Annotations

Kotlin annotation usage and creation of annotation classes

Creating an annotation in Kotlin

To create an annotation in Kotlin prefix the class definition with annotation and annotate the class with the desired @Target and @Retention scope.

Example:

@Target(AnnotationTarget.FUNCTION)
@Retention(AnnotationRetention.SOURCE)
annotation class IgnoreNull

The constructor of the annotation are the properties that can be set while annotating the desired target. For instance:

@Target(AnnotationTarget.FUNCTION)
@Retention(AnnotationRetention.SOURCE)
annotation class IgnoreNull(val scope:String)