# Writing Plugins

Play 2.0 comes with a few plugins predefined for all applications, these plugins are the following: 

* ```DBPlugin``` -> providing a JDBC datasource
* ```EvolutionPlugin``` -> provides migration  _(only available if db was configured)_
* ```EbeanPlugin``` -> provides Ebean support_ (only available if db was configured)_
* ```MessagesPlugin``` - > provides i18n support
* ```BasicCachePlugin``` -> provides in-memory caching
* ```GlobalPlugin``` -> executes application's settings

However, one can easily add a new plugin to an application by following these steps:

* implement ```play.Plugin``` (see [this](https://github.com/playframework/Play20/blob/master/framework/src/play/src/main/java/play/db/ebean/EbeanPlugin.java) for an example)
* this plugin should be available in the application either through pulling in it from a maven repository and referencing it
as an app dependency or the plugin code can be part of a play application
* you can access it like 

```java
import static play.api.Play.*;
import static play.libs.Scala.*;

public Myplugin plugin() {
   return orNull(unsafeApplication().plugin(MyPlugin.class)).api();
}
``` 

which will return an instance or subclass of ```MyPlugin``` fully initialized or ```null```.

* in your app create a file: ```conf/play.plugins``` and add a reference to your plugin, just like this  ```5000:com.example.MyPlugin```

_the number represents the plugin loading order, by setting it to > 1000 we can make sure it's loaded after the global plugins_