

    declare(strict_types=1);

    use Rector\Config\RectorConfig;
    use Rector\Set\ValueObject\LevelSetList;
    use Rector\Symfony\Set\JMSSetList;

    return static function (RectorConfig $rectorConfig) {
        $rectorConfig->paths([
            __DIR__ . '/src',
        ]);
        $rectorConfig->sets([
            JMSSetList::ANNOTATIONS_TO_ATTRIBUTES,
            LevelSetList::UP_TO_PHP_80,
        ]);
    };



#[ExclusionPolicy]
~~~~~~~~~~~~~~~~~~
This attribute can be defined on a class to indicate the exclusion strategy
that should be used for the class.

+----------+----------------------------------------------------------------+
| Policy   | Description                                                    |
+==========+================================================================+
| all      | all properties are excluded by default; only properties marked |
|          | with #Expose will be serialized/unserialized                   |
+----------+----------------------------------------------------------------+
| none     | no properties are excluded by default; all properties except   |
|          | those marked with #Exclude will be serialized/unserialized     |
+----------+----------------------------------------------------------------+

#[Exclude]
~~~~~~~~~~
This attribute can be defined on a property or a class to indicate that the property or class
should not be serialized/unserialized. Works only in combination with NoneExclusionPolicy.

If the ``ExpressionLanguageExclusionStrategy`` exclusion strategy is enabled, it will
be possible to use ``#[Exclude(if:"expression")]`` to exclude dynamically a property
or an object if used on class level.

#[Expose]
~~~~~~~~~
This attribute can be defined on a property to indicate that the property should
be serialized/unserialized. Works only in combination with AllExclusionPolicy.

If the ``ExpressionLanguageExclusionStrategy`` exclusion strategy is enabled, will
be possible to use ``#Expose[if:"expression"]`` to expose dynamically a property.

#[SkipWhenEmpty]
~~~~~~~~~~~~~~~~
This attribute can be defined on a property to indicate that the property should
not be serialized if the result will be "empty".

Works option works only when serializing.

#[SerializedName]
~~~~~~~~~~~~~~~~~
This attribute can be defined on a property to define the serialized name for a
property. If this is not defined, the property will be translated from camel-case
to a lower-cased underscored name, e.g. camelCase -> camel_case.

Note that this attribute is not used when you're using any other naming
strategy than the default configuration (which includes the
``SerializedNameattributeStrategy``). In order to re-enable the attribute, you
will need to wrap your custom strategy with the ``SerializedNameattributeStrategy``.

.. code-block :: php

    <?php
    $serializer = \JMS\Serializer\SerializerBuilder::create()
        ->setPropertyNamingStrategy(
            new \JMS\Serializer\Naming\SerializedNameattributeStrategy(
                new \JMS\Serializer\Naming\IdenticalPropertyNamingStrategy()
            )
        )
        ->build();

#[Since]
~~~~~~~~
This attribute can be defined on a property to specify starting from which
version this property is available. If an earlier version is serialized, then
this property is excluded automatically. The version must be in a format that is
understood by PHP's ``version_compare`` function.

#[Until]
~~~~~~~~
This attribute can be defined on a property to specify until which version this
property was available. If a later version is serialized, then this property is
excluded automatically. The version must be in a format that is understood by
PHP's ``version_compare`` function.

#[Groups]
~~~~~~~~~
This attribute can be defined on a property to specify if the property
should be serialized when only serializing specific groups (see
:doc:`../cookbook/exclusion_strategies`).

#[MaxDepth]
~~~~~~~~~~~
This attribute can be defined on a property to limit the depth to which the
content will be serialized. It is very useful when a property will contain a
large object graph.

#[AccessType]
~~~~~~~~~~~~~
This attribute can be defined on a property, or a class to specify in which way
the properties should be accessed. By default, the serializer will retrieve, or
set the value via reflection, but you may change this to use a public method instead:

.. code-block :: php

    <?php
    use JMS\Serializer\Annotation\AccessType;

    #[AccessType(type: 'public_method')]
    class User
    {
        private $name;

        public function getName()
        {
            return $this->name;
        }

        public function setName($name)
        {
            $this->name = trim($name);
        }
    }

