# Notification.Extender

Added in[API level 20](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)

# Extender

*** ** * ** ***

Kotlin\|[Java](https://developer.android.com/reference/android/app/Notification.Extender "View this page in Java")  

```
interface Extender
```

|------------------------------------------------------------------------------------------------------------------------|
| [android.app.Notification.Extender](https://developer.android.com/reference/kotlin/android/app/Notification.Extender#) |

|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Known Direct Subclasses [Notification.CarExtender](https://developer.android.com/reference/kotlin/android/app/Notification.CarExtender),[Notification.TvExtender](https://developer.android.com/reference/kotlin/android/app/Notification.TvExtender),[Notification.WearableExtender](https://developer.android.com/reference/kotlin/android/app/Notification.WearableExtender) |---------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------| | [Notification.CarExtender](https://developer.android.com/reference/kotlin/android/app/Notification.CarExtender)           | Helper class to add Android Auto extensions to notifications. | | [Notification.TvExtender](https://developer.android.com/reference/kotlin/android/app/Notification.TvExtender)             | Helper class to add Android TV extensions to notifications.   | | [Notification.WearableExtender](https://developer.android.com/reference/kotlin/android/app/Notification.WearableExtender) | Helper class to add wearable extensions to notifications.     | |

Extender interface for use with[Builder.extend](https://developer.android.com/reference/kotlin/android/app/Notification.Builder#extend(android.app.Notification.Extender)). Extenders may be used to add metadata or change options on a notification builder.

## Summary

|                                                                                                                                                                                                        Public methods                                                                                                                                                                                                         ||
|------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| abstract[Notification.Builder](https://developer.android.com/reference/kotlin/android/app/Notification.Builder)! | [extend](https://developer.android.com/reference/kotlin/android/app/Notification.Extender#extend(android.app.Notification.Builder))`(`builder:` `[Notification.Builder](https://developer.android.com/reference/kotlin/android/app/Notification.Builder)!`)` Apply this extender to a notification builder. |

## Public methods

### extend

Added in[API level 20](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)  

```
abstract fun extend(builder: Notification.Builder!): Notification.Builder!
```

Apply this extender to a notification builder.

|                                                                   Parameters                                                                   ||
|-----------|-------------------------------------------------------------------------------------------------------------------------------------|
| `builder` | [Notification.Builder](https://developer.android.com/reference/kotlin/android/app/Notification.Builder)!:the builder to be modified |

|                                                                 Return                                                                  ||
|----------------------------------------------------------------------------------------------------------|-------------------------------|
| [Notification.Builder](https://developer.android.com/reference/kotlin/android/app/Notification.Builder)! | the build object for chaining |