Package groovy.lang

Annotation Type DelegatesTo

@Documented
@Retention(RUNTIME)
@Target(PARAMETER)
public @interface DelegatesTo
This annotation can be used by API or DSL writers to document parameters which accept a closure. In that case, using this annotation, you can specify what the delegate type of the closure will be. This is important for IDE support.

This annotation can also be used to help the type checker (TypeChecked) which would not report errors then if the delegate is of the documented type. Of course, it is also compatible with CompileStatic.

Example: 

 // Document the fact that the delegate of the closure will be an ExecSpec
 ExecResult exec(@DelegatesTo(ExecSpec) Closure closure) { ... }
Since:
2.1.0

  • Nested Class Summary

    Nested Classes
    Modifier and Type Class Description
    static interface  DelegatesTo.Target
    Parameter annotation used to specify the delegate for a @DelegatesTo annotated parameter of the same method.

  • Optional Element Summary

    Optional Elements
    Modifier and Type Optional Element Description
    int genericTypeIndex
    The index of the generic type that will be the type of the closure's delegate.
    int strategy
    The Closure.resolveStrategy used by the closure.
    java.lang.String target
    In cases when there are multiple @DelegatesTo.Target annotated parameters, this member should be set to the DelegatesTo.Target.value() of the correct target.
    java.lang.String type
    The type member should be used when the type of the delegate cannot be represented with value(), genericTypeIndex() or target().
    java.lang.Class value  

  • Element Details

    • value

      java.lang.Class value
      Default:
      groovy.lang.DelegatesTo.Target.class

    • strategy

      int strategy
      The Closure.resolveStrategy used by the closure.
      Default:
      0

    • genericTypeIndex

      int genericTypeIndex
      The index of the generic type that will be the type of the closure's delegate. The generic types are considered with respect to the @DelegatesTo.Target annotated parameter for this usage, with the index starting at 0.
      Default:
      -1

    • target

      java.lang.String target
      In cases when there are multiple @DelegatesTo.Target annotated parameters, this member should be set to the DelegatesTo.Target.value() of the correct target.
      Default:
      ""

    • type

      java.lang.String type
      The type member should be used when the type of the delegate cannot be represented with value(), genericTypeIndex() or target(). In this case, it is possible to use a String to represent the type, at the cost of potential uncaught errors at compile time if the type is invalid and increased compile time.
      Returns:
      a String representation of a type
      Since:
      2.4.0
      Default:
      ""