#[Accessor]
~~~~~~~~~~~
This attribute can be defined on a property to specify which public method should
be called to retrieve, or set the value of the given property:

.. code-block :: php

    <?php
    use JMS\Serializer\Annotation\Accessor;

    class User
    {
        private $id;

        #[Accessor(getter: 'getTrimmedName', setter: 'setName')]
        private $name;

        // ...
        public function getTrimmedName()
        {
            return trim($this->name);
        }

        public function setName($name)
        {
            $this->name = $name;
        }
    }

.. note ::

    If you need only to serialize your data, you can avoid providing a setter by
    setting the property as read-only using the ``#[ReadOnlyProperty]`` attribute.

#[AccessorOrder]
~~~~~~~~~~~~~~~~
This attribute can be defined on a class to control the order of properties. By
default the order is undefined, but you may change it to either "alphabetical", or
"custom".

.. code-block :: php

    <?php

    use JMS\Serializer\Annotation\AccessorOrder;
    use JMS\Serializer\Annotation\VirtualProperty;
    use JMS\Serializer\Annotation\SerializedName;

    #[AccessorOrder('alphabetical')]
    class User
    {
        private $id;
        private $name;
    }

    /**
     * Resulting Property Order: name, id
     */
    #[AccessorOrder(order: 'custom', custom: ['name', 'id'])]
    class User
    {
        private $id;
        private $name;
    }

    /**
     * Resulting Property Order: name, mood, id
     */
    #[AccessorOrder(order: 'custom', custom: ['name', 'someMethod', 'id'])]
    class User
    {
        private $id;
        private $name;

        #[VirtualProperty]
        #[SerializedName(name: 'mood')]

        public function getSomeMethod(): string
        {
            return 'happy';
        }
    }


#[VirtualProperty]
~~~~~~~~~~~~~~~~~~
This attribute can be defined on a method to indicate that the data returned by
the method should appear like a property of the object.

A virtual property can be defined for a method of an object to serialize and can be
also defined at class level exposing data using the Symfony Expression Language.

.. code-block :: php

    #[Serializer\VirtualProperty(name: 'firstName', exp: 'object.getFirstName()', options: [[Serializer\SerializedName::class, ['my_first_name']]])]
    class Author
    {
        #[Serializer\Expose]
        private $id;

        #[Serializer\Exclude]
        private $firstName;

        #[Serializer\Exclude]
        private $lastName;

        #[Serializer\VirtualProperty]
        public function getLastName(): string
        {
            return $this->lastName;
        }

        public function getFirstName(): string
        {
            return $this->firstName;
        }
    }

In this example:

- ``id`` is exposed using the object reflection.
- ``lastName`` is exposed using the ``getLastName`` getter method.
- ``firstName`` is exposed using the ``object.getFirstName()`` expression (``exp`` can contain any valid symfony expression).


``#[VirtualProperty]`` can also have an optional property ``name``, used to define the internal property name
(for sorting proposes as example). When not specified, it defaults to the method name with the "get" prefix removed.

.. note ::

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

In PHP 8, due to the missing support for nested attributes, in the options array you need to pass an array with the class name and an array with the arguments for its constructor.

.. code-block :: php

    /**
     * @Serializer\VirtualProperty(
     *     "firstName",
     *     exp="object.getFirstName()",
     *     options={@Serializer\SerializedName("my_first_name")}
     *  )
     */
    #[Serializer\VirtualProperty(name: "firstName", exp: "object.getFirstName()", options: [[Serializer\SerializedName::class, ["my_first_name"]]])]
    class Author
    {
    ...

#[Inline]
~~~~~~~~~
This attribute can be defined on a property to indicate that the data of the property
should be inlined.

**Note**: AccessorOrder will be using the name of the property to determine the order.

#[ReadOnlyProperty]
~~~~~~~~~~~~~~~~~~~
This attribute can be defined on a property to indicate that the data of the property
is read only and cannot be set during deserialization.

A property can be marked as non read only with ``#[ReadOnlyProperty(readOnly: false)]`` attribute
(useful when a class is marked as read only).

#[PreSerialize]
~~~~~~~~~~~~~~~
This attribute can be defined on a method which is supposed to be called before
the serialization of the object starts.

#[PostSerialize]
~~~~~~~~~~~~~~~~
This attribute can be defined on a method which is then called directly after the
object has been serialized.

#[PostDeserialize]
~~~~~~~~~~~~~~~~~~
This attribute can be defined on a method which is supposed to be called after
the object has been deserialized.

