Custom Annotation Classes

If you want to define your own annotations, you just have to group them in a namespace. Annotation classes have to contain a class-level docblock with the text @Annotation:

.. code-block:: php

namespace MyCompany\Annotations;

/** @Annotation */
class Bar
{
    // some code
}

Inject annotation values

The annotation parser checks if the annotation constructor has arguments, if so then it will pass the value array, otherwise it will try to inject values into public properties directly:

.. code-block:: php

namespace MyCompany\Annotations;

/**
 * @Annotation
 *
 * Some Annotation using a constructor
 */
class Bar
{
    private $foo;

    public function __construct(array $values)
    {
        $this->foo = $values['foo'];
    }
}

/**
 * @Annotation
 *
 * Some Annotation without a constructor
 */
class Foo
{
    public $bar;
}

Optional: Constructors with Named Parameters

Starting with Annotations v1.11 a new annotation instantiation strategy is available that aims at compatibility of Annotation classes with the PHP 8 attribute feature. You need to declare a constructor with regular parameter names that match the named arguments in the annotation syntax.

To enable this feature, you can tag your annotation class with @NamedArgumentConstructor (available from v1.12) or implement the Doctrine\Common\Annotations\NamedArgumentConstructorAnnotation interface (available from v1.11 and deprecated as of v1.12). When using the @NamedArgumentConstructor tag, the first argument of the constructor is considered as the default one.

Usage with the @NamedArgumentConstructor tag

.. code-block:: php

namespace MyCompany\Annotations;

/**
 * @Annotation
 * @NamedArgumentConstructor
 */
class Bar implements NamedArgumentConstructorAnnotation
{
    private $foo;

    public function __construct(string $foo)
    {
        $this->foo = $foo;
    }
}

/** Usable with @Bar(foo="baz") */
/** Usable with @Bar("baz") */

In combination with PHP 8's constructor property promotion feature you can simplify this to:

.. code-block:: php

namespace MyCompany\Annotations;

/**
 * @Annotation
 * @NamedArgumentConstructor
 */
class Bar implements NamedArgumentConstructorAnnotation
{
    public function __construct(private string $foo) {}
}

Usage with the Doctrine\Common\Annotations\NamedArgumentConstructorAnnotation interface (v1.11, deprecated as of v1.12): .. code-block:: php

namespace MyCompany\Annotations;

use Doctrine\Common\Annotations\NamedArgumentConstructorAnnotation;

/** @Annotation */
class Bar implements NamedArgumentConstructorAnnotation
{
    private $foo;

    public function __construct(private string $foo) {}
}

/** Usable with @Bar(foo="baz") */

Annotation Target

@Target indicates the kinds of class elements to which an annotation type is applicable. Then you could define one or more targets:

CLASS Allowed in class docblocks
PROPERTY Allowed in property docblocks
METHOD Allowed in the method docblocks
FUNCTION Allowed in function docblocks
ALL Allowed in class, property, method and function docblocks
ANNOTATION Allowed inside other annotations

If the annotations is not allowed in the current context, an AnnotationException is thrown.

.. code-block:: php

namespace MyCompany\Annotations;

/**
 * @Annotation
 * @Target({"METHOD","PROPERTY"})
 */
class Bar
{
    // some code
}

/**
 * @Annotation
 * @Target("CLASS")
 */
class Foo
{
    // some code
}

Attribute types

The annotation parser checks the given parameters using the phpdoc annotation @var, The data type could be validated using the @var annotation on the annotation properties or using the @Attributes and @Attribute annotations.

If the data type does not match you get an AnnotationException

.. code-block:: php

namespace MyCompany\Annotations;

/**
 * @Annotation
 * @Target({"METHOD","PROPERTY"})
 */
class Bar
{
    /** @var mixed */
    public $mixed;

    /** @var boolean */
    public $boolean;

    /** @var bool */
    public $bool;

    /** @var float */
    public $float;

    /** @var string */
    public $string;

    /** @var integer */
    public $integer;

    /** @var array */
    public $array;

    /** @var SomeAnnotationClass */
    public $annotation;

    /** @var array<integer> */
    public $arrayOfIntegers;

    /** @var array<SomeAnnotationClass> */
    public $arrayOfAnnotations;
}

/**
 * @Annotation
 * @Target({"METHOD","PROPERTY"})
 * @Attributes({
 *   @Attribute("stringProperty", type = "string"),
 *   @Attribute("annotProperty",  type = "SomeAnnotationClass"),
 * })
 */
class Foo
{
    public function __construct(array $values)
    {
        $this->stringProperty = $values['stringProperty'];
        $this->annotProperty = $values['annotProperty'];
    }

    // some code
}

Annotation Required

@Required indicates that the field must be specified when the annotation is used. If it is not used you get an AnnotationException stating that this value can not be null.

