Annotations

Annotations for class discovery and metadata description.

The Drupal plugin system has a set of reusable components that developers can use, override, and extend in their modules. Most of the plugins use annotations, which let classes register themselves as plugins and describe their metadata. (Annotations can also be used for other purposes, though at the moment, Drupal only uses them for the plugin system.)

To annotate a class as a plugin, add code similar to the following to the end of the documentation block immediately preceding the class declaration:

* @ContentEntityType(
*   id = "comment",
*   label = @Translation("Comment"),
*   ...
*   base_table = "comment"
* )

Note that you must use double quotes; single quotes will not work in annotations.

Some annotation types, which extend the "@ PluginID" annotation class, have only a single 'id' key in their annotation. For these, it is possible to use a shorthand annotation. For example:

* @ViewsArea("entity")

in place of

* @ViewsArea(
*   id = "entity"
*)

The available annotation classes are listed in this topic, and can be identified when you are looking at the Drupal source code by having "@ Annotation" in their documentation blocks (without the space after @). To find examples of annotation for a particular annotation class, such as EntityType, look for class files that have an @ annotation section using the annotation class.

See also

Annotation for translatable text

Annotation for context definition

File

core/core.api.php, line 1841

Classes