#[Discriminator]
~~~~~~~~~~~~~~~~

This attribute allows serialization/deserialization of relations which are polymorphic, but
where a common base class exists. The ``#[Discriminator]`` attribute has to be applied
to the least super type:

.. code-block :: php

    #[Serializer\Discriminator(field: 'type', disabled: false, map: ['car' => 'Car', 'moped' => 'Moped'], groups=["foo", "bar"])]
    abstract class Vehicle { }
    class Car extends Vehicle { }
    class Moped extends Vehicle { }
    ...

.. note ::

    `groups` is optional and is used as exclusion policy.

#[UnionDiscriminator]
~~~~~~~~~~~~~~~~~~~~~

This attribute allows deserialization of unions.  The ``#[UnionDiscriminator]`` attribute has to be applied
to an attribute that can be one of many types.

.. code-block :: php

    class Vehicle {
        #[UnionDiscriminator(field: 'typeField', map: ['manual' => 'FullyQualified/Path/Manual', 'automatic' => 'FullyQualified/Path/Automatic'])]
        private Manual|Automatic $transmission;
    }

In the case of this example, both Manual and Automatic should contain a string attribute named `typeField`.  The value of that field will be passed
to the `map` option to determine which class to instantiate.

#[Type]
~~~~~~~
This attribute can be defined on a property to specify the type of that property.
For deserialization, this attribute must be defined.
The ``#[Type]`` attribute can have parameters and parameters can be used by serialization/deserialization
handlers to enhance the serialization or deserialization result; for example, you may want to
force a certain format to be used for serializing DateTime types and specifying at the same time a different format
used when deserializing them.

Available Types:

+------------------------------------------------------------+--------------------------------------------------+
| Type                                                       | Description                                      |
+============================================================+==================================================+
| boolean or bool                                            | Primitive boolean                                |
+------------------------------------------------------------+--------------------------------------------------+
| integer or int                                             | Primitive integer                                |
+------------------------------------------------------------+--------------------------------------------------+
| double or float                                            | Primitive double                                 |
+------------------------------------------------------------+--------------------------------------------------+
| double<2> or float<2>                                      | Primitive double with precision                  |
+------------------------------------------------------------+--------------------------------------------------+
| double<2, 'HALF_DOWN'> or float<2, 'HALF_DOWN'>            | Primitive double with precision and              |
|                                                            | Rounding Mode.                                   |
|                                                            | (HALF_UP, HALF_DOWN, HALF_EVEN HALF_ODD)         |
+------------------------------------------------------------+--------------------------------------------------+
| double<2, 'HALF_DOWN', 2> or float<2, 'HALF_DOWN', 2>      | Primitive double with precision,                 |
| double<2, 'HALF_DOWN', 3> or float<2, 'HALF_DOWN', 3>      | Rounding Mode and decimals padding up to         |
|                                                            | N digits. As example, the float ``1.23456`` when |
|                                                            | specified as  ``double<2, 'HALF_DOWN', 5>`` will |
|                                                            | be serialized as ``1.23000``.                    |
|                                                            | NOTE: this is available only for the XML         |
|                                                            | serializer.                                      |
+------------------------------------------------------------+--------------------------------------------------+
| string                                                     | Primitive string                                 |
+------------------------------------------------------------+--------------------------------------------------+
| array                                                      | An array with arbitrary keys, and values.        |
+------------------------------------------------------------+--------------------------------------------------+
| list                                                       | A list with arbitrary values.                    |
+------------------------------------------------------------+--------------------------------------------------+
| array<T>                                                   | An array of type T (T can be any available type).|
|                                                            | Examples:                                        |
|                                                            | array<string>, array<MyNamespace\MyObject>, etc. |
+------------------------------------------------------------+--------------------------------------------------+
| list<T>                                                    | A list of type T (T can be any available type).  |
|                                                            | Examples:                                        |
|                                                            | list<string>, list<MyNamespace\MyObject>, etc.   |
+------------------------------------------------------------+--------------------------------------------------+
| array<K, V>                                                | A map of keys of type K to values of type V.     |
|                                                            | Examples: array<string, string>,                 |
|                                                            | array<string, MyNamespace\MyObject>, etc.        |
+------------------------------------------------------------+--------------------------------------------------+
| enum<'Color'>                                              | Enum of type Color, use its case values          |
|                                                            | for serialization and deserialization            |
|                                                            | if the enum is a backed enum,                    |
|                                                            | use its case names if it is not a backed enum.   |
+------------------------------------------------------------+--------------------------------------------------+
| enum<'Color', 'name'>                                      | Enum of type Color, use its case names           |
|                                                            | (as string) for serialization                    |
|                                                            | and deserialization.                             |
