    001// Copyright 2006, 2007, 2009 The Apache Software Foundation
    002//
    003// Licensed under the Apache License, Version 2.0 (the "License");
    004// you may not use this file except in compliance with the License.
    005// You may obtain a copy of the License at
    006//
    007//     http://www.apache.org/licenses/LICENSE-2.0
    008//
    009// Unless required by applicable law or agreed to in writing, software
    010// distributed under the License is distributed on an "AS IS" BASIS,
    011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012// See the License for the specific language governing permissions and
    013// limitations under the License.
    014
    015package org.apache.tapestry5.annotations;
    016
    017import java.lang.annotation.Documented;
    018import static java.lang.annotation.ElementType.FIELD;
    019import java.lang.annotation.Retention;
    020import static java.lang.annotation.RetentionPolicy.RUNTIME;
    021import java.lang.annotation.Target;
    022
    023import static org.apache.tapestry5.ioc.annotations.AnnotationUseContext.COMPONENT;
    024import org.apache.tapestry5.ioc.annotations.UseWith;
    025
    026/**
    027 * Defines an <em>implementation</em> mixin for a component.
    028 */
    029@Target(FIELD)
    030@Documented
    031@Retention(RUNTIME)
    032@UseWith({COMPONENT})
    033public @interface Mixin
    034{
    035
    036    /**
    037     * Defines the type of mixin, using a logical mixin name. This value takes precedence over the type of field (to
    038     * which the annotation is attached). In such cases, it is presumed that the field's type is an interface
    039     * implemented by the actual mixin. The default value (the empty string) directs Tapestry to use the field type as
    040     * the mixin class to instantiate and attach to the component.
    041     */
    042    String value() default "";
    043
    044    /**
    045     * Defines an ordering constraint for when the mixin should be applied in relation to other mixins.
    046     * The string is analagous exactly to the strings used to define ordered contributions.
    047     * Eg: @Mixin(order={"before:mixina","after:mixinb"}). The ids are mixin names and are case insensitive.
    048     * @since 5.2.0.0
    049     */
    050    String[] order() default {};
    051}