Declaring a required field:

.. code-block:: php

/**
 * @Annotation
 * @Target("ALL")
 */
class Foo
{
    /** @Required */
    public $requiredField;
}

Usage:

.. code-block:: php

/** @Foo(requiredField="value") */
public $direction;                  // Valid

 /** @Foo */
public $direction;                  // Required field missing, throws an AnnotationException

Enumerated values

An annotation property marked with @Enum is a field that accepts a fixed set of scalar values.
You should use @Enum fields any time you need to represent fixed values.
The annotation parser checks the given value and throws an AnnotationException if the value does not match.

Declaring an enumerated property:

.. code-block:: php

/**
 * @Annotation
 * @Target("ALL")
 */
class Direction
{
    /**
     * @Enum({"NORTH", "SOUTH", "EAST", "WEST"})
     */
    public $value;
}

Annotation usage:

.. code-block:: php

/** @Direction("NORTH") */
public $direction;                  // Valid value

 /** @Direction("NORTHEAST") */
public $direction;                  // Invalid value, throws an AnnotationException

Constants

The use of constants and class constants is available on the annotations parser.

The following usages are allowed:

.. code-block:: php

namespace MyCompany\Entity;

use MyCompany\Annotations\Foo;
use MyCompany\Annotations\Bar;
use MyCompany\Entity\SomeClass;

/**
 * @Foo(PHP_EOL)
 * @Bar(Bar::FOO)
 * @Foo({SomeClass::FOO, SomeClass::BAR})
 * @Bar({SomeClass::FOO_KEY = SomeClass::BAR_VALUE})
 */
class User
{
}

Be careful with constants and the cache !

.. note::

The cached reader will not re-evaluate each time an annotation is
loaded from cache. When a constant is changed the cache must be
cleaned.

Usage

Using the library API is simple. Using the annotations described in the previous section, you can now annotate other classes with your annotations:

.. code-block:: php

namespace MyCompany\Entity;

use MyCompany\Annotations\Foo;
use MyCompany\Annotations\Bar;

/**
 * @Foo(bar="foo")
 * @Bar(foo="bar")
 */
class User
{
}

Now we can write a script to get the annotations above:

.. code-block:: php

$reflClass = new ReflectionClass('MyCompany\Entity\User');
$classAnnotations = $reader->getClassAnnotations($reflClass);

foreach ($classAnnotations AS $annot) {
    if ($annot instanceof \MyCompany\Annotations\Foo) {
        echo $annot->bar; // prints "foo";
    } else if ($annot instanceof \MyCompany\Annotations\Bar) {
        echo $annot->foo; // prints "bar";
    }
}

You have a complete API for retrieving annotation class instances from a class, property or method docblock:

Reader API


Access all annotations of a class
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: php

    public function getClassAnnotations(\ReflectionClass $class);

Access one annotation of a class
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: php

    public function getClassAnnotation(\ReflectionClass $class, $annotationName);

Access all annotations of a method
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: php

    public function getMethodAnnotations(\ReflectionMethod $method);

Access one annotation of a method
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: php

    public function getMethodAnnotation(\ReflectionMethod $method, $annotationName);

Access all annotations of a property
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: php

    public function getPropertyAnnotations(\ReflectionProperty $property);

Access one annotation of a property
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: php

    public function getPropertyAnnotation(\ReflectionProperty $property, $annotationName);

Access all annotations of a function
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: php

    public function getFunctionAnnotations(\ReflectionFunction $property);

Access one annotation of a function
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: php

    public function getFunctionAnnotation(\ReflectionFunction $property, $annotationName);