+------------------------------------------------------------+--------------------------------------------------+
| enum<'Color', 'value'>                                     | Backed Enum of type Color, use its case value    |
|                                                            | for serialization and deserialization.           |
+------------------------------------------------------------+--------------------------------------------------+
| enum<'Color', 'value', 'integer'>                          | Backed Enum of type Color, use its case value    |
|                                                            | (forced as integer) for serialization            |
|                                                            | and deserialization.                             |
+------------------------------------------------------------+--------------------------------------------------+
| DateTime                                                   | PHP's DateTime object (default format*/timezone) |
+------------------------------------------------------------+--------------------------------------------------+
| DateTime<'format'>                                         | PHP's DateTime object (custom format/default     |
|                                                            | timezone).                                       |
+------------------------------------------------------------+--------------------------------------------------+
| DateTime<'format', 'zone'>                                 | PHP's DateTime object (custom format/timezone)   |
+------------------------------------------------------------+--------------------------------------------------+
| DateTime<'format', 'zone', 'deserializeFormats'>           | PHP's DateTime object (custom format/timezone,   |
|                                                            | deserialize format). If you do not want to       |
|                                                            | specify a specific timezone, use an empty        |
|                                                            | string (''). DeserializeFormats can either be a  |
|                                                            | string or an array of string.                    |
+------------------------------------------------------------+--------------------------------------------------+
| DateTimeImmutable                                          | PHP's DateTimeImmutable object (default format*/ |
|                                                            | timezone).                                       |
+------------------------------------------------------------+--------------------------------------------------+
| DateTimeImmutable<'format'>                                | PHP's DateTimeImmutable object (custom format/   |
|                                                            | default timezone)                                |
+------------------------------------------------------------+--------------------------------------------------+
| DateTimeImmutable<'format', 'zone'>                        | PHP's DateTimeImmutable object (custom format/   |
|                                                            | timezone)                                        |
+------------------------------------------------------------+--------------------------------------------------+
| DateTimeImmutable<'format', 'zone', 'deserializeFormats'>  | PHP's DateTimeImmutable object (custom format/   |
|                                                            | timezone/deserialize format). If you do not want |
|                                                            | to specify a specific timezone, use an empty     |
|                                                            | string (''). DeserializeFormats can either be a  |
|                                                            | string or an array of string.                    |
+------------------------------------------------------------+--------------------------------------------------+
| DateTimeInterface                                          | PHP's DateTimeInterface interface (default       |
|                                                            | format*/timezone).                               |
|                                                            | Data will be always deserialised into            |
|                                                            | `\DateTime` object                               |
+------------------------------------------------------------+--------------------------------------------------+
| DateTimeInterface<'format'>                                | PHP's DateTimeInterface interface (custom        |
|                                                            | format/default timezone)                         |
|                                                            | Data will be deserialised into                   |
|                                                            | `\\DateTime` object                              |
+------------------------------------------------------------+--------------------------------------------------+
| DateTimeInterface<'format', 'zone'>                        | PHP's DateTimeInterface interface (custom        |
|                                                            | format/timezone)                                 |
|                                                            | Data will be deserialised into                   |
|                                                            | `\\DateTime` object                              |
+------------------------------------------------------------+--------------------------------------------------+
| DateTimeInterface<'format', 'zone', 'deserializeFormats'>  | PHP's DateTimeInterface interface (custom        |
|                                                            | format/timezone/deserialize format). If you do   |
|                                                            | not want to specify a specific timezone, use an  |
|                                                            | empty string (''). DeserializeFormats can either |
|                                                            | be a string or an array of string.               |
|                                                            | Data will be deserialised into                   |
|                                                            | `\\DateTime` object                              |
+------------------------------------------------------------+--------------------------------------------------+
| DateInterval                                               | PHP's DateInterval object using ISO 8601 format  |
+------------------------------------------------------------+--------------------------------------------------+
| T                                                          | Where T is a fully qualified class name.         |
+------------------------------------------------------------+--------------------------------------------------+
| iterable                                                   | Similar to array. Will always be deserialized    |
