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
:
namespace MyCompany\Annotations;
/** @Annotation */
class Bar
{
// some code
}
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:
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;
}
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
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:
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 MyCompanyAnnotations;
use DoctrineCommonAnnotationsNamedArgumentConstructorAnnotation;
/** @Annotation */ class Bar implements NamedArgumentConstructorAnnotation {
private $foo;
public function __construct(private string $foo) {}
}
/** Usable with @Bar(foo="baz") */
@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 docblocksPROPERTY
Allowed in property docblocksMETHOD
Allowed in the method docblocksFUNCTION
Allowed in function dockblocksALL
Allowed in class, property, method and function docblocksANNOTATION
Allowed inside other annotations
If the annotations is not allowed in the current context, an
AnnotationException
is thrown.
namespace MyCompany\Annotations;
/**
* @Annotation
* @Target({"METHOD","PROPERTY"})
*/
class Bar
{
// some code
}
/**
* @Annotation
* @Target("CLASS")
*/
class Foo
{
// some code
}
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
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
}
@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:
/**
* @Annotation
* @Target("ALL")
*/
class Foo
{
/** @Required */
public $requiredField;
}
Usage:
/** @Foo(requiredField="value") */
public $direction; // Valid
/** @Foo */
public $direction; // Required field missing, throws an AnnotationException
- 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:
/**
* @Annotation
* @Target("ALL")
*/
class Direction
{
/**
* @Enum({"NORTH", "SOUTH", "EAST", "WEST"})
*/
public $value;
}
Annotation usage:
/** @Direction("NORTH") */
public $direction; // Valid value
/** @Direction("NORTHEAST") */
public $direction; // Invalid value, throws an AnnotationException
The use of constants and class constants is available on the annotations parser.
The following usages are allowed:
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.
Using the library API is simple. Using the annotations described in the previous section, you can now annotate other classes with your annotations:
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:
$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:
public function getClassAnnotations(\ReflectionClass $class);
public function getClassAnnotation(\ReflectionClass $class, $annotationName);
public function getMethodAnnotations(\ReflectionMethod $method);
public function getMethodAnnotation(\ReflectionMethod $method, $annotationName);
public function getPropertyAnnotations(\ReflectionProperty $property);
public function getPropertyAnnotation(\ReflectionProperty $property, $annotationName);
public function getFunctionAnnotations(\ReflectionFunction $property);
public function getFunctionAnnotation(\ReflectionFunction $property, $annotationName);