de.japkit.metaannotations.Param Maven / Gradle / Ivy
package de.japkit.metaannotations;
import de.japkit.metaannotations.classselectors.None;
public @interface Param {
//TODO: Do we really want to allow overriding for such an "inner" annotation as @Param ?
String _prefix() default "";
/**
* An expression to determine the source object for generating this element.
* The source element is available as "src" in expressions and is used in
* matchers and other rules. If the src expression is not set, the src
* element of the parent element is used (usually the enclosing element).
*
* If this expression results in an Iterable, each object provided by the
* Iterator is use as source object. That is, the element is generated
* multiple times, once for each object given by the iterator.
*
* @return
*/
String src() default "";
/**
* As an alternative to the src expression, a function can be called to determine the source object.
*
* @return
*/
Class[] srcFun() default {};
/**
* A filter expression to be applied to src in case it is a collection. Must be boolean.
* The variable name for the current collection element to be filtered is "src".
* @return
*/
String srcFilter() default "";
/**
* As an alternative to srcFilter, one or more boolean functions can be called.
* Only if the conjunction of their results is true, the rule is applied for the considered element of the src collection.
*
* @return
*/
Class[] srcFilterFun() default {};
/**
* An expression to be applied to the result of the expression or function(s) in case it is a collection. It's applied to each element.
* The variable name for the current collection element is "src". Collect is applied after filtering.
*
* @return
*/
String srcCollect() default "";
/**
* As an alternative or additionally to the collect expression, one or more functions can be called.
* In case of more than one function, they are called in a "fluent" style. That is each one is applied to the result of the previous one.
* The first function is always applied to the result of the collect expression or to the current collection element if collect expression is empty.
*
* @return
*/
Class[] srcCollectFun() default {};
/**
* If true, and src is a collection, it is transformed to a LinkedHashSet to remove duplicates while preserving order.
*
* @return
*/
boolean srcToSet() default false;
/**
* If src is a collection, and srcGroupBy and / or srcGroupByFun are set, the collection elements are grouped as a map, where
* the keys are the results of applying srcGroupBy and / or srcGroupByFun to the collection elements and the values are lists
* of collection elements with same key. SrcGroupBy is an expression and srcGroupByFun is a list of functions.
* They are applied in a fluent style (like src.srcGroupBy().srcGroupByFun[0]().srcGroupByFun[1]()...).
*
* @return the expression to derive the key from a collection element. The collection element is provided as "src".
*/
String srcGroupBy() default "";
/**
* If src is a collection, and srcGroupBy and / or srcGroupByFun are set, the collection elements are grouped as a map, where
* the keys are the results of applying srcGroupBy and / or srcGroupByFun to the collection elements and the values are lists
* of collection elements with same key. SrcGroupBy is an expression and srcGroupByFun is a list of functions.
* They are applied in a fluent style (like src.srcGroupBy().srcGroupByFun[0]().srcGroupByFun[1]()...).
*
* @return function(s) to derive the key from a collection element. The collection element is provided as "src".
*/
Class[] srcGroupByFun() default {};
/**
*
* @return the language of the src expression. Defaults to Java EL.
*/
String srcLang() default "";
/**
* By default, the current source object has the name "src" on the value stack.
* If this annotation value is set, the source object will additionally provided under the given name.
*
* @return the name of the source variable
*/
String srcVar() default "";
/**
* How to map annotations of the source element (???) to the method parameter
*
*
* @return the annotation mappings
*/
Annotation[] annotations() default {};
/** name of the parameter*/
String name() default "";
/**
* For more complex cases: a Java EL expression to generate the name of the
* parameter.
*
* @return
*/
String nameExpr() default "";
/**
*
* @return the language of the name expression. Defaults to Java EL.
*/
String nameLang() default "";
Class type() default None.class;
Class[] typeArgs() default {};
}