Deprecation notice
==================
PHP 8 introduced `attributes
<https://www.php.net/manual/en/language.attributes.overview.php>`_,
which are a native replacement for annotations. As such, this library is
considered feature complete, and should receive exclusively bugfixes and
security fixes.
Introduction
============
Doctrine Annotations allows to implement custom annotation
functionality for PHP classes and functions.
.. code-block:: php
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.
Installation
============
You can install the Annotation component with composer:
.. code-block::
$ composer require doctrine/annotations
Create an annotation class
==========================
An annotation class is a representation of the later used annotation
configuration in classes. The annotation class of the previous example
looks like this:
.. code-block:: php
/**
* @Annotation
*/
final class MyAnnotation
{
public $myProperty;
}
The annotation class is declared as an annotation by ``@Annotation``.
:ref:`Read more about custom annotations. <custom>`
Reading annotations
===================
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``:
.. code-block:: php
use Doctrine\Common\Annotations\AnnotationReader;
$reflectionClass = new ReflectionClass(Foo::class);
$property = $reflectionClass->getProperty('bar');
$reader = new AnnotationReader();
$myAnnotation = $reader->getPropertyAnnotation(
$property,
MyAnnotation::class
);
echo $myAnnotation->myProperty; // result: "value"
A reader has multiple methods to access the annotations of a class or
function.
:ref:`Read more about handling annotations. <annotations>`
IDE Support
-----------
Some IDEs already provide support for annotations:
- Eclipse via the `Symfony2 Plugin <https://github.com/pulse00/Symfony-2-Eclipse-Plugin>`_
- PhpStorm via the `PHP Annotations Plugin <https://plugins.jetbrains.com/plugin/7320-php-annotations>`_ or the `Symfony Plugin <https://plugins.jetbrains.com/plugin/7219-symfony-support>`_
.. _Read more about handling annotations.: annotations
.. _Read more about custom annotations.: custom
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