|                                                            | into array as implementation info is lost during |
|                                                            | serialization.                                   |
+------------------------------------------------------------+--------------------------------------------------+
| iterable<T>                                                | Similar to array<T>. Will always be deserialized |
|                                                            | into array as implementation info is lost during |
|                                                            | serialization.                                   |
+------------------------------------------------------------+--------------------------------------------------+
| iterable<K, V>                                             | Similar to array<K, V>. Will always be           |
|                                                            | deserialized into array as implementation info   |
|                                                            | is lost during serialization.                    |
+------------------------------------------------------------+--------------------------------------------------+
| ArrayCollection<T>                                         | Similar to array<T>, but will be deserialized    |
|                                                            | into Doctrine's ArrayCollection class.           |
+------------------------------------------------------------+--------------------------------------------------+
| ArrayCollection<K, V>                                      | Similar to array<K, V>, but will be deserialized |
|                                                            | into Doctrine's ArrayCollection class.           |
+------------------------------------------------------------+--------------------------------------------------+
| Generator                                                  | Similar to array, but will be deserialized       |
|                                                            | into Generator class.                            |
+------------------------------------------------------------+--------------------------------------------------+
| Generator<T>                                               | Similar to array<T>, but will be deserialized    |
|                                                            | into Generator class.                            |
+------------------------------------------------------------+--------------------------------------------------+
| Generator<K, V>                                            | Similar to array<K, V>, but will be deserialized |
|                                                            | into Generator class.                            |
+------------------------------------------------------------+--------------------------------------------------+
| ArrayIterator                                              | Similar to array, but will be deserialized       |
|                                                            | into ArrayIterator class.                        |
+------------------------------------------------------------+--------------------------------------------------+
| ArrayIterator<T>                                           | Similar to array<T>, but will be deserialized    |
|                                                            | into ArrayIterator class.                        |
+------------------------------------------------------------+--------------------------------------------------+
| ArrayIterator<K, V>                                        | Similar to array<K, V>, but will be deserialized |
|                                                            | into ArrayIterator class.                        |
+------------------------------------------------------------+--------------------------------------------------+
| Iterator                                                   | Similar to array, but will be deserialized       |
|                                                            | into ArrayIterator class.                        |
+------------------------------------------------------------+--------------------------------------------------+
| Iterator<T>                                                | Similar to array<T>, but will be deserialized    |
|                                                            | into ArrayIterator class.                        |
+------------------------------------------------------------+--------------------------------------------------+
| Iterator<K, V>                                             | Similar to array<K, V>, but will be deserialized |
|                                                            | into ArrayIterator class.                        |
+------------------------------------------------------------+--------------------------------------------------+

(*) If the standalone jms/serializer is used then default format is `\DateTime::ISO8601` (which is not compatible with ISO-8601 despite the name). For jms/serializer-bundle the default format is `\DateTime::ATOM` (the real ISO-8601 format) but it can be changed in `configuration`_.

(**) The key type K for array-linke formats as ``array``. ``ArrayCollection``, ``iterable``, etc., is only used for deserialization,
for serializaiton is treated as ``string``.

Examples:

.. code-block :: php

    <?php

    namespace MyNamespace;

    use JMS\Serializer\Annotation\Type;

    class BlogPost
    {
        #[Type(name: "ArrayCollection<MyNamespace\Comment>")]
        private $comments;

        #[Type(name: "string")]
        private $title;

        #[Type(name: Author:class)]
        private $author;

        #[Type(name: DateTime:class)]
        private $startAt;

        #[Type(name: 'DateTime<'Y-m-d'>')]
        private $endAt;

        #[Type(name: 'DateTime<'Y-m-d'>')]

        #[Type(name:"DateTime<'Y-m-d', '', ['Y-m-d', 'Y/m/d']>")]
        private $publishedAt;

        #[Type(name:'DateTimeImmutable')]
        private $createdAt;

        #[Type(name:"DateTimeImmutable<'Y-m-d'>")]
        private $updatedAt;

        #[Type(name:"DateTimeImmutable<'Y-m-d', '', ['Y-m-d', 'Y/m/d']>")]
        private $deletedAt;

        #[Type(name:'boolean')]
        private $published;

        #[Type(name:'array<string, string>')]
        private $keyValueStore;
    }

.. note ::

    if you are using ``PHP attributes`` with PHP 8.1 you can pass an object which implements ``__toString()`` method as a value for ``#[Type]`` attribute.

    .. code-block :: php

        <?php

        namespace MyNamespace;

        use JMS\Serializer\Annotation\Type;

        class BlogPost
        {
            #[Type(new ArrayOf(Comment::class))]
            private $comments;
        }

        class ArrayOf implements \Stringable
        {
            public function __construct(private string $className) {}

            public function __toString(): string
            {
                return "array<$className>";
            }
        }

.. _configuration: https://jmsyst.com/bundles/JMSSerializerBundle/master/configuration#configuration-block-2-0

#[XmlRoot]
~~~~~~~~~~
This allows you to specify the name of the top-level element.

