PHP 8 introduced attributes, which are a native replacement for annotations. As such, this library is deprecated, and should receive exclusively bugfixes and security fixes.
Doctrine Annotations allows to implement custom annotation functionality for PHP classes and functions.
class Foo
{
/**
* @MyAnnotation(myProperty="value")
*/
private $bar;
}
Annotations aren't implemented in PHP itself which is why this component offers a way to use the PHP doc-blocks as a place for the well known annotation syntax using the @
char.
Annotations in Doctrine are used for the ORM configuration to build the class mapping, but it can be used in other projects for other purposes too.
You can install the Annotation component with composer:
$ composer require doctrine/annotations
An annotation class is a representation of the later used annotation configuration in classes. The annotation class of the previous example looks like this:
/**
* @Annotation
*/
final class MyAnnotation
{
public $myProperty;
}
The annotation class is declared as an annotation by @Annotation
.
Read more about custom annotations. <custom>
The access to the annotations happens by reflection of the class or function containing them. There are multiple reader-classes implementing the Doctrine\Common\Annotations\Reader
interface, that can access the annotations of a class. A common one is Doctrine\Common\Annotations\AnnotationReader
:
use Doctrine\Common\Annotations\AnnotationReader;
use Doctrine\Common\Annotations\AnnotationRegistry;
// Deprecated and will be removed in 2.0 but currently needed
AnnotationRegistry::registerLoader('class_exists');
$reflectionClass = new ReflectionClass(Foo::class);
$property = $reflectionClass->getProperty('bar');
$reader = new AnnotationReader();
$myAnnotation = $reader->getPropertyAnnotation(
$property,
MyAnnotation::class
);
echo $myAnnotation->myProperty; // result: "value"
Note that AnnotationRegistry::registerLoader('class_exists')
only works if you already have an autoloader configured (i.e. composer autoloader). Otherwise, please take a look to the other annotation autoload mechanisms <annotations>
.
A reader has multiple methods to access the annotations of a class or function.
Read more about handling annotations. <annotations>
Some IDEs already provide support for annotations:
- Eclipse via the Symfony2 Plugin
- PhpStorm via the PHP Annotations Plugin or the Symfony Plugin