/*
 * Copyright (c) 2010 Mysema Ltd.
 * All rights reserved.
 * 
 */
package com.mysema.rdfbean.annotations;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;

import java.lang.annotation.Documented;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * @Mixin defines that a property's value is another instance of the same
 * subject. Thus it is never used in conjunction with @Predicate. @Mixin
 * property's type may not be assignable from the host type (self reference).
 * <p>
 * Mixin references are useful when there's multiple projections (DTOs) for the
 * same underlying resource, e.g. one containing only basic information about
 * the subject and another containing everything else. The class containing
 * details don't have to repeat info classes properties as it can reuse it using
 * @Mixin property.
 * </p>
 * <p>
 * For example
 * 
 * <pre>
 * @ClassMapping(ns=OWL.NS, ln="Class")
 * public class ClassInfo {
 *   
 *   @Id
 *   private UID id;
 *   
 *   @Predicate(ns=RDFS.NS)
 *   private String label;
 * }
 * 
 * @ClassMapping(ns=OWL.NS, ln="Class")
 * public class ClassDetails {
 * 
 *   @Predicate(ns=RDFS.NS)
 *   private Set<ClassInfo> subClassOf;
 *   
 *   @Mixin
 *   private ClassInfo info;
 *   
 *   @Predicate
 *   private Set<OWLClass> complementOf = new LinkedHashSet<OWLClass>();
 *   
 *   @Predicate
 *   private Set<OWLClass> disjointWith = new LinkedHashSet<OWLClass>();
 *   
 *   ...
 * }
 * </pre>
 * 
 * 
 * @author sasa
 */
@Documented
@Target({ METHOD, FIELD, PARAMETER })
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface Mixin {

}