.. code-block :: php

    <?php

    use JMS\Serializer\Annotation\XmlRoot;

    #[XmlRoot('user')]
    class User
    {
        private $name = 'Johannes';
    }

Resulting XML:

.. code-block :: xml

    <user>
        <name><![CDATA[Johannes]]></name>
    </user>

.. note ::

    #[XmlRoot] only applies to the root element, but is for example not taken into
    account for collections. You can define the entry name for collections using
    #[XmlList], or #[XmlMap].

#[XmlAttribute]
~~~~~~~~~~~~~~~
This allows you to mark properties which should be set as attributes,
and not as child elements.

.. code-block :: php

    <?php

    use JMS\Serializer\Annotation\XmlAttribute;

    class User
    {
        #[XmlAttribute]
        private $id = 1;
        private $name = 'Johannes';
    }

Resulting XML:

.. code-block :: xml

    <result id="1">
        <name><![CDATA[Johannes]]></name>
    </result>


#[XmlDiscriminator]
~~~~~~~~~~~~~~~~~~~
This attribute allows to modify the behaviour of ``#[Discriminator]`` regarding handling of XML.


Available Options:

+-------------------------------------+--------------------------------------------------+
| Type                                | Description                                      |
+=====================================+==================================================+
| attribute                           | use an attribute instead of a child node         |
+-------------------------------------+--------------------------------------------------+
| cdata                               | render child node content with or without cdata  |
+-------------------------------------+--------------------------------------------------+
| namespace                           | render child node using the specified namespace  |
+-------------------------------------+--------------------------------------------------+

Example for "attribute":

.. code-block :: php

    <?php

    use JMS\Serializer\Annotation\Discriminator;
    use JMS\Serializer\Annotation\XmlDiscriminator;

    #[Discriminator(field: 'type', map: ['car' => 'Car', 'moped' => 'Moped'], groups: ['foo', 'bar'])]
    #[XmlDiscriminator(attribute: true)]
    abstract class Vehicle { }
    class Car extends Vehicle { }

Resulting XML:

.. code-block :: xml

    <vehicle type="car" />


Example for "cdata":

.. code-block :: php

    <?php

    use JMS\Serializer\Annotation\Discriminator;
    use JMS\Serializer\Annotation\XmlDiscriminator;

    #[Discriminator(field: 'type', map: ['car' => 'Car', 'moped' => 'Moped'], groups: ['foo', 'bar'])]
    #[XmlDiscriminator]
    abstract class Vehicle { }
    class Car extends Vehicle { }

Resulting XML:

.. code-block :: xml

    <vehicle><type>car</type></vehicle>


#[XmlValue]
~~~~~~~~~~~
This allows you to mark properties which should be set as the value of the
current element. Note that this has the limitation that any additional
properties of that object must have the #[XmlAttribute] attribute.
XMlValue also has property cdata. Which has the same meaning as the one in
XMLElement.

.. code-block :: php

    <?php

    use JMS\Serializer\Annotation\XmlAttribute;
    use JMS\Serializer\Annotation\XmlValue;
    use JMS\Serializer\Annotation\XmlRoot;

    #[XmlRoot('price')]
    class Price
    {
        #[XmlAttribute]
        private $currency = 'EUR';

        #[XmlValue]
        private $amount = 1.23;
    }


Resulting XML:

.. code-block :: xml

    <price currency="EUR">1.23</price>

#[XmlList]
~~~~~~~~~~
This allows you to define several properties of how arrays should be
serialized. This is very similar to #[XmlMap], and should be used if the
keys of the array are not important.

