    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
    015    package org.apache.tapestry5.annotations;
    016
    017    import java.lang.annotation.Documented;
    018    import static java.lang.annotation.ElementType.FIELD;
    019    import java.lang.annotation.Retention;
    020    import static java.lang.annotation.RetentionPolicy.RUNTIME;
    021    import java.lang.annotation.Target;
    022
    023    import static org.apache.tapestry5.ioc.annotations.AnnotationUseContext.COMPONENT;
    024    import 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})
    033    public @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    }