@Documented @Retention(RetentionPolicy.RUNTIME) @Target({ElementType.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) { ... }
| Modifiers | Name | Description |
|---|---|---|
@interface | DelegatesTo.Target | Parameter annotation used to specify the delegate for a @DelegatesTo annotated parameter of the same method. |
| Type | Name and Description |
|---|---|
int | genericTypeIndexThe index of the generic type that will be the type of the closure's delegate. |
int | strategyThe Closure.resolveStrategy used by the closure. |
String | targetIn cases when there are multiple @DelegatesTo.Target annotated parameters, this member should be set to the DelegatesTo.Target#value() of the correct target. |
String | typeThe type member should be used when the type of the delegate cannot be represented with value(), genericTypeIndex() or target(). |
Class | value
|
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.
The Closure.resolveStrategy used by the closure.
In cases when there are multiple @DelegatesTo.Target annotated parameters, this member should be set to the DelegatesTo.Target#value() of the correct target.
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.