.. code-block :: php

    <?php

    use JMS\Serializer\Annotation\XmlList;
    use JMS\Serializer\Annotation\XmlRoot;

    #[XmlRoot('post')]
    class Post
    {
        public function __construct(
            #[XmlList(inline: true, entry: 'comment')]
            private array $comments
        )
        {
        }
    }

    class Comment
    {
        public function __construct(private string $text)
        {
        }
    }

Resulting XML:

.. code-block :: xml

    <post>
        <comment>
            <text><![CDATA[Foo]]></text>
        </comment>
        <comment>
            <text><![CDATA[Bar]]></text>
        </comment>
    </post>

You can also specify the entry tag namespace using the ``namespace`` attribute (``#[XmlList(inline: true, entry: 'comment', namespace: 'http://www.example.com/ns')]``).

#[XmlMap]
~~~~~~~~~
Similar to #[XmlList], but the keys of the array are meaningful.

#[XmlKeyValuePairs]
~~~~~~~~~~~~~~~~~~~
This allows you to use the keys of an array as xml tags.

.. note ::

    When a key is an invalid xml tag name (e.g. 1_foo) the tag name *entry* will be used instead of the key.

#[XmlAttributeMap]
~~~~~~~~~~~~~~~~~~

This is similar to the #[XmlKeyValuePairs], but instead of creating child elements, it creates attributes.

.. code-block :: php

    <?php

    use JMS\Serializer\Annotation\XmlAttributeMap;

    class Input
    {
        #[XmlAttributeMap]
        private $id = ['name' => 'firstname', 'value' => 'Adrien'];
    }


Resulting XML:

.. code-block :: xml

    <result name="firstname" value="Adrien"/>

#[XmlElement]
~~~~~~~~~~~~~
This attribute can be defined on a property to add additional xml serialization/deserialization properties.

.. code-block :: php

    <?php

    use JMS\Serializer\Annotation\XmlElement;
    use JMS\Serializer\Annotation\XmlNamespace;

    #[XmlNamespace(uri: 'http://www.w3.org/2005/Atom', prefix: 'atom')]
    class User
    {
        #[XmlElement(cdata: false, namespace: 'http://www.w3.org/2005/Atom')]
        private $id = 'my_id';
    }

Resulting XML:

.. code-block :: xml

    <atom:id>my_id</atom:id>

#[XmlNamespace]
~~~~~~~~~~~~~~~
This attribute allows you to specify Xml namespace/s and prefix used.

.. code-block :: php

    <?php

    use JMS\Serializer\Annotation\Groups;
    use JMS\Serializer\Annotation\SerializedName;
    use JMS\Serializer\Annotation\Type;
    use JMS\Serializer\Annotation\XmlElement;
    use JMS\Serializer\Annotation\XmlNamespace;

    #[XmlNamespace(uri: 'http://example.com/namespace')]
    #[XmlNamespace(uri: 'http://www.w3.org/2005/Atom', prefix: 'atom')]
    class BlogPost
    {
        #[Type(\JMS\Serializer\Tests\Fixtures\Author::class)]
        #[Groups(['post'])]
        #[XmlElement(namespace: 'http://www.w3.org/2005/Atom')]
        private $author;
    }

    class Author
    {
        #[Type('string')]
        #[SerializedName('full_name')]
        private $name;
    }


Resulting XML:

.. code-block :: xml

    <?xml version="1.0" encoding="UTF-8"?>
    <blog-post xmlns="http://example.com/namespace" xmlns:atom="http://www.w3.org/2005/Atom">
        <atom:author>
            <full_name><![CDATA[Foo Bar]]></full_name>
        </atom:author>
    </blog>


Enum support
~~~~~~~~~~~~~~

Enum support is disabled by default, to enable it run:

.. code-block :: php

    $builder = SerializerBuilder::create();
    $builder->enableEnumSupport();

    $serializer = $builder->build();


With the enum support enabled, enums are automatically detected using typed properties typehints.
When typed properties are no available (virtual properties as example), it is necessary to explicitly typehint
the underlying type using the ``#[Type]`` attribute.

- If the enum is a ``BackedEnum``, the case value will be used for serialization and deserialization by default;
- If the enum is not a ``BackedEnum``, the case name will be used for serialization and